Protective effect of mesenchymal stem cells on the pressure ulcer formation by the regulation of oxidative and endoplasmic reticulum stress

Topical hADSCs-HA Gel Promotes Skin Regeneration and Angiogenesis in Pressure Ulcers by Paracrine Activating PPARβ/δ Pathway

Background

Pressure ulcer is common in the bedridden elderly with high mortality and lack of effective treatment. In this study, human-adipose-derived-stem-cells-hyaluronic acid gel (hADSCs-HA gel) was developed and applied topically to treat pressure ulcers, of which efficacy and paracrine mechanisms were investigated through in vivo and in vitro experiments.

Methods

Pressure ulcers were established on the backs of C57BL/6 mice and treated topically with hADSCs-HA gel, hADSCs, hyaluronic acid, and normal saline respectively. The rate of wound closure was observed continuously during the following 14 days and the wound samples were obtained for Western blot, histopathology, immunohistochemistry, and proteomic analysis. Human dermal fibroblasts (HDFs) and human venous endothelial cells (HUVECs) under normal or hypoxic conditions were treated with conditioned medium of human ADSCs (ADSC-CM), then CCK-8, scratch test, tube formation, and Western blot were conducted to evaluate the paracrine effects of hADSCs and to explore the underlying mechanism.

Results

The in vivo data demonstrated that hADSCs-HA gel significantly accelerated the healing of pressure ulcers by enhancing collagen expression, angiogenesis, and skin proliferation. The in vitro data revealed that hADSCs strengthened the proliferation and wound healing capabilities of HDFs and HUVECs, meanwhile promoted collagen secretion and tube formation through paracrine mode. ADSC-CM was also proved to exert protective effects on hypoxic HDFs and HUVECs. Besides, the results of proteomic analysis and Western blot elucidated that lipid metabolism and PPARβ/δ pathway mediated the healing effect of hADSCs-HA gel on pressure ulcers.

Conclusion

Our research showed that topical application of hADSCs-HA gel played an important role in dermal regeneration and angiogenesis. Therefore, hADSCs-HA gel exhibited the potential as a novel stem-cell-based therapeutic strategy of treating pressure ulcers in clinical practices.

Exposure to volatile ferroptosis inhibitor, TEMPO, reduced cutaneous ischemia-reperfusion injury progression to pressure ulcer formation in a mouse model

BACKGROUND

Ischemia- reperfusion (I/R) injury-induced oxidative stress is a key factor in the pathogenesis of pressure ulcer formation. Ferroptosis is an iron-dependent programmed cell death that connects oxidative stress and inflammation in various diseases. Recent studies revealed the protective effect of inhibition of ferroptosis in I/R injury. However, the role of ferroptosis in cutaneous I/R injury remains elusive.

OBJECTIVE

To assess the role of ferroptosis in the progression of cutaneous I/R injury.

METHODS

Cutaneous I/R injury experiments and histopathological studies were performed in wild-type mice with or without exposure to volatile ferroptosis inhibitor, TEMPO (2,2,6,6-Tetramethylpiperidine-1-oxyl). The suppressive effects of TEMPO on ferroptosis inducing cell death and oxidative stress were examined in vitro.

RESULTS

Inhibition of ferroptosis with TEMPO significantly reduced ulcer formation after cutaneous I/R injury. Fluctuated ferroptosis markers, such as GPX4, ACSL4, and 4-HNE expression in the I/R skin site, were reversed by TEMPO treatment. Inhibition of ferroptosis reduced apoptosis, CD3+ infiltrating lymphocytes, and improved vascularity in the I/R skin site. Inhibition of ferroptosis also suppressed the enhancement of Nrf2 activation. In vitro, ferroptosis and the activation of ferroptosis-related gene expression by RSL3 stimulation were markedly ameliorated by TEMPO treatment in mouse fibroblasts. Inhibiting ferroptosis also suppressed the elevation of the mRNA levels of NOX2 and HO-1 caused by ferroptosis.

CONCLUSION

Cutaneous I/R injury-induced ferroptosis likely promotes cell death, vascular loss, infiltration of inflammatory cells, and oxidative stress. The inhibition of ferroptosis with TEMPO might have potential clinical application as novel therapeutic agent for cutaneous I/R injury.

Preliminary evidence for the presence of programmed cell death in pressure injuries

Pressure injuries (PIs) are a common healthcare problem worldwide and are considered to be the most expensive chronic wounds after arterial ulcers. Although the gross factors including ischemia-reperfusion (I/R) have been identified in the etiology of PIs, the precise cellular and molecular mechanisms contributing to PIs development remain unclear. Various forms of programmed cell death including apoptosis, autophagy, pyroptosis, necroptosis and ferroptosis have been identified in PIs. In this paper, we present a detailed overview on various forms of cell death; discuss the recent advances in the roles of cell death in the occurrence and development of PIs and found much of the evidence is novel and based on animal experiments. Herein, we also state critical evaluation of the existing data and future perspective in the field. A better understanding of the programmed cell death mechanism in PIs may have important implications in driving the development of new preventive and therapeutic strategies.

Tryptanthrin promotes pressure ulcers healing in mice by inhibiting macrophage-mediated inflammation via cGAS/STING pathways

BACKGROUND

Pressure ulcers (PUs) is ischemic necrosis caused by long-term local tissue pressure, directly affecting postoperative functional recovery. There is evidence that inflammation has an adverse impact on the development of PUs and contributes to unfavorable outcomes, suggesting that blocking the inflammatory response may be a promising therapeutic strategy for PUs. Tryptanthrin (Tryp), a natural product isolated from indigenous plants, has an anti-inflammatory biological function. However, the efficacy of Tryp in PUs remains unclear.

METHODS

Efficacy of Tryp suppressed inflammation was assessed using magnets-induced PUs model in mice. Hematoxylin-Eosin staining, masson staining and immunohistochemistry were used to evaluate the histologic changes after the formation of PUs. The expression of inflammatory cytokines was detected by qRT-PCR. And we detected the expression of protein by Western blotting.

RESULTS

Tryp could promote wound healing, such as epidermal thickening, revascularization, and nerve regeneration. Then the treatment of Tryp was able to promote fibroblast migration and collagen deposition. Moreover, Tryp attenuated inflammation through inducing macrophage polarization to M2 phenotype by suppressing the activation of cGAS-STING pathway.

CONCLUSION

Tryp could reduce the release of inflammatory cytokines, and induce RAW 264.7 polarization to M2 phenotype by targeting cGAS/STING/TBK1 pathways. In summary, Tryp may be a novel medicine for the treatment of PUs in the future.

Plasma-Based Scaffold Containing Bone-Marrow Mononuclear Cells Promotes Wound Healing in a Mouse Model of Pressure Injury

Pressure injuries, or pressure ulcers, are a common problem that may lead to infections and major complications, besides being a social and economic burden due to the costs of treatment and hospitalization. While surgery is sometimes necessary, this also has complications such as recurrence or wound dehiscence. Among the newer methods of pressure injury treatment, advanced therapies are an interesting option. This study examines the healing properties of bone marrow mononuclear cells (BM-MNCs) embedded in a plasma-based scaffold in a mouse model. Pressure ulcers were created on the backs of mice (2 per mouse) using magnets and assigned to a group of ulcers that were left untreated (Control, n = 15), treated with plasma scaffold (Plasma, n = 15), or treated with plasma scaffold containing BM-MNC (Plasma + BM-MNC, n = 15). Each group was examined at three time points (3, 7, and 14 days) after the onset of treatment. At each time point, animals were subjected to biometric assessment, bioluminescence imaging, and tomography. Once treatment had finished, skin biopsies were processed for histological and wound healing reverse transcription polymerase chain reaction (RT-PCR) array studies. While wound closure percentages were higher in the Plasma and Plasma + BM-MNC groups, differences were not significant, and thus descriptive data are provided. In all individuals, the presence of donor cells was revealed by immunohistochemistry on posttreatment onset Days 3, 7, and 14. In the Plasma + BM-MNC group, less inflammation was observed by positron emission tomography-computed tomography (PET/CT) imaging of the mice at 7 days, and a complete morphometabolic response was produced at 14 days, in accordance with histological results. A much more pronounced inflammatory process was observed in controls than in the other two groups, and this persisted until Day 14 after treatment onset. RT-PCR array gene expression patterns were also found to vary significantly, with the greatest difference noted between both treatments at 14 days when 11 genes were differentially expressed.

Mesenchymal Stromal Cell Healing Outcomes in Clinical and Pre-Clinical Models to Treat Pressure Ulcers: A Systematic Review

BACKGROUND

Despite numerous measures used to prevent pressure ulcers, their growing prevalence in recent years is expected to continue as the population ages. This review aims to report the outcomes of the regenerative potential of MSCs in treating pressure ulcers, assessing the effectiveness of MSCs in treating pressure ulcers.

METHODS

A computerized search for articles on animal models that use MSCs as primary therapy to treat pressure ulcers, published from conception to present, was conducted using PubMed, MEDLINE, Embase, and CINAHL. Our search yielded 52 articles, narrowed to 44 after excluding duplicates.

RESULTS

Out of 52 articles collected from four databases, 11 met the inclusion criteria. A total of 11 articles published between 2008 and 2020 met the inclusion criteria. Eight studies were observational descriptive papers in animal models, and three were prospective. Six studies used autologous MSCs, while five used allogenic MSCs. Three studies were conducted in humans, and the remaining eight were conducted in animals. The most common method of cell delivery was an intradermal injection in the margins of the ulcer. All studies reported positive results, including improved wound healing, reduced inflammation, and improved tissue regeneration.

CONCLUSIONS

MSCs have shown promising results in treating pressure ulcers in animal and clinical trials. The combination of MSCs and scaffold materials has also been studied and found to be effective in wound healing. A standardized human wound model has been proposed further to investigate the efficacy of cell-based therapies for chronic wounds. However, more research is needed to determine the best quantity of cells to apply for pressure ulcers and to ensure the safety and efficacy of these treatments in clinical settings.

The Potential of Mesenchymal Stem/Stromal Cell Therapy in Mustard Keratopathy: Discovering New Roads to Combat Cellular Senescence

Mesenchymal stem/stromal cells (MSCs) are considered a valuable option to treat ocular surface disorders such as mustard keratopathy (MK). MK often leads to vision impairment due to corneal opacification and neovascularization and cellular senescence seems to have a role in its pathophysiology. Herein, we utilized intrastromal MSC injections to treat MK. Thirty-two mice were divided into four groups based on the exposure to 20 mM or 40 mM concentrations of mustard and receiving the treatment or not. Mice were clinically and histopathologically examined. Histopathological evaluations were completed after the euthanasia of mice after four months and included hematoxylin and eosin (H&E), CK12, and beta-galactosidase (β-gal) staining. The treatment group demonstrated reduced opacity compared to the control group. While corneal neovascularization did not display significant variations between the groups, the control group did register higher numerical values. Histopathologically, reduced CK12 staining was detected in the control group. Additionally, β-gal staining areas were notably lower in the treatment group. Although the treated groups showed lower severity of fibrosis compared to the control groups, statistical difference was not significant. In conclusion, it seems that delivery of MSCs in MK has exhibited promising therapeutic results, notably in reducing corneal opacity. Furthermore, the significant reduction in the β-galactosidase staining area may point towards the promising anti-senescence potential of MSCs.

Human umbilical cord-derived mesenchymal stem cells alleviate oxidative stress-induced islet impairment via the Nrf2/HO-1 axis

Hyperglycaemia-induced oxidative stress may disrupt insulin secretion and β-cell survival in diabetes mellitus by overproducing reactive oxygen species. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) exhibit antioxidant properties. However, the mechanisms by which hUC-MSCs protect β-cells from high glucose-induced oxidative stress remain underexplored. In this study, we showed that intravenously injected hUC-MSCs engrafted into the injured pancreas and promoted pancreatic β-cell function in a mouse model of type 1 diabetes mellitus. The in vitro study revealed that hUC-MSCs attenuated high glucose-induced oxidative stress and prevented β-cell impairment via the Nrf2/HO-1 signalling pathway. Nrf2 knockdown partially blocked the anti-oxidative effect of hUC-MSCs, resulting in β-cell decompensation in a high-glucose environment. Overall, these findings provide novel insights into how hUC-MSCs protect β-cells from high glucose-induced oxidative stress.

Therapeutic Effects and Underlying Mechanism of SOCS-com Gene-Transfected ADMSCs in Pressure Ulcer Mouse Models

Although the proportion of ulcer patients with medical problems among the elderly has increased with the extension of human life expectancy, treatment efficiency is drastically low, incurring substantial social costs. MSCs have independent regeneration potential, making them useful in clinical trials of difficult-to-treat diseases. In particular, ADMSCs are promising in the stem cell therapy industry as they can be obtained in vast amounts using non-invasive methods. Furthermore, studies are underway to enhance the regeneration potential of ADMSCs using cytokines, growth factors, and gene delivery to generate highly functional ADMSCs. In this study, key regulators of wound healing, SOCS-1, -3, and -5, were combined to maximize the regenerative potential of ADMSCs in pressure ulcer treatments. After transfecting SOCS-1, -3, -5, and SOCS-com into ADMSCs using a non-viral method, the expression of the inflammatory factors TNF-alpha, INF-gamma, and IL-10 was confirmed. ADMSCs transfected with SOCS-com showed decreased overall expression of inflammatory factors and increased expression of anti-inflammatory factors. Based on these results, we implanted ADMSCs transfected with SOCS-com into a pressure ulcer mouse model to observe their subsequent wound-healing effects. Notably, SOCS-com improved wound closure in ulcers, and reconstruction of the epidermis and dermis was observed. The healing mechanism of ADMSCs transfected with SOCS-com was examined by RNA sequencing. Gene analysis results confirmed that expression changes occurred in genes of key regulators of wound healing, such as chemokines, MMP-1, 9, CSF-2, and IL-33, and that such genetic changes enhanced wound healing in ulcers. Based on these results, we demonstrate the potential of ADMSCs transfected with SOCS-com as an ulcer treatment tool.

Mechanism of mesenchymal stem cells and exosomes in the treatment of age-related diseases

Mesenchymal stem cells (MSCs) from multiple tissues have the capability of multidirectional differentiation and self-renewal. Many reports indicated that MSCs exert curative effects on a variety of age-related diseases through regeneration and repair of aging cells and organs. However, as research has progressed, it has become clear that it is the MSCs derived exosomes (MSC-Exos) that may have a real role to play, and that they can be modified to achieve better therapeutic results, making them even more advantageous than MSCs for treating disease. This review generalizes the biological characteristics of MSCs and exosomes and their mechanisms in treating age-related diseases, for example, MSCs and their exosomes can treat age-related diseases through mechanisms such as oxidative stress (OS), Wnt/β-catenin signaling pathway, mitogen-activated protein kinases (MAPK) signaling pathway, and so on. In addition, current in vivo and in vitro trials are described, and ongoing clinical trials are discussed, as well as the prospects and challenges for the future use of exosomes in disease treatment. This review will provide references for using exosomes to treat age-related diseases.

Effects of piperlonguminine on lung injury in severe acute pancreatitis <em>via</em> the TLR4/NF-κB pathway

Acute pancreatitis is an inflammatory response in the pancreas, involving activation of pancreatic enzymes. Severe acute pancreatitis (SAP) often causes systemic complications that affect distant organs, including the lungs. The aim of this study was to explore the therapeutic potential of piperlonguminine on SAP-induced lung injury in rat models. Acute pancreatitis was induced in rats by repetitive injections with 4% sodium taurocholate. Histological examination and biochemical assays were used to assess the severity of lung injury, including tissue damage, and levels of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4), reactive oxygen species (ROS), and inflammatory cytokines. We found that piperlonguminine significantly ameliorated pulmonary architectural distortion, hemorrhage, interstitial edema, and alveolar thickening in rats with SAP. In addition, NOX2, NOX4, ROS, and inflammatory cytokine levels in pulmonary tissues were notably decreased in piperlonguminine-treated rats. Piperlonguminine also attenuated the expression levels of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). Together, our findings demonstrate for the first time that piperlonguminine can ameliorate acute pancreatitis-induced lung injury via inhibitory modulation of inflammatory responses by suppression of the TLR4/NF-κB signaling pathway.

Stem cell and tissue engineering approaches in pressure ulcer treatment

CONTEXT

Pressure ulcers or injuries, arise from ischemic damage to soft tissues induced by unrelieved pressure over a bony prominence. They are usually difficult to treat with standard medical therapy and often they recur. In the search for better treatment options, promising alternative forms of treatment are today emerging. Within the field of regenerative medicine, ongoing research on advanced therapies seeks to develop medicinal products based on gene therapy, somatic cell therapy, tissue-engineering and combinations of these.

OBJECTIVE

The main objective is to perform an overview of experimental and clinical developments in somatic cell therapy and tissue engineering targeting the treatment of pressure injuries.

METHODS

Searching terms as "PRESSURE ULCER", "STEM CELL THERAPY", "TISSUE ENGINEERING" or "WOUND HEALING" were used in combination or alone, including publications refered to basic and clinical research and focusing on articles showing results obtained in a clinical context. A total of 80 references are cited, including 23 references published in the 3 last years.

RESULTS

The results suggest that this form of treatment could be an interesting option in patients with difficult-to-treat ulcers as spinal cord injury patients.

CONCLUSION

This field of regenerative medicine is very broad and further research is warranted.

Protective effects of conditioned media of immortalized stem cells from human exfoliated deciduous teeth on pressure ulcer formation

Pressure ulcers (PUs) are increasing with aging worldwide, but there is no effective causal therapy. Although mesenchymal stem cells (MSCs) promote cutaneous wound healing, the effects of the conditioned medium (CM) of MSCs on cutaneous PU formation induced by ischemia-reperfusion injury have been poorly investigated. To address this issue, herein, we first established an immortalized stem cell line from human exfoliated deciduous teeth (SHED). This cell line was revealed to have superior characteristics in that it grows infinitely and vigorously, and stably and consistently secretes a variety of cytokines. Using the CM obtained from the immortalized SHED cell line, we investigated the therapeutic potential on a cutaneous ischemia-reperfusion mouse model for PU formation using two magnetic plates. This is the first study to show that CM from immortalized SHEDs exerts therapeutic effects on PU formation by promoting angiogenesis and oxidative stress resistance through vascular endothelial growth factor and hepatocyte growth factor. Thus, the CM of MSCs has potent therapeutic effects, whereas these therapies have not been implemented in human medicine. To try to meet the regulatory requirements for manufacturing and quality control as much as possible, it is necessary to produce CM that is consistently safe and effective. The immortalization of stem cells could be one of the breakthroughs to meet the regulatory requirements and consequently open up a novel avenue to create a novel type of cell-free regenerative medicine, although further investigation into the quality control is warranted.

Therapeutic Potential of Mesenchymal Stem Cell-Secreted Factors on Delay in Corneal Wound Healing by Nitrogen Mustard

Ocular surface exposure to nitrogen mustard (NM) leads to severe ocular toxicity which includes the separation of epithelial and stromal layers, loss of endothelial cells, cell death, and severe loss of tissue function. No definitive treatment for mustard gas-induced ocular surface disorders is currently available. The research was conducted to investigate the therapeutic potential of mesenchymal stem cell-conditioned media (MSC-CM) in NM-induced corneal wounds. NM was added to different types of corneal cells, the ocular surface of porcine, and the ocular surface of mice, followed by MSC-CM treatment. NM significantly induced apoptotic cell death, cellular ROS (Reactive oxygen species), and reduced cell viability, metabolic gene expression, and mitochondrial function, and, in turn, delayed wound healing. The application of MSC-CM post NM exposure partially restored mitochondrial function and decreased intracellular ROS generation which promoted cell survival. MSC-CM therapy enhanced wound healing process. MSC-CM inhibited NM-induced apoptotic cell death in murine and porcine corneal tissue. The application of MSC-CM following a chemical insult led to significant improvements in the preservation of corneal structure and wound healing. In vitro, ex vivo, and in vivo results suggest that MSC-CM can potentially provide targeted therapy for the treatment of chemical eye injuries, including mustard gas keratopathy (MGK) which presents with significant loss of vision alongside numerous corneal pathologies.

Gossypol Induces Apoptosis of Human Pancreatic Cancer Cells via CHOP/Endoplasmic Reticulum Stress Signaling Pathway

Gossypol, a natural phenolic aldehyde present in cotton plants, was originally used as a means of contraception, but is currently being studied for its anti-proliferative and anti-metastatic effects on various cancers. However, the intracellular mechanism of action regarding the effects of gossypol on pancreatic cancer cells remains unclear. Here, we investigated the anti-cancer effects of gossypol on human pancreatic cancer cells (BxPC-3 and MIA PaCa-2). Cell counting kit-8 assays, annexin V/propidium iodide staining assays, and transmission electron microscopy showed that gossypol induced apoptotic cell death and apoptotic body formation in both cell lines. RNA sequencing analysis also showed that gossypol increased the mRNA levels of CCAAT/enhancer-binding protein homologous protein (CHOP) and activating transcription factor 3 (ATF3) in pancreatic cancer cell lines. In addition, gossypol facilitated the cleavage of caspase-3 via protein kinase RNA-like ER kinase (PERK), CHOP, and Bax/Bcl-2 upregulation in both cells, whereas the upregulation of ATF was limited to BxPC-3 cells. Finally, a three-dimensional culture experiment confirmed the successful suppression of cancer cell spheroids via gossypol treatment. Taken together, our data suggest that gossypol may trigger apoptosis in pancreatic cancer cells via the PERK-CHOP signaling pathway. These findings propose a promising therapeutic approach to pancreatic cancer treatment using gossypol.

Human Amnion Membrane-Derived Mesenchymal Stem Cells and Conditioned Medium Can Ameliorate X-Irradiation-Induced Testicular Injury by Reducing Endoplasmic Reticulum Stress and Apoptosis

Today, infertility affects 15% of couples and half of this rate is due to reproductive problems in men. Radiation-induced damage to the testicles causes sterility depending on the dose. Radiation causes endoplasmic reticulum (ER) stress and ER stress induces apoptosis. In this study, the effect of human amniotic membrane-derived mesenchymal stem cells (hAMSCs) and conditioned medium (hAMSCs-CM) on testicular damage induced by ionizing radiation is aimed to be elucidated through ER stress and apoptosis mechanisms. Six gray scrotal irradiation was used to create a testicular injury model. hAMSCs isolated and characterized with immunofluorescence and flow cytometry, while 2.5 × 10⁵ hAMSCs were transplanted into testis and hAMSCs-CM was applied. Fertility assessment was performed. Expressions of ER stress markers GRP78, Ire1, Chop and Caspase-12, and Caspase-3 were determined. TUNEL was performed. Serum FSH, LH, and testosterone were measured. After hAMSC transplantation and administration of hAMSCs-CM, offsprings were obtained. Seminiferous tubule diameter and seminiferous epithelial height increased. The expression of GRP78, IRE1α, CHOP, Caspase-12, and Caspase-3 decreased. Percentages of tunel positive cells decreased. While FSH and LH levels decreased, testosterone increased. After irradiation, both hAMSCs transplantation and paracrine activity of hAMSCs may have a role in reducing ER stress by suppressing the UPR response. Decrease in FSH and LH and increase in testosterone level after MSCs transplantation may have contributed to the improvement of spermatogenesis. Thus, it can be said that MSCs derived from human amniotic membrane can improve ionized radiation-induced testicular damage by reducing ER stress and apoptosis.

Inhibition of skin fibrosis in systemic sclerosis by botulinum toxin B via the suppression of oxidative stress

Oxidative stress has been reported to play an important role in the pathogenesis of skin fibrosis in systemic sclerosis (SSc). We previously identified that botulinum toxin (BTX) injection suppresses pressure ulcer formation in a cutaneous ischemia-reperfusion injury mouse model by regulation of oxidative stress. However, the therapeutic possibility of BTX administration for preventing skin fibrosis in SSc is unclear. The objective of this study was to investigate the effect of BTX-B on skin fibrosis in a murine model of SSc and determine the underlying mechanism. We found that BTX-B injection significantly reduced dermal thickness and inflammatory cell infiltration in bleomycin-induced skin fibrosis lesion in mice. We also identified that the oxidative stress signal detected through bioluminescence in OKD48 mice after bleomycin injection in the skin was significantly decreased by BTX-B. Additionally, mRNA levels of oxidative stress associated factors (NOX2, HO-1, Trx2) were significantly decreased by BTX-B. Apoptotic cells in the lesional skin of bleomycin-treated mice were significantly reduced by BTX-B. Oxidant-induced intracellular accumulation of reactive oxygen species in SSc fibroblasts was also inhibited by BTX-B. In conclusion, BTX-B might improve bleomycin-induced skin fibrosis via the suppression of oxidative stress and inflammatory cells in the skin. BTX-B injection may have a therapeutic effect on skin fibrosis in SSc.

An Update on the Potential of Mesenchymal Stem Cell Therapy for Cutaneous Diseases

Mesenchymal stem or stromal cells (MSCs) are nonhematopoietic postnatal stem cells with self-renewal, multipotent differentiation, and potent immunomodulatory and anti-inflammatory capabilities, thus playing an important role in tissue repair and regeneration. Numerous clinical and preclinical studies have demonstrated the potential application of MSCs in the treatment of tissue inflammation and immune diseases, including inflammatory skin diseases. Therefore, understanding the biological and immunological characteristics of MSCs is important to standardize and optimize MSC-based regenerative therapy. In this review, we highlight the mechanisms underlying MSC-mediated immunomodulation and tissue repair/regeneration and present the latest development of MSC-based clinical trials on cutaneous diseases.

The loss of microglia activities facilitates glaucoma progression in association with CYP1B1 gene mutation (p.Gly61Glu)

Background

Glaucoma represents the second main cause of irreversible loss of eyesight worldwide. Progression of the disease is due to changes around the optic nerve, eye structure and optic nerve environment. Focusing on primary congenital glaucoma, which is not completely understood, we report an evaluation of an untested mutation (c.182G>A, p.Gly61Glu) within the CYP1B1 gene in the context of microglia, astrocytes and mesenchymal stem cells. We investigated the behaviours of these cells, which are needed to maintain eye homeostasis, in response to the CYP1B1 mutation.

Methods and results

CRISPR technology was used to edit normal CYP1B1 genes within normal astrocytes, microglia and stem cells in vitro. Increased metabolic activities were found in microglia and astrocytes 24 hours after CYP1B1 manipulation. However, these activities dropped by 40% after 72 hrs. In addition, the nicotinamide adenine dinucleotide phosphate (NADP)/NADPH reducing equivalent process decreased by 50% on average after 72 hrs of manipulation. The cytokines measured in mutated microglia showed progressive activation leading to apoptosis, which was confirmed with annexin-V. The cytokines evaluated in mutant astrocytes were abnormal in comparison to those in the control.

Conclusions

The results suggest a progressive inflammation that was induced by mutations (p.Gly61Glu) on CYP1B1. Furthermore, the mutations enhanced the microglia’s loss of activity. We are the first to show the direct impact of the mutation on microglia. This progressive inflammation might be responsible for primary congenital glaucoma complications, which could be avoided via an anti-inflammatory regimen. This finding also reveals that progressive inflammation affects recovery failure after surgeries to relieve glaucoma. Moreover, microglia are important for the survival of ganglion cells, along with the clearing of pathogens and inflammation. The reduction of their activities may jeopardise homeostasis within the optic nerve environment and complicate the protection of optic nerve components (such as retinal ganglion and glial cells).

A comparative study on the cellular stressors in mesenchymal stem cells (MSCs) and pancreatic β-cells under hyperglycemic milieu

β-cell dysfunction is a critical determinant for both type 1 diabetes and type 2 diabetes and β-cells are shown to be highly susceptible to cellular stressors. Mesenchymal stem cells (MSCs) on the other hand are known to have immunomodulatory potential and preferred in clinical applications. However, there is paucity of a comparative study on these cells in relation to several cellular stressors in response to hyperglycemia and this forms the rationale for the present study. INS1 β-cells and MSCs were subjected to high-glucose treatment without and with Metformin, Lactoferrin, or TUDCA and assessed for stress signaling alterations using gene expression, protein expression, as well as functional read-outs. Compared to the untreated control cells, INS1 β-cells or MSCs treated with high glucose showed significant increase in mRNA expressions of ER stress, senescence, and proinflammation. This was accompanied by increased miR146a target genes and decreased levels of SIRT1, NRF2, and miR146a in both the cell types. Consistent with the mRNA results, protein expression levels do reflect the same alterations. Notably, the alterations are relatively less extent in MSCs compared to INS1 β-cells. Interestingly, three different agents, viz., Metformin, Lactoferrin, or TUDCA, were found to overcome the high glucose-induced cellular stresses in a concerted and inter-linked way and restored the proliferation and migration capacity in MSCs as well as normalized the glucose-stimulated insulin secretion in INS1 β-cells. While our study gives a directionality for potential supplementation of metformin/lactoferrin/TUDCA in optimization protocols of MSCs, we suggest that in vitro preconditioning of MSCs with such factors should be further explored with in-depth investigations to harness and enhance the therapeutic capacity/potential of MSCs.

miR-132-3p priming enhances the effects of mesenchymal stromal cell-derived exosomes on ameliorating brain ischemic injury

Backgrounds/aims

Mesenchymal stromal cell-derived exosomes (MSC-EXs) could exert protective effects on recipient cells by transferring the contained microRNAs (miRs), and miR-132-3p is one of angiogenic miRs. However, whether the combination of MSC-EXs and miR-132-3p has better effects in ischemic cerebrovascular disease remains unknown.

Methods

Mouse MSCs transfected with scrambler control or miR-132-3p mimics were used to generate MSC-EXs and miR-132-3p-overexpressed MSC-EXs (MSC-EXs^miR-132-3p). The effects of EXs on hypoxia/reoxygenation (H/R)-injured ECs in ROS generation, apoptosis, and barrier function were analyzed. The levels of RASA1, Ras, phosphorylations of PI3K, Akt and endothelial nitric oxide synthesis (eNOS), and tight junction proteins (Claudin-5 and ZO-1) were measured. Ras and PI3K inhibitors were used for pathway analysis. In transient middle cerebral artery occlusion (tMCAO) mouse model, the effects of MSC-EXs on the cerebral vascular ROS production and apoptosis, cerebral vascular density (cMVD), Evans blue extravasation, brain water content, neurological deficit score (NDS), and infarct volume were determined.

Results

MSC-EXs could deliver their carried miR-132-3p into target ECs, which functionally downregulated the target protein RASA1, while upregulated the expression of Ras and the downstream PI3K phosphorylation. Compared to MSC-EXs, MSC-EXs^miR-132-3p were more effective in decreasing ROS production, apoptosis, and tight junction disruption in H/R-injured ECs. These effects were associated with increased levels of phosphorylated Akt and eNOS, which could be abolished by PI3K inhibitor (LY294002) or Ras inhibitor (NSC 23766). In the tMCAO mouse model, the infusion of MSC-EXs^miR-132-3p was more effective than MSC-EXs in reducing cerebral vascular ROS production, BBB dysfunction, and brain injury.

Conclusion

Our results suggest that miR-132-3p promotes the beneficial effects of MSC-EXs on brain ischemic injury through protecting cerebral EC functions.

Biocompatibility of Bone Marrow-Derived Mesenchymal Stem Cells in the Rat Inner Ear following Trans-Tympanic Administration

Recent advancements in stem cell therapy have led to an increased interest within the auditory community in exploring the potential of mesenchymal stem cells (MSCs) in the treatment of inner ear disorders. However, the biocompatibility of MSCs with the inner ear, especially when delivered non-surgically and in the immunocompetent cochlea, is not completely understood. In this study, we determined the effect of intratympanic administration of rodent bone marrow MSCs (BM-MSCs) on the inner ear in an immunocompetent rat model. The administration of MSCs did not lead to the generation of any oxidative stress in the rat inner ear. There was no significant production of proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-12, due to BM-MSCs administration into the rat cochlea. BM-MSCs do not activate caspase 3 pathway, which plays a central role in sensory cell damage. Additionally, transferase dUTP nick end labeling (TUNEL) staining determined that there was no significant cell death associated with the administration of BM-MSCs. The results of the present study suggest that trans-tympanic administration of BM-MSCs does not result in oxidative stress or inflammatory response in the immunocompetent rat cochlea.

Mesenchymal Stem Cells for Chronic Wound Healing: Current Status of Preclinical and Clinical Studies

Healing skin wounds with anatomic and functional integrity, especially under chronic pathological conditions, remain an enormous challenge. Due to their outstanding regenerative potential, mesenchymal stem cells (MSCs) have been explored in many studies to determine the healing ability for difficult-to-treat diseases. In this article, we review current animal studies and clinical trials of MSC-based therapy for chronic wounds, and discuss major challenges that confront future clinical applications. We found that a wealth of animal studies have revealed the versatile roles and the benefits of MSCs for chronic wound healing. MSC treatment results in enhanced angiogenesis, facilitated reepithelialization, improved granulation, and accelerated wound closure. There are some evidences of the transdifferentiation of MSCs into skin cells. However, the healing effect of MSCs depends primarily on their paracrine actions, which alleviate the harsh microenvironment of chronic wounds and regulate local cellular responses. Consistent with the findings of preclinical studies, some clinical trials have shown improved wound healing after transplantation of MSCs in chronic wounds, mainly lower extremity ulcers, pressure sores, and radiation burns. However, there are some limitations in these clinical trials, especially a small number of patients and imperfect methodology. Therefore, to better define the safety and efficiency of MSC-based wound therapy, large-scale controlled multicenter trials are needed in the future. In addition, to build a robust pool of clinical evidence, standardized protocols, especially the cultivation and quality control of MSCs, are recommended. Altogether, based on current data, MSC-based therapy represents a promising treatment option for chronic wounds. Impact statement Chronic wounds persist as a significant health care problem, particularly with increasing number of patients and the lack of efficient treatments. The main goal of this article is to provide an overview of current status of mesenchymal stem cell (MSC)-based therapy for chronic wounds. The roles of MSCs in skin wound healing, as revealed in a large number of animal studies, are detailed. A critical view is made on the clinical application of MSCs for lower extremity ulcers, pressure sores, and radiation burns. Main challenges that confront future clinical applications are discussed, which hopefully contribute to innovations in MSC-based wound treatment.

Safety of Human Adipose Stromal Vascular Fraction Cells Isolated with a Closed System Device in an Immunocompetent Murine Pressure Ulcer Model

Pressure ulcers (PUs) result in part due to ischemia-reperfusion injury to the skin and present frequently in elderly or quadriplegic patients with reduced mobility. Despite the high economic and societal cost of this condition, PU therapy relies primarily on preventive strategies and invasive surgical intervention. A growing body of clinical literature suggests that localized injection of adipose-derived cells can accelerate and enhance the closure of PUs. The current study systematically evaluated the safety of human adipose stromal vascular fraction (SVF) cells isolated using a closed system device when injected into a murine PU injury model. The human SVF cells were characterized by colony-forming unit-fibroblast and differentiation assays before use. Young (2 months) immunocompetent C57BL/6 mice subjected to a magnet-induced ischemia-reperfusion injury were injected subcutaneously with human SVF cells at increasing doses (0.25-2 million cells). The size of the PU was monitored over a 20-day period. Both female and male mice tolerated the concentration-dependent injection of the SVF cells without complications. While male mice trended toward more rapid wound closure rates in response to lower SVF cell concentrations (0.25-0.5 million cells), female mice responded favorably to higher SVF cell concentrations (1-2 million cells); however, outcomes did not reach statistical significance in either sex. Overall, the study demonstrates that human SVF cells prepared with a closed system device designed for use at point of care can be safely administered for PU therapy in an immunocompetent host animal model.

Safety and Efficacy of Human Adipose-Derived Stromal/Stem Cell Therapy in an Immunocompetent Murine Pressure Ulcer Model

Pressure injuries/ulcers are frequent complications in elderly, paraplegic, and quadriplegic patients, which account for considerable cost to the international health care economy and remain refractory to current treatment options. Autologous or allogeneic adult stromal/stem cells represent an alternative therapeutic approach. The current study extends prior findings by exploring the safety and efficacy of human adipose-derived stromal/stem cell (ASC) therapy in an established immunocompetent murine skin pressure ulcer model where dermal fibroblast cells (DFCs) served as a control. Human adipose tissue was processed using a closed system device designed for point-of-care use in the operating room and on file with the Food and Drug Administration. Cell characterization was performed using colony-forming unit-fibroblast, differentiation, and immunophenotypic assays in vitro. Wound healing was assessed over a 20-day period based on photomicrographs, histology, and immunohistochemistry. The isolated human ASCs displayed significantly greater colony formation relative to DFCs while both populations exhibited comparable immunophenotype and differentiation potential. Both fresh and cryopreserved human ASCs significantly accelerated and enhanced wound healing in young (2 month) mice of both sexes relative to DFC controls based on tissue architecture and CD68⁺ cell infiltration. In contrast, while injection of either fresh or cryopreserved human ASCs was safe in older mice, the fresh ASCs significantly enhanced wound closure relative to the cryopreserved ASCs. Overall, these findings support the safety and efficacy of human ASCs isolated using a closed system device designed for clinical procedures in the future treatment of pressure injuries.

Apelin/APJ signaling suppresses the pressure ulcer formation in cutaneous ischemia-reperfusion injury mouse model

Several studies have demonstrated potential roles for apelin/APJ signaling in the regulation of oxidative stress associated with ischemia-reperfusion (I/R) injury in several organs. Objective was to assess the role of apelin/APJ signaling in the development of pressure ulcers (PUs) formation after cutaneous I/R injury in mice. We identified that cutaneous I/R injury increased the expression of apelin in the skin at I/R site. Administration of apelin significantly inhibited the formation of PUs. The reductions of blood vessels, hypoxic area and apoptosis in I/R site were inhibited by apelin injection. Oxidative stress signals in OKD48 mice and the expressions of oxidative stress related genes in the skin were suppressed by apelin injection. H₂O₂-induced intracellular ROS and apoptosis in endothelial cells and fibroblasts were suppressed by apelin in vitro. Furthermore, MM07, biased agonist of APJ, also significantly suppressed the development of PUs after cutaneous I/R, and the inhibitory effect of MM07 on PUs formation was higher than that in apelin. We conclude that apelin/APJ signaling may inhibit cutaneous I/R injury-induced PUs formation by protecting the reduction of vascularity and tissue damage via suppression of oxidative stress. Exogenous application of apelin or MM07 might have therapeutic potentials against the development of PUs.

Synergistic Effects of Human Platelet-Rich Plasma Combined with Adipose-Derived Stem Cells on Healing in a Mouse Pressure Injury Model

Pressure injury (PI) affects quality of life and results in economic and social burdens. Local transplantation of human adipose-derived stem cells (ASCs) is considered an effective treatment. However, ASC suspension alone is vulnerable to the immune system and results in a shortened cell survival. There is increasing evidence of a synergistic effect of platelet-rich plasma (PRP) combined with ASCs on wound healing. This study investigated the effectiveness, synergy, and mechanism of wound healing following local injection of PRP combined with ASCs in a rodent PI model. PRP or ASCs alone were the control intervention. Wound healing, inflammatory infiltration, collagen deposition, angiogenesis, neurogenesis, and cell homing were investigated. PI healing was promoted by the synergistic effects of PRP combined with ASCs. The combination was more effective than ASCs alone for modulating inflammation, increasing collagen deposition, angiogenesis, neurogenesis, and the persistence of the injected ASCs. These data provide a theoretical foundation for the clinical administration of ASCs combined with PRP in PI healing and skin regeneration.

The significance of tumor cells-derived MFG-E8 in tumor growth of angiosarcoma

BACKGROUND

Previous studies have indicated that MFG-E8 enhances tumor cell survival, invasion and angiogenesis. However, the role of MFG-E8 in angiosarcoma (AS) has not been clarified.

OBJECTIVE

Objective was to elucidate the mechanism of the regulation by MFG-E8 in AS and the association between MFG-E8 and clinicopathological features of AS.

METHODS

The effects of the depletion of MFG-E8 by siRNA on tube formation, migration and proliferation in murine AS cells were examined. The effect of administration of anti-MFG-E8 antibody (Ab) on tumor growth of AS in mice was examined. The associations of MFG-E8 expression and clinicopathological features of human AS were assessed.

RESULTS

The expressions of MFG-E8 in murine and human AS cells were significantly higher than those in melanoma cells, macrophages and endothelial cells. Depletion of MFG-E8 in murine AS cells by siRNA significantly inhibited the formation of capillary-like structures and migration, but not proliferation. Administration of anti-MFG-E8 Ab significantly inhibited tumor growth and decreased the number of tumor-associated macrophages (TAMs) in AS tumors. Tumor size and the number of TAMs in human AS with high expression of MFG-E8 were significantly increased compared to those of AS with low expression of MFG-E8. Progression-free survival and overall survival time of the patients of AS with high expression of MFG-E8 were significantly shorter than those of AS with low expression of MFG-E8.

CONCLUSIONS

AS-derived MFG-E8 might enhance tumor growth via angiogenesis and the induction of TAMs in autocrine/paracrine manner, and administration of anti-MFG-E8 Ab could be a therapeutic potential for AS.

Zinc deficiency exacerbates pressure ulcers by increasing oxidative stress and ATP in the skin

BACKGROUND

Zinc deficiency is believed to be a predisposing factor for the development and intractable healing of pressure ulcers (PUs); however, the mechanisms of this association have not been elucidated.

OBJECTIVE

Objective was to elucidate the mechanisms of the formation of severe and prolonged PUs under the zinc deficiency condition.

METHODS

We assessed PUs formation after cutaneous ischemia-reperfusion (I/R) injury in mice fed with a zinc-adequate (ZA) or a zinc-deficient (ZD) diet from 2 weeks before I/R injury. Wound size, vascular damage, apoptotic cells, adenosine triphosphate (ATP) amount, and the number of Langerhans cells (LCs) in I/R area were analyzed. We evaluated the extent of oxidative stress in I/R area in OKD48 mice through bioluminescence detection.

RESULTS

We found that dietary zinc deficiency caused the formation of severe and prolonged PUs in mice. Zinc deficiency increased the vascular disorder, oxidative stress, and apoptosis induced by cutaneous I/R injury. I/R injury-induced oxidative stress signals were significantly higher in ZD OKD48 mice than in ZA OKD48 mice. Additionally, zinc deficiency reduced the number of LCs and increased the amount of ATP in cutaneous I/R-injured skin. Oral supplementation of zinc improved zinc deficiency-associated PUs.

CONCLUSION

Zinc deficiency might increase cutaneous I/R injury-induced vascular damages, oxidative stress, and apoptosis, as well as ATP amount in I/R area due to the loss of LCs. These mechanisms might partly account for zinc deficiency-induced formation of severe and prolonged PUs. Oral supplementation of zinc might be a reasonable therapeutic choice for patients with PUs and zinc deficiency.

Ulinastatin inhibits apoptosis induced by serum deprivation in mesenchymal stem cells

Mesenchymal stem cells (MSCs) have exhibited great potential in the therapy of cardiovascular disease. However, the application of MSCs is hampered by apoptosis, which reduces the number of cells in the host cardiac microenvironment. Ulinastatin (UTI), a broad‑spectrum protease inhibitor that can be purified from human urine, has attracted attention for its protective effects through its immunomodulatory and anti‑inflammatory properties. The present study aimed to evaluate the effects of UTI on serum deprivation‑induced apoptosis of MSCs and investigate its molecular mechanisms. Cell viability was determined by the MTT assay. Apoptosis was assessed by flow cytometric analysis with Annexin V/propidium iodide staining. The protein levels of cleaved caspase‑3, B‑cell lymphoma‑2 (Bcl‑2) family proteins, total‑Akt and phospho‑Akt were evaluated by western blot. The results of the present study demonstrated that UTI exhibited a protective effect in serum deprived MSCs, as indicated by increased cell viability, and a reduction in the rate of apoptosis and caspase‑3 activation. In addition, treatment with UTI significantly decreased the expression levels of Bcl‑2, Bcl‑extra large and Bcl‑associated X protein. Furthermore, activation of the Akt signaling pathway was involved in the UTI‑induced anti‑apoptotic effects. The present findings indicated that UTI is able to promote the survival of MSCs under serum deprivation conditions. The present study may be helpful in improving the therapeutic efficacy of MSC transplantation used to cure chronic ischemic heart disease.

A Novel, Sterilized Microvascular Tissue Product Improves Healing in a Murine Pressure Ulcer Model

Background:

Processed microvascular tissue (PMVT), a human structural allograft, is derived from lyophilized human tissue containing microcirculatory cellular components. Since PMVT serves as a source of extracellular matrix (ECM), growth factors, cytokines, and chemokines modulating angiogenesis, inflammation, apoptosis, and endogenous cell recruitment, we hypothesized its application would accelerate wound regeneration in a validated pressure ulcer (PU) model developed in C57BL/6 mice using two 24-hour cycles of skin ischemia/reperfusion created by placement and removal of external magnets.

Methods:

Two identical PU injuries (n = 50 female mice) were treated with (a) topical particulate PMVT, (b) injected rehydrated PMVT, or (c) saline control injection, and assessed daily for closure rates, scab formation/removal, and temperature. A baseline control cohort (n = 5) was euthanized at day 0 and treatment group cohorts (n = 5) were killed at 3, 7, or 14 days postinjury. The PU injuries were collagenase-digested for flow cytometric analysis of inflammatory, reparative, and stem cell frequencies and analyzed by hematoxylin and eosin (H&E) histology and immunofluorescence.

Results:

PMVT-accelerated wound closure, most notably, topical PMVT significantly increased mean closure from d5 (13% versus -9%) through d13 (92% versus 38%) compared with phosphate-buffered saline (PBS) controls (P < 0.05). PMVT also hastened scab formation/removal, significantly accelerated disappearance of inflammatory myeloid (CD11b+) cells while upregulating α-smooth muscle actin, vascular endothelial growth factor A, and placental growth factor and raised skin temperature surrounding the PU site, consistent with increased blood flow.

Conclusions:

These results indicate that PMVT has potential as an advanced treatment for restoring normal tissue function in ischemic wounds and merits clinical study.

Mesenchymal Stem Cells Shift Mitochondrial Dynamics and Enhance Oxidative Phosphorylation in Recipient Cells

Mesenchymal stem cells (MSCs) are the most commonly used cells in tissue engineering and regenerative medicine. MSCs can promote host tissue repair through several different mechanisms including donor cell engraftment, release of cell signaling factors, and the transfer of healthy organelles to the host. In the present study, we examine the specific impacts of MSCs on mitochondrial morphology and function in host tissues. Employing in vitro cell culture of inherited mitochondrial disease and an in vivo animal experimental model of low-grade inflammation (high fat feeding), we show human-derived MSCs to alter mitochondrial function. MSC co-culture with skin fibroblasts from mitochondrial disease patients rescued aberrant mitochondrial morphology from a fission state to a more fused appearance indicating an effect of MSC co-culture on host cell mitochondrial network formation. In vivo experiments confirmed mitochondrial abundance and mitochondrial oxygen consumption rates were elevated in host tissues following MSC treatment. Furthermore, microarray profiling identified 226 genes with differential expression in the liver of animals treated with MSC, with cellular signaling, and actin cytoskeleton regulation as key upregulated processes. Collectively, our data indicate that MSC therapy rescues impaired mitochondrial morphology, enhances host metabolic capacity, and induces widespread host gene shifting. These results highlight the potential of MSCs to modulate mitochondria in both inherited and pathological disease states.

Connexin 43-Mediated Mitochondrial Transfer of iPSC-MSCs Alleviates Asthma Inflammation

We previously identified an immunomodulatory role of human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (MSCs) in asthmatic inflammation. Mitochondrial transfer from bone marrow MSCs to epithelial cells can result in the attenuation of acute lung injury in mice. However, the effects of mitochondrial transfer from iPSC-MSCs to epithelial cells in asthma and the mechanisms underlying these effects are unclear. We found that iPSC-MSC transplantation significantly reduced T helper 2 cytokines, attenuated the mitochondrial dysfunction of epithelial cells, and alleviated asthma inflammation in mice. Tunneling nanotubes (TNTs) were formed between iPSC-MSCs and epithelial cells, and mitochondrial transfer from iPSC-MSCs to epithelial cells via TNTs was observed both in vitro and in mice. Overexpression or silencing of connexin 43 (CX43) in iPSC-MSCs demonstrated that CX43 plays a critical role in the regulation of TNT formation by mediating mitochondrial transfer between iPSC-MSCs and epithelial cells. This study provides a therapeutic strategy for targeting asthma inflammation.

Apoptosis of bone marrow mesenchymal stromal/stem cells via the MAPK and endoplasmic reticulum stress signaling pathways

Therapy for myocardial regeneration using bone marrow stromal cells (BM-MSCs) has been applied to improve the cardiac function of subjects with acute myocardial infarction. However, the study of this therapy has encountered a bottleneck because BM-MSCs are prone to apoptosis in ischemic and anoxic environments. The goal of this study was to investigate the expression of mitogen activated protein kinase (MAPK) (p-38, JNK and ERK) and endoplasmic reticulum stress protein (caspase-12 and CHOP) during BM-MSC apoptosis. In a BM-MSC model of hypoxia and serum deprivation (H/SD), we observed the morphology and apoptotic rate of BM-MSCs for 24 h and found that the nuclear shrinkage and apoptosis rate increased gradually and reached a maximum apoptosis rate at the 6 h time point. Then, with the prolongation of the hypoxia time, the number of nuclear shrinkage cells and the apoptosis rate gradually decreased. The expression levels of p-38, JNK, ERK, procaspase-12, caspase-12 and CHOP increased at each H/SD time point. In addition, compared with the H/SD 6 h group, the nuclear shrinkage and apoptosis rate were decreased in the SB202190 and SP600125 groups but increased in the PD98059 group. Further, the expression of caspase-12 in the SB202190 group decreased, while the expression of procaspase-12 increased, compared with the H/SD 6 h group. Overall, our findings suggested that p-38, JNK, CHOP and caspase-12 play important roles in promoting the apoptosis of BM-MSCs, while ERK is contrary to other signals. Moreover, the apoptosis of BM-MSCs was induced by H/SD via the p-38-caspase-12 signaling pathway.

[Effect of human adipose-derived stem cells on pressure ulcer healing in mouse]

Objective

To investigate the effect of human adipose-derived stem cells (hADSCs) on pressure ulcers in mouse.

Methods

The subcutaneous adipose tissue from voluntary donation was harvested. Then the hADSCs were isolated and cultured by mechanical isolation combined with typeⅠcollagenase digestion. The 3rd generation cells were identified by osteogenic, adipogenic, chondrogenic differentiations and flow cytometry. The platelet rich plasma (PRP) from peripheral blood donated by healthy volunteers was prepared by centrifugation. The pressure ulcer model was established in 45 C57BL/6 mice by two magnets pressurized the back skin, and randomly divided into 3 groups ( n=15). The wounds were injected with 100 μL of hADSCs (1×10 ⁶ cells) transfected with a green fluorescent protein (GFP)-carrying virus, 100 μL human PRP, and 100 μL PBS in hADSCs group, PRP group, and control group, respectively. The wound healing was observed after injection. The wound healing rate was calculated on the 5th, 9th, and 13th days. On the 5th, 11th, and 21st day, the specimens were stained with HE staing, Masson staining, and CD31 and S100 immunohistochemical staining to observe the vascular and nerve regeneration of the wound. In hADSCs group, fluorescence tracer method was used to observe the colonization and survival of the cells on the 11th day.

Results

The cultured cells were identified as hADSCs by induced differentiation and flow cytometry. The platelet counting was significantly higher in PRP group than in normal peripheral blood group ( t=5.781, P=0.029). General observation showed that the wound healing in hADSCs group was superior to those in PRP group and control group after injection. On the 5th, 9th, and 13th days, the wound healing rate in hADSCs group was significantly higher than those in PRP group and control group ( P<0.05). Histological observation showed that compared with PRP group and control group, inflammatory cell infiltration and inflammatory reaction were significantly reduced in hADSCs group, collagen deposition was significantly increased, and skin appendage regeneration was seen on the 21st day; at each time point, the expression of collagen was significantly higher in hADSCs group than in PRP group and control group ( P<0.05). Immunohistochemical staining showed that the number of neovascularization and the percentage of S100-positive cells in hADSCs group were significantly better than those in PRP group and control group on the 5th, 9th, and 13th days ( P<0.05). Fluorescent tracer method showed that the hADSCs could colonize the wound and survive during 11 days after injection.

Conclusion

Local transplantation of hADSCs can accelerate healing of pressure ulcer wounds in mice and improve healing quality by promoting revascularization and nerve regeneration.

Gastroprotective and antioxidant effects of fluvoxamine on stress-induced peptic ulcer in rats

Objectives

Stress-induced peptic ulcer disease (SPUD) refers to erosions in the mucosa of the upper gastrointestinal tract that are caused by stress. Some antidepressants are reported to have antioxidant and antiulcer effects. However, histopathological and biochemical evaluation of the anti-ulcer activity of a comparable antidepressant, fluvoxamine, has not been adequately investigated. This study aims to determine the anti-ulcer efficacy of fluvoxamine in reducing stress-induced histopathological and biochemical changes in the gastric mucosa.

Methods

Thirty adult male albino rats were divided into three groups of 10 rats each: the control groups, the SPUD group, and the fluvoxamine-pre-treated group, which received fluvoxamine for eight days before stress exposure. The cold-restraint stress method was used to induce stomach ulcers in the SPUD and fluvoxamine groups. Afterward, the stomachs of rats were removed, opened, and ulcer indices were calculated. Light microscopy was performed following haematoxylin and eosin staining, periodic acid Schiff's, Masson's trichrome staining, and proliferating cell nuclear antigen immunostaining. Gastric tissue levels of oxidative stress markers were measured and compared among groups.

Results

The stomachs of the fluvoxamine-treated rats showed a significantly lower number of ulcers with minimal mucosal injury compared with those of rats from the SPUD group. The oxidative stress marker levels and SPUD ulcer indices were significantly different among groups.

Conclusion

Fluvoxamine pre-treatment exerted a gastroprotective effect against ulcer development and promoted healing of the developed lesions.