Alzheimer’s disease (AD) is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved...Alzheimer’s disease (AD) is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved success in preclinical models addressing the pathological hallmarks of the disease, these efforts have not translated into any effective disease-modifying therapies. This could be because interventions are being tested too late in the disease process. While existing therapies provide symptomatic and clinical benefit, they do not fully address the molecular abnormalities that occur in AD neurons. The pathophysiology of AD is complex; mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress are antecedent and potentially play a causal role in the disease pathogenesis. Dysfunctional mitochondria accumulate from the combination of impaired mitophagy, which can also induce injurious inflammatory responses, and inadequate neuronal mitochondrial biogenesis. Altering the metabolic capacity of the brain by modulating/potentiating its mitochondrial bioenergetics may be a strategy for disease prevention and treatment. We present insights into the mechanisms of mitochondrial dysfunction in AD brain as well as an overview of emerging treatments with the potential to prevent, delay or reverse the neurodegenerative process by targeting mitochondria.展开更多
Alzheimer’s disease is a neurodegenerative disease that affected over 6.5 million people in the United States in 2021,with this number expected to double in the next 40 years without any sort of treatment.Due to its ...Alzheimer’s disease is a neurodegenerative disease that affected over 6.5 million people in the United States in 2021,with this number expected to double in the next 40 years without any sort of treatment.Due to its heterogeneity and complexity,the etiology of Alzheimer’s disease,especially sporadic Alzheimer’s disease,remains largely unclear.Compelling evidence suggests that brain glucose hypometabolism,preceding Alzheimer’s disease hallmarks,is involved in the pathogenesis of Alzheimer’s disease.Herein,we discuss the potential causes of reduced glucose uptake and the mechanisms underlying glucose hypometabolism and Alzheimer’s disease pathology.Specifically,decreased O-Glc NAcylation levels by glucose deficiency alter mitochondrial functions and together contribute to Alzheimer’s disease pathogenesis.One major problem with Alzheimer’s disease research is that the disease progresses for several years before the onset of any symptoms,suggesting the critical need for appropriate models to study the molecular changes in the early phase of Alzheimer’s disease progression.Therefore,this review also discusses current available sporadic Alzheimer’s disease models induced by metabolic abnormalities and provides novel directions for establishing a human neuronal sporadic Alzheimer’s disease model that better represents human sporadic Alzheimer’s disease as a metabolic disease.展开更多
When confronted with severe environmental stress, some animals are able to undergo a substantial reorganization of their cellular environment that enables long-term survival. One molecular mechanism of adaptation that...When confronted with severe environmental stress, some animals are able to undergo a substantial reorganization of their cellular environment that enables long-term survival. One molecular mechanism of adaptation that has received considerable attention in recent years has been the action of reversible transcriptome regulation by microRNA. The implementation of new computational and high-throughput experimental approaches has started to uncover the vital contributions of microRNA towards stress adaptation. Indeed, recent studies have suggested that microRNA may have a major regulatory influence over a number of cellular processes that are essential to prolonged environmental stress survival. To date, a number of studies have highlighted the role of microRNA in the regulation of a metabolically depressed state, documenting stress-responsive microRNA expression during mammalian hibernation, frog and insect freeze tolerance, and turtle and marine snail anoxia tolerance. These studies collectively indicate a conserved principle of microRNA stress response across phylogeny. As we are on the verge of dissecting the role of microRNA in environmental stress adaptation, this review summarizes recent research advances and the hallmark expression patterns that facilitate stress survival.展开更多
Micro RNAs(mi RNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 mi RNAs in brown(BAT) and white adi...Micro RNAs(mi RNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 mi RNAs in brown(BAT) and white adipose tissue(WAT) during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six mi RNAs including let-7a, let-7b, mi R-107, mi R-150, mi R-222 and mi R-31 was significantly downregulated in WAT(P 〈 0.05), which was 16%–54% of euthermic non-torpid control squirrels,whereas expression of three mi RNAs including mi R-143, mi R-200 a and mi R-519 d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more mi RNAs was downregulated in BAT during torpor. We detected reduced expression of 6 mi RNAs including mi R-103 a, mi R-107, mi R-125 b, mi R-21, mi R-221 and mi R-31(48%–70% of control), while only expression of mi R-138 was significantly upregulated(2.91 ± 0.8-fold of the control, P 〈 0.05). Interestingly,mi RNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas mi RNAs with altered expression in BAT during torpor were linked to mitochondrial b-oxidation. mi RPath target prediction analysis showed that mi RNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase(MAPK) signaling, while the mi RNAs upregulated in WAT were linked to transforming growth factor b(TGFb) signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-mi RNAs for the mi RNAs used in this study, suggesting no structure-influenced changes in pre-mi RNA processing efficiency in the squirrel. As well, the expression of mi RNA processingenzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of mi RNA expression in adipose tissues may be linked展开更多
A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that h...A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaperones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study characterizes antioxidant and heat shock protein(HSP) responses in various organs of control(aroused)and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90 a was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control(P 〈 0.05). Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu–Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle(P 〈 0.05). Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor(P 〈 0.05), while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.展开更多
Mammalian hibernation is associated with multiple physiological, biochemical, and molecular changes that allow animals to endure colder temperatures. We hypothesize that long non-coding RNAs(lnc RNAs), a group of no...Mammalian hibernation is associated with multiple physiological, biochemical, and molecular changes that allow animals to endure colder temperatures. We hypothesize that long non-coding RNAs(lnc RNAs), a group of non-coding transcripts with diverse functions, are differentially expressed during hibernation. In this study, expression levels of lncRNAs H19 and TUG1 were assessed via qRT-PCR in liver, heart, and skeletal muscle tissues of the hibernating thirteen-lined ground squirrels(Ictidomys tridecemlineatus). TUG1 transcript levels were significantly elevated 1.94-fold in skeletal muscle of hibernating animals when compared with euthermic animals. Furthermore, transcript levels of HSF2 also increased 2.44-fold in the skeletal muscle in hibernating animals. HSF2 encodes a transcription factor that can be negatively regulated by TUG1 levels and that influences heat shock protein expression. Thus, these observations support the differential expression of the TUG1-HSF2 axis during hibernation. To our knowledge, this study provides the first evidence for differential expression of lnc RNAs in torpid ground squirrels, adding lnc RNAs as another group of transcripts modulated in this mammalian species during hibernation.展开更多
A variety of mammals employ torpor as an energy-saving strategy in environments of marginal or severe stress either on a daily basis during their inactive period or on a seasonal basis during prolonged multi-day hiber...A variety of mammals employ torpor as an energy-saving strategy in environments of marginal or severe stress either on a daily basis during their inactive period or on a seasonal basis during prolonged multi-day hibernation. Recently, a few Madagascar lemur species have been identified as the only primates that exhibit torpor; one of these is the gray mouse lemur(Microcebus murinus). To explore the regulatory mechanisms that underlie daily torpor in a primate, we analyzed the expression of 28 selected genes that represent crucial survival pathways known to be involved in squirrel and bat hibernation. Array-based real-time PCR was used to compare gene expression in control(aroused) versus torpid lemurs in five tissues including the liver, kidney,skeletal muscle, heart, and brown adipose tissue. Significant differences in gene expression during torpor were revealed among genes involved in glycolysis, fatty acid metabolism, antioxidant defense, apoptosis, hypoxia signaling, and protein protection. The results showed upregulation of select genes primarily in liver and brown adipose tissue. For instance, both tissues showed elevated gene expression of peroxisome proliferator activated receptor gamma(ppargc), ferritin(fth1), and protein chaperones during torpor. Overall, the data show that the expression of only a few genes changed during lemur daily torpor, as compared with the broader expression changes reported for hibernation in ground squirrels. These results provide an indication that the alterations in gene expression required for torpor in lemurs are not as extensive as those needed for winter hibernation in squirrel models. However, identification of crucial genes with altered expression that support lemur torpor provides key targets to be explored and manipulated toward a goal of translational applications of inducible torpor as a treatment option in human biomedicine.展开更多
Aestivation is a common strategy of sea cucumbers(Apostichopus japonicus)in response to high-temperature conditions.Previous studies have individually investigated the immune and physiological alterations at the aesti...Aestivation is a common strategy of sea cucumbers(Apostichopus japonicus)in response to high-temperature conditions.Previous studies have individually investigated the immune and physiological alterations at the aestivation stage.However,these studies have not evaluated the relationship between immunity and physiology.In this study,we explored the transcriptome and metabolome of A.japonicus during the aestivation stage to study the relationship.The transcriptome analysis of dormant(aestivation)and revived A.japonicus generated 2368 differentially expressed genes,including 927 downregulated genes and 1441 upregulated genes.Based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses,the downregulated genes in the dormant group were found to be involved in DNA replication,RNA metabolic process,and protein metabolism,which results in the inhibition of motility,skeletal development,neural activity,cell proliferation,and development of A.japonicus.In contrast,the upregulated genes were found to be associated with fatty acid metabolism,carbohydrate hydrolysis,and phagocytosis.In the metabolome analysis,the downregulated metabolites were found to be associated with fatty acid metabolism,starch and sucrose metabolism,and TCA cycle.This indicates that dormant sea cucumbers consume reserved carbohydrates and fatty acids to maintain low levels of energy supply.The protein-protein interaction network analysis further revealed that carbohydrate hydrolysis promoted phagocytosis activity in the dormant group.This study provides new insights into potential molecular mechanisms of sea cucumber survival in high-temperature conditions,which is critical in aquaculture of sea cucumbers.展开更多
Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain ...Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain have not been fully elucidated.This study aims to identify the metabolic nodes and connection integrity of specific brain regions in rats with global cerebral ischemia that are most affected by hypothermia treatment.18F-fluorodeoxyglucose positron emission tomography was used to quantitatively determine glucose metabolism in different brain regions in a rat model of global cerebral ischemia established at 31–33℃.Diffusion tensor imaging was also used to reconstruct and explore the brain connections involved.The results showed that,compared with the model rats established at 37–37.5℃,the rat models of global cerebral ischemia established at 31–33℃had smaller hypometabolic regions in the thalamus and primary sensory areas and sustained no obvious thalamic injury.Hypothermia selectively preserved the integrity of the anterior forebrain mesocircuit,exhibiting protective effects on the brain during the global cerebral ischemia.The study was approved by the Institutional Animal Care and Use Committee at Capital Medical University(approval No.XW-AD318-97-019)on December 15,2019.展开更多
文摘Alzheimer’s disease (AD) is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved success in preclinical models addressing the pathological hallmarks of the disease, these efforts have not translated into any effective disease-modifying therapies. This could be because interventions are being tested too late in the disease process. While existing therapies provide symptomatic and clinical benefit, they do not fully address the molecular abnormalities that occur in AD neurons. The pathophysiology of AD is complex; mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress are antecedent and potentially play a causal role in the disease pathogenesis. Dysfunctional mitochondria accumulate from the combination of impaired mitophagy, which can also induce injurious inflammatory responses, and inadequate neuronal mitochondrial biogenesis. Altering the metabolic capacity of the brain by modulating/potentiating its mitochondrial bioenergetics may be a strategy for disease prevention and treatment. We present insights into the mechanisms of mitochondrial dysfunction in AD brain as well as an overview of emerging treatments with the potential to prevent, delay or reverse the neurodegenerative process by targeting mitochondria.
基金supported by the Georgia Research Alliance and the University of Georgia(to GWH)。
文摘Alzheimer’s disease is a neurodegenerative disease that affected over 6.5 million people in the United States in 2021,with this number expected to double in the next 40 years without any sort of treatment.Due to its heterogeneity and complexity,the etiology of Alzheimer’s disease,especially sporadic Alzheimer’s disease,remains largely unclear.Compelling evidence suggests that brain glucose hypometabolism,preceding Alzheimer’s disease hallmarks,is involved in the pathogenesis of Alzheimer’s disease.Herein,we discuss the potential causes of reduced glucose uptake and the mechanisms underlying glucose hypometabolism and Alzheimer’s disease pathology.Specifically,decreased O-Glc NAcylation levels by glucose deficiency alter mitochondrial functions and together contribute to Alzheimer’s disease pathogenesis.One major problem with Alzheimer’s disease research is that the disease progresses for several years before the onset of any symptoms,suggesting the critical need for appropriate models to study the molecular changes in the early phase of Alzheimer’s disease progression.Therefore,this review also discusses current available sporadic Alzheimer’s disease models induced by metabolic abnormalities and provides novel directions for establishing a human neuronal sporadic Alzheimer’s disease model that better represents human sporadic Alzheimer’s disease as a metabolic disease.
文摘When confronted with severe environmental stress, some animals are able to undergo a substantial reorganization of their cellular environment that enables long-term survival. One molecular mechanism of adaptation that has received considerable attention in recent years has been the action of reversible transcriptome regulation by microRNA. The implementation of new computational and high-throughput experimental approaches has started to uncover the vital contributions of microRNA towards stress adaptation. Indeed, recent studies have suggested that microRNA may have a major regulatory influence over a number of cellular processes that are essential to prolonged environmental stress survival. To date, a number of studies have highlighted the role of microRNA in the regulation of a metabolically depressed state, documenting stress-responsive microRNA expression during mammalian hibernation, frog and insect freeze tolerance, and turtle and marine snail anoxia tolerance. These studies collectively indicate a conserved principle of microRNA stress response across phylogeny. As we are on the verge of dissecting the role of microRNA in environmental stress adaptation, this review summarizes recent research advances and the hallmark expression patterns that facilitate stress survival.
基金supported by a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada (Grant No. 6793)supported by the NSERC postgraduate fellowships
文摘Micro RNAs(mi RNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 mi RNAs in brown(BAT) and white adipose tissue(WAT) during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six mi RNAs including let-7a, let-7b, mi R-107, mi R-150, mi R-222 and mi R-31 was significantly downregulated in WAT(P 〈 0.05), which was 16%–54% of euthermic non-torpid control squirrels,whereas expression of three mi RNAs including mi R-143, mi R-200 a and mi R-519 d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more mi RNAs was downregulated in BAT during torpor. We detected reduced expression of 6 mi RNAs including mi R-103 a, mi R-107, mi R-125 b, mi R-21, mi R-221 and mi R-31(48%–70% of control), while only expression of mi R-138 was significantly upregulated(2.91 ± 0.8-fold of the control, P 〈 0.05). Interestingly,mi RNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas mi RNAs with altered expression in BAT during torpor were linked to mitochondrial b-oxidation. mi RPath target prediction analysis showed that mi RNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase(MAPK) signaling, while the mi RNAs upregulated in WAT were linked to transforming growth factor b(TGFb) signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-mi RNAs for the mi RNAs used in this study, suggesting no structure-influenced changes in pre-mi RNA processing efficiency in the squirrel. As well, the expression of mi RNA processingenzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of mi RNA expression in adipose tissues may be linked
基金supported by a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada (Grant No. 6793)a grant from the Heart and Stroke Foundation of Canada (Grant No. G-140005874) to KBS. KBS holds the Canada Research Chair in Molecular PhysiologyCWW, KKB, and SNT all held NSERC postgraduate scholarships
文摘A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaperones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study characterizes antioxidant and heat shock protein(HSP) responses in various organs of control(aroused)and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90 a was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control(P 〈 0.05). Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu–Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle(P 〈 0.05). Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor(P 〈 0.05), while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.
基金supported by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada (Grant No. RGPIN/402222-2012) awarded to PJM
文摘Mammalian hibernation is associated with multiple physiological, biochemical, and molecular changes that allow animals to endure colder temperatures. We hypothesize that long non-coding RNAs(lnc RNAs), a group of non-coding transcripts with diverse functions, are differentially expressed during hibernation. In this study, expression levels of lncRNAs H19 and TUG1 were assessed via qRT-PCR in liver, heart, and skeletal muscle tissues of the hibernating thirteen-lined ground squirrels(Ictidomys tridecemlineatus). TUG1 transcript levels were significantly elevated 1.94-fold in skeletal muscle of hibernating animals when compared with euthermic animals. Furthermore, transcript levels of HSF2 also increased 2.44-fold in the skeletal muscle in hibernating animals. HSF2 encodes a transcription factor that can be negatively regulated by TUG1 levels and that influences heat shock protein expression. Thus, these observations support the differential expression of the TUG1-HSF2 axis during hibernation. To our knowledge, this study provides the first evidence for differential expression of lnc RNAs in torpid ground squirrels, adding lnc RNAs as another group of transcripts modulated in this mammalian species during hibernation.
基金supported by a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada (Grant No. 6793)a grant from the Heart and Stroke Foundation of Canada (Grant No. G-140005874) to KBS. KBS holds the Canada Research Chair in Molecular PhysiologySNT, KKB, and CWW all held NSERC postgraduate scholarships
文摘A variety of mammals employ torpor as an energy-saving strategy in environments of marginal or severe stress either on a daily basis during their inactive period or on a seasonal basis during prolonged multi-day hibernation. Recently, a few Madagascar lemur species have been identified as the only primates that exhibit torpor; one of these is the gray mouse lemur(Microcebus murinus). To explore the regulatory mechanisms that underlie daily torpor in a primate, we analyzed the expression of 28 selected genes that represent crucial survival pathways known to be involved in squirrel and bat hibernation. Array-based real-time PCR was used to compare gene expression in control(aroused) versus torpid lemurs in five tissues including the liver, kidney,skeletal muscle, heart, and brown adipose tissue. Significant differences in gene expression during torpor were revealed among genes involved in glycolysis, fatty acid metabolism, antioxidant defense, apoptosis, hypoxia signaling, and protein protection. The results showed upregulation of select genes primarily in liver and brown adipose tissue. For instance, both tissues showed elevated gene expression of peroxisome proliferator activated receptor gamma(ppargc), ferritin(fth1), and protein chaperones during torpor. Overall, the data show that the expression of only a few genes changed during lemur daily torpor, as compared with the broader expression changes reported for hibernation in ground squirrels. These results provide an indication that the alterations in gene expression required for torpor in lemurs are not as extensive as those needed for winter hibernation in squirrel models. However, identification of crucial genes with altered expression that support lemur torpor provides key targets to be explored and manipulated toward a goal of translational applications of inducible torpor as a treatment option in human biomedicine.
基金supported by the Science and Technology Program of Fujian Province(Nos.2018R1003-1 and 2019R1013-5)the Special Funds for Marine and Fishery Structure Adjustment(No.2020HYJG02)the Marine Economy Innovation and Area Development Demonstration Project of Fujian Province(No.FJHJF-L-2020-4)。
文摘Aestivation is a common strategy of sea cucumbers(Apostichopus japonicus)in response to high-temperature conditions.Previous studies have individually investigated the immune and physiological alterations at the aestivation stage.However,these studies have not evaluated the relationship between immunity and physiology.In this study,we explored the transcriptome and metabolome of A.japonicus during the aestivation stage to study the relationship.The transcriptome analysis of dormant(aestivation)and revived A.japonicus generated 2368 differentially expressed genes,including 927 downregulated genes and 1441 upregulated genes.Based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses,the downregulated genes in the dormant group were found to be involved in DNA replication,RNA metabolic process,and protein metabolism,which results in the inhibition of motility,skeletal development,neural activity,cell proliferation,and development of A.japonicus.In contrast,the upregulated genes were found to be associated with fatty acid metabolism,carbohydrate hydrolysis,and phagocytosis.In the metabolome analysis,the downregulated metabolites were found to be associated with fatty acid metabolism,starch and sucrose metabolism,and TCA cycle.This indicates that dormant sea cucumbers consume reserved carbohydrates and fatty acids to maintain low levels of energy supply.The protein-protein interaction network analysis further revealed that carbohydrate hydrolysis promoted phagocytosis activity in the dormant group.This study provides new insights into potential molecular mechanisms of sea cucumber survival in high-temperature conditions,which is critical in aquaculture of sea cucumbers.
基金supported by Beijing Municipal Health Commission of China,No.Jing2019-2(to TLW)。
文摘Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain have not been fully elucidated.This study aims to identify the metabolic nodes and connection integrity of specific brain regions in rats with global cerebral ischemia that are most affected by hypothermia treatment.18F-fluorodeoxyglucose positron emission tomography was used to quantitatively determine glucose metabolism in different brain regions in a rat model of global cerebral ischemia established at 31–33℃.Diffusion tensor imaging was also used to reconstruct and explore the brain connections involved.The results showed that,compared with the model rats established at 37–37.5℃,the rat models of global cerebral ischemia established at 31–33℃had smaller hypometabolic regions in the thalamus and primary sensory areas and sustained no obvious thalamic injury.Hypothermia selectively preserved the integrity of the anterior forebrain mesocircuit,exhibiting protective effects on the brain during the global cerebral ischemia.The study was approved by the Institutional Animal Care and Use Committee at Capital Medical University(approval No.XW-AD318-97-019)on December 15,2019.