Correlation between intracerebral pH and expression of Hv1 proton channel and myelin-related proteins after hypoxic-ischemic brain injury in newborn pigs

doi:10.21203/rs.3.rs-1943496/v1

Download PDF

Research Article

Correlation between intracerebral pH and expression of Hv1 proton channel and myelin-related proteins after hypoxic-ischemic brain injury in newborn pigs

https://doi.org/10.21203/rs.3.rs-1943496/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Background

Myelin sheath injury after cerebral hypoxia-ischemia is well known and is associated with multiple factors. In this study, changes in pH and expression of voltage-gated proton channel (Hv1) as well as myelin-related proteins in the brain, after hypoxic-ischemic brain injury (HIBI) in neonatal pigs were analyzed.

Methods

A total of 53 healthy male neonatal pigs were used to establish an HIBI model. The control group was without HI process. The model group underwent hypoxic-ischemic process for 40 min. The pH and expression of Hv1, myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG), and myelin-associated glycoprotein (MAG) in the brain tissue of neonatal pigs were then analyzed at different time points after HI.

Results

After HIBI, the expression of Hv1 expression reached a peak at 2–6 h. The pH in this brain region reached a minimum at 0–2 h after HI, and was then gradually restored. Regarding the expression of myelin-related proteins, we observed an initial decrease in their levels, followed by an increase. MAG and MBP expression reached a minimum at 6–12 h, while MOG expression reached a minimum at 2–6 h. Furthermore, a correlation was found between pH and Hv1, MBP, and MOG expression, but not with MAG expression.

Conclusions

Our findings indicate that brain pH is correlated with Hv1, MBP, and MOG expression after HIBI, suggesting that changes in the brain environment impact myelin damage and repair to some extent.

Hypoxic-ischemic brain injury

Hv1

myelin protein

The brain tissue of newborns keeps developing and maturing continuously. Under normal physiological conditions, the internal environment of the brain tissue is at steady state, which is particularly important for protein structure and enzyme function in this organ. During hypoxic-ischemic brain injury (HIBI), aerobic energy metabolism is impaired [1] and converted to anaerobic metabolism, which produces lactate (Lac) [2, 3]. Lac accumulation inhibits glucose metabolism, depletes adenosine triphosphate (ATP), and aggravates intracellular acidosis [4]. Moreover, studies have shown that astrocyte swelling can occur at early stages after hypoxia-ischemia (HI) [5]. Cell swelling and HI lead to energy failure, which in turn leads to deionization, causing the opening of various ion channels. Disorders involving Na⁺-H⁺ and K⁺-H⁺ ion exchange result in the retention of hydrogen ion (H⁺) in the cell, while changes in H⁺ inside and outside the cell can cause intracellular pH alterations. This increase in H⁺ plays an important role in pH changes in the brain tissue.

Microglia are among the cells that respond the earliest during HI [6] and perform various functions, including chemotaxis, phagocytosis, antigen presentation, and cytokine secretion [7]. Microglia activation produces a large number of oxygen-free radicals, which react with lipids, proteins, coenzymes, and DNA, subsequently activating signaling pathways associated with apoptosis and leading to neuron or glial cell damage and death [8, 9]. Voltage-gated proton channels (Hv1) are expressed primarily in the microglia of the central nervous system (CNS) [10] and are highly selective for protons, mainly mediating H⁺ efflux and preventing other cations from passing through [11, 12]. Hv1 can be activated by an acidic cellular environment and can regulate intracellular pH while itself being regulated by pH [13–15].

Under normal physiological conditions, a dynamic balance is maintained between nerve cells and their surrounding environment. After HI reperfusion, the microenvironment in the brain tissue changes, which includes failure of ATP supply; such as changes in ion homeostasis, inflammation, release of various cytokines; and abnormal release of neurotransmitters. In addition, neural stem cells are induced to proliferate and migrate to the infarct site to repair damaged brain tissue. The neonatal brain is characterized by a strong plasticity and regeneration ability following injury. When a suitable microenvironment is provided for the damaged brain tissue, the injured axons of neurons can be regenerated [16]. However, the factors that aid an effective repair of the CNS are rather complex and primarily include the formation of glial scars in the injured area, absence of neurotrophic factors, and presence of molecules that inhibit the growth and correctly target axons.

Myelin is a substance that is located around the axons of nerve cells and is primarily composed of myelin basic protein (MBP), myelin-associated glycoprotein (MAG), and myelin oligodendrocyte (OL) glycoprotein (MOG). Myelin prevents nerve electrical impulses from being inappropriately transmitted from the axon of one neuron to that of another neuron and is essential for rapid and effective conduction of electrical impulses along the axon, as well as for maintaining the integrity of the axon. OLs are the myelin-forming cells of the CNS, accounting for approximately 5–10% of the total glial population. OLs wrap around axons, forming an insulating myelin structure that supports efficient saltatory conduction of bioelectrical signals and maintains and protects the normal function of neurons. OLs and their precursor cells are highly susceptible to damage through a variety of mechanisms, including excitotoxicity, oxidative stress, and inflammation [17]. The differentiation of OLs and OL progenitor cells (OPCs) is coordinated by a variety of intrinsic and extrinsic factors in the CNS that work together to regulate cell survival, proliferation, differentiation, apoptosis, and expression and secretion of associated cytokines [18].

In this study, we aimed to investigate the correlation between brain pH and myelin damage and repair after HI using a HIBI model in neonatal pigs.

2.1. Experimental animals

A total of 59 healthy male neonatal pigs (Yorkshire Piglets, also known as Large White Pigs), aged 3–5 days and weighing 1–1.5 kg, were selected. Of these, 6 pigs died mid-experiment, failed to establish the model, or exhibited motion artifacts, and a total of 53 pigs were considered for data collection. The pigs were randomly divided into a control group (n = 10) and a model group (n = 43). The model group was further subdivided into six time-point groups based on the time of magnetic resonance imaging (MRI) scanning after HIBI (0–2 h, n = 8; 2–6 h, n = 8; 6–12 h, n = 6; 12–24 h, n = 10; 24–48 h, n = 5; and 48–72 h, n = 6). Experiments were performed under a project license (Regulations for the Administration of Affairs Concerning Experimental Animals” and “Measures for the Administration of Licenses Concerning Experimental Animals”, Ethical Code: 2022PS250K) granted by China Medical University ethics committee, in compliance with China Medical University guidelines for the care and use of animals.

2.2. Establishment of the animal model

2.2.1. Control group

The indoor temperature was maintained at 28–30°C. Su-mian-xin (a compound preparation of haloperidol, baodingning, and dihydroetorphine; Veterinarian Research Center, Jilin University, Changchun, China) was intramuscularly injected at a dose of 0.6 mL/kg [19]. Animals were subjected to tracheal intubation (diameter 2.5 mm) and mechanical ventilation using a small animal ventilator (TKR-200C, Jiangxi Teli Anesthesia Respiration Co., Ltd.). The ventilator parameters were as follows: 100% oxygen; respiratory ratio (I/E), 1:1.5; respiratory rate, 30 breaths/min; and pressure, 0.05–0.06 MPa. A palm pulse oximeter (TuffSat, GE, USA) was used to monitor the heart rate and blood oxygen saturation. The jugular vein was catheterized and fixed. The skin of the neck was disinfected using iodophor, a median incision was made, the bilateral common carotid arteries were separated, and the incision was sutured. The animal was carefully wrapped in a thick heating pad during surgery and immediately placed in an incubator (Shenzhen Reward Life Technology Co. Ltd. 912-005) after model establishment. Rectal temperature was maintained between 38 and 40°C.

2.2.2. Model group

The same process described above was performed on the model group. After the animals were stabilized for 30 min, the blood flow of the bilateral common carotid arteries was blocked using arterial clamps, and 6% oxygen was simultaneously provided by mechanical ventilation (Dalian Date Qiti Co., Ltd.), maintaining this state for 40 min. Next, the animals were provided 100% oxygen (Dalian Date Qiti Co., Ltd.), and, simultaneously, the blood supply of both carotid arteries was restored, and the incision was then sutured. Blood oxygen saturation and the heart rate were monitored throughout the process. Animals were weaned from ventilation after they resumed spontaneous breathing and were placed in an incubator (Shenzhen Reward Life Technology Co. Ltd. 912-005) immediately after model establishment. This HI model is a whole-brain ischemia-reperfusion model. The model can simulate HIE basal ganglia injury with symmetric high signal visible in bilateral basal ganglia on DWI sequences [Yang and Wang, 2021; Wang et al,. 2012] and a brain injury caused by acute hypoxia and ischemia in the brain, for example, subcortical white matter injury.

2.3. Intracerebral pH and histological examination

Prior to the pH measurement, MRI sagittal imaging was performed to measure the precise distance from the cranial vault to the basal ganglia. This was done to localize the basal ganglia region and determine the depth of the pH meter in the brain tissue. HIBI model animals were sacrificed at the designated time points. The skull was opened, exposing the whole brain. The cerebral hemispheres were separated, a pH electrode (Sartorius PB-10) was carefully inserted into the region of interest (basal ganglia), and the neonatal pig was placed prone on the experimental table. The pH electrode was inserted vertically from the top into the brain tissue to a depth of approximately 20–25 mm (Fig. 1). The pH of the brain tissue was measured, the position was changed, and the pH electrode was reinserted, with four measurements being made. The pH in the bilateral basal ganglia region was measured. This process was completed in 3 min after sacrifice.

2.4. Immunofluorescence

After model establishment, the brain tissue was rapidly removed after pH measurement. The removed cerebral hemispheres were placed in 10% neutral formaldehyde, fixed for 24–48 h, and cut into 4 mm coronal tissue slices. The slices containing the basal ganglia and hippocampus were selected, and immunofluorescence staining for Hv1, MBP, MOG, and MAG was performed. Hv1 (ab117520, 1:100) and secondary antibody (goat anti-rabbit, Immunoway, RS3211, 1:200) and MBP (ab209328, 1:100), MOG (ab254026, 1:100), MAG (ab277524, 1:100), and secondary antibody (goat anti-mouse, Immunoway, RS3208, 1:100). A confocal microscope (ZEISS LSM880) was used for image acquisition. Each field of view was selected randomly. The average optical density (OD) value was used to express the intensity of immunofluorescent and immunohistochemical staining for each slide to exclude the effect caused by differences in cell density. The OD value is independent of the number of cells, and it is able to express the average level of staining intensity in the designated area.

The results of Hv1, MBP, MOG, and MAG immunofluorescence staining were analyzed by two pathologists. The samples were observed under a microscope at 400× magnification, and the optical density (OD) values of the immunofluorescence images were analyzed. Five fields of view in each of the basal ganglia were observed, and then the data of these five fields of view were combined to analyze and determine Hv1, MBP, MOG, and MAG expression in different brain areas of pigs from each group at each time point. ImageJ software was used for image analysis.

2.5. Statistical analyses

SPSS software for Windows (Version 17.0, Chicago, IL, USA) was used for statistical processing of data. Data are expressed as mean ± standard deviation (± SD). The Levene test was first used to test the homogeneity of data and verify that each group of data was normally distributed and homoscedastic. One-way analysis of variance was used for analyzing homoscedastic data, and the Dunnett t-test was used for comparison of means between groups. Spearman’s rank correlation analysis was used to test the correlation between pH and Hv1, MBP, MOG, and MAG expression. Differences with p < 0.05 were considered statistically significant.

3.1. Hv1 expression and pH in the basal ganglia at different time points after HIBI

After HIBI, maximum Hv1 expression in the basal ganglia occurred at 2–6 h (Fig. 2); Differences in Hv1 expression between the control group and the 0–2 h, 2–6 h, and 6–12 h groups were statistically significant (p = 0.000), whereas those between the control group and the 12–24 h, 24–48 h, and 48–72 h groups were not (p = 0.054, p = 0.253, and p = 0.410, respectively).

Regarding the pH in the basal ganglia, it reached a minimum at 0–2 h after HIBI, which was significantly different from the pH in the control group (p = 0.000; Fig. 3). Conversely, there were no statistically significant differences in pH between the control group and 24–48 h and 48–72 h groups (p = 0.171 and p = 0.377, respectively), but statistically significant differences were observed between the control group and the remaining groups (p = 0.000).

3.2. MBP, MOG, and MAG expression in the basal ganglia at different time points after HIBI

After HIBI, MAG and MBP expression in the basal ganglia reached a minimum at 6–12 h, and that of MOG at 2–6 h (Fig. 4). Differences in MAG expression between the control group and the model groups were all statistically significant (6–12 h vs 12–24 h, p = 0.016; all others, p = 0.000), with a similar trend for differences in MBP expression (6–12 h vs. 2–6 h, p = 0.045; all others, p = 0.000). Differences in MOG expression between the control group and the model groups were also statistically significant (p < 0.05), except for those between the 2–6 h and 6–12 h groups (p = 0.079).

3.3. Correlation of pH and Hv1, MBP, MOG, and MAG expression

There was a positive correlation between pH and MBP expression (ρ = 0.623, p = 0.000) and between pH and MOG expression (ρ = 0.385, p = 0.004), whereas a negative correlation was found between pH and Hv1 expression (ρ = − 0.726, p = 0.000) (Fig. 5). However, no correlation was observed between pH and MAG expression (p = 0.081).

Moreover, the correlations were found between Hv1 and MBP expression and between Hv1 and MOG expression, with correlation coefficients of − 0.639 (p = 0.000) and − 0.509 (p = 0.000), respectively.

The pathophysiological process of brain HI is extremely complex and involves the imbalance of intracellular and extracellular ion homeostasis, abnormal electrical activity in the cells, excessive release of excitatory amino acids, and excessive production of free radicals. Loss of ion steady state occurs at the early stages of HI, triggering a series of cascade reactions.

In this study, using a model of HIBI established in neonatal pigs, we found that pH decreases after HI, reaching a minimum at 0–2 h, and that Hv1 expression increases. This is attributed to anaerobic fermentation in cells after HIBI, which produces a large amount of Lac. Hydrolysis of ATP leads to the release of a large amount of H⁺, which acidifies the intracellular environment, and in turn, leads to increased Hv1 expression. When the intracellular H⁺ concentration exceeds the inherent buffering capacity of the cell, H⁺ flows out of the cell through the expressed Hv1 channels and aggregates outside the cell, decreasing the extracellular pH to 6.5 or lower [20]. After HI, the highly expressed Hv1 transports the excess H⁺ from the cell to the extracellular space. The increase in extracellular H⁺ activates acid-sensitive ion channels, Na⁺ and Ca²⁺ influx [21], and cell depolarization, subsequently activating voltage-gated Ca²⁺ channels and glutamate (Glu)-activated N-methyl-D-aspartic acid (NMDA) receptors to cause a large amount of intracellular Ca²⁺ overload and secondary neuronal damage [22, 23]. In addition, HI reperfusion leads to injury and necrosis of some neurons, in turn leading to decreased Hv1 expression.

Hv1 transports H⁺ out of the cell, reduces intracellular acidosis, and stabilizes the intracellular environment, a mechanism that protects the body. With the restoration of aerobic metabolism and blood flow, the H⁺ generated from anaerobic metabolism is excreted, restoring the pH to normal levels, and the expression of Hv1 decreases.

The pH of brain cells after HI has a major impact on cell survival and outcome. Mild acidosis has a protective effect on nerves against excitotoxicity and ischemia reperfusion [24–27]. This is because a small decrease in intracellular pH uncouples the activation of neuronal nicotinamide adenine dinucleotide phosphate oxidase (NOX) from that of NMDA receptors, thereby preventing neuronal death [28]. After the brain tissue experiences a short-term decrease in pH, the pH rebounds, causing “alkalosis,” and the increased Glu level in this alkaline environment aggravates excitotoxicity of neurons [28–31].

The immune response in acute HI is the pathological basis of neonatal brain injury [32]. Cerebral HI triggers a cascade of inflammation processes in blood vessels, further enhancing damage to brain parenchymal cells by activating innate and peripheral immune cells, which can lead to secondary damage to brain tissue [33]. Hypoxic-ischemic white matter injury, in which the white matter of the brain becomes sparse or even softens, is the principal pathological change in disorders of myelin production. The damage to OPCs caused by the activation of microglia is considered the principal pathophysiological feature of periventricular leukomalacia [34].

MBP expression is specific to the CNS, particularly in OLs [35, 36]. MBP is located in the innermost layer of the myelin sheath and maintains close contact with the axonal membrane to keep the structure and function of the myelin sheath, promote rapid nerve conduction, and maintain insulation for nerve conduction [37]. A decreased MBP level is a sign of CNS injury. MBP is expressed at high levels in infants and young children, and its decreased expression indicates some degree of damage to myelin [38, 39]. In vitro studies have shown that hypoxia can cause neural stem cells to differentiate into OLs and astrocytes and can inhibit their differentiation into neurons [4]. In the present study, MBP expression after HI decreased compared to that in the control group, reaching a minimum at 6–12 h, which indicates that myelin damage occurred after HI. Moreover, MBP expression increased at 12 h after HI, indicating that myelin damage was accompanied by OL proliferation. Increased MBP expression indicates that HI-caused damage to the myelin sheath, which over time was accompanied by myelin sheath repair.

MOG is expressed on the outer surface of the myelin sheath and on the surface of OLs in the CNS, making it a good marker for mature OLs [40]. Compared to other major myelin-related proteins, the expression of MOG is delayed for 24–48 h. MOG can inhibit the growth of axons [41]. The results of the present study show that MOG expression initially decreased after HI, reaching a minimum at 2–6 h. Decreased MOG expression can temporarily inhibit the growth of axons and provide an opportunity for axonal regeneration. With time, the number of mature OLs gradually increases, which in turn increases MOG expression. Increased MOG expression inhibits axonal overgrowth and may also interfere with the repair of damaged nerves.

MAG is located on the cell membrane of Schwann cells and OLs [42] and plays a role in glial cell-axons. It enhances long-term axon–myelin stability and regulates the axon cytoskeleton. MAG has a dual function, as it either inhibits or promotes the growth of nerve fibers, depending on the developmental stage of the animal and type of neuron. MAG is not only an axonal growth factor but can also inhibit axon regeneration. Furthermore, it acts as an activator during fetal development but becomes an inhibitor after myelination is completed. In addition, MAG inhibits axon regeneration after injury [43, 44]. Studies have shown that MAG maintains the myelin–axon spacing by interacting with specific neuronal glycolipids (gangliosides), inhibits axon regeneration, and controls myelin formation [45, 46]. In the present study, MAG expression initially decreased after HI. This is because myelin was affected by HI and the OLs were damaged, which in turn reduced MAG expression. Over time, as neural stem cells differentiated into OLs, the latter began to proliferate, and then MAG expression increased, promoting axon regeneration after injury.

We also determined that pH in the brain after HIBI is correlated with Hv1, MBP, and MOG expression. After HI, pH decreases, Hv1 expression increases, and myelin-related protein expression decreases. Over time, pH is restored and Hv1 expression decreases, while that of myelin-associated proteins increases. This can be explained by the fact that Hv1 is required for production of NOX-dependent reactive oxygen species (ROS) in the brain. Microglia injury and demyelination require the involvement of the Hv1 proton channel. In Hv1^−/− mice, ROS production is reduced, microglia activation is improved, OL progenitor cell (NG2) proliferation is increased, and the number of mature OLs is increased [47]. The Hv1 proton channel is a unique target for NOX-dependent ROS production in the mechanism that controls the pathogenesis of myelin injury. As Hv1 expression is affected by pH, we infer that pH has some effect on myelin damage and repair.

Furthermore, this study demonstrates that after HIBI, the expression of myelin-related proteins in the model group was slightly lower than that in the control group. This may be due to changes in the microenvironment of the damaged brain regions after HI. Although endogenous neural stem cells have strong proliferation and migration capabilities, their ability to ultimately promote the differentiation and maturation of new cells and form a complete neural network with other neurons in the colonized site remains limited. This shows that the microenvironment of neural stem cells contains major factors that affect their survival, regeneration, and differentiation.

After HIBI in newborn pigs, pH and Hv1 expression in the brain are negatively correlated. Both pH and myelin-associated protein expression initially decrease and then increase, suggesting that myelin in the brain is damaged by acidosis following HI. As the pH gradually recovers, the repair of damaged myelin begins.

Funding

This work was supported by the National Natural Science Foundation of China (NO.81871408), National Science Foundation for Young Scientists of China (NO.81801658), Outstanding Scientific Fund of Shengjing Hospital (NO. 201402) and 345 Talent Project of Shengjing Hospital.

Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Author Contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Zheng Yang, and Wang Xiaoming. The first draft of the manuscript was written by Zheng Yang and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Data Availability

The datasets generated during and/or analysed during the current study are available in the Zheng Yang and Wang Xiaoming repository (Please contact us by email).

Ethics approval

This study was performed in line with the principles of the Declaration of Helsinki. Experiments were performed under a project license (Regulations for the Administration of Affairs Concerning Experimental Animals” and “Measures for the Administration of Licenses Concerning Experimental Animals”, Ethical Code: 2022PS250K) granted by China Medical University ethics committee, in compliance with China Medical University guidelines for the care and use of animals.

Consent to participate

Not applicable

Consent to publish

Not applicable

Acknowledgments

Malik GK, Pandey M, Kumar R, Chawla S, Rathi B, Gupta RK (2002) MR imaging and in vivo proton spectroscopy of the brain in neonates with hypoxic ischemic encephalopathy. Eur J Radiol 43(1):6–13
Zheng Y, Wang XM (2017) Measurement of Lactate Content and Amide Proton Transfer Values in the Basal Ganglia of a Neonatal Piglet Hypoxic-Ischemic Brain Injury Model Using MRI. AJNR Am J Neuroradiol 38(4):827–834
Khong P-L, Tse C, Ivan YC, Wong, Barbara CC, Lam P-T, Cheung, Winnie HS, Goh (2004) Diffusion-weighted imaging and proton magnetic resonance spectroscopy in perinatal hypoxic-ischemic encephalopathy: association with neuromotor outcome at 18 months of age. J Child Neurol 19(11):872–881Ngai Shan Kwong, and Gaik-Cheng Ooi
Distefano G, Pratico AD (2010) Actualities on molecular pathogenesis and repairing processes of cerebral damage in perinatal hypoxic-ischemic encephalopathy. Ital J Pediatr 36:63
Walz W, Klimaszewski A, Paterson IA (1993) Glial swelling in ischemia: a hypothesis. Dev Neurosci 15(3–5):216–225
Yenari MA, Kauppinen TM, Swanson RA (2010) Microglial activation in stroke: therapeutic targets. Neurotherapeutics 7(4):378–391
Mackenzie A, Michell-Robinson H, Touil LM, Healy DR, Owen, Bryce A, Durafourt A, Bar-Or, Jack P, Antel, Craig S, Moore (2015) Roles of microglia in brain development, tissue maintenance and repair. Brain 138(Pt 5):1138–1159
Nathan C, Ding A (2010) SnapShot: Reactive Oxygen Intermediates (ROI). Cell 140(6):951–951e2
Lo EH, Dalkara T, Moskowitz MA (2003) Mechanisms, challenges and opportunities in stroke. Nat Rev Neurosci 4(5):399–415
Wu LJ (2014) Microglial voltage-gated proton channel Hv1 in ischemic stroke. Transl Stroke Res 5(1):99–108
Decoursey TE (2003) Voltage-gated proton channels and other proton transfer pathways. Physiol Rev 83(2):475–579
DeCoursey TE (2008) Voltage-gated proton channels: what's next? J Physiol 586(22):5305–5324
Jennifer L, Meitzler S, Antony Y, Wu A, Juhasz H, Liu G, Jiang J, Lu K, Roy, James H, Doroshow (2014) NADPH oxidases: a perspective on reactive oxygen species production in tumor biology. Antioxid Redox Signal 20(17):2873–2889
DeCoursey TE, Hosler J (2014) Philosophy of voltage-gated proton channels. J R Soc Interface 11(92):20130799
Yang, Zheng Xiaoming Wang*. (2021) APT Imaging–Based Study on the Correlation Between Brain pH and Voltage-Gated Proton Channels in Piglets After Hypoxic-Ischemic Brain Injury.Quantitative Imaging in Medicine and Surgery.11(10)4408–4417
Chicha L, Smith T, Guzman R (2014) Stem cells for brain repair in neonatal hypoxia-ischemia. Childs Nerv Syst 30(1):37–46
Andreia Barateiro D, Brites, Adelaide Fernandes (2016) Oligodendrocyte Development and Myelination in Neurodevelopment: Molecular Mechanisms in Health and Disease. Curr Pharm Des 22(6):656–679
Maryna Baydyuk VE, Morrison PS, Gross JK, Huang (2020) Extrinsic Factors Driving Oligodendrocyte Lineage Cell Progression in CNS Development and Injury. Neurochem Res 45(3):630–642
Chew LJ, Takanohashi A, Bell M (2006) Microglia and inflammation: impact on developmental brain injuries. Ment Retard Dev Disabil Res Rev 12(2):105–112
Vannucci RC (1990) Experimental biology of cerebral hypoxia-ischemia: relation to perinatal brain damage. Pediatr Res 27(4 Pt 1):317–326
Zhou J, Payen JF, Wilson DA, Traystman RJ, van Zijl PC (2003) Using the amide proton signals of intracellular proteins and peptides to detect pH effects in MRI. Nat Med 9(8):1085–1090
Gao Su, Yu Y, Ma Z-Y, Sun H, Zhang Y-L, Wang X-T, Wang C Wei-Ming Fan, Qing-Yin Zheng, and Chun-Lei Ma. (2015) NMDAR-Mediated Hippocampal Neuronal Death is Exacerbated by Activities of ASIC1a.Neurotoxicity research, 28(2):122–137
Yelenis Herrera C, Katnik JD, Rodriguez, Aaron A, Hall A, Willing KR, Pennypacker, Javier Cuevas (2008) Sigma-1 receptor modulationof acid-sensing ion channel a (asic1a) and asic1a-induced ca2 + influx in rat cortical neurons. J Pharmacol Exp Ther 327(2):491–502
Tina I, Lam AM, Brennan-Minnella SJ, Won Y, Shen C, Hefner Y, Shi D, Sun, Raymond AS (2013) Intracellular pH reduction prevents excitotoxic and ischemic neuronal death by inhibiting NADPH oxidase. Proc Natl Acad Sci USA 110(46):E4362–E4368
Yun Li RM, Ritzel J, He T, Cao B, Sabirzhanov H, Li S, Liu L-J, Wu, Junfang Wu (2021) The voltage-gated proton channel Hv1 plays a detrimental role in contusion spinal cord injury via extracellular acidosis-mediated neuroinflammation. Brain Behav Immun 91:267–283
Rodney M, Ritzel J, He Y, Li T, Cao N, Khan B, Shim B, Sabirzhanov T, Aubrecht, Bogdan A, Stoica AI, Faden L-J, Wu, Junfang Wu (2021) Proton extrusion during oxidative burst in microglia exacerbates pathological acidosis following traumatic brain injury. Glia 69(3):746–764
Li W, Ward R, Dong G, Ergul A, Paul, O'Connor (2019) Neurovascular protection in voltage-gated proton channel Hv1 knock-out rats after ischemic stroke: interaction with Na ⁺ /H ⁺ exchanger-1 antagonism. Physiol Rep 7(13):e14142
Uria-Avellanal C, Robertson NJ (2014) Na⁺/H⁺ exchangers and intracellular pH in perinatal brain injury. Transl Stroke Res 5(1):79–98
Traynelis SF, Cull-Candy SG (1990) Proton inhibition of N-methyl-D-aspartate receptors in cerebellar neurons. Nature 345(6273):347–350
Hugg JW, Duijn JH, Matson GB, Maudsley AA, Tsuruda JS, Gelinas DF, Weiner MW (1992) Elevated lactate and alkalosis in chronic human brain infarction observed by 1H and 31P MR spectroscopic imaging. J Cereb Blood Flow Metab 12(5):734–744
Robertson NJ, Cowan FM, Cox IJ, Edwards AD (2002) Brain alkaline intracellular pH after neonatal encephalopathy. Ann Neurol 52(6):732–742
Li B, Concepcion K, Meng X, Zhang L (2017) Brain-immune interactions in perinatal hypoxic-ischemic brain injury. Prog Neurobiol 159:50–68
Greco P, Nencini G, Piva I, Scioscia M, Volta CA, Spadaro S, Neri M, Bonaccorsi G, Greco F, Cocco I, Sorrentino F, Antonio FD, Nappi L (2020) Pathophysiology of hypoxic-ischemic encephalopathy: a review of the past and a view on the future. Acta Neurol Belg 120(2):277–288
Yu Y, Yu Z, Xie M, Wang W, Xiang Luo (2018) Hv1 proton channel facilitates production of ROS and pro-inflammatory cytokines in microglia and enhances oligodendrocyte progenitor cells damage from oxygen-glucose deprivation in vitro. Biochem Biophys Res Commun 498(1):1–8
Lopez PH (2014) Role of myelin-associated glycoprotein (siglec-4a) in the nervous system. Adv Neurobiol 9:245–262
Quarles RH (2007) Myelin-associated glycoprotein (MAG): past, present and beyond. J Neurochem 100(6):1431–1448
Harauz G, Ladizhansky V, Boggs JM (2009) Structural polymorphism and multifunctionality of myelin basic protein. Biochemistry 48(34):8094–8104
Boggs JM (2006) Myelin basic protein: a multifunctional protein. Cell Mol Life Sci 63(17):1945–1961
Galiano MR, Andrieux A, Deloulme JC, Bosc C, Schweitzer A, Job D, Hallak ME (2006) Myelin basic protein functions as a microtubule stabilizing protein in differentiated oligodendrocytes. J Neurosci Res 84(3):534–541
Johns TG, Bernard CC (1999) The structure and function of myelin oligodendrocyte glycoprotein. J Neurochem 72(1):1–9
Kevin C, Wang V, Koprivica JA, Kim R, Sivasankaran Y, Guo RL, Neve, Zhigang He (2002) Oligodendrocyte-myelin glycoprotein is a Nogo receptor ligand that inhibits neurite outgrowth. Nature 417(6892):941–944
Schnaar RL, Lopez PH (2009) Myelin-associated glycoprotein and its axonal receptors. J Neurosci Res 87(15):3267–3276
Cai D, Qiu J, Cao Z, McAtee M, Bregman BS, Filbin MT (2001) Neuronal cyclic AMP controls the developmental loss in ability of axons to regenerate. J Neurosci 21(13):4731–4739
McKerracher L, Rosen KM (2015) MAG, myelin and overcoming growth inhibition in the CNS.Front Mol Neurosci. 8(51)
Matti F, Pronker S, Lemstra J, Snijder AJR, Heck, Dominique ME, Thies-Weesie RJ, Pasterkamp, Bert JC, Janssen (2016) Structural basis of myelin-associated glycoprotein adhesion and signalling. Nat Commun 7:13584
Yang LJ, Zeller CB, Shaper NL, Kiso M, Hasegawa A, Shapiro RE, Schnaar RL (1996) Gangliosides are neuronal ligands for myelin-associated glycoprotein. Proc Natl Acad Sci U S A 93(2):814–818
Junli Liu D, Tian M, Murugan UB, Eyo CF, Dreyfus W, Wang L-J (2015) Wu. Microglial Hv1 proton channel promotes cuprizone-induced demyelination through oxidative damage. J Neurochem. 135(2):347–356

Download PDF

Version 1

posted

You are reading this latest preprint version

Correlation between intracerebral pH and expression of Hv1 proton channel and myelin-related proteins after hypoxic-ischemic brain injury in newborn pigs

Status:

Version 1

Abstract

Background

Methods

Results

Conclusions

Figures

1. Introduction

2. Materials And Methods

2.1. Experimental animals

2.2. Establishment of the animal model

2.2.1. Control group

2.2.2. Model group

2.3. Intracerebral pH and histological examination

2.4. Immunofluorescence

2.5. Statistical analyses

3. Results

3.1. Hv1 expression and pH in the basal ganglia at different time points after HIBI

3.2. MBP, MOG, and MAG expression in the basal ganglia at different time points after HIBI

3.3. Correlation of pH and Hv1, MBP, MOG, and MAG expression

4. Discussion

Declarations

References

Status:

Version 1