Resveratrol inhibits proliferation and promotes apoptosis of keloid fibroblasts by targeting HIF-1α.

A keloid is characterized by red, tickling, hard, and irregular raised tissues, and it tends to outgrow its origin. It frequently occurs in young adults and appears to be refractory to prevailing therapies. Resveratrol is a new drug that has anti-proliferative effect. In this study, keloid-derived fibroblasts were cultured under hypoxia environment and was treated by resveratrol. CCK-8 assay and Annexin V-FITC were used to evaluate cell activity and apoptosis level. Western blot and RT-qPCR were also used to assess the expression of HIF-α, Collagen I and Collagen III. Besides, siRNA was also used to explore the mechanisms of resveratrol's effect. In this study, hypoxia promotes proliferation and inhibits apoptosis of keloid fibroblasts. These findings highlight the potential obstacle in treating keloids. Furthermore, we demonstrated that resveratrol could reverse the effect of hypoxia on keloids through down-regulation of HIF-1α. Moreover, collagen synthesis in keloid fibroblasts was also inhibited by resveratrol, which corresponded with HIF-1α suppression. These results provide evidence for resveratrol's treatment effect against keloids through inhibiting cell proliferation and promoting cell apoptosis, while, HIF-1α may play the key role in this process.

Induction of human umbilical cord mesenchymal stem cells into tissue-forming cells in a murine model: implications for pelvic floor reconstruction.

HUMSCs were isolated, differentiated and characterized in vitro. Both HUMSCs and smooth muscle cells differentiated from HUMSCs were used to fabricate tissue-engineered fascia equivalents. Forty-eight mature female Sprague Dawley rats were randomly assigned to four groups: group A (GynemeshTMPS, n = 12), group B (GynemeshTMPS + HUMSCs; n = 12), group C (GynemeshTMPS + smooth muscle cells differentiated from HUMSCs; n = 12) and group D (GynemeshTMPS + HUMSCs + smooth muscle cells differentiated from HUMSCs; n = 12). The posterior vaginal wall was incised from the introitus and the mesh was then implanted. Three implants of each type were tested at 1, 4, 8 and 12 weeks. Fibrotic remodeling, inflammation, vascularization and tissue regeneration were histologically assessed. The levels of type I and type III collagen were determined. There was no difference in fibrotic remodeling between cell-seeded and unseeded meshes at any time (p > 0.05). At 12 weeks, there did not appear to be fewer inflammatory cells around the filament bundles in the mesh with cells compared with the mesh alone (P > 0.05). Group D showed a trend toward better vascularization at 12 weeks compared with group A (P < 0.05). Twelve weeks after implantation, a thin layer of new tissue growth covered the unseeded scaffold and a thicker layer covered the cell-seeded scaffold (P < 0.05). No significant difference in the ratio of collagen type I/III could be detected among the different groups after 12 weeks (P > 0.05). HUMSCs with differentiated smooth muscle cells might have a potential role in fascia tissue engineering to repair POP in the future.

Sensitization of keloid fibroblasts by quercetin through the PI3K/Akt pathway is dependent on regulation of HIF-1α.

Keloids are raised, red, hard and irregular tumors that are prone to extend beyond the wound borders. Surgical excision is not sufficient to eradicate a keloid. Adjuvant therapy with radiation is a recommended treatment that reportedly achieves improved efficacy. However, radiation does not only kill cells in the keloid tissue but also stimulates their resistance, and intractable cases can display continuous recurrence. Quercetin was initially extracted from natural products and is used as a dietary supplement. The role of quercetin as an oxidant scavenger has been highlighted in many studies and has drawn interest to the application of ionizing radiation (IR) sensitization. In this study, we first demonstrate that keloid fibroblasts acquire resistance after IR treatment, and this can be relieved by treatment with quercetin. Further, we showed that hypoxia-inducible factor 1 (HIF-1), a prognostic marker used in clinical practice after radiation therapy, was associated with stronger radioresistance in keloid fibroblasts, which was downregulated after quercetin treatment. The inhibition of HIF-1 expression by quercetin was found to be dependent on the phosphatidylinositol-3-kinase (PI3K)/Akt pathway. Quercetin has been reported to reduce the phosphorylation of Akt. Taken together, we revealed one mechanism underlying the suppression of radioresistance by quercetin, which involved the regulation of HIF-1α by the PI3K/Akt pathway. Our study provides a molecular basis for the application of quercetin in radiation sensitization in the treatment of keloids.

Mesenchymal stem cells inhibit Th17 cells differentiation via IFN-γ-mediated SOCS3 activation.

Mesenchymal stem cells (MSCs) are immunoregulatory, and the administration of them has been shown to ameliorate inflammation caused by Th17 cells. However, the mechanisms that contribute to MSC regulation on Th17 cell development are unclear. Here, we found that MSCs could inhibit Th17 cell differentiation through the activation of suppressors of cytokine signaling 3 (SOCS3) when coculture of MSCs and CD4(+)CD25(low)CD44(low)CD62L(high) T cells. Further analysis demonstrated that the inhibitory action was mediated via interferon gamma (IFN-γ), which activated signal transducer and activator of transcription-1 (STAT1) to enhance the expression of SOCS3, leading to STAT3 inhibition. Moreover, stable and reciprocal changes in H3K4me3 and H3K27me3 at the promoters of STAT1, STAT3 and RORγt determined the fate of Th17 cells. These results demonstrate that MSCs may inhibit Th17 differentiation via IFN-γ that activates SOCS3 leading to immunomodulatory effects, suggesting a possible mechanism by which MSCs could act as a cellular approach to attenuate the clinical and pathological manifestations of some autoimmune diseases.

Allogeneic bone marrow mesenchymal stem cell transplantation in patients with UDCA-resistant primary biliary cirrhosis.

The objective of this study was to evaluate the safety and efficacy of allogeneic bone marrow mesenchymal stromal/stem cell transplantation (BM-MSCT) for patients with ursodeoxycholic acid (UDCA)-resistant primary biliary cirrhosis (PBC). Ten patients were enrolled in this trial of BM-MSCT. All patients were permitted to concurrently continue their previous UDCA treatment. The efficacy of BM-MSCT in UDCA-resistant PBC was assessed at various time points throughout the 12-month follow up. No transplantation-related side effects were observed. The life quality of the patients was improved after BM-MSCT as demonstrated by responses to the PBC-40 questionnaire. Serum levels of ALT, AST, γ-GT, and IgM significantly decreased from baseline after BM-MSCT. In addition, the percentage of CD8+ T cells was reduced, while that of CD4+CD25+Foxp3+ T cells was increased in peripheral lymphocytic subsets. Serum levels of IL-10 were also elevated. Notably, the optimal therapeutic outcome was acquired in 3 to 6 months and could be maintained for 12 months after BM-MSCT. In conclusion, allogeneic BM-MSCT in UDCA-resistant PBC is safe and appears to be effective.

Transplantation of Flk-1+ human bone marrow-derived mesenchymal stem cells promotes behavioral recovery and anti-inflammatory and angiogenesis effects in an intracerebral hemorrhage rat model.

Mesenchymal stem cells (MSCs) have been successfully used for the treatment of experimental intracerebral hemorrhage (ICH). However, the neuroprotective mechanisms through which MSCs improve neurological functional recovery are not fully understood. In the present study, we tested the hypothesis that treatment with MSCs inhibits inflammation after ICH and reduces subsequent brain injury. Adult rats subjected to stereotaxic injection of collagenase VII were transplanted with a subpopulation of human bone marrow-derived MSCs (hBMSCs), termed fetal liver kinase (Flk)-1(+) hBMSCs, or saline into the ipsilateral brain parenchyma 1 day after ICH. Significant recovery of behavior was noted in the Flk-1(+) hBMSC-treated rats beginning 3 days after ICH compared with the control group. Brain water content was significantly decreased in the ipsilateral hemispheres of the Flk-1(+) hBMSC-treated rats when compared with the controls 3 days after ICH. The relative hemorrhage volume was reduced 55 days after Flk-1(+) hBMSC treatment. However, this change was not statistically significant. Flk-1(+) hBMSCs significantly inhibited the proliferation of rat peripheral blood mononuclear cells (rPBMCs) induced in a mixed lymphocyte reaction. Consistently, we found a significant anti-inflammatory effect of Flk-1(+) hBMSCs on the ICH brain, including a decrease in neutrophil infiltration and microglial activation in the peri-ICH area, and downregulation of inflammatory mediators, such as interleukin (IL)-1ß, IL-2, IL-4, IL-6, and tumor necrosis factor (TNF)-α. In addition, Flk-1+ hBMSC treatment significantly increased vascular density in the peri-ICH area, and transplanted Flk-1(+) hBMSCs were found to be incorporated into the cerebral vasculature 55 days after transplantation. Overall, these data suggest an essential role for Flk-1(+) hBMSCs in reducing inflammatory infiltration, promoting angiogenesis, and improving functional recovery after ICH in rats.

Migration and differentiation of human mesenchymal stem cells in the normal rat brain.

OBJECTIVES: Transplanted mesenchymal stem cells migrate toward brain lesions and differentiate into neurons, glial cells, and neural stem cells in diseased or injured animal models. The migratory routes and differentiation patterns of mesenchymal stem cells in normal rats are, however, unknown. Here, labelled human mesenchymal stem cells (or saline) were transplanted into the striatum of adult rats to observe their migration and differentiation. METHODS: Labelled human mesenchymal stem cells were transplanted into the right striatum of adults rats (n = 24). Brain sections were examined for migratory routes of labelled human mesenchymal stem cells by immunohistochemistry method, fluorescence microscope and laser scanning confocal microscopy observation, and Prussian blue staining. Moreover, the differentiation of human mesenchymal stem cells was detected by double immunohistochemistry. RESULTS: After 3 days, most human mesenchymal stem cells resided around the injection sites. Human mesenchymal stem cells were found in or around the corpus callosum and the subependymal layer after 7 days. A great number of human mesenchymal stem cells were detected throughout the brain on both ipsilateral and contralateral sides after 14 days. A high concentration of donor cells persisted in the corpus callosum, the external capsule and the subventricular zone. In addition, the incorporated human mesenchymal stem cells were neuronal nuclei- and glial fibrillary acidic protein-positive. CONCLUSION: Human mesenchymal stem cells migrate throughout the brain mainly along with the axis of corpus callosum external capsule and the subependymal layer, and differentiate into neurons and astrocytes rather than neural stem cells.

[Mice adipose derived Flk-1+ mesenchymal stem cells can ameliorate Duchenne's muscular dystrophy in Mdx mice for their multilineage potential].

Duchenne muscular dystrophy (DMD) is a common X-linked disease characterized by widespread muscle damage that invariably leads to paralysis and death. There is currently no therapy for this disease. This study was purposed to investigate the feasibility to use adult adipose-derived mesenchymal stem cells (AD-MSCs) in the therapy of DMD. The Flk-1(+) MSCs were isolated from adipose tissue of adult GFP mice; the phenotype and cell cycle of MSCs were analyzed by flow cytometry; the AD-MSCs were directionally differentiated by myoblast and endotheliablast induction system in vitro and were identified by immumofluorecence staining and RT-PCR; the AD-MSCs were transplanted into CTX-injured mice model or mdx mice (DMD animal model) through tail vein; the distribution and differentiation of AD-MSCs were detected by immunofluorescence staining and RT-PCR respectively, and statistic analysis was performed. The results showed that the Flk-1(+) AD-MSCs could be induced to differentiate into myoblasts and endothelial cells in vitro. After transplanted into CTX-injured mice model or mdx mice, GFP-positive cells could be detected in damaged muscle, and these donor-derived cells were also positive for MHC, vWF, or Pax7. Flk-1(+) AD-MSC transplantation also partly reconstituted the expression of dystrophin, and reduced the percentage of centronucleated myofibers in mdx mice. It is concluded that Flk-1(+) AD-MSCs represent a possible tool for future cell therapy applications in DMD disease, as they can be delivered through the circulation for their potential of muscle homing. And Flk-1(+) AD-MSCs also show the ability to contribute to muscle repair, improvement of blood supply and long term reconstitution of dystrophy muscle.

Improvement of cardiac function after transplantation of autologous bone marrow mesenchymal stem cells in patients with acute myocardial infarction.

BACKGROUND: The infarct size determines the long-term prognosis of patients with acute myocardial infarction (AMI). There is a growing interest in repairing scar area by transplanting bone marrow stem cells. However, effectiveness of intracoronary injection of bone marrow mesenchymal stem cells (BMSCs) in patients with AMI still remains unclear. METHODS: Sixty-nine patients with AMI after percutaneous coronary intervention (PCI) were randomly divided into intracoronary injection of BMSCs (n = 34) and saline (control group, n = 35) groups. Serial single positron emission computer tomography (SPECT), cardiac echo and cardiac electromechanical mapping were done at the designed time intervals until six months after transplantation of BMSCs or injection of saline. RESULTS: The proportion with functional defect decreased significantly in the BMSCs patients after three months [(13 +/- 5)%] compared with that pre-transplantation [(32 +/- 11)%] and the control group [(28 +/- 10)%] at three month follow-up (P < 0.05, respectively). Wall movement velocity over the infracted region increased significantly in the BMSCs group [(4.2 +/- 2.5) cm/s vs (2.2 +/- 1.3) cm/s, P < 0.05], but not in the control group [(2.2 +/- 1.5) cm/s vs (2.7 +/- 1.7) cm/s, P > 0.05]. Left ventricular ejection fraction (LVEF) three months after transplantation in BMSCs group increased significantly compared with that pre-implantation and with that of the control group at three months post-injection [(67 +/- 11)% vs (49 +/- 9)% and (53 +/- 8)%, P < 0.05 respectively]. SPECT scan results showed that perfusion defect was improved significantly in BMSCs group at three-month follow-up compared with that in the control group [(134 +/- 66) cm(2) vs (185 +/- 87) cm(2), P < 0.01]. At the same time, left ventricular end-diastolic volume [(136 +/- 31) ml vs (162 +/- 27) ml, P < 0.05] and end-systolic volume [(63 +/- 20) ml vs (88 +/- 19) ml, P < 0.05] decreased synchronously. The ratio of end-systolic pressure to end-systolic volume [Psyst/ESV, (2.84 +/- 1.30) mmHg/ml vs (1.72 +/- 1.23) mmHg/ml, P < 0.05] increased significantly. Cardiac electromechanical mapping demonstrated significant improvement at three months after implantation of BMSCs compared with that pre-injection in both cardiac mechanical capability as left line local shorting [LLS, (11.29 +/- 1.64)% vs (7.32 +/- 1.86)%, P < 0.05] and electrical property as left ventricular endocardial unipolar voltage [UV, (10.38 +/- 1.12) mV vs (7.61 +/- 1.09) mV, P < 0.01]; perfusion defect decreased from (36.2 +/- 6.2)% to (20.3 +/- 5.31)% (P < 0.01). Twenty-four-hour electrocardiographic monitoring demonstrated no arrhythmias occurred at three-months follow-up. CONCLUSIONS: The transplantation of BMSCs might improve the cardiac function and it is safe and feasible with no deaths or malignant arrhythmias.