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Updated: Aug 22, 2026
Single Fiber Isolation Assay for the Assessment of Oxidative Myofiber Behavior
Published on: March 31, 2026
Anti-oxidative response of carbonic anhydrase III in skeletal muscle
Un-Jin Zimmerman1, Ping Wang, Xiangming Zhang
1Department of Physiology, University of Pennsylvania School of Medicine, A201 Richard Building, 37th and Hamilton Walk, Philadelphia, PA 19104, USA. unjin@mail.med.upenn.edu
Abstract:
We propose that carbonic anhydrase III (CAIII) functions as an anti-oxidant agent in skeletal muscle. To explore this hypothesis, we analyzed the gene expression profile of skeletal muscle in mice deficient in CAIII gene utilizing the murine genome U74Av2 set microarray. Pairwise comparison between CAIII knockout mice and their wild-type littermates revealed that more than 500 of 12,000 genes in the array showed an altered level of transcription. Of particular note were transcriptional alterations among genes associated with the glutathione redox cycle, suggesting a possible involvement of CAIII in the glutathione-mediated anti-oxidant activity. We therefore investigated S-glutathiolation and irreversible oxidation of the 2 reactive sulfhyryls of CAIII in skeletal muscle under oxidative stresses of ischemia, or exhaustive exercise. Analysis by isoelectric focusing followed by Western blot revealed that the two sulfhydryls were differentially and progressively oxidized. Brief ischemia of 10-20 min provoked partial (one of the suflhydryls) modification of CAIII via reversible S-glutathiolation. Protracted 60 min ischemia yielded equal amounts of both partially and completely (both sulfhydryls) modified CAIII due to irreversible oxidization. Twenty minutes of repetitive electrical stimulation, simulating exhaustive exercise, produced a mixed yield: partial modification by reversible S-glutathiolation and complete modification by irreversible oxidation. Thus CAIII responds to oxidative stress with a distinctive sulfhydryl oxidation patterns reflecting duration and severity that may prove sensitive indices of extent and type of damage in muscle injury.
Insights
Carbonic anhydrase III (CAIII) acts as an antioxidant in skeletal muscle. Its sulfhydryl groups change in response to oxidative stress, indicating its role in muscle injury.
Area of Science:
- Biochemistry
- Skeletal Muscle Physiology
- Oxidative Stress Research
Background:
- Carbonic anhydrase III (CAIII) is a key enzyme in skeletal muscle.
- Its potential antioxidant role has not been fully elucidated.
- Understanding CAIII's function is crucial for muscle health research.
Purpose of the Study:
- To investigate the antioxidant function of CAIII in skeletal muscle.
- To analyze gene expression changes in CAIII-deficient mice.
- To examine CAIII's response to oxidative stress.
Main Methods:
- Gene expression profiling using murine genome U74Av2 microarray.
- Comparative analysis of CAIII knockout and wild-type mice.
- Investigation of S-glutathiolation and sulfhydryl oxidation under ischemia and exhaustive exercise using isoelectric focusing and Western blot.
Main Results:
- Over 500 genes showed altered transcription in CAIII knockout mice.
- Significant changes were observed in genes of the glutathione redox cycle.
- CAIII sulfhydryls exhibited differential oxidation patterns (S-glutathiolation and irreversible oxidation) in response to varying durations of ischemia and exercise.
Conclusions:
- CAIII plays a significant role in the antioxidant defense of skeletal muscle.
- CAIII's sulfhydryl oxidation patterns serve as sensitive indicators of muscle damage extent and type.
- This research provides novel insights into CAIII's protective mechanisms against oxidative stress in muscle.
