Deficiency and absence of endogenous isoprene in adults, disqualified its putative origin
Background: Isoprene (C5H8) is a clinically important breath metabolite. Although, hundreds of studies have reported differential expressions in isoprene exhalation as breath biomarker for diverse diseases, the substance couldn’t enter to clinical practice as diagnostic marker. Moreover, many experimental/basic observations upon breath isoprene remained unrelated to the corresponding pathophysiological effects on its putative metabolic origin (i.e. mevalonate pathway). Here, we investigated the fundamental reason that hindered the rational interpretation and translation of this marker from basic to clinical science.
Methods: Via high-resolution mass-spectrometry based breathomics in 1026 human subjects, we discovered adults with significant deficiency (order of magnitude lower than the normal) and complete absence of breath isoprene. We prospectively applied real-time breathomics, quantitative gene expression analysis of the mevalonate pathway enzymes, lipid-profiling and hemodynamic monitoring on those isoprene deficient subjects and controls. Additionally, the subject with absence of isoprene was followed up throughout different phases of her womanhood.
Results: In contrast to convention, we witnessed that adults can live healthy without exhaling isoprene or with significant deficiency. This rare phenotype represents a recessive inheritance. Despite physio-metabolic changes during menstrual cycle (that is known to profoundly affect isoprene exhalation) and profoundly increased plasma cholesterol during pregnancy and after childbirth, isoprene remained absent. All genes of mevalonate pathway enzymes were normally expressed in all participants, without any down-regulation or compensatory up-regulation.
Conclusions: Absence/deficiency of isoprene despite normal lipid profiles and no mevalonate pathway malfunction disqualifies the long-believed metabolic origin of isoprene from cholesterol biosynthesis. Thus, clinical translation of breath isoprene expressions should not be generally attributed to corresponding pathophysiological effects onto mevalonate/cholesterol pathway. Our finding has refined and optimized the clinical interpretation of isoprene as biomarker in volatile metabolomics and breathomics. Future studies will address the correct metabolic origin of isoprene to imply this important marker to routine practice.
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This is a wonderful finding. It has provided some interesting insights towards a fundamental finding in clinical breathomics. Surprisingly, the authors have very well demonstrated that the conventional origin of isoprene is wrong. This finding can now be translated to breath analysis driven detection of Cancer and other diseases. Eagerly waiting to read this research in its final version.
Dear Dr. Taunk, Greetings from Rostock! Thanks for your kind appreciation and interest in our research. I do substantially agree with your opinion upon our present discovery. I am glad to inform you that the original article is formally accepted last week (05/01/2021) in the Cell-Press (https://www.cell.com/heliyon/home) and it will be published next week. I will keep you posted with the journal DOI as soon as we receive the same. With cordial regards, Sukul
Isoprene has been widely discussed to be associated with various diseases, including hyperlipidemia, chronic kidney diseases, and hepatic disease. However, it is hardly possible for researchers to predict a particular range of this vital marker for a specific disease and thus, its transformation from basic to practical clinical interest is suppressed. This study has tried to understand the reason behind it. Genetic evidence is appreciable. It will draw more attention to biomedical scientists.
These are very interesting results given the increasing interest in breath analysis and several studies linking changes in breath isoprene with different pathologies and suggesting it as a biomarker. In spite of the fact that gene expression was checked in PBMCs and connecting gene expression to biochemical output and phenotype is far more nuanced calling for more detailed pan-omic and functional investigations, this study is a very important one towards our quest for understanding of biochemical origin of isoprene in breath. More such studies to elucidate biochemical origin or putative breath or biofluid biomarkers would help us to inch closer towards a personalized healthcare regime. These results justify the multi-pronged approach and would help us in viewing changes breath in composition in the COVID-19 study with right perspective.
Dear Prof. Manna, Thanks for your valuable remarks and appreciation. I do agree with you on your point regarding further detailed mapping of endogenous origin of biomarkers. That’s certainly the way and we are on it. I am also looking forward to certain changes under respiratory viral infections e.g. CoV-2 and co-infections (viro-bacterial) etc. Cordially, Pritam
Congratulations for your outstanding work, very interesting and with very promising results. Excellent!!
Dear Prof. Camara, Thanks a lot for your kind appreciation and encouragements. It's our genuine pleasure to have your expert opinion. Cordially, Pritam
Was a joy to read and you all had again a look far beyond the box. The results itself are very interesting and should shake a few people awake. The substantiating of your initial findings with additional methods outside of your "comfort zone" makes the conclusion way more reliable and underlines the necessity of interdisciplinary work in the field of biomedical sciences. I stay curious about this work and cannot wait to read the final version and upcoming studies.
Dear Dr. Zanaty, Thanks a lot for your kind comments and appreciation. We are glad to see your interest in our findings. The final version of this article will be published this week by the Cell-Press, ELSEVIER and Science-Direct. I will keep you posted. Cordially, Pritam
Congratulations for the wonderful finding. This is a very fundamental study for finding the biochemical origin of isoprene in exhaled breath.
Dear Dr. Mandal, Thanks for your kind compliment and comment. The original article is just published online in Cell-Press: (https://www.sciencedirect.com/science/article/pii/S240584402100027X) Cordially, Pritam
Posted 05 Jan, 2021
On 12 Jan, 2021
Deficiency and absence of endogenous isoprene in adults, disqualified its putative origin
Posted 05 Jan, 2021
On 12 Jan, 2021
Background: Isoprene (C5H8) is a clinically important breath metabolite. Although, hundreds of studies have reported differential expressions in isoprene exhalation as breath biomarker for diverse diseases, the substance couldn’t enter to clinical practice as diagnostic marker. Moreover, many experimental/basic observations upon breath isoprene remained unrelated to the corresponding pathophysiological effects on its putative metabolic origin (i.e. mevalonate pathway). Here, we investigated the fundamental reason that hindered the rational interpretation and translation of this marker from basic to clinical science.
Methods: Via high-resolution mass-spectrometry based breathomics in 1026 human subjects, we discovered adults with significant deficiency (order of magnitude lower than the normal) and complete absence of breath isoprene. We prospectively applied real-time breathomics, quantitative gene expression analysis of the mevalonate pathway enzymes, lipid-profiling and hemodynamic monitoring on those isoprene deficient subjects and controls. Additionally, the subject with absence of isoprene was followed up throughout different phases of her womanhood.
Results: In contrast to convention, we witnessed that adults can live healthy without exhaling isoprene or with significant deficiency. This rare phenotype represents a recessive inheritance. Despite physio-metabolic changes during menstrual cycle (that is known to profoundly affect isoprene exhalation) and profoundly increased plasma cholesterol during pregnancy and after childbirth, isoprene remained absent. All genes of mevalonate pathway enzymes were normally expressed in all participants, without any down-regulation or compensatory up-regulation.
Conclusions: Absence/deficiency of isoprene despite normal lipid profiles and no mevalonate pathway malfunction disqualifies the long-believed metabolic origin of isoprene from cholesterol biosynthesis. Thus, clinical translation of breath isoprene expressions should not be generally attributed to corresponding pathophysiological effects onto mevalonate/cholesterol pathway. Our finding has refined and optimized the clinical interpretation of isoprene as biomarker in volatile metabolomics and breathomics. Future studies will address the correct metabolic origin of isoprene to imply this important marker to routine practice.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
This is a wonderful finding. It has provided some interesting insights towards a fundamental finding in clinical breathomics. Surprisingly, the authors have very well demonstrated that the conventional origin of isoprene is wrong. This finding can now be translated to breath analysis driven detection of Cancer and other diseases. Eagerly waiting to read this research in its final version.
Dear Dr. Taunk, Greetings from Rostock! Thanks for your kind appreciation and interest in our research. I do substantially agree with your opinion upon our present discovery. I am glad to inform you that the original article is formally accepted last week (05/01/2021) in the Cell-Press (https://www.cell.com/heliyon/home) and it will be published next week. I will keep you posted with the journal DOI as soon as we receive the same. With cordial regards, Sukul
Isoprene has been widely discussed to be associated with various diseases, including hyperlipidemia, chronic kidney diseases, and hepatic disease. However, it is hardly possible for researchers to predict a particular range of this vital marker for a specific disease and thus, its transformation from basic to practical clinical interest is suppressed. This study has tried to understand the reason behind it. Genetic evidence is appreciable. It will draw more attention to biomedical scientists.
Dear Dr. Ghosh, Thanks for your valuable opinion and interest in our observations. I second your opinion. Best regards from Rostock! Cordially, Pritam
These are very interesting results given the increasing interest in breath analysis and several studies linking changes in breath isoprene with different pathologies and suggesting it as a biomarker. In spite of the fact that gene expression was checked in PBMCs and connecting gene expression to biochemical output and phenotype is far more nuanced calling for more detailed pan-omic and functional investigations, this study is a very important one towards our quest for understanding of biochemical origin of isoprene in breath. More such studies to elucidate biochemical origin or putative breath or biofluid biomarkers would help us to inch closer towards a personalized healthcare regime. These results justify the multi-pronged approach and would help us in viewing changes breath in composition in the COVID-19 study with right perspective.
Dear Prof. Manna, Thanks for your valuable remarks and appreciation. I do agree with you on your point regarding further detailed mapping of endogenous origin of biomarkers. That’s certainly the way and we are on it. I am also looking forward to certain changes under respiratory viral infections e.g. CoV-2 and co-infections (viro-bacterial) etc. Cordially, Pritam
Congratulations for your outstanding work, very interesting and with very promising results. Excellent!!
Dear Prof. Camara, Thanks a lot for your kind appreciation and encouragements. It's our genuine pleasure to have your expert opinion. Cordially, Pritam
Was a joy to read and you all had again a look far beyond the box. The results itself are very interesting and should shake a few people awake. The substantiating of your initial findings with additional methods outside of your "comfort zone" makes the conclusion way more reliable and underlines the necessity of interdisciplinary work in the field of biomedical sciences. I stay curious about this work and cannot wait to read the final version and upcoming studies.
Dear Dr. Zanaty, Thanks a lot for your kind comments and appreciation. We are glad to see your interest in our findings. The final version of this article will be published this week by the Cell-Press, ELSEVIER and Science-Direct. I will keep you posted. Cordially, Pritam
Congratulations for the wonderful finding. This is a very fundamental study for finding the biochemical origin of isoprene in exhaled breath.
Dear Dr. Mandal, Thanks for your kind compliment and comment. The original article is just published online in Cell-Press: (https://www.sciencedirect.com/science/article/pii/S240584402100027X) Cordially, Pritam
Pritam Sukul
ORCiDreplied on 11 January, 2021
Dear Dr. Ghosh, Thanks for your valuable opinion and interest in our observations. I second your opinion. Best regards from Rostock! Cordially, Pritam