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Murray KO, Brant JO, Spradlin RA, Thome T, Laitano O, Ryan TE, Riva A, Kladde MP, Clanton TL. Exertional heat stroke causes long-term skeletal muscle epigenetic reprogramming, altered gene expression, and impaired satellite cell function in mice. Am J Physiol Regul Integr Comp Physiol 2024; 326:R160-R175. [PMID: 38047316 PMCID: PMC11283893 DOI: 10.1152/ajpregu.00226.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/26/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
The effect of exertional heat stroke (EHS) exposure on skeletal muscles is incompletely understood. Muscle weakness is an early symptom of EHS but is not considered a major target of multiorgan injury. Previously, in a preclinical mouse model of EHS, we observed the vulnerability of limb muscles to a second EHS exposure, suggesting hidden processes contributing to declines in muscle resilience. Here, we evaluated the possible molecular origins of EHS-induced declines in muscle resilience. Female C57BL/6 mice [total n = 56; 28/condition, i.e., EHS and exercise control (EXC)] underwent forced wheel running at 37.5°C/40% relative humidity until symptom limitation (unconsciousness). EXC mice exercised identically at room temperature (22-23°C). After 1 mo of recovery, the following were assessed: 1) specific force and caffeine-induced contracture in soleus (SOL) and extensor digitorum longus (EDL) muscles; 2) transcriptome and DNA methylome responses in gastrocnemius (GAST); and 3) primary satellite cell function (proliferation and differentiation). There were no differences in specific force in either SOL or EDL from EXC. Only EHS solei exhibited lower caffeine sensitivity. EHS GAST exhibited higher RNA expression of genes encoding structural proteins of slow fibers, heat shock proteins, and myogenesis. A total of ∼2,500 differentially methylated regions of DNA that could potentially affect many cell functions were identified. Primary satellite cells exhibited suppressed proliferation rates but normal differentiation responses. Results demonstrate long-term changes in skeletal muscles 1 mo after EHS that could contribute to declines in muscle resilience. Skeletal muscle may join other, more recognized tissues considered vulnerable to long-term effects of EHS.NEW & NOTEWORTHY Exertional heat stroke (EHS) in mice induces long-term molecular and functional changes in limb muscle that could reflect a loss of "resilience" to further stress. The phenotype was characterized by altered caffeine sensitivity and suppressed satellite cell proliferative potential. This was accompanied by changes in gene expression and DNA methylation consistent with ongoing muscle remodeling and stress adaptation. We propose that EHS may induce a prolonged vulnerability of skeletal muscle to further stress or injury.
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Affiliation(s)
- Kevin O Murray
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Jason O Brant
- Department of Biostatistics, University of Florida, Gainesville, Florida, United States
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
| | - Ray A Spradlin
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Trace Thome
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Orlando Laitano
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Terence E Ryan
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Alberto Riva
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, United States
| | - Michael P Kladde
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, United States
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
| | - Thomas L Clanton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
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Huang W, Zhao S, Liu H, Pan M, Dong H. The Role of Protein Degradation in Estimation Postmortem Interval and Confirmation of Cause of Death in Forensic Pathology: A Literature Review. Int J Mol Sci 2024; 25:1659. [PMID: 38338938 PMCID: PMC10855206 DOI: 10.3390/ijms25031659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/04/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
It is well known that proteins are important bio-macromolecules in human organisms, and numerous proteins are widely used in the clinical practice, whereas their application in forensic science is currently limited. This limitation is mainly attributed to the postmortem degradation of targeted proteins, which can significantly impact final conclusions. In the last decade, numerous methods have been established to detect the protein from a forensic perspective, and some of the postmortem proteins have been applied in forensic practice. To better understand the emerging issues and challenges in postmortem proteins, we have reviewed the current application of protein technologies at postmortem in forensic practice. Meanwhile, we discuss the application of proteins in identifying the cause of death, and postmortem interval (PMI). Finally, we highlight the interpretability and limitations of postmortem protein challenges. We believe that utilizing the multi-omics method can enhance the comprehensiveness of applying proteins in forensic practice.
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Affiliation(s)
- Weisheng Huang
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Hankou, Wuhan 430030, China; (W.H.)
| | - Shuquan Zhao
- Faculty of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China;
| | - Huine Liu
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Hankou, Wuhan 430030, China; (W.H.)
| | - Meichen Pan
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Hankou, Wuhan 430030, China; (W.H.)
| | - Hongmei Dong
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Hankou, Wuhan 430030, China; (W.H.)
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Garcia CK, Gambino BJ, Robinson GP, Rua MT, Alzahrani JM, Clanton TL. Delayed metabolic disturbances in the myocardium after exertional heat stroke: contrasting effects of exertion and thermal load. J Appl Physiol (1985) 2023; 135:1186-1198. [PMID: 37795530 PMCID: PMC10979828 DOI: 10.1152/japplphysiol.00372.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/05/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023] Open
Abstract
Epidemiological studies report higher risks of cardiovascular disease in humans exposed to heat stroke earlier in life. Previously, we explored mechanistic links between heat stroke and developing cardiac abnormalities using a preclinical mouse model of exertional heat stroke (EHS). Profound metabolic abnormalities developed in the ventricles of females but not males after 2 wk of recovery. Here we tested whether this lack of response in males could be attributed to the lower exercise performances or reduced thermal loads they experienced with the same running protocol. We systematically altered environmental temperature (Te) during EHS to manipulate heat exposure and exercise performance in the males. Three groups of adult C57BL/6 male mice were studied: "EHS-34" (Te = 34°C), "EHS-41" (Te = 41°C), and "EHS-39.5" (Te = 39.5°C). Mice ran until symptom limitation (unconsciousness), reaching max core temperature (Tc,max). After a 2-wk recovery, the mice were euthanized, and the ventricles were removed for untargeted metabolomics. Results were compared against age-matched nonexercise controls. The EHS-34 mice greatly elevated their exercise performance but reached lower Tc,max and lower thermal loads. The EHS-41 mice exhibited equivalent thermal loads, exercise times, and Tc,max compared with EHS-39.5. The ventricles from EHS-34 mice exhibited the greatest metabolic disturbances in the heart, characterized by shifts toward glucose metabolism, reductions in acylcarnitines, increased amino acid metabolites, elevations in antioxidants, altered TCA cycle flux, and increased xenobiotics. In conclusion, delayed metabolic disturbances following EHS in male myocardium appear to be greatly amplified by higher levels of exertion in the heat, even with lower thermal loads and max core temperatures.NEW & NOTEWORTHY Epidemiological data demonstrate greater cardiovascular risk in patients with previous heat stroke exposure. Using a preclinical mouse model of exertional heat stroke, male mice were exposed to one of three environmental temperatures (Te) during exercise. Paradoxically, after 2 wk, the mice in the lowest Te, exhibiting the largest exercise response and lowest heat load, had the greatest ventricular metabolic disturbances. Metabolic outcomes resemble developing left ventricular hypertrophy or stress-induced heart disease.
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Affiliation(s)
- Christian K Garcia
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
| | - Bryce J Gambino
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
| | - Gerard P Robinson
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
| | - Michael T Rua
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
| | - Jamal M Alzahrani
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
| | - Thomas L Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States
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