The role of bone marrow mononuclear cell-conditioned medium in the proliferation and migration of human dermal fibroblasts

Inducing Vertebrate Limb Regeneration: A Review of Past Advances and Future Outlook

Limb loss due to traumatic injury or amputation is a major biomedical burden. Many vertebrates exhibit the ability to form and pattern normal limbs during embryogenesis from amorphous clusters of precursor cells, hinting that this process could perhaps be activated later in life to rebuild missing or damaged limbs. Indeed, some animals, such as salamanders, are proficient regenerators of limbs throughout their life span. Thus, research over the last century has sought to stimulate regeneration in species that do not normally regenerate their appendages. Importantly, these efforts are not only a vital aspect of regenerative medicine, but also have fundamental implications for understanding evolution and the cellular control of growth and form throughout the body. Here we review major recent advances in augmenting limb regeneration, summarizing the degree of success that has been achieved to date in frog and mammalian models using genetic, biochemical, and bioelectrical interventions. While the degree of whole limb repair in rodent models has been modest to date, a number of new technologies and approaches comprise an exciting near-term road map for basic and clinical progress in regeneration.

β-acetoxyisovaleryl alkannin (AAN-II) from Alkanna tinctoria promotes the healing of pressure-induced venous ulcers in a rabbit model through the activation of TGF-β/Smad3 signaling

Alkannin-based pharmaceutical formulations for improving wound healing have been on the market for several years. However, detailed molecular mechanisms of their action have yet to be elucidated. Here, we investigated the potential roles of AAN-II in improving the healing of pressure-induced venous ulcers using a rabbit model generated by combining deep vein thrombosis with a local skin defect/local skin defect. The extent of healing was evaluated using hematoxylin and eosin (HE) or vimentin staining. Rabbit skin fibroblasts were cultured for AAN-II treatment or TGFB1-sgRNA lentivirus transfection. ELISA was used to evaluate the levels of various cytokines, including IL-1β, IL-4, IL-6, TNF-α, VEGF, bFGF, TGF-β and PDGF. The protein levels of TGF-β sensors, including TGF-β, Smad7 and phosphor-Smad3, and total Smad3, were assayed via western blotting after TGF-β knockout or AAN-II treatment. The results show that, for this model, AAN-II facilitates ulcer healing by suppressing the development of inflammation and promoting fibroblast proliferation and secretion of proangiogenic factors. AAN-II enhances the activation of the TGF-β1-Smad3 signaling pathway during skin ulcer healing. In addition, the results demonstrate that AAN-II and TGF-β have synergistic effects on ulcer healing. Our findings indicate that AAN-II can promote healing of pressure-induced venous skin ulcers via activation of TGF-β-Smad3 signaling in fibroblast cells and provide evidence that could be used in the development of more effective treatments.

MANF Produced by MRL Mouse-Derived Mesenchymal Stem Cells Is Pro-regenerative and Protects From Osteoarthritis

The super healer Murphy Roths Large (MRL) mouse represents the “holy grail” of mammalian regenerative model to decipher the key mechanisms that underlies regeneration in mammals. At a time when mesenchymal stem cell (MSC)-based therapy represents the most promising approach to treat degenerative diseases such as osteoarthritis (OA), identification of key factors responsible for the regenerative potential of MSC derived from MRL mouse would be a major step forward for regenerative medicine. In the present study, we assessed and compared MSC derived from MRL (MRL MSC) and C57BL/6 (BL6 MSC) mice. First, we compare the phenotype and the differentiation potential of MRL and BL6 MSC and did not observe any difference. Then, we evaluated the proliferation and migration potential of the cells and found that while MRL MSC proliferate at a slower rate than BL6 MSC, they migrate at a significantly higher rate. This higher migration potential is mediated, in part, by MRL MSC-secreted products since MRL MSC conditioned medium that contains a complex of released factors significantly increased the migration potential of BL6 MSC. A comparative analysis of the secretome by quantitative shotgun proteomics and Western blotting revealed that MRL MSC produce and release higher levels of mesencephalic astrocyte-derived neurotrophic factor (MANF) as compared to MSC derived from BL6, BALB/c, and DBA1 mice. MANF knockdown in MRL MSC using a specific small interfering RNA (siRNA) reduced both MRL MSC migration potential in scratch wound assay and their regenerative potential in the ear punch model in BL6 mice. Finally, injection of MRL MSC silenced for MANF did not protect mice from OA development. In conclusion, our results evidence that the enhanced regenerative potential and protection from OA of MRL mice might be, in part, attributed to their MSC, an effective reservoir of MANF.

Human fetal skin-derived stem cell secretome enhances radiation-induced skin injury therapeutic effects by promoting angiogenesis

Background

Radiation dermatitis is a refractory skin injury caused by radiotherapy. Human fetal skin-derived stem cell (hFSSC) is a preferable source for cell therapy and skin tissue regeneration. In the present study, we investigated the repair effect of using hFSSC secretome on a radiation skin injury model in rats.

Methods

We prepared the hFSSC secretome and studied its effects on the proliferation and tube formation of human umbilical vein endothelial cell (HUVEC) in vitro. Furthermore, we used a Sr-90 radiation-induced skin injury model of rats and evaluated the effects of hFSSC secretome on radiation skin injury in vivo.

Results

The results showed that hFSSC secretome significantly promoted the proliferation and tube formation of HUVEC in vitro; in addition, hFSSC secretome-treated rats exhibited higher healing quality and faster healing rate than the other two control groups; the expression level of collagen type III α 1 (Col3A1), transforming growth factor β3 (TGF-β3), angiotensin 1 (Ang-1), angiotensin 2 (Ang-2), vascular endothelial growth factor (VEGF), and placental growth factor (PLGF) was significantly increased, while collagen type I α 2 (Col1A2) and transforming growth factor β1 (TGF-β1) were decreased in hFSSC secretome group.

Conclusions

In conclusion, our results provided the first evidence on the effects of hFSSC secretome towards radiation-induced skin injury. We found that hFSSC secretome significantly enhanced radiation dermatitis angiogenesis, and the therapeutic effects could match with the characteristics of fetal skin. It may act as a kind of novel cell-free therapeutic approach for radiation-induced cutaneous wound healing.

Antler stem cell-conditioned medium stimulates regenerative wound healing in rats

Background

When the deer antler is cast, it leaves a cutaneous wound that can achieve scarless healing due to the presence of antler stem cells (ASCs). This provides an opportunity to study regenerative wound healing.

Methods

In this study, we investigated the therapeutic effects and mechanism of antler stem cell-conditioned medium (ASC-CM) on cutaneous wound healing in rats. In vitro, we investigated the effects of the ASC-CM on proliferation of HUVEC and NIH-3T3 cell lines. In vivo, we evaluated the effects of ASC-CM on cutaneous wound healing using full-thickness skin punch-cut wounds in rats.

Results

The results showed that ASC-CM significantly stimulated proliferation of the HUVEC and NIH-3T3 cells in vitro. In vivo, completion of healing of the rat wounds treated with ASC-CM was on day 16 (± 3 days), 9 days (± 2 days) earlier than the control group (DMEM); the area of the wounds treated with ASC-CM was significantly smaller (p < 0.05) than the two control groups. Further molecular characterization showed that the ratios of Col3A1/Col1A2, TGF-β3/TGF-β1, MMP1/TIMP1, and MMP3/TIMP1 significantly increased (p < 0.01) in the healed tissue in the ASC-CM group.

Conclusions

In conclusion, ASC-CM effectively accelerated the wound closure rate and enhanced the quality of healing, which might be through transforming wound dermal fibroblasts into the fetal counterparts. Therefore, the ASC-CM may have potential to be developed as a novel cell-free therapeutic for scarless wound healing.

Conditioned medium from 3D culture system of stromal vascular fraction cells accelerates wound healing in diabetic rats

Aim: We investigated the healing effects of conditioned medium (CM) derived from a physiological 3D culture system engineered to use an extracellular matrix/stromal vascular fraction (SVF) gel enriched for adipose on diabetic wounds in rats. This CM (Gel-CM) was compared with that from a 2D culture system that used SVF cells (SVF-CM). Materials & methods: Keratinocytes, fibroblasts and wounds were treated with Gel-CM and SVF-CM, and cytokine levels in the CM types were quantified. Results: Proliferation and migration of keratinocytes and fibroblasts were significantly higher after treatment with Gel-CM than with SVF-CM. Collagen secretion by fibroblasts and wound closure were highly stimulated by Gel-CM. Proteomic analyses revealed a higher concentration of growth factors in Gel-CM than in SVF-CM. Conclusion: Gel-CM is a promising therapeutic option for treating diabetic wounds.

The Healing Effects of Conditioned Medium Derived from Mesenchymal Stem Cells on Radiation-Induced Skin Wounds in Rats

Radioactive dermatitis is caused by the exposure of skin and mucous membranes to radiation fields. The pathogenesis of radioactive dermatitis is complex and difficult to cure. Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) may serve as a promising candidate for the therapy of cutaneous wounds. The aim of this study was to investigate whether a WJ-MSC-derived conditioned medium (MSC-CM) could be used to treat radiation-induced skin wounds in rats using a radiation-induced cutaneous injury model. The present study was designed to examine MSC-CM therapy in the recovery of radiation-induced skin wounds in vitro and in vivo. Firstly, we prepared the MSC-CM and tested the effects of the MSC-CM on human umbilical vein endothelial cell proliferation in vitro. After that, we used a β-ray beam to make skin wounds in rats and tested the effects of MSC-CM on cutaneous wound healing in vivo. Our results indicated that MSC-CM secreted factors that promoted HUVEC proliferation, regeneration of sebaceous glands, and angiogenesis. Importantly, MSC-CM promoted wound healing in excess of the positive control (epidermal growth factor), with no, or smaller, scar formation. In conclusion, MSC-CM significantly accelerated wound closure and enhanced the wound healing quality. MSC-CM has a beneficial therapeutic effect on radiation-induced cutaneous injury skin in rats and in this way MSC-CM may serve as a basis of a novel cell-free therapeutic approach for radiation dermatitis.

Fibroblast-myofibroblast crosstalk after exposure to mesenchymal stem cells secretome

AIM

The aim of the present study was to investigate the effect of human bone marrow-derived mesenchymal stem cells conditioned medium on fibroblast to myofibroblast differentiation.

BACKGROUND

Mesenchymal stem cells have a long-term clinical application and widely have used in autoimmune disease and regenerative medicine. However, some MSCs derived cytokines such as TGF-β could have a dual role in suppression or progression of disease. Fibroblast activation and extracellular matrix production are two key features of wound healing which mostly are controlled with multifunctional cytokine TGF-β1.

METHODS

Bone marrow MSCs were isolated, cultured and used for conditioned medium preparation. The flow cytometry analysis was done for MSCs cell surface markers. MRC-5 subconfluent cells were starved with the medium containing 0.5 % FBS for 24h, then treated with exogenous TGF-β1 (10ng/ml as positive control) and MSCs-conditioned medium for 48h. Finally, the mRNA expression of three target genes: collagen I, collagen III and α-SMA were evaluated by RT-PCR technique.

RESULTS

Our findings demonstrated that bone marrow-derived mesenchymal stem cells-conditioned medium (secretome) significantly upregulated type I and III collagen expression but non-significantly α-SMA gene expression.

CONCLUSION

Totally, Real Time PCR results suggest that MSCs conditioned medium activates differentiation of fibroblast to myofibroblast phenotype as confirmed through the presence of α-SMA, collagen I and collagen III expression compared to control in MRC 5 cells.