Article
Physiology
Xuli Gao, Siqi Wang, Jie Zhang, Shuyao Wang, Feiyan Bai, Jing Liang, Jiawei Wu, Huiping Wang, Yunfang Gao, Hui Chang
Summary: Hindlimb unloaded rats showed significant bone loss, while hibernating ground squirrels demonstrated better adaptation in mitigating disuse-induced bone loss, involving differential protein expression of key molecules in bone remodeling. Promoting osteoblast differentiation through activating canonical GSK-3β/β-catenin signaling involving Runx2 might be an adaptation to natural disuse in femur of hibernating Daurian ground squirrels. However, there was no statistical change in the protein levels of bone formation related proteins, GSK-3β, and phospho-beta-catenin in tibia of hibernating Daurian ground squirrels.
JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMS AND ENVIRONMENTAL PHYSIOLOGY
(2021)
Article
Physiology
Xuli Gao, Siqi Wang, Siqi Shen, Shuyao Wang, Manjiang Xie, Kenneth B. Storey, Caiyong Yu, Etienne Lefai, Wenqian Song, Hui Chang, Changbin Yang
Summary: This study assesses the bone remodeling mechanisms in hibernating ground squirrels and hindlimb unloaded squirrels. The results show differences in body weight, bone microstructure, and protein expression between hibernating and hindlimb unloaded squirrels. Hibernating squirrels have a natural anti-osteoporosis mechanism, while this mechanism is not effective in hindlimb unloaded squirrels.
JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMS AND ENVIRONMENTAL PHYSIOLOGY
(2023)
Article
Endocrinology & Metabolism
Seth W. Donahue, Samantha J. Wojda, Meghan E. McGee-Lawrence, Janene Auger, Hal L. Black
Summary: Disuse osteoporosis is caused by lack of physical activity, which leads to increased bone resorption, decreased bone mass, and higher risk of fractures. Hibernating animals have evolved compensatory mechanisms to preserve skeletal muscle and bone during periods of prolonged inactivity.
Article
Physiology
Moriah Hunstiger, Michelle Marie Johannsen, S. Ryan Oliver
Summary: By analyzing the protein expression and metabolites of wild Arctic ground squirrels, it was found that they have different thermoregulation mechanisms during the hibernation season. White adipose tissue does not express uncoupling protein 1, while brown adipose tissue peaks in the expression of uncoupling protein 1 in winter and decreases after arousal in spring. Non-shivering thermogenesis in muscles decreases during hibernation and recovers in spring. These findings suggest distinct thermogenic functions may depend on temperature, resources, and seasonal demands.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Endocrinology & Metabolism
Jie Zhang, Hui Chang, Rongrong Yin, Shenhui Xu, Huiping Wang, Yunfang Gao
Summary: The study found that the musculoskeletal morphology of hibernating squirrels was largely preserved after prolonged inactivity, and musculoskeletal metabolism was generally maintained, indicating that musculoskeletal metabolism may be a vital mechanism underlying the preservation of the musculoskeletal system during hibernation.
Article
Biochemistry & Molecular Biology
Rongrong Yin, Jie Zhang, Shenhui Xu, Yong Kong, Huiping Wang, Yunfang Gao
Summary: The study found that iron levels were lower in the femur and liver of torpid squirrels, with bone formation and resorption balanced and no iron overload observed. This may be a potential mechanism for hibernators to avoid disuse-induced bone loss.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY
(2022)
Article
Physiology
Fiammetta Zanetti, Chao-Yin Chen, Hailey A. Baker, M. Hoshi Sugiura, Kelly L. Drew, Zeinab Barati
Summary: The decrease in heart rate during hibernation is a regulated fall that is mediated by increased cardiac parasympathetic activity, while the increase in heart rate during arousal is driven by the sympathetic nervous system. This study aimed to investigate the temporal information on cardiac parasympathetic regulation throughout a complete hibernation bout. The results showed that parasympathetic activation initiates and regulates the heart rate decrease during entrance into hibernation, while the withdrawal of parasympathetic activation initiates arousal.
PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Aleksandra Jankovic, Andjelika Kalezic, Aleksandra Korac, Biljana Buzadzic, Kenneth B. Storey, Bato Korac
Summary: This article discusses how hibernating animals survive by utilizing adaptive responses such as lowering body temperature and metabolic suppression, and how their tissues and organs sustain no damage during hibernation. Discovering the molecular mechanisms behind these hibernation processes can provide insights not only into hibernation itself, but also into complex medical conditions and overcoming limitations in space travel.
ANTIOXIDANTS & REDOX SIGNALING
(2023)
Article
Cell Biology
Yingyu Yang, Ziwei Hao, Ning An, Yuting Han, Weilan Miao, Kenneth B. Storey, Etienne Lefai, Xiaoxuan Liu, Junshu Wang, Shuo Liu, Manjiang Xie, Hui Chang
Summary: Hibernating mammals, such as Daurian ground squirrels, exhibit adaptive cardio-protection mechanisms to endure multiple torpor-arousal cycles. This study investigated the morphological, functional, genetic, and metabolic changes in the hearts of ground squirrels during different hibernation stages. Results showed significant cardiac function changes without irreversible damage in the torpor and interbout arousal groups compared to the summer active group. Transcriptomic and metabolomic analysis revealed differential gene expression and metabolite levels, indicating active mitochondrial oxidative phosphorylation and inhibition of ferroptosis signaling pathways during hibernation. These findings provide new insights into the molecular basis of cardio-protection in hibernators.
JOURNAL OF CELLULAR PHYSIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Xuli Gao, Shenyang Shen, Qiaohua Niu, Weilan Miao, Yuting Han, Ziwei Hao, Ning An, Yingyu Yang, Yu Zhang, Han Zhang, Kenneth B. B. Storey, Hui Chang
Summary: This study compared the effects of pathological obesity and healthy obesity on bone metabolism and morphology. The results showed that pathological obesity had a certain protective effect on bones, while healthy obesity enhanced the microstructure of bones and the expression levels of proteins related to bone formation.
JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE B
(2022)
Article
Biochemistry & Molecular Biology
Seth W. Donahue
Summary: Hibernating bears and rodents have evolved mechanisms to prevent disuse osteoporosis during hibernation, including reduced bone turnover and balanced bone remodeling. The hibernation process does not negatively impact bone strength in rodents, while some hibernating rodents experience varying degrees of bone loss. More than 5000 genes are differentially expressed in bear bone tissue during hibernation, indicating the complexity of hibernation-induced changes in bone. Understanding the mechanisms regulating bone metabolism in hibernators may lead to new treatment strategies for osteoporosis in humans.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
(2023)
Article
Physiology
Nisred K. Klichkhanov, Elena R. Nikitina, Zainab M. Shihamirova, Maria D. Astaeva, Shamil I. Chalabov, Aleksandr I. Krivchenko
Summary: Small ground squirrels exhibit low levels of ROS and RNS production during hibernation, while oxidative stress increases during arousal, but decreases as body temperature recovers.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Genetics & Heredity
Kirsten Grond, C. Loren Buck, Khrystyne N. Duddleston
Summary: Obligate seasonal hibernators can fast for several months during hibernation without muscle loss. The gut microbiome may play a role in nitrogen metabolism and protein conservation. A study on arctic ground squirrels showed that pre-hibernation diet did not affect bacterial amino acid pathway genes, but individual genes in essential amino acid pathways were differentially expressed in squirrels fed higher protein diets. The small intestine had the highest expression of amino acid and urease genes, and six bacterial genera were responsible for most of the urease gene expression. Although pre-hibernation diet may modulate gut microbiota function during hibernation, further investigation is needed.
FRONTIERS IN GENETICS
(2023)
Article
Biochemistry & Molecular Biology
Yue He, Yong Kong, Rongrong Yin, Huajian Yang, Jie Zhang, Huiping Wang, Yunfang Gao
Summary: Bone iron metabolism in hibernating Daurian ground squirrels showed remarkable plasticity, which may serve as a mechanism to prevent bone loss during extended periods of inactivity.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Biochemistry & Molecular Biology
Khalil Abnous, Kenneth B. Storey
Summary: Hibernation is a crucial winter survival strategy for small mammals, allowing them to conserve energy for extended periods without eating. AMPD plays a key role in managing adenylate pool size during torpor, with hibernating animals showing different AMPD activity and properties compared to euthermic animals. The primary driver of these differences seems to be covalent phosphorylation of AMPD.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY
(2021)