The conditioned medium from mesenchymal stromal cells pretreated with proinflammatory cytokines promote fibroblasts migration and activation

Mapping the causal associations of cytokines with sarcopenia and aging traits: Evidence from bidirectional Mendelian randomization

BACKGROUND

Cytokines and growth factors may serve as a bridge in studying the causal relationships between inflammaging and sarcopenia due to their roles in inflammaging. In this study, we aim to explore the causal association of cytokines with sarcopenia and aging traits and further identify the significant inflammation factors.

METHODS

Bidirectional Mendelian randomization (MR) analysis was used to identify the causality. Forty-one kinds of circulation cytokines and growth factors were set as exposures, and the data were from a summary genome-wide association study (GWAS) containing three cohorts with 8293 healthy participants of European ancestry from 1983 to 2011. Hand grip strength, adjusted appendicular lean mass (AALM), usual walking pace, moderate-to-vigorous physical activity (MVPA) levels, able to walk or cycle unaided for 10 min (AWCU10) and telomere length were selected as outcomes. Data for outcomes were obtained from meta-GWAS and the UK Biobank, and sample sizes ranged from 69 537 to 472 174. Low hand grip strength was defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and Foundation for the National Institutes of Health (FNIH) cut-off points, respectively. Other outcome traits were defined and measured according to the UK Biobank and raw cohorts' criteria. We set two significance thresholds for single nucleotide polymorphisms (SNPs) associated with exposures to obtain adequate SNPs (5 × 10-6 and 5 × 10-8). Inverse-variance weighted, MR-Egger and weighted median were employed to estimate the causality.

RESULTS

Twenty-seven factors were identified to relate to sarcopenia and aging traits causally, and most were associated with only one outcome trait. IL16 (interleukin-16), CTACK (cutaneous T-cell attracting chemokine), MIP1b (macrophage inflammatory protein 1b) and PDGFbb (platelet-derived growth factor BB) were proven to relate causally to at least one sarcopenia and aging trait in both analyses with two significance thresholds. IL16 was causally associated with hand grip strength (0.977 [0.956-0.998] for EWGSOP and 0.933 [0.874-0.996] for FNIH), AALM (0.991 [0.984, 0.998]), MVPA (0.997 [0.995-1.000]) and AWCU10 (1.008 [1.003-1.013]). CTACK was proven to relate causally to hand grip strength (1.013 [1.007-1.019] for EWGSOP and 1.090 [1.041-1.142] for FNIH), AWCU10 (0.990 [0.986-0.994]) and telomere length (0.998 [0.983-0.994]). The results indicated that MIP1b has a causal effect on hand grip strength (1.032 [1.001-1.063] for EWGSOP), AWCU10 (0.994 [0.988-1.000] and 0.993 [0.988-0.998]) and telomere length (1.006 [1.000-1.012]). PDGFbb may causally relate to AALM (1.016 [1.001-1.030]) and telomere length (1.011 [1.007-1.015]). Reserve MR analyses also proved their unidirectional causal effects.

CONCLUSIONS

Twenty-seven factors were causally related to sarcopenia and aging traits, and the causal effects of IL16, CTACK, MIP1b and PDGFbb were proven in both analyses with two significance thresholds.

Attachment and proliferation of human gingival fibroblasts seeded on barrier membranes using Wharton's jelly-derived stem cells conditioned medium: An in vitro study

The effect of Wharton's jelly mesenchymal stem cells conditioned medium (WJMSCs-CM) and zinc oxide nanoparticles (ZnO-NPs) on cultured human gingival fibroblasts on various barrier membranes was investigated in this study. In this study, human gingival fibroblasts were prepared and cultured on three membranes: collagen membrane, acellular dermal matrix (ADM) with ZnO-NPs, and ADM without ZnO-NPs. WJMSCs-CM was given to the testing groups, while control groups received the same membranes without WJMSCs-CM. Following 48 and 72 h, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were performed to assess cell survival. Cell proliferation on the membranes was also evaluated using 4',6-diamidino-2-phenylindole (DAPI) staining after 48 and 72 h. Field emission scanning electron microscopy was used to determine membrane surface structure and cell adhesion. Nanoparticles were also subjected to an energy-dispersive x-ray analysis to identify their chemical structure. Two-way analysis of variance was used to conduct the statistical analysis. The p-value ≤.05 was considered significant. When ADM-ZnO-NPs were combined with CM, fibroblast viability, and adhesion significantly differed from ADM-ZnO-NPs alone. DAPI results confirmed cell proliferation in all six groups on both experiment days. The abundance and concentrated distribution of cells during cell proliferation were found in CM-containing membranes, specifically the ADM-ZnO-NPs membrane, demonstrating the improved biocompatibility of the ADM-ZnO-NPs membrane for cell proliferation. The other groups did not significantly differ from one another. WJMSCs-CM positively affected the viability and proliferation of gingival fibroblasts, but only marginally. Under certain conditions, ZnO-NPs below a specific concentration increased the biocompatibility of the membranes.

Apoptotic effects of mesenchymal stem cells' conditioned medium on colorectal cancer cell lines

Multipotent Mesenchymal stem cells (MSCs) have vigorous immunomodulatory activity, apoptotic effects, and the capacity to migrate to inflammatory and tumor sites. This study focuses on the apoptotic effects of MSCs conditioned medium (CM) on colorectal cancer cell lines. MSCs were preconditioned with lipopolysaccharide (LPS) to induce apoptosis in colorectal cancer cells. The conditioned medium (LPS-CM) from the preconditioned cells was isolated and used to treat colorectal cancer cells (HT29 and SW48). The survival and proliferation of cancer cells were assessed using Trypan blue staining and MTT assay. The apoptosis rate was evaluated through flow cytometry analysis and caspase-3 activity. Additionally, Real-Time PCR was used to measure the mRNA level of apoptotic and anti-apoptotic factors, including bcl2, bax, and p53 genes. The results showed that LPS-CM significantly increased (p < 0.001) the percentage of apoptosis in the SW48 and HT29 cell lines. Caspase-3 activity significantly increased (p < 0.001) in these cell lines after treatment with LPS-CM. The mRNA level of bcl2 was significantly decreased (p < 0.001), while bax and p53 genes were significantly overexpressed (p < 0.001) in the LPS-CM treated cell lines. Notably, the mRNA level of bcl2 and bax genes was significantly altered at a higher concentration of LPS-CM. In conclusion, the conditioned medium from LPS-preconditioned MSCs can effectively induce apoptosis in colorectal cancer cells. This finding suggests that LPS-CM could be a potential strategy for inhibiting the proliferation and progression of colorectal cancer cells.

Application of hypoxia-mesenchymal stem cells in treatment of anaerobic bacterial wound infection: wound healing and infection recovery

Mesenchymal stromal cells, commonly referred to as MSCs, are a type of multipotent stem cells that are typically extracted from adipose tissue and bone marrow. In the field of tissue engineering and regenerative medicine, MSCs and their exosomes have emerged as revolutionary tools. Researchers are now devoting greater attention to MSCs because of their ability to generate skin cells like fibroblasts and keratinocytes, as well as their distinctive potential to decrease inflammation and emit pro-angiogenic molecules at the site of wounds. More recent investigations revealed that MSCs can exert numerous direct and indirect antimicrobial effects that are immunologically mediated. Collectively, these antimicrobial properties can remove bacterial infections when the MSCs are delivered in a therapeutic setting. Regardless of the positive therapeutic potential of MSCs for a multitude of conditions, transplanted MSC cell retention continues to be a major challenge. Since MSCs are typically administered into naturally hypoxic tissues, understanding the impact of hypoxia on the functioning of MSCs is crucial. Hypoxia has been postulated to be among the factors determining the differentiation of MSCs, resulting in the production of inflammatory cytokines throughout the process of tissue regeneration and wound repair. This has opened new horizons in developing MSC-based systems as a potent therapeutic tool in oxygen-deprived regions, including anaerobic wound infection sites. This review sheds light on the role of hypoxia-MSCs in the treatment of anaerobic bacterial wound infection in terms of both their regenerative and antimicrobial activities.

Impact of Canine Amniotic Mesenchymal Stem Cell Conditioned Media on the Wound Healing Process: In Vitro and In Vivo Study

The aim of this study was to provide a beneficial treatment effect of mesenchymal stem cell products derived from the canine amniotic membrane (AM-MSC) on the complicated wound healing process in dogs. AM-MSCs were characterized in terms of morphology, phenotypic profile, and multilineage differentiation potential. The in vitro study of the effect of canine amniotic mesenchymal stem cell conditioned media (AMMSC-CM) on a primary skin fibroblast cell culture scratch assay showed a decrease in the measured scratch area of about 66.39% against the negative control (Dulbecco's Modified Eagle's Medium-32.55%) and the positive control (Dulbecco's Modified Eagle's Medium supplemented with FGF2, N2, B27, and EGF-82.077%) after 72 h treatment. In the experimental study, seven dogs with complicated nonhealing wounds were treated with a combination of antibiotics, NSAIDs, and local AMMSC-CM application. After 15 days of therapy, we observed a 98.47% reduction in the wound surface area as opposed to 57.135% in the control group treated by conventional therapy based on debridement of necrotic tissue, antibiotic therapy, pain management, and change of wound dressing.

In vivo and in vitro studies of a propolis-enriched silk fibroin-gelatin composite nanofiber wound dressing

In this study, electrospun nanofibers (NFs) used in trauma dressings were prepared using silk fibroin (SF) and gelatin (GT) as materials and highly volatile formic acid as the solvent, with three different concentrations of propolis extracts (EP), which were loaded through a simple process. The resulting samples were characterized by surface morphology, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), contact angle meter, water absorption, degradation rate, and mechanical property tests. The incorporation of propolis improved its antibacterial properties against Escherichia coli, and Staphylococcus aureus, compared to those of the silk gelatin nanofiber material (SF/GT) alone. In vitro biocompatibility assays showed that SF/GT-1%EP had good cytocompatibility and hemocompatibility. In addition, it can also significantly promote the migration of L929 cells. SF/GT-1%EP was applied to a mouse model of full thickness skin defects, and it was found to significantly promote wound healing. These results indicate that the SF/GT-EP nanofiber material has good biocompatibility, migrating-promoting capability, antibacterial properties, and healing-promoting ability, providing a new idea for the treatment of full thickness skin defects.

Role of fibroblast plasticity and heterogeneity in modulating angiogenesis and healing in the diabetic foot ulcer

Chronic diabetic foot ulcers (DFUs) are an important clinical issue faced by clinicians despite the advanced treatment strategies consisting of wound debridement, off-loading, medication, wound dressings, and keeping the ulcer clean. Non-healing DFUs are associated with the risk of amputation, increased morbidity and mortality, and economic stress. Neo-angiogenesis and granulation tissue formation are necessary for physiological DFU healing and acute inflammation play a key role in healing. However, chronic inflammation in association with diabetic complications holds the ulcer in the inflammatory phase without progressing to the resolution phase contributing to non-healing. Fibroblasts acquiring myofibroblasts phenotype contribute to granulation tissue formation and angiogenesis. However, recent studies suggest the presence of five subtypes of fibroblast population and of changing density in non-healing DFUs. Further, the association of fibroblast plasticity and heterogeneity with wound healing suggests that the switch in fibroblast phenotype may affect wound healing. The fibroblast phenotype shift and altered function may be due to the presence of chronic inflammation or a diabetic wound microenvironment. This review focuses on the role of fibroblast plasticity and heterogeneity, the effect of hyperglycemia and inflammatory cytokines on fibroblasts, and the interaction of fibroblasts with other cells in diabetic wound microenvironment in the perspective of DFU healing. Next, we summarize secretory, angiogenic, and angiostatic phenotypes of fibroblast which have been discussed in other organ systems but not in relation to DFUs followed by the perspective on the role of their phenotypes in promoting angiogenesis in DFUs.