Cognitive impairment is induced by BDNF-TrkB signaling mediating synaptic damage and reduction of amino acid neurotransmitters in heart failure rats

doi:10.21203/rs.3.rs-2992098/v1

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Cognitive impairment is induced by BDNF-TrkB signaling mediating synaptic damage and reduction of amino acid neurotransmitters in heart failure rats

https://doi.org/10.21203/rs.3.rs-2992098/v1

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Background

Heart failure (HF) is often accompanied by cognitive impairment (CI). Yet, the underlying molecular mechanism is still not fully understood.

Methods

A HF model was prepared by ligation of the anterior descending coronary artery of the rat for 8 weeks. Echocardiography and morris water maze were performed to evaluate cardiac and cognitive function. Electron microscopy was conducted to quantify postsynaptic density (PSD) thickness, length, and cleft width of synapses. Thirteen neurotransmitters were detected by high-performance liquid chromatography, and proteins associated with the BDNF-TrkB pathway were determined by Western blot. The intervention of BDNF siRNA in fetal rat cortical neurons was chosen for further validation of the BDNF-TrkB pathway.

Results

HF rats passed through the original platform position in the probe trials fewer times and took more time and distance to reach the platform in the reversal phase compared with Sham rats; also, they had reduced thickness and length of PSD and increased synaptic cleft width. Expression of BDNF, TrkB, PSD95, and VGLUT1 was significantly decreased in HF rats brain. In addition, compared with Sham rats, amino acids were significantly reduced with no changes in the acetylcholine and monoamine neurotransmitters. Further examination showed that the number of synaptic bifurcation and the expression of BDNF, TrkB, PSD95, and VGLUT1 were all decreased in the neurons that interfered with BDNF-siRNA compared with those in the negative control neurons.

Conclusions

These data suggest that CI in HF is regulated by BDNF-TrkB signaling, mediating synaptic damage and reduction of amino acid neurotransmitters.

Heart failure

Cognitive impairment

BDNF

Amino acids neurotransmitters

Synaptic plasticity

Cognitive impairment (CI) is a commonly co-occurring chronic condition among patients with heart failure (HF), often accompanied by memory impairment, slower information processing, and impaired executive function ^{[1, 2]}. Patients with HF have a more than four-fold higher risk of developing CI than healthy control subjects ^[3]. These cognitive changes result in forgetfulness and poor learning ability, ultimately increasing HF mortality and hospitalization rates ^{[4, 5]}.

Over the years, some studies have focused on increased oxidative stress and neuroinflammation ^{[6, 7]}, dysfunction of wnt signaling pathway ^[8], and changes in active factors like cortisol and catecholamines ^{[9, 10]} as potential mechanisms involved in HF with CI. Moreover, some studies have indicated that CI in neurodegenerative diseases is closely associated with synapse structural and functional damage ^{[11, 12]}. Brain-derived neurotrophic factor (BDNF) is a key molecule distributed in the central nervous system, which is also an important regulator of synaptic plasticity ^[13]. It is believed that BDNF exerts its roles via its receptor tyrosine receptor kinase B (TrkB) ^{[14, 15]}, which then regulates the expression of postsynaptic density (PSD95) to participate in the regulation of structural synaptic plasticity and the expression of vesicular glutamate receptor 1 (VGLUT 1) to promote the release of neurotransmitters ^[16–18]. BDNF has been proposed in HF as a biomarker with predictive potential ^[19]. Lower plasma levels of BDNF are associated with poor outcomes in patients with HF ^[20]. Yet, despite significant advances in the knowledge of BDNF-TrkB signaling dysfunction in neurodegenerative disease, signaling changes of BDNF-TrkB in HF with cognitive impairment are still not fully understood.

This study aimed to clarify whether the BDNF-TrkB signaling pathway is involved in CI after heart failure and whether its pathogenesis is related to neurotransmitter and synaptic plasticity abnormalities. Given previous evidence, a rat model of heart failure was prepared by anterior descending branch ligation to detect cognitive ability, synaptic structure, neurotransmitter, and BDNF-TrkB signaling pathway in this study. At the same time, the BDNF gene was knocked down in primary neurogenic culture to verify changes in the signaling pathway and downstream proteins.

Animals

Sprague-Dawley rats (240g ± 10g) were purchased from Beijing Vital River Laboratory Animal Technology Company. All the animals were housed in an environment with a temperature of 24 ± 1 ºC, relative humidity of 50 ± 1%, and a light/dark cycle of 12/12 hr and were given normal food and water ad libitum. All animal studies (including the rats euthanasia procedure) were done in compliance with the regulations and guidelines of Beijing University of Chinese Medicine institutional animal care and conducted according to the AAALAC and the IACUC guidelines.

The experiment was conducted 3 days after the acclimation of rats to the new environment. Rats were then divided into Model group and Sham group, 12 per group.

Induction of HF

Heart failure was induced as previously described ^[21]. Briefly, rats were anesthetized with 40 mg/kg pentobarbital sodium, after which positive-pressure ventilation was applied. The skin was then incised, and the chest was opened at the level of the 3rd intercostal space, after which the heart was gently exposed. The left anterior descending coronary artery was ligated ≈ 3 mm from its origin to induce myocardial infarction. The result of the electrocardiogram of the following day, i.e., pathological Q waves in 6–8 leads, including lead I, AVL, and V1-V6, suggested that surgery was successfully constructed. For sham operation, the surgical silk was passed around in an identical fashion but was not tied off.

Penicillin was intraperitoneally injected once a day for 3 days. The animal model was evaluated with ultrasound 8 weeks post-surgery. An ejection fraction (EF) of less than 40% suggested that we had successfully established HF model.

Electrocardiographic and echocardiographic examination

A 12-lead electrocardiogram was obtained before and 2 days after the surgery. Rats were anesthetized by injecting 40 mg/kg sodium pentobarbital, and echocardiography was performed as previously described ^[21]. Using a Vevo 2100 Imaging System Ultrasonic Diagnostic Equipment (VisualSonics, Canada) with a real-time high-frequency scan head of 15 MHz. M-mode 2-dimensional echocardiography images were obtained at the level of the papillary muscle from the parasternal long-axis view.

Morris Water Maze (MWM)

The water maze learning task assessed the cognitive function of rats. The MWM platform (XR-XM101, Shanghai, China) was conducted in a pool consisting of a circular tank (1.6 m diameter) filled with opaque water at 23°C ± 1°C. The pool was divided into four equal size quadrants (NE, SW, SE, and NW). A platform (12 cm diameter) was submerged 1.5 cm under the water's surface. A blue curtain with specific distant visual cues (like triangle, square, circle, and pentagon) surrounded the water maze. A spatial acquisition trial, probe trial and reverse trial were conducted. A spatial acquisition trial was conducted over three consecutive days with three trials per day. The rats were first placed on the platform for 5 s. Next, rats were placed into the pool and looked for a platform for 120s from one of 4 starting points facing the wall. On day 4, the platform was removed, and the 120 s probe test was conducted. On day 5, the platform was moved to the opposite quadrant. Then the rats were placed into the pool from the opposite quadrant of the platform. The time to find the platform, movement tracking, movement speed, and times across the platform were recorded. The experiment was carried out in a quiet and soundproof room.

Transmission electron microscopy

Cardiac perfusion with normal saline, followed by 4% paraformaldehyde perfusion, was performed to clear blood and fix brain tissue. Rats' frontal cortex tissue was rapidly minced into approximately 1 mm³ after decapitation and immediately fixed in 2.5% glutaraldehyde with 2% paraformaldehyde. After washing phosphate-buffered saline (PBS), tissues were cryoprotected in PBS at 4°C. The tissues were subsequently postfixed with 1% osmium tetroxide and dehydrated with graded ethanol (50%-100%) and 100% acetone. Then, tissue blocks were embedded in Epon (Epon-812 SPI-CHEM). Embedded tissue was finally placed in capsules containing embedding medium (Ultra Rapid Tissue Processor: Leica EM TP). A Leica EM UC7 microtome was used to cut semi-thin sections. Sections were stained with methylene blue and observed by light microscopy to choose representative areas. Ultra-thin sections (40–60 nm) were made, positioned on copper grids, then stained with uranium acetate for 1% and lead. Neurons and synapses were observed under the transmission electron microscope (H-7650, Hitachi, Japan). The synaptic counts were analyzed without the experimenter knowing group allocation. For each group, 100 synapses were randomly selected to make statistics. The measurements of PSD thickness and synaptic cleft width were performed three times and averaged.

Western Blot

After sacrificing SD rats, brain tissues were immediately collected. Whole tissue protein was prepared using RIPA lysis buffer (Applygen Technologies, Beijing, China). Proteins were quantified using a bicinchoninic acid kit (Applygen Technologies, Beijing, China). Then, proteins (80 µg per lane) were resolved on a 4–12% gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel (Genscript, Nanjing, China) followed by electrotransfer to NC membranes. Tris-buffered saline wash buffer with 0.05% Tween 20 (TBST) with 5% skim milk powder was used to block the membrane for 1 h at room temperature. Samples were then incubated with rabbit monoclonal BDNF (1:1000, ab108319, abcam, USA), rabbit monoclonal TrkB (1:1000, ab187041, abcam, USA), rabbit polyclonal PSD95 (1:1000, ab18258, abcam, USA), rabbit monoclonal VGluT1 (1:1000, ab227805, abcam, USA), and mouse monoclonal GAPDH (1:5000, C1312, Applygen Technologies, China) at 4°C overnight. Afterward, samples were washed with TBST and incubated with the secondary antibody conjugated with HRP goat anti-rabbit (mouse) IgG (1:5000, BA1054, BOSTER, China) at room temperature for 1 h. The membrane was then washed again with TBST and finally detected by chemiluminescence. The signal intensities were quantified with ImageJ software.

Neurotransmitter identification

The centrifuge tube containing the brain tissue homogenate was mixed with 5ml/g of distilled water to homogenize the tissue sample. Samples were then centrifuged at 5,000 × g for 10 min at 4°C, and the supernatant was collected. After centrifugation, the supernatant was diluted 100 times, and an additional 1:5 ratio of the 1 mmol·L-1 d9-Ach was added. The samples were centrifuged again at 10,000 rpm for 10 min. Then, 200 µL brain tissue homogenate was mixed with 600 µL of precooled acetonitrile and centrifuged at 14,000 rpm for 10 minutes at 4°C. Consequently, 400 µL of supernatant were collected and blow-dried with nitrogen, mixed with 75 µL 0.1% formic acid to reconstitute the residue. Finally, the obtained supernatant was used to identify neurotransmitters using high-performance liquid chromatography (1200, Agilent, USA).

Cell culture and transfections

The primary cortical neurons were harvested from Sprague–Dawley rat brains at embryonic day (E)18. Cortical tissue was dissected from the embryos into a cold dissection medium (Hank’s Balanced Salt Solution, HBSS). HBSS was removed, and tissues were digested with 2mg/ml papain at 37°C for 30 minutes. Enzymatic digestion was stopped by the addition of 1ml of fetal bovine serum (GIBCO). Cells were diluted to 10⁶ cells/ml in Dulbecco's modified Eagle's medium (DMEM) supplemented with 4.5g/L glucose and L- glutamine. Then the cells were seeded on a plate precoated with 0.01mg/ml poly-l-lysine (Sigma, P1399). After 4 hours, DMEM was replaced with neurobasal medium (GIBCO) containing 2% B27 Supplement (GIBCO) and 0.25% l-glutamine. Small interfering RNA (siRNA) was synthesized by Sangon Biotechnology (Shanghai, China). Lipofectamine 3000 reagents (Invitrogen) were used for primary neuron transfection. The cells were harvested for protein or immunostaining 48 hours after transfection.

Immunofluorescence

Cells in 24-well plates were washed with 0.01M PBS three times. Then, cells were fixed with 4% paraformaldehyde for 20 minutes at room temperature, washed 3 times with PBS for 5min/wash again, and cross-linked with 1% Triton100 for 10min at room temperature. After washing with PBS, the non-specific binding sites were blocked using goat serum at room temperature for 30 min. Samples were then mixed with antibody (rabbit polyclonal NF-M, 1:200, BIOSS, China) (30 µL per well) and incubated overnight at 4℃. The next day, plates were washed 3 times with PBS and incubated with secondary antibodies (goat anti-rabbit DyLight 649, 1:1000, A23620, abbkine, China) (30 µL per well) for 1h in the dark at 37℃. After incubation with a secondary antibody, cells were washed six times each time for 5 minutes with PBS and covered with a DAPI working solution. Observation and photographing was accomplished using laser confocal microscope (Leica TCS SP8X, Germany).

Statistical analysis

All data are presented as mean ± standard deviation (Mean ± SD). For the behavioral test, measurement data were analyzed using repeated measures ANOVA^[21]. For all other analyses, if the distribution of the variables were normal, the independent sample t-test was adopted; otherwise, the Mann-Whitney U test was used. The level of significance was defined as p < 0.05. All statistical analyses were performed with IBM SPSS Statistics 20.

Decreased cardiac function in HF rats

The echocardiographic features of the HF model are shown in Fig. 1. Compared to Sham rats, HF rats displayed a decreased ejection fraction, fractional shortening, left ventricular end-systolic (-diastolic) anterior wall thickness, and left ventricular end-systolic posterior wall thickness, without significant differences in left ventricular end-diastolic posterior wall thickness (Fig. 1A, C, F). Also, HF rats displayed a significant increase in left ventricle internal diameter and volume during ventricular diastole and systole compared to Sham rats (Fig. 1D, E). Accordingly, HF rats showed significant infarct wall thinning and cardiac dilatation (Fig. 1A, B).

HF rats display cognitive impairment

To assess cognitive function, particularly learning and memory function, Sham and HF rats were tested using the Morris water maze (MWM) paradigm. In the spatial acquisition trial, no changes in average latency and mean total path length to the target platform were found between the Sham and HF groups (Fig. 2B1-2). The probe trial was tested the day after the last trial session of the spatial acquisition trial, which was used to measure memory retention. Compared to Sham rats, HF rats passed over the former location of the platform fewer times (Fig. 2C1-3). On day 5, the ability of the rats to find a new platform location was tested. As shown in Fig. 2D1-3, HF rats displayed a significant increase in average latency and mean total path length compared to Sham rats. No differences on average swimming speeds during the tests between groups(Fig. 2B3, C4, D3).These data strongly showed that HF rats displayed impairment of memory consolidation, ruling out the possibility of limb weakness or poor vision.

Damaged synaptic structures and reduced BDNF-TrkB signaling in HF

As the important ultrastructure of brain information communication, synapses are fundamental to cognitive function. Compared with the Sham group, transmission electron microscopy images of the HF group showed reduced thickness and length of postsynaptic density (PSD) and increasing synaptic cleft width (P<0.001, Fig. 3A1, 2, B1, 2). Considering that BDNF-TrkB signaling plays an important role in synaptic plasticity regulation, we assessed whether HF might affect classic BDNF-TrkB signaling in the brain. HF rats displayed a decreased level of BDNF, TrkB, PSD95, and VGLUT1, providing evidence of dysfunction in the BDNF-TrkB signaling in HF. Furthermore, the decreased PSD95 and VGLUT1 expression suggested impaired synaptic structure and function .

Reduced excitatory and inhibitory neurotransmitters in the brain of HF

Appropriate transmission of neurotransmitters is required throughout the brain and participates in many processes, including learning and memory. Therefore, 13 neurotransmitters of the brain were detected by high-performance liquid chromatography. Numerous amino acids, including excitatory amino acids (glutamate, aspartate) and inhibitory amino acids (glycine, GABA), were significantly reduced in the HF group compared to sham rats (Fig. 4A1, 2), while the ratio of excitatory amino acids (ASP, GLU)/inhibitory amino acid (GLY, GABA) did not change. Interestingly, there was no significant difference in Ach and monoamine neurotransmitters (Fig. 4B1, 2, C1, 2). The obtained data highlight the HF-specificity of these amino acid neurotransmitters.

Knockdown of BDNF decreases the number of synaptic bifurcations and the protein of TrkB-PSD95/VGLUT1 in vitro

In light of the above results, we knocked down the BDNF gene in rat fetal cortical and hippocampal neurons by small interference (siRNA). The purity of the rat fetal cortical and hippocampal neurons was evaluated to be 97.75% (Figure S1). Fluorescence micrographs were taken after 24h of transfection by confocal laser microscopy, showing that siRNA knockdown of BDNF significantly decreased the number of synaptic bifurcations (Fig. 5A-D), suggesting that deficiency of BDNF disrupts synaptic structures. Consistent with Fig. 3, the reduction of BDNF expression in neurons down-regulated the expression levels of TrkB, PSD95, and VGLUT1 (Fig. 5E1-4). These results indicate that the regulation of structural synaptic plasticity by BDNF levels activates the TrkB-PSD95/ VGLUT1 signaling.

We conducted behavioral and molecular biological methods to comprehensively detect and analyze the mechanism of CI in rats with HF. The main findings of this study are as follows: (1) HF rats displayed impaired spatial learning and memory; (2) the number of synapses decreased, and the structure was damaged in HF rats; (3) amino acid neurotransmitters, including excitatory amino acids (glutamate, aspartate) and inhibitory amino acids (glycine, GABA), were significantly reduced in HF rats; (4) BDNF-TrkB pathway evidence was reduced by lowering BDNF, TrkB, PSD95, and VGLUT; (5) knockdown BDNF mRNA significantly decreased the expression of BDNF, TrkB, PSD95, and VGLUT in cortical neurons, which was consistent with the results of the animal experiments. Taken together, our results strongly suggest that impaired synaptic structure and decreased amino acid neurotransmitters are the main pathological manifestation of CI in HF, which may be attributed to downregulation in the BDNF-TrkB pathway.

Although the prevalence of both HF and CI increases substantially with age, older population-based studies showed that the risk of CI is more pronounced in patients with HF ^{[22, 23]}. In the early stage of HF, the main manifestation is mild cognitive impairment, including learning and memory impairment. Alzheimer's disease or vascular dementia is found in a clinical situation in the late stages of HF^[24].

We conducted the morris water maze test in the present study to quantify possible spatial learning and memory alterations. In the spatial acquisition trial, we did not find statistical differences in average latency and mean total path length between HF rats and sham rats, indicating that HF rats exhibit a similar reference memory ability compared to sham rats. However, in the probe trial (when the platform was removed), the HF rats were observed to have significantly fewer platform crossings. As we continued to increase the task difficulty, we found that HF rats took longer time and traveled longer distances to find the platform when the platform was moved to the opposite side, which is considered a memory consolidation disorder. Thus, our data strongly suggest cognitive deficits in HF rats. Therefore, the animal model of HF constructed using this method can more directly reflect the clinical changes in the cognitive function of HF patients.

Synapses are the structural basis for the normal nervous system operation, which is responsible for the transmission of neural information. Neurotransmitters are released from presynaptic neurons into the synaptic cleft and then pass information to the postsynaptic membrane, causing excitatory or inhibitory changes in another postsynaptic neuron. Abundant neurotransmitter receptors concentrate over the postsynaptic density (PSD) close to the postsynaptic membrane. Therefore, the damage to synaptic structures is closely related to brain cognition ^{[25, 26]}. In the present study, we found that HF rats presented a significant increase in the width of the synaptic cleft. This means that the postsynaptic membrane will receive the neurotransmitter-filled synaptic vesicles released into the synaptic cleft for longer. In addition, the PSD was significantly shorter and thinner in HF rats, which resulted in the loss of the neurotransmitter receptors attached to the PSD. This will further lead to slowing down synaptic transmission.

Correspondingly, reducing excitatory and inhibitory amino acid neurotransmitters in the brain of HF rats may ultimately lead to a decrease in associated nerve impulses. Previous research has found that amino acid neurotransmitters are closely related to cognitive function and participate in the pathological process of various neurodegenerative diseases ^{[27, 28]}. Combined with the findings of synapse structural change, we speculate that thinner postsynaptic density and bigger synaptic cleft will allow harder transmission of neurotransmitters. Importantly, this study first reported that a decrease of amino acid neurotransmitters is more sensitive to HF, while there was no change in Ach and monoamine neurotransmitters. Central amino acid neurotransmitters mainly consist of excitatory and inhibitory amino acid neurotransmitters. Excitatory amino acids mainly include glutamate and aspartate, which are the main mediators of excitatory signals and synaptic plasticity. The appropriate concentration of neurotransmitters is a prerequisite for normal brain functions. Either too much or too few amino acids will affect nerve function. Too few excitatory amino acids will decrease excitatory neurotransmission, while too many excitatory amino acids will lead to excitotoxicity^[29]. GABA and glycine are the major inhibitory amino acid neurotransmitters in the brain, which are involved in preventing neuroexcitotoxicity, exerting neuroprotective and neurotrophic effects ^{[30, 31]}.

In this study, HF rats exhibited decreased excitatory and inhibitory amino acid neurotransmitters in the brain but did not alter the excitatory/inhibitory amino acid neurotransmitters ratio. These results suggest that the excitatory impulse of amino acid neurotransmitters is weakened and neurotrophic function is decreased. The imbalance between excitatory and inhibitory amino acid neurotransmitters in the brain has also been found in cerebral ischemic injury ^{[32, 33]}. Previous study has found that cholinergic deficits are a key factor for cognitive decline in Alzheimer's disease or vascular dementia ^{[34, 35]} but are not associated with heart failure, suggesting that the mechanisms of cognitive impairment between HF and other neurodegenerative diseases are not identical.

In addition, other literature has reported that this HF rat model exhibited depression and anxiety ^{[36, 37]}. However, enhanced glutamate transmission with increased inflammatory response and no change in BDNF has been implicated in anxiety disorders of HF ^[38]. These findings indicate that amino acid neurotransmitters might be involved in both cognitive impairment and depression/anxiety but vary differently in both disorders; yet, further research is needed to explain this interaction.

BDNF has an important role in cognitive function by regulating synaptic plasticity, excitatory synaptic transmission, and inhibitory synaptic transmission ^{[39, 40]} by activating its receptor TrkB. Tissue hypoxia, oxidative stress, and inflammation may lead to decreased BDNF protein expression ^[41–43], also considered a core pathological process of HF ^[44]. PSD95 association with TrkB is critical for intact BDNF signaling ^[45]. Also, studies have found that PSD95 is involved in synapse formation and promoting synaptic plasticity ^{[46, 47]}. Moreover, BDNF-TrkB can promote the release of amino acid neurotransmitters by upregulating the activation of VGLUT1 ^{[17, 18]}. Decreased VGLUT1 will lead to reduced amino acid neurotransmitters ^{[48, 49]}.

Our results showed for the first time that BDNF, TrkB, PSD95, and VGLUT1 protein expression were significantly decreased in the brain of HF rats. After BDNF siRNA treatment in neurons, the number of synaptic bifurcations reduced, indicating synapse loss. Simultaneously, protein expression of BDNF, TrkB, PSD95, and VGLUT1 was decreased. For HF rats, decreased BDNF- TrkB- PSD95 or VGLUT1 may directly lead to synaptic structure injury and reduced amino acid neurotransmitters. These results were consistent with those of the animal experiments.

To explore the mechanism of cognitive impairment caused by HF, synaptic structures, neurotransmitters, and BDNF-TrkB signaling pathway were examined in a rat model with HF. HF rats showed obvious impairment in learning and memory, mainly manifested as a memory consolidation disorder. In addition, we found that HF rats displayed synaptic damage, including reduced thickness and length of the postsynaptic density, increasing synaptic cleft width. Importantly, amino acids neurotransmitters (excitatory and inhibitory) were significantly reduced, while Ach was unchanged in CI after HF. The reduced protein of BDNF, TrkB, PSD95, and VGLUT1 levels were observed in the brain tissue of rats with HF and in BDNF knockdown neurons. Thus, the reduction of the BDNF-TrkB signaling pathway after HF could both lead to synaptic structural damage via PSD95 and reduce the release of amino acid neurotransmitters via VGLUT1, ultimately leading to cognitive dysfunction. These results might provide a new alternative for diagnosing and treating CI in HF.

Authors' contributions Lei Wang: Experiment conduction, data analyses, and manuscript writing. Ziwen Lu and Yu Teng: Assisted in performing the animal experiments. Weibing Pan: participated in the manuscript revision. Yang Li and Sha Su: offered help in the cell culture and data analysis. Jingling Chang and Mingjing Zhao: conceived and designed experiments, review and edit the manuscript and provided expertise and continuous guidance as well as necessary reagents and equipment.

Funding This work was supported by the National Natural Science Foundation of China (Grant No. 81973787) and National Postdoctoral Fund of China (20221M70017).

Data Availability The datasets supporting the conclusions of this article are included within the article and its Supplementary documents. All material used in this manuscript are available to researchers.

Ethics approval

All procedures performed in this study observed the ethical standards of Key Laboratory of Chinese Internal Medicine of Ministry of Education and Dongzhimen Hospital of Beijing University of Chinese Medicine.

Consent to participate

All the authors declared that they had participated in this work.

Consent for publication

All the authors stated that they agreed to the publication of the paper.

Competing Interests

Authors declare no competing interest.

Hajduk AM, Kiefe CI, Person SD, Gore JG, Saczynski JS. Cognitive change in heart failure: a systematic review. Circulation Cardiovascular quality and outcomes 2013, 6(4): 451-460.
Frey A, Sell R, Homola GA, Malsch C, Kraft P, Gunreben I, Morbach C, Alkonyi B, Schmid E, Colonna I, Hofer E, Mullges W, Ertl G, Heuschmann P, Solymosi L, Schmidt R, Stork S, Stoll G. Cognitive Deficits and Related Brain Lesions in Patients With Chronic Heart Failure. JACC Heart failure 2018, 6(7): 583-592.
Sauvé MJ, Lewis WR, Blankenbiller M, Rickabaugh B, Pressler SJ. Cognitive impairments in chronic heart failure: a case controlled study. Journal of cardiac failure 2009, 15(1): 1-10.
Dickson VV, Tkacs N, Riegel B. Cognitive influences on self-care decision making in persons with heart failure. American heart journal 2007, 154(3): 424-431.
Pressler SJ, Kim J, Riley P, Ronis DL, Gradus-Pizlo I. Memory dysfunction, psychomotor slowing, and decreased executive function predict mortality in patients with heart failure and low ejection fraction. Journal of cardiac failure 2010, 16(9): 750-760.
Toledo C, Andrade DC, Díaz HS, Inestrosa NC, Del Rio R. Neurocognitive Disorders in Heart Failure: Novel Pathophysiological Mechanisms Underpinning Memory Loss and Learning Impairment. Molecular neurobiology 2019, 56(12): 8035-8051.
Almeida OP, Garrido GJ, Beer C, Lautenschlager NT, Arnolda L, Flicker L. Cognitive and brain changes associated with ischaemic heart disease and heart failure. European heart journal 2012, 33(14): 1769-1776.
Toledo C, Lucero C, Andrade DC, Díaz HS, Schwarz KG, Pereyra KV, Arce-Álvarez A, López NA, Martinez M, Inestrosa NC, Del Rio R. Cognitive impairment in heart failure is associated with altered Wnt signaling in the hippocampus. Aging 2019, 11(16): 5924-5942.
Havakuk O, King KS, Grazette L, Yoon AJ, Fong M, Bregman N, Elkayam U, Kloner RA. Heart Failure-Induced Brain Injury. Journal of the American College of Cardiology 2017, 69(12): 1609-1616.
van der Velpen IF, Feleus S, Bertens AS, Sabayan B. Hemodynamic and serum cardiac markers and risk of cognitive impairment and dementia. Alzheimer's & dementia : the journal of the Alzheimer's Association 2017, 13(4): 441-453.
Taoufik E, Kouroupi G, Zygogianni O, Matsas R. Synaptic dysfunction in neurodegenerative and neurodevelopmental diseases: an overview of induced pluripotent stem-cell-based disease models. Open biology 2018, 8(9).
Gowda P, Reddy PH, Kumar S. Deregulated mitochondrial microRNAs in Alzheimer's disease: Focus on synapse and mitochondria. Ageing research reviews 2022, 73: 101529.
Skilleter AJ, Weickert CS, Vercammen A, Lenroot R, Weickert TW. Peripheral BDNF: a candidate biomarker of healthy neural activity during learning is disrupted in schizophrenia. Psychological medicine 2015, 45(4): 841-854.
Suzuki S, Numakawa T, Shimazu K, Koshimizu H, Hara T, Hatanaka H, Mei L, Lu B, Kojima M. BDNF-induced recruitment of TrkB receptor into neuronal lipid rafts: roles in synaptic modulation. The Journal of cell biology 2004, 167(6): 1205-1215.
Minichiello L. TrkB signalling pathways in LTP and learning. Nature reviews Neuroscience 2009, 10(12): 850-860.
Luikart BW, Nef S, Virmani T, Lush ME, Liu Y, Kavalali ET, Parada LF. TrkB has a cell-autonomous role in the establishment of hippocampal Schaffer collateral synapses. The Journal of neuroscience : the official journal of the Society for Neuroscience 2005, 25(15): 3774-3786.
Melo CV, Mele M, Curcio M, Comprido D, Silva CG, Duarte CB. BDNF regulates the expression and distribution of vesicular glutamate transporters in cultured hippocampal neurons. PloS one 2013, 8(1): e53793.
Fattorini G, Ciriachi C, Conti F. Few, Activity-Dependent, and Ubiquitous VGLUT1/VGAT Terminals in Rat and Mouse Brain. Frontiers in cellular neuroscience 2017, 11: 229.
Shibata A, Hanatani A, Izumi Y, Kitada R, Iwata S, Yoshiyama M. Serum brain-derived neurotrophic factor level and exercise tolerance complement each other in predicting the prognosis of patients with heart failure. Heart and vessels 2018, 33(11): 1325-1333.
Barman HA, Şahin I, Atıcı A, Durmaz E, Yurtseven E, Ikitimur B, Okuyan E, Keleş I. Prognostic significance of brain-derived neurotrophic factor levels in patients with heart failure and reduced left ventricular ejection fraction. Anatolian journal of cardiology 2019, 22(6): 309-316.
Yang T, Lu Z, Wang L, Zhao Y, Nie B, Xu Q, Han X, Li T, Zhao J, Cheng W, Wang B, Wu A, Zhu H, Meng W, Shang H, Zhao M. Dynamic Changes in Brain Glucose Metabolism and Neuronal Structure in Rats with Heart Failure. Neuroscience 2020, 424: 34-44.
Cacciatore F, Abete P, Ferrara N, Calabrese C, Napoli C, Maggi S, Varricchio M, Rengo F. Congestive heart failure and cognitive impairment in an older population. Osservatorio Geriatrico Campano Study Group. Journal of the American Geriatrics Society 1998, 46(11): 1343-1348.
Dodson JA, Truong TT, Towle VR, Kerins G, Chaudhry SI. Cognitive impairment in older adults with heart failure: prevalence, documentation, and impact on outcomes. The American journal of medicine 2013, 126(2): 120-126.
Adelborg K, Horváth-Puhó E, Ording A, Pedersen L, Sørensen HT, Henderson VW. Heart failure and risk of dementia: a Danish nationwide population-based cohort study. European journal of heart failure 2017, 19(2): 253-260.
Harris KP, Littleton JT. Transmission, Development, and Plasticity of Synapses. Genetics 2015, 201(2): 345-375.
Cohen S, Greenberg ME. Communication between the synapse and the nucleus in neuronal development, plasticity, and disease. Annual review of cell and developmental biology 2008, 24: 183-209.
Lewis DA, Curley AA, Glausier JR, Volk DW. Cortical parvalbumin interneurons and cognitive dysfunction in schizophrenia. Trends in neurosciences 2012, 35(1): 57-67.
Hynd MR, Scott HL, Dodd PR. Glutamate-mediated excitotoxicity and neurodegeneration in Alzheimer's disease. Neurochemistry international 2004, 45(5): 583-595.
Zhou Y, Danbolt NC. Glutamate as a neurotransmitter in the healthy brain. Journal of neural transmission (Vienna, Austria : 1996) 2014, 121(8): 799-817.
Wu C, Sun D. GABA receptors in brain development, function, and injury. Metabolic brain disease 2015, 30(2): 367-379.
Sowa AR, Brooks AF, Shao X, Henderson BD, Sherman P, Arteaga J, Stauff J, Lee AC, Koeppe RA, Scott PJH, Kilbourn MR. Development of Positron Emission Tomography Radiotracers for the GABA Transporter 1. ACS chemical neuroscience 2018, 9(11): 2767-2773.
Huang L, Shi Y, Zhao L. Ginkgolide B Alleviates Learning and Memory Impairment in Rats With Vascular Dementia by Reducing Neuroinflammation via Regulating NF-κB Pathway. Frontiers in pharmacology 2021, 12: 676392.
Liu J, Yang L, Niu Y, Su C, Wang Y, Ren R, Chen J, Ma X. Potential Therapeutic Effects of Mi-Jian-Chang-Pu Decoction on Neurochemical and Metabolic Changes of Cerebral Ischemia-Reperfusion Injury in Rats. Oxidative medicine and cellular longevity 2022, 2022: 7319563.
Hampel H, Mesulam MM, Cuello AC, Farlow MR, Giacobini E, Grossberg GT, Khachaturian AS, Vergallo A, Cavedo E, Snyder PJ, Khachaturian ZS. The cholinergic system in the pathophysiology and treatment of Alzheimer's disease. Brain : a journal of neurology 2018, 141(7): 1917-1933.
Wang J, Zhang HY, Tang XC. Cholinergic deficiency involved in vascular dementia: possible mechanism and strategy of treatment. Acta pharmacologica Sinica 2009, 30(7): 879-888.
Henze M, Hart D, Samarel A, Barakat J, Eckert L, Scrogin K. Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat. American journal of physiology Heart and circulatory physiology 2008, 295(1): H29-38.
Wang HW, Ahmad M, Jadayel R, Najjar F, Lagace D, Leenen FHH. Inhibition of inflammation by minocycline improves heart failure and depression-like behaviour in rats after myocardial infarction. PloS one 2019, 14(6): e0217437.
Su J, Wang J, Ma Y, Li Q, Yang Y, Huang L, Wang H, Li H, Wang Z, Tong J, Huang D, Bai X, Yu M, Bu L, Fei J, Huang F. Inflammation associated with chronic heart failure leads to enhanced susceptibility to depression. The FEBS journal 2019, 286(14): 2769-2786.
Chen SD, Wu CL, Hwang WC, Yang DI. More Insight into BDNF against Neurodegeneration: Anti-Apoptosis, Anti-Oxidation, and Suppression of Autophagy. International journal of molecular sciences 2017, 18(3).
Lu B, Nagappan G, Lu Y. BDNF and synaptic plasticity, cognitive function, and dysfunction. Handbook of experimental pharmacology 2014, 220: 223-250.
Netto MB, de Oliveira Junior AN, Goldim M, Mathias K, Fileti ME, da Rosa N, Laurentino AO, de Farias BX, Costa AB, Rezin GT, Fortunato JJ, Giustina AD, Barichello T, Dal-Pizzol F, Petronilho F. Oxidative stress and mitochondrial dysfunction contributes to postoperative cognitive dysfunction in elderly rats. Brain, behavior, and immunity 2018, 73: 661-669.
Turovskaya MV, Gaidin SG, Vedunova MV, Babaev AA, Turovsky EA. BDNF Overexpression Enhances the Preconditioning Effect of Brief Episodes of Hypoxia, Promoting Survival of GABAergic Neurons. Neuroscience bulletin 2020, 36(7): 733-760.
Calabrese F, Rossetti AC, Racagni G, Gass P, Riva MA, Molteni R. Brain-derived neurotrophic factor: a bridge between inflammation and neuroplasticity. Frontiers in cellular neuroscience 2014, 8: 430.
Kramer F, Voss S, Roessig L, Igl BW, Butler J, Lam CSP, Maggioni AP, Shah SJ, Pieske B. Evaluation of high-sensitivity C-reactive protein and uric acid in vericiguat-treated patients with heart failure with reduced ejection fraction. European journal of heart failure 2020, 22(9): 1675-1683.
Cao C, Rioult-Pedotti MS, Migani P, Yu CJ, Tiwari R, Parang K, Spaller MR, Goebel DJ, Marshall J. Impairment of TrkB-PSD-95 signaling in Angelman syndrome. PLoS biology 2013, 11(2): e1001478.
Bae JS, Han M, Shin HS, Shon DH, Lee ST, Shin CY, Lee Y, Lee DH, Chung JH. Lycopersicon esculentum Extract Enhances Cognitive Function and Hippocampal Neurogenesis in Aged Mice. Nutrients 2016, 8(11).
Shi H, Yu Y, Lin D, Zheng P, Zhang P, Hu M, Wang Q, Pan W, Yang X, Hu T, Li Q, Tang R, Zhou F, Zheng K, Huang XF. β-glucan attenuates cognitive impairment via the gut-brain axis in diet-induced obese mice. Microbiome 2020, 8(1): 143.
Carvalho AL, Caldeira MV, Santos SD, Duarte CB. Role of the brain-derived neurotrophic factor at glutamatergic synapses. British journal of pharmacology 2008, 153 Suppl 1(Suppl 1): S310-324.
Waterhouse EG, An JJ, Orefice LL, Baydyuk M, Liao GY, Zheng K, Lu B, Xu B. BDNF promotes differentiation and maturation of adult-born neurons through GABAergic transmission. The Journal of neuroscience : the official journal of the Society for Neuroscience 2012, 32(41): 14318-14330.

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Cognitive impairment is induced by BDNF-TrkB signaling mediating synaptic damage and reduction of amino acid neurotransmitters in heart failure rats

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Abstract

Background

Methods

Results

Conclusions

Figures

Introduction

Methods

Induction of HF

Electrocardiographic and echocardiographic examination

Morris Water Maze (MWM)

Transmission electron microscopy

Western Blot

Neurotransmitter identification

Cell culture and transfections

Immunofluorescence

Statistical analysis

Results

HF rats display cognitive impairment

Damaged synaptic structures and reduced BDNF-TrkB signaling in HF

Reduced excitatory and inhibitory neurotransmitters in the brain of HF

Discussion

Conclusions

Declarations

References

Supplementary Files

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