Identification of a distinct subpopulation of fibroblasts from murine dermis: CD73(-) CD105(+) as potential marker of dermal fibroblasts subset with multipotency

An optimized method for obtaining clinical-grade specific cell subpopulations from human umbilical cord-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) are heterogeneous populations with broad application prospects in cell therapy, and using specific subpopulations of MSCs can enhance their particular capability under certain conditions and achieve better therapeutic effects. However, no studies have reported how to obtain high‐quality specific MSC subpopulations in vitro culture. Here, for the first time, we established a general operation process for obtaining high‐quality clinical‐grade cell subpopulations from human umbilical cord MSCs (hUC‐MSCs) based on particular markers. We used the MSC‐CD106⁺ subpopulations, whose biological function has been well documented, as an example to explore and optimize the crucial links of primary preparation, pre‐treatment, antibody incubation, flow sorting, quality and function test. After comprehensively evaluating the quality and function of the acquired MSC‐CD106⁺ subpopulations, including in vitro cell viability, apoptosis, proliferation, marker stability, adhesion ability, migration ability, tubule formation ability, immunomodulatory function and in vivo wound healing ability and proangiogenic activity, we defined an important pre‐treatment scheme which might effectively improve the therapeutic efficiency of MSC‐CD106⁺ subpopulations in two critical clinical application scenarios—direct injection after cell sorting and post‐culture injection into bodies. Based on the above, we tried to establish a general five‐step operation procedure for acquiring high‐quality clinical‐grade MSC subpopulations based on specific markers, which cannot only improve their enrichment efficiency and the reliability of preclinical studies, but also provide valuable methodological guidance for the rapid clinical transformation of specific MSC subpopulations.

A Single-cell Transcriptome Atlas of Cashmere Goat Hair Follicle Morphogenesis

Cashmere, also known as soft gold, is produced from the secondary hair follicles (SHFs) of cashmere goats. The number of SHFs determines the yield and quality of cashmere; therefore, it is of interest to investigate the transcriptional profiles present during cashmere goat hair follicle development. However, mechanisms underlying this development process remain largely unexplored, and studies regarding hair follicle development mostly use a murine research model. In this study, to provide a comprehensive understanding of cellular heterogeneity and cell fate decisions, single-cell RNA sequencing was performed on 19,705 single cells of the dorsal skin from cashmere goat fetuses at induction (embryonic day 60; E60), organogenesis (E90), and cytodifferentiation (E120) stages. For the first time, unsupervised clustering analysis identified 16 cell clusters, and their corresponding cell types were also characterized. Based on lineage inference, a detailed molecular landscape was revealed along the dermal and epidermal cell lineage developmental pathways. Notably, our current data also confirmed the heterogeneity of dermal papillae from different hair follicle types, which was further validated by immunofluorescence analysis. The current study identifies different biomarkers during cashmere goat hair follicle development and has implications for cashmere goat breeding in the future.

Targeting AXL and RAGE to prevent geminin overexpression-induced triple-negative breast cancer metastasis

Dissemination of metastatic precursors from primaries is the primary reason for patient death. Dissemination encompasses tumor cells invasion of stroma, followed by intravasation through the endothelium barrier into the bloodstream. Here, we describe how geminin-overexpressing tumor cells acquire dissemination ability. Acetylated HMGB1 (Ac-HMGB1) secreted by geminin-overexpressing cells activates RAGE and CXCR4 expression on mesenchymal stem cells (MSCs) located in tumor stroma. Through secreting CXCL12, geminin-overexpressing cells recruit these CXCR4⁺-MSCs into the tumor. Within the tumor, MSCs differentiate into S100A4-secreting cancer-associated fibroblasts (CAFs). S100A4, in a reciprocal manner, activates geminin-overexpressing cells to secrete CCL2 that recruits M0-macrophages from the stroma into the tumor. Within the tumor, CCL2 polarizes M0-macrophages into Gas6-secreting M2-tumor-associated macrophages (M2-TAMs). In concert, geminin-overexpression, S100A4/RAGE and Gas6/AXL signaling promote the invasive and intravasation abilities in geminin-overexpressing cells through exacerbating their stemness and epithelial-to-mesenchymal phenotypes and enhancing expression and functional interaction of CD151 and α3β1-integrin in geminin-overexpressing cells. Tumors formed following injection of geminin-overexpressing cells admixed with MSCs/CAFs grew faster, metastasized earlier, especially to lungs, and were extremely sensitive to anti-c-Abl, anti-RAGE, and anti-AXL drugs. These data support an intrinsic ability in geminin-overexpressing tumor cells to promote their metastatic potential through recruitment and bi-directional interactions with MSCs/CAFs and M2-TAMs.

Utilizing Human Dermal Fibroblast Heterogeneity in Autologous Dermal Fibroblast Therapy: An Overcomplicated Strategy or a Promising Approach?

Although human dermal fibroblast heterogeneity has been acknowledged for several decades and a large body of in vitro studies has been performed with zonal dermal fibroblast, current autologous dermal fibroblast therapies do not reflect human dermal fibroblast heterogeneity. To determine if the utilization of human dermal fibroblast heterogeneity in autologous dermal fibroblast therapy is more of a translational perspective that may thus be more likely to make it to the clinic, this article critically reviews the previous studies on dermal fibroblast heterogeneity performed to date. We found that in vitro studies of human dermal fibroblast heterogeneity have run nearly parallel to the in vivo study of autologous dermal fibroblast therapy. Although several human to nude mice xenotransplantation experiments have been performed in different layers of human dermal fibroblast, their clinical significance remains to be considered. We conclude that there is still a great gap between basic experiments and the clinical employment of human dermal fibroblast heterogeneity. To overcome this, it is necessary to conduct clinical trials, which might be restricted by ethical issues. Alternatively, it might be easier to conduct in vivo studies in animal models. Based on our previous study of dermal fibroblast heterogeneity in pigs, we propose the use of pigs as a good animal model for dermal fibroblast heterogeneity. Time will show whether the utilization of human dermal fibroblast heterogeneity in autologous dermal fibroblast therapy is an overcomplicated strategy or a promising approach. Anat Rec, 302:2126-2131, 2019. © 2019 American Association for Anatomy.

Effects of silymarin on p65 NF-κB, p38 MAPK and CYP450 in LPS-induced hoof dermal inflammatory cells of dairy cows

Background

Laminitis is considered as one of the most important causes of hoof lameness in dairy cows, which can lead to enormous economic losses. However, the etiology and pathogenesis of laminitis have not been clarified yet. Besides, it is of great significant to find alternative herbs for the prevention and treatment of dairy hooves to avoid the antibiotic abuse. In this study, the primary hoof dermal cells of dairy cows were isolated, the inflammatory model was induced by LPS, and treated with silymarin to find whether silymarin has protective effect on the inflammatory dermal cells. The viability of dermal cells, the levels of IL-1β and TNF-α, the degree of p65 NF-κB and p38 MAPK phosphorylation, the expressions of CYP3A4 and CYP1A1 were measured.

Results

Hoof dermal cells of dairy cows were successfully isolated and cultured by tissue adherent culture method. Certain concentrations of LPS can increase the levels of IL-1β and TNF-α, promote the phosphorylation of p65 NF-κB and p38 MAPK, and inhibit the mRNA expressions of CYP3A4 and CYP1A1. The optimal concentration for LPS to establish a hoof dermal cells inflammatory model was 10 μg/mL. Certain concentrations of silymarin can markedly decrease the secretions of IL-1β and TNF-α, inhibit the phosphorylation of p65 NF-κB and p38 MAPK, and promote the mRNA expressions of CYP3A4 and CYP1A1 in LPS-induced dermal inflammatory model.

Conclusions

LPS can be used for inducing the hoof dermal cells inflammatory model of dairy cows. Silymarin has protective effects on the LPS-induced inflammatory model.

Bone morphogenetic protein 7 enhances the osteogenic differentiation of human dermal-derived CD105+ fibroblast cells through the Smad and MAPK pathways

The skin, as the largest organ of the human body, is an important source of stromal stem cells with multipotent differentiation potential. CD105⁺ mesenchymal stem cells exhibit a higher level of stemness than CD105⁻ cells. In the present study, human dermal-derived CD105⁺ fibroblast cells (CD105⁺ hDDFCs) were isolated from human foreskin specimens using immunomagnetic isolation methods to examine the role of bone morphogenetic protein (BMP)-7 in osteogenic differentiation. Adenovirus-mediated recombinant BMP7 expression enhanced osteogenesis-associated gene expression, calcium deposition, and alkaline phosphatase activity. Investigation of the underlying mechanisms showed that BMP7 activated small mothers against decapentaplegic (Smad) and p38/mitogen-activated protein kinase signaling in CD105⁺ hDDFCs. The small interfering RNA-mediated knockdown of Smad4 or inhibition of p38 attenuated the BMP7-induced enhancement of osteogenic differentiation. In an in vivo ectopic bone formation model, the adenovirus-mediated overexpression of BMP7 enhanced bone formation from CD105⁺ hDDFCs. Taken together, these data indicated that adenoviral BMP7 gene transfer in CD105⁺ hDDFCs may be developed as an effective tool for bone tissue engineering.

Insight into skin cell-based osteogenesis: a review

For decades, researchers have been fascinated by the strategy of using cell therapy for bone defects; some progress in the field has been made. Owing to its ample supply and easy access, skin, the largest organ in the body, has gained attention as a potential source of stem cells. Despite extensive applications in skin and nerve regeneration, an increasing number of reports indicate its potential use in bone tissue engineering and regeneration. Unfortunately, few review articles are available to outline current research efforts in skin-based osteogenesis. This review first summarizes the latest findings on stem cells or progenitors in skin and their niches and then discusses the strategies of skin cell-based osteogenesis. We hope this article elucidates this topic and generates new ideas for future studies.

PPARβ/δ: A master regulator of mesenchymal stem cell functions

Peroxisome proliferator-activated receptors (PPARs) have emerged as key regulators of physiological and immunological processes. Recently, one of their members PPARβ/δ has been identified as major player in the maintenance of bone homeostasis, by promoting Wnt signalling activity in osteoblast and mesenchymal stem cells (MSC). PPARβ/δ not only controls the fate of MSC but also regulates their immunosuppressive properties by directly modulating their NF-κB activity. In this review, we discuss how the regulation of PPARβ/δ provides an innovative strategy for an optimisation of MSC-based therapy.