Effects of Vitamin C on Cytotherapy-Mediated Muscle Regeneration

Vitamin C Promotes Muscle Development Mediated by the Interaction of CSRP3 with MyoD and MyoG

Previous studies have reported that vitamin C (VC), an essential nutrient, exerts beneficial effects on muscle health. However, the molecular mechanism involved in the VC-mediated regulation of muscle development is still unclear. The roles of VC in muscle development and the underlying molecular mechanisms were examined using cell and molecular biology, transcriptomics, proteomics, and animal experiments in this study. VC upregulated the expression of sodium-dependent vitamin C transporter 2 (SVCT2) and cysteine rich protein 3 (CSRP3). Additionally, VC promoted the differentiation of C2C12 cells and the repair of mouse muscle injury by upregulating the nuclear translocation of CSRP3, which subsequently interacted with MyoD and MyoG. This study provided a theoretical basis for elucidating the mechanism underlying the VC-mediated regulation of muscle development, as well as for developing animal nutritional supplements and therapeutic drugs for muscle diseases.

Vitamin C enhances the ex vivo proliferation of porcine muscle stem cells for cultured meat production

Cultured meat technology is a promising alternative strategy for supplying animal protein taking advantage of its efficiency, safety, and sustainability. The muscle stem cell (MuSC) is one of the most important seed cells for producing muscle fibers, but its weak ex vivo proliferation capacity limits the industrialization of cultured meat. Here we reported that vitamin C (VC) is an excellent supplement for the long-term culture of porcine MuSCs (pMuSCs) ex vivo with considerable proliferative and myogenic effects. After 29 days of culture with 100 μM VC, pMuSCs achieved a 2.8 × 10⁷ ± 0.8 × 10⁷-fold increase in the total cell number, which was 360 times higher than that of cells without VC treatment. pMuSCs that were exposed to VC were less arrested in the G0/G1 phase and showed a significant increase in the expression of cell cycle-related genes such as Cdk1, Cdk2, and Ki67. Additionally, the differentiation potential of pMuSCs was enhanced when cells were proliferated with VC, as evidenced by increased expression of MyoD and MyHC. Furthermore, we demonstrated that VC exerted its proliferative effect through activating the PI3K/AKT/mTOR pathway via the IGF-1 signaling. These findings highlighted the potential application of VC in the ex vivo expansion of pMuSCs for cultured meat production.

Ascorbic Acid Attenuates Multifidus Muscles Injury and Atrophy After Posterior Lumbar Spine Surgery by Suppressing Inflammation and Oxidative Stress in a Rat Model

STUDY DESIGN

A rat model of multifidus muscles injury and atrophy after posterior lumbar spine surgery.

OBJECTIVE

We determined the effect of ascorbic acid (AA) on the postoperative multifidus muscles in rat model.

SUMMARY OF BACKGROUND DATA

Previous studies show oxidative stress and inflammation are two main molecular mechanisms in multifidus muscle injury and atrophy after posterior lumbar surgery. AA may have a protective effect in postoperative multifidus muscles.

METHODS

Rats were divided into sham surgery, control surgery, and surgery plus AA groups. Multifidus muscles of the control and AA groups were excised from the osseous structures. The muscles were retracted continuously for 2 hours. In the sham and AA groups, AA was administered via oral gavage daily in the first week. In each group, the oxidative stress was evaluated by measuring malondialdehyde (MDA) and Total superoxide dismutase (T-SOD). The inflammation, fat degeneration, or fibrosis of multifidus muscle were evaluated by quantitative real-time polymerase chain reaction (q-PCR), histology, or immunohistochemical analysis.

RESULTS

T-SOD activity was significantly lower in the control group than that in the AA group in the first week. MDA levels were significantly higher in the AA group. Interleukin-6 and tumor necrosis factor-α in multifidus muscles also showed significant differences when treated with AA. The inflammation score on histology was significantly lower in the AA group postoperatively in the first week. In the long run, marker genes for fibrosis and fat degeneration, and fibrosis and fat degeneration scores, were significantly lower in the AA than the control group on days 14 and 28 postoperatively.

CONCLUSION

In conclusion, AA attenuated the oxidative stress and inflammation response in the postoperative multifidus muscles, and remarkable differences were observed from the histological assessment and related marker genes expression. Our results provided important insight into the anti-inflammatory and anti-oxidative effects of AA in the postoperative multifidus muscles.

LEVEL OF EVIDENCE

N/A.

Vitamin C Improves Therapeutic Effects of Adipose-derived Stem Cell Transplantation in Mouse Tendonitis Model

BACKGROUND/AIM

We hypothesized that combined therapy using adipose-derived stem cells (ASCs) and vitamin C might improve tendon regeneration in tendonitis. To determine combined effects of ASC transplantation with vitamin C, we used senescence marker protein 30 (SMP30)-knockout (KO) mice that cannot biosynthesize vitamin C by themselves.

MATERIALS AND METHODS

SMP30-KO were divided into four groups: Control, vitamin C, ASCs, and vitamin C plus ASCs. Tendonitis was induced in the achilles tendons via injection of collagenase type I. After 1 week, ASCs were injected into the intratendonal region. After 30 days, all mice were sacrificed and Achilles tendons were isolated.

RESULTS

Gross and microscopic findings showed mice treated with combination of ASC transplantation and vitamin C showed better tendon regeneration than those in other groups. This combination led to higher serum vitamin C levels than use of vitamin C alone. This indicates that the vitamin C-treated group used more vitamin C as a precursor to collagen synthesis, whereas vitamin C was in excess in the combination group because of the added effect of ASCs on tendon healing.

CONCLUSION

This study showed that vitamin C improved the effect of ASC transplantation on tendonitis by inducing a better stem cell niche.

Human Adipose Stem Cells Differentiated on Braided Polylactide Scaffolds Is a Potential Approach for Tendon Tissue Engineering

Growing number of musculoskeletal defects increases the demand for engineered tendon. Our aim was to find an efficient strategy to produce tendon-like matrix in vitro. To allow efficient differentiation of human adipose stem cells (hASCs) toward tendon tissue, we tested different medium compositions, biomaterials, and scaffold structures in preliminary tests. This is the first study to report that medium supplementation with 50 ng/mL of growth and differentiation factor-5 (GDF-5) and 280 μM l-ascorbic acid are essential for tenogenic differentiation of hASCs. Tenogenic medium (TM) was shown to significantly enhance tendon-like matrix production of hASCs compared to other tested media groups. Cell adhesion, proliferation, and tenogenic differentiation of hASCs were supported on braided poly(l/d)lactide (PLA) 96l/4d copolymer filament scaffolds in TM condition compared to foamed poly(l-lactide-co-ɛ-caprolactone) (PLCL) 70L/30CL scaffolds. A uniform cell layer formed on braided PLA 96/4 scaffolds when hASCs were cultured in TM compared to maintenance medium (MM) condition after 14 days of culture. Furthermore, total collagen content and gene expression of tenogenic marker genes were significantly higher in TM condition after 2 weeks of culture. The elastic modulus of PLA 96/4 scaffold was more similar to the elastic modulus reported for native Achilles tendon. Our study showed that the optimized TM is needed for efficient and rapid in vitro tenogenic extracellular matrix production of hASCs. PLA 96/4 scaffolds together with TM significantly stimulated hASCs, thus demonstrating the potential clinical relevance of this novel and emerging approach to tendon injury treatments in the future.