A novel long non-coding RNA SLNCR1 promotes proliferation, migration, and invasion of melanoma via transcriptionally regulating SOX5.

Steroid receptor RNA activator (SRA)-like non-coding RNA (SLNCR1) has been implicated in various tumorigenic processes, but the precise regulatory role in melanoma progression remains uncertain. We performed a comprehensive analysis to investigate the prognostic value of SLNCR1 expression in patients with melanoma by TCGA database and melanoma tissue samples via the Kaplan-Meier method. Subsequently, we conducted qRT-PCR and Fluorescence in Situ Hybridization (FISH) assays to identify SLNCR1 expression levels and localization in tissues and cells, respectively. Loss-of-function assays utilizing shRNAs vectors were used to investigate the potential impact of SLNCR1. Our data showed that SLNCR1 is significantly up-regulated in human malignant melanoma tissues and cell lines and functions as an oncogene. Silencing of SLNCR1 suppressed melanoma cell proliferation, migration, invasion, and inhibited tumorigenesis in a mouse xenograft model. Additionally, we employed bioinformatic predictive analysis, combined with dual-luciferase reporter analysis and functional rescue assays, to elucidate the mechanistic target of the SLNCR1/SOX5 axis in melanoma. Mechanistically, we discovered that SLNCR1 promotes EMT of human melanoma by targeting SOX5, as downregulation of SLNCR1 expression leads to a decrease in SOX5 protein levels and inhibits melanoma tumorigenesis. Our research offers promising insights for more precise diagnosis and treatment of human melanoma.

Identification of potential biomarkers for aging diagnosis of mesenchymal stem cells derived from the aged donors.

BACKGROUND: The clinical application of human bone-marrow derived mesenchymal stem cells (MSCs) for the treatment of refractory diseases has achieved remarkable results. However, there is a need for a systematic evaluation of the quality and safety of MSCs sourced from donors. In this study, we sought to assess one potential factor that might impact quality, namely the age of the donor. METHODS: We downloaded two data sets from each of two Gene Expression Omnibus (GEO), GSE39035 and GSE97311 databases, namely samples form young (< 65 years of age) and old (> 65) donor groups. Through, bioinformatics analysis and experimental validation to these retrieved data, we found that MSCs derived from aged donors can lead to differential expression of gene profiles compared with those from young donors, and potentially affect the function of MSCs, and may even induce malignant tumors. RESULTS: We identified a total of 337 differentially expressed genes (DEGs), including two upregulated and eight downregulated genes from the databases of both GSE39035 and GSE97311. We further identified 13 hub genes. Six of them, TBX15, IGF1, GATA2, PITX2, SNAI1 and VCAN, were highly expressed in many human malignancies in Human Protein Atlas database. In the MSCs in vitro senescent cell model, qPCR analysis validated that all six hub genes were highly expressed in senescent MSCs. Our findings confirm that aged donors of MSCs have a significant effect on gene expression profiles. The MSCs from old donors have the potential to cause a variety of malignancies. These TBX15, IGF1, GATA2, PITX2, SNAI1, VCAN genes could be used as potential biomarkers to diagnosis aging state of donor MSCs, and evaluate whether MSCs derived from an aged donor could be used for therapy in the clinic. Our findings provide a diagnostic basis for the clinical use of MSCs to treat a variety of diseases. CONCLUSIONS: Therefore, our findings not only provide guidance for the safe and standardized use of MSCs in the clinic for the treatment of various diseases, but also provide insights into the use of cell regeneration approaches to reverse aging and support rejuvenation.

Hypoxia promotes non-small cell lung cancer cell stemness, migration, and invasion via promoting glycolysis by lactylation of SOX9.

BACKGROUND: Lung cancer is the deadliest form of malignancy and the most common subtype is non-small cell lung cancer (NSCLC). Hypoxia is a typical feature of solid tumor microenvironment. In the current study, we clarified the effects of hypoxia on stemness and metastasis and the molecular mechanism. METHODS: The biological functions were assessed using the sphere formation assay, Transwell assay, and XF96 extracellular flux analyzer. The protein levels were detected by western blot. The lactylation modification was assessed by western blot and immunoprecipitation. The role of SOX9 in vivo was explored using a xenografted tumor model. RESULTS: We observed that hypoxia promoted sphere formation, migration, invasion, glucose consumption, lactate production, glycolysis, and global lactylation. Inhibition of glycolysis suppressed cell stemness, migration, invasion, and lactylation. Moreover, hypoxia increased the levels of SOX9 and lactylation of SOX9, whereas inhibition of glycolysis reversed the increase. Additionally, knockdown of SOX9 abrogated the promotion of cell stemness, migration, and invasion. In tumor-bearing mice, overexpression of SOX9 promoted tumor growth, and inhibition of glycolysis suppressed tumor growth. CONCLUSION: Hypoxia induced the lactylation of SOX9 to promote stemness, migration, and invasion via promoting glycolysis. The findings suggested that targeting hypoxia may be an effective way for NSCLC treatment and reveal a new mechanism of hypoxia in NSCLC.

Lenvatinib Suppresses Protein Kinase B Signaling and Induces Apoptosis in Osteosarcoma Cells.

BACKGROUND/AIM: Lenvatinib, an oral multikinase inhibitor, has demonstrated promising activity in patients with osteosarcoma (OS). Therefore, it is worth exploring the inhibitory efficacy and mechanism of action of lenvatinib in osteosarcoma. The primary goal of this study was to examine the inhibitory effectiveness and mechanism of lenvatinib on the growth and invasion of OS cells. MATERIALS AND METHODS: The effects of lenvatinib on cell viability, apoptosis, protein kinase B (AKT) activation, its downstream effector proteins involved in tumor progression, and invasion capability were assessed using MTT assay, flow cytometry, western blotting, and invasion/migration assay on U-2 OS and MG63 cells. RESULTS: Lenvatinib effectively induced cytotoxicity, apoptosis, as well as extrinsic and intrinsic apoptotic signaling in OS cells. Lenvatinib also significantly decreased the invasion/migration capability, AKT activation, and downstream effector proteins. CONCLUSION: The anti-OS effect of lenvatinib may be associated with the induction of apoptosis and the inactivation of AKT.

Extracellular Vesicles Derived From 3D Cultured Antler Stem Cells Serve as a New Drug Vehicle in Osteosarcoma Treatment.

Extracellular vesicles (EVs) from antler reserve mesenchymal (RM) cells play an important role in the paracrine regulation during rapid growth of antler without forming a tumor; therefore, RM-EVs become novel materials for anti-tumor studies, such as osteosarcoma treatment. However, the problem of low production of RM-EVs in traditional 2D culture limits its mechanism research and application. In this study, we established an optimal 3D culture system for antler RM cells to produce EVs (3D-RM-EVs). Morphology and property of harvested 3D-RM-EVs were normal compared with EVs from conventional 2D culture, and the miRNA profile in them was basically the same through transcriptome sequencing analysis. Based on the same number of RM cells, the volume of the culture medium collected by 3D cultural system concentrated nearly 30 times, making it more convenient for subsequent purification. In addition, EVs were harvested 30 times in 3D cultural system, greatly increasing the total amount of EVs (harvested a total of 2-3 times in 2D culture). Although 3D-RM-EVs had a limited inhibitory effect on the proliferation of K7M2 cells, the inhibition effect of 3D-RM-EVs loaded drugs (Ifosfamide + Etoposide) were more significant than that of positive drug group alone (P < 0.05). Furthermore, in vivo studies showed that 3D-RM-EVs loaded drugs (Ifosfamide + Etoposide) had the most significant tumor inhibition effect, with decreased tumor size, and could slow down body weight loss compared with Ifosfamide + Etoposide (IFO + ET) group. These results demonstrated that 3D-RM-EVs were efficiently prepared from antler RM cells and were effective as drug vehicles for the treatment of osteosarcoma.

Antler stem cell-derived exosomes promote regenerative wound healing via fibroblast-to-myofibroblast transition inhibition.

INTRODUCTION: The typical outcome of mammalian wound healing is scarring, a fibrotic process mediated by myofibroblast aggregation. Perfect healing in a clinical setting is relatively unexplored. Surprisingly, our previous studies have shown that the large wound (10 cm diameter or more) of the pedicle of deer naturally achieves regenerative restoration, realized through a paracrine pathway from adjacent antler stem cells (AnSCs). METHODS: AnSC-derived exosomes (AnSC-exos) were topically injected around the full-thickness wounds in a rat model. The effects on the rate of wound healing and the quality of healing were evaluated via morphological, histological, and molecular biological techniques on days 14 and 28 after surgery. RESULTS: The results showed that AnSC-exos significantly accelerated the rate of wound healing and improved healing quality, including regeneration of cutaneous appendages (hair follicles and sebaceous glands) and the distribution pattern of collagen (basket-weave-like) in the healed skin. These effects of AnSC-exos were comparable to those of AnSCs but were significantly more potent than those of exosomes derived from bone marrow mesenchymal stem cells (bMSC-exos). Furthermore, AnSC-exos treatment effectively inhibited fibroblast-to-myofibroblast transition (FMT), as evidenced by the reduction of full-thickness skin injury-induced FMT in vivo and TGF-ß1-induced FMT in vitro. CONCLUSION: AnSC-exos could effectively promote regenerative cutaneous wound healing, highly likely through FMT inhibition. This suggests that AnSC-exos treatment could provide the potential for a novel approach to induce regenerative wound healing in the clinical setting.

Microbacterium nymphoidis sp. nov. and Microbacterium festucae sp. nov., two novel species with high plant-promoting potential isolated from wetland plants in China.

Two novel plant growth-promoting, rod-shaped, Gram-positive and non-motile rhizobacteria, W1NT and W2RT, were isolated from wetland plants Festuca elata and Nymphoides peltatum, respectively, in China. The results of the 16S rRNA sequence alignment analysis showed that they were related to Microbacterium, with the highest similarity to Microbacterium ketosireducens (98.7 %) and Microbacterium laevaniformans (98.5 %) for strain W1NT, and to Microbacterium terricola (98.1 %) and Microbacterium marinum (98.0 %) for strain W2RT. Phylogenetic analyses based on 16S rRNA gene sequences and 92 conserved concatenated proteins suggested that the two strains belong to the genus Microbacterium and were placed in two separate novel phylogenetic clades. The genome sizes of the two strains were 3.2 and 3.7 Mb, and the G+C contents were 71.7 and 68.5 mol%, respectively. The comparative genome results showed that the average nucleotide identity values between W1NT and W2RT and other species ranged from 73.5 to 83.6 %, and the digital DNA-DNA hybridization values ranged from 19.7 to 26.8 %. These two strains show physiological and biochemical features that differ from those of closely related species. Rhamnose, galactose and glucose were present in the characteristic sugar fractions of strains W1NT and W2RT. The peptidoglycan of strains W1NT and W2RT contained the amino acids ornithine, alanine and aspartic acid. C15 : 0 anteiso, C17 : 0 anteiso and C16 : 0 iso were the predominant cellular fatty acids in W1NT and W2RT. Phosphatidylglycerol and diphosphatidylglycerol are major polar lipid components. Strain W1NT not only formed bacterial biofilms but also had the ability to solubilize phosphorus and produce indole-3-acetic acid. Strain W2RT had siderophore-producing and lignin-degrading properties. Based on their genetic and phenotypic characteristics, strains W1NT and W2RT were classified as novel bacteria in the genus Microbacterium and designated as Microbacterium festucae sp. nov. (type strain W1NT=ACCC 61807T=GDMCC 1.2966T=JCM 35339T) and Microbacterium nymphoidis sp. nov. (type strain W2RT=ACCC 61808T=GDMCC 1.2967T=JCM 35340T).

Deer antlers: the fastest growing tissue with least cancer occurrence.

Deer antlers are a bony organ solely able to acquired distinct unique attributes during evolution and all these attributes are against thus far known natural rules. One of them is as the fastest animal growing tissue (2 cm/day), they are remarkably cancer-free, despite high cell division rate. Although tumor-like nodules on the long-lived castrate antlers in some deer species do occur, but they are truly benign in nature. In this review, we tried to find the answer to this seemingly contradictory phenomenon based on the currently available information and give insights into possible clinic application. The antler growth center is located in its tip; the most intensive dividing cells are resident in the inner layer of reserve mesenchyme (RM), and these cells are more adopted to osteosarcoma rather than to normal bone tissues in gene expression profiles but acquire their energy mainly through aerobic oxidative phosphorylation pathway. To counteract propensity of neoplastic transformation, antlers evolved highly efficient apoptosis exactly in the RM, unparalleled by any known tissues; and annual wholesale cast to jettison the corps. Besides, some strong cancer suppressive genes including p53 cofactor genes and p53 regulator genes are highly positively selected by deer, which would have certainly contributed to curb tumorigenesis. Thus far, antler extracts and RM cells/exosomes have been tried on different cancer models either in vitro or in vivo, and all achieved positive results. These positive experimental results together with the anecdotal folklore that regular consumption of velvet antler is living with cancer-free would encourage us to test antlers in clinic settings.

Macrophage lineage cells-derived migrasomes activate complement-dependent blood-brain barrier damage in cerebral amyloid angiopathy mouse model.

Accumulation of amyloid beta protein (Aß) in brain vessels damages blood brain barrier (BBB) integrity in cerebral amyloid angiopathy (CAA). Macrophage lineage cells scavenge Aß and produce disease-modifying mediators. Herein, we report that Aß40-induced macrophage-derived migrasomes are sticky to blood vessels in skin biopsy samples from CAA patients and brain tissue from CAA mouse models (Tg-SwDI/B and 5xFAD mice). We show that CD5L is packed in migrasomes and docked to blood vessels, and that enrichment of CD5L impairs the resistance to complement activation. Increased migrasome-producing capacity of macrophages and membrane attack complex (MAC) in blood are associated with disease severity in both patients and Tg-SwDI/B mice. Of note, complement inhibitory treatment protects against migrasomes-mediated blood-brain barrier injury in Tg-SwDI/B mice. We thus propose that macrophage-derived migrasomes and the consequent complement activation are potential biomarkers and therapeutic targets in CAA.

Bone Marrow Mesenchymal Stem Cell-Derived Dermcidin-Containing Migrasomes enhance LC3-Associated Phagocytosis of Pulmonary Macrophages and Protect against Post-Stroke Pneumonia.

Pneumonia is one of the leading causes of death in patients with acute ischemic stroke (AIS). Antibiotics fail to improve prognosis of patients with post-stroke pneumonia, albeit suppressing infection, due to adverse impacts on the immune system. The current study reports that bone marrow mesenchymal stem cells (BM-MSC) downregulate bacterial load in the lungs of stroke mice models. RNA-sequencing of the lung from BM-MSC-treated stroke models indicates that BM-MSC modulates pulmonary macrophage activities after cerebral ischemia. Mechanistically, BM-MSC promotes the bacterial phagocytosis of pulmonary macrophages through releasing migrasomes, which are migration-dependent extracellular vesicles. With liquid chromatography-tandem mass spectrometry (LC-MS/MS), the result shows that BM-MSC are found to load the antibacterial peptide dermcidin (DCD) in migrasomes upon bacterial stimulation. Besides the antibiotic effect, DCD enhances LC3-associated phagocytosis (LAP) of macrophages, facilitating their bacterial clearance. The data demonstrate that BM-MSC is a promising therapeutic candidate against post-stroke pneumonia, with dual functions of anti-infection and immunol modulation, which is more than a match for antibiotics treatment.

Conditioned media of deer antler stem cells accelerate regeneration of alveolar bone defects in rats.

The destruction of periodontal alveolar bone (AB) caused by periodontitis is regarded as one of the major reasons for tooth loss. The inhibition of bone resorption and regeneration of lost AB are the desirable outcomes in clinical practice but remain in challenge. The use of mesenchymal stem cells (MSCs) is one current approach for achieving true restoration of AB defects (ABD). Antler stem cells (AnSC) are capable of renewing a huge mammalian bony appendage, the deer antler, suggesting an unparalleled potential for bone regeneration. Herein, we investigated the effectiveness of deer AnSCs conditioned medium (CM, AnSC-CM) for repair of surgically-created ABD using a rat model and sought to define the underlying mechanisms. The results showed that AnSC-CM effectively induced regeneration of AB tissue; the outcome was significantly better than human bone marrow mesenchymal stem cell conditioned medium (hBMSC-CM). AnSC-CM treatment upregulated osteogenic factors and downregulated osteoclastic differentiation factors; stimulated proliferation, migration and differentiation of resident MSCs toward osteogenic lineage cells; modulated macrophage polarization toward the M2 phenotype and suppressed osteoclastogenesis. That AnSC-CM resulted in better outcomes than hBMSC-CM in treating ABD was attributed to the cell compatibility as both AnSCs and AB tissue are neural crest-derived. In conclusion, the effects of AnSC-CM on AB tissue regeneration were achieved through both promotion of osteogenesis and inhibition of osteoclastogenesis. We believe that AnSC-CM is a candidate for effective treatment of ABD in dental clinical practice but will require investment in further development.

A population of stem cells with strong regenerative potential discovered in deer antlers.

The annual regrowth of deer antlers provides a valuable model for studying organ regeneration in mammals. We describe a single-cell atlas of antler regrowth. The earliest-stage antler initiators were mesenchymal cells that express the paired related homeobox 1 gene (PRRX1+ mesenchymal cells). We also identified a population of "antler blastema progenitor cells" (ABPCs) that developed from the PRRX1+ mesenchymal cells and directed the antler regeneration process. Cross-species comparisons identified ABPCs in several mammalian blastema. In vivo and in vitro ABPCs displayed strong self-renewal ability and could generate osteochondral lineage cells. Last, we observed a spatially well-structured pattern of cellular and gene expression in antler growth center during the peak growth stage, revealing the cellular mechanisms involved in rapid antler elongation.

FOXP3+ macrophage represses acute ischemic stroke-induced neural inflammation.

Proper termination of cell-death-induced neural inflammation is the premise of tissue repair in acute ischemic stroke (AIS). Macrophages scavenge cell corpses/debris and produce inflammatory mediators that orchestrate immune responses. Here, we report that FOXP3, the key immune-repressive transcription factor of Tregs, is conditionally expressed in macrophages in stroke lesion. FOXP3 ablation in macrophages results in detrimental stroke outcomes, emphasizing the beneficial role of FOXP3+ macrophages. FOXP3+ macrophages are distinct from the M1 or M2 subsets and display superactive efferocytic capacity. With scRNAseq and analysis of FOXP3-bound-DNA isolated with CUT & RUN, we show that FOXP3 facilitates macrophage phagocytosis through enhancing cargo metabolism. FOXP3 expression is controlled by macroautophagic/autophagic protein degradation in resting macrophages, while initiation of LC3-associated phagocytosis (LAP) competitively occupies the autophagic machineries, and thus permits FOXP3 activation. Our data demonstrate a distinct set of FOXP3+ macrophages with enhanced scavenging capability, which could be a target in immunomodulatory therapy against AIS.Abbreviations: ADGRE1/F4/80: adhesion G protein-coupled receptor E1; AIF1/Iba1: allograft inflammatory factor 1; AIS: acute ischemic stroke; ARG1: arginase 1; ATP: adenosine triphosphate; BECN1/Beclin1: Beclin 1, autophagy related; BMDM: bone marrow-derived macrophages; CKO: conditional knockout; CSF1/M-CSF: colony stimulating factor 1 (macrophage); CSF2/GM-CSF: colony stimulating factor 2; CSF3/G-CSF: colony stimulating factor 3; CUT & RUN: cleavage under targets and release using nuclease; CyD: cytochalasin D; DAMP: danger/damage-associated molecular pattern; DIL: dioctadecyl-3,3,3,3-tetramethylin docarbocyanine; ELISA: enzyme linked immunosorbent assay; GO: Gene Ontology; FCGR3/CD16: Fc receptor, IgG, low affinity III; HMGB1: high mobility group box 1; IFNG/IFNγ: interferon gamma; IP: immunoprecipitation; KEGG: Kyoto Encyclopedia of Genes and Genomes; ITGAM/CD11b: integrin subunit alpha M; ITGAX/CD11c: integrin subunit alpha X; LAP: LC3-associated phagocytosis; LC-MS: liquid chromatography-mass spectrometry; LPS: lipopolysaccharide; MRC1/CD206: mannose receptor, C type 1; O4: oligodendrocyte marker O4; PBMC: peripheral blood mononuclear cells; RBC: red blood cells; PTPRC/CD45: protein tyrosine phosphatase, receptor type, C; RBFOX3/NeuN: RNA binding protein, fox 1 homolog (C. elegans) 3; RUBCN/Rubicon: RUN domain and cysteine-rich domain containing, Beclin 1-interacting protein; scRNAseq: single cell RNA sequencing; SQSTM1/p62 (sequestosome 1); TGFB/TGFß: transforming growth factor, beta; tMCAO: transient middle cerebral artery occlusion; TNF/TNFα: tumor necrosis factor; Treg: regulatory T cell.

First Discovery of Imidazo[1,2-a]pyridine Mesoionic Compounds Incorporating a Sulfonamide Moiety as Antiviral Agents.

The applications of mesoionic compounds and their analogues as agents against plant viruses remain unexplored. This was the first evaluation of the antiviral activities of mesoionic compounds on this issue. Our study involved the design and synthesis of a series of novel imidazo[1,2-a]pyridine mesoionic compounds containing a sulfonamide moiety and the assessment of their antiviral activities against potato virus Y (PVY). Compound A33 was assessed on the basis of three-dimensional quantitative structure-activity relationship (3D-QSAR) model analysis and displayed good curative, protective, and inactivating activity effects against PVY at 500 mg/L, up to 51.0, 62.0, and 82.1%, respectively, which were higher than those of commercial ningnanmycin (NNM, at 47.2, 50.1, and 81.4%). Significantly, defensive enzyme activities and proteomics results showed that compound A33 could enhance the defense response by activating the activity of defense enzymes, inducing the glycolysis/gluconeogenesis pathway of tobacco to resist PVY infection. Therefore, our study indicates that compound A33 could be applied as a potential viral inhibitor.

Vanillin Attenuates Proinflammatory Factors in a tMCAO Mouse Model via Inhibition of TLR4/NF-kB Signaling Pathway.

Vanillin has been reported to reduce hippocampal neuronal death in rat models of global cerebral ischemia. However, the immunoregulatory mechanism of vanillin in ischemic stroke is still unclear. To investigate the role of vanillin in a mouse model of ischemic stroke, we administered vanillin to mice after transient middle cerebral artery occlusion (tMCAO) by tail vein injection. Vanillin reduced infarct volume and improved motor function in mice after ischemia and reperfusion. IL-1ß and TNF-α were decreased in ischemic brain tissue of tMCAO mice after vanillin treatment compared with saline treatment. Similar effects were observed using the in vitro LPS-stimulated microglia cell model. Moreover, the reduced expression of proinflammatory cytokines in the vanillin group was related to TLR4/NF-κB signaling. Taken together, the findings suggest that vanillin decreased microglial activation by inhibiting the TLR4 /NF-κB signaling pathway, which reduced expression of proinflammatory cytokines IL-1ß and TNF-α, and finally reduced the infarct volume and improved motor function in tMCAO mice.

Effect of simultaneous treatment combining ultrasonication and rutin on gliadin in the formation of nanoparticles.

Proteins, one of the vital nutritional compounds sensitive to the environment, can be modified by interaction with polyphenols. Ultrasonication has been applied for enhancing the functional properties of proteins. In this study, the interactions of gliadin (G) and rutin (R) in the absence and presence of ultrasonication (0, 150, 300, 450, and 600 W) for 20 min were investigated, with a focus on the properties of emulsions prepared by G-R complexes. Ultrasonication improved the interaction, which increased the content of ß-type secondary structure. Ultrasonication at 450 W increased the particle size of the conjugates. For Pickering emulsions, treating the covering of R on G with ultrasonication improves the stability of the G-based emulsion significantly, owing to the strong films formed on the oil-water interfaces. The G-R complexes treated at 450 W ultrasonication formed emulsions that showed higher potential and storage modulus (G') and denser microstructures than those of the untreated emulsions. Nevertheless, ultrasound treatment at 600 W weakened the emulsion properties that were stabilized by the conjugates. Ultrasound combined R was shown to be a potential processing technology for changing the protein structure and producing stable emulsions. PRACTICAL APPLICATION: The interactions between proteins and polyphenols are able to preserve the stability of the functional compounds, allow targeted and controlled release, and improve the texture of these complexes employed in the food industry. Improvements in the functional characteristics of the protein-polyphenol complexes so that they possess high emulsifying stability during food processing is a crucial factor for employing them in the food industry. Therefore, the aim of this research is using a soluble complex of gliadin-rutin for the development of its functional characteristics.

The periosteum: a simple tissue with many faces, with special reference to the antler-lineage periostea.

Periosteum is a thin membrane covering bone surfaces and consists of two layers: outer fibrous layer and inner cambium layer. Simple appearance of periosteum has belied its own complexity as a composite structure for physical bone protection, mechano-sensor for sensing mechanical loading, reservoir of biochemical molecules for initiating cascade signaling, niche of osteogenic cells for bone formation and repair, and "umbilical cord" for nourishing bone tissue. Periosteum-derived cells (PDCs) have stem cell attributes: self-renewal (no signs of senescence until 80 population doublings) and multipotency (differentiate into fibroblasts, osteoblasts, chondrocytes, adipocytes and skeletal myocytes). In this review, we summarized the currently available knowledge about periosteum and with special references to antler-lineage periostea, and demonstrated that although periosteum is a type of simple tissue in appearance, with multiple faces in functions; antler-lineage periostea add another dimension to the properties of somatic periostea: capable of initiation of ectopic organ formation upon transplantation and full mammalian organ regeneration when interacted with the covering skin. Very recently, we have translated this finding into other mammals, i.e. successfully induced partial regeneration of the amputated rat legs. We believe further refinement along this line would greatly benefit human health.

Substances for regenerative wound healing during antler renewal stimulated scar-less restoration of rat cutaneous wounds.

Scarification is the outcome of cutaneous wound healing under normal conditions. Although considerable effort has been expended in this field, scar-less healing has not been achieved satisfactorily. The lack of a good model of scar-free healing has contributed to this undesirable situation. However, the annual regeneration of deer antlers, which starts from regenerative wound healing over the top of the pedicles (permanent bony protuberances), may provide such a model. Therefore, in this study, we investigated the process of pedicle wound healing at the organ, tissue, cell, and molecular levels. Our results convincingly demonstrate that wounds over the pedicle preceded a regenerative healing process including regeneration of skin appendages, such as hair follicles. Compared to the scar healing in rats, regenerative healing of the pedicle wound exhibited a weaker inflammatory response, lack of myofibroblast induction, and higher ratios of Col III/Col I, TGF-ß3/TGF-ß1, and MMP/TIMP. Importantly, our periosteal transplantation experiments in vivo revealed that this regenerative healing process was achieved through induction of antler stem cells (ASCs). Further study showed that this effect of ASCs on regenerative healing was not species-specific but more generic and could be applied to other mammalian species, as injection of ASCs stimulated regenerative healing of full-thickness excisional cutaneous wounds in rats. Overall, our findings show that ASCs may have therapeutic potential in enhancing the quality of wound healing and preventing scar formation in clinical settings.

Extracellular vesicles derived from umbilical cord mesenchymal stromal cells alleviate pulmonary fibrosis by means of transforming growth factor-ß signaling inhibition.

BACKGROUND: Pulmonary fibrosis (PF), the end point of interstitial lung diseases, is characterized by myofibroblast over differentiation and excessive extracellular matrix accumulation, leading to progressive organ dysfunction and usually a terminal outcome. Studies have shown that umbilical cord-derived mesenchymal stromal cells (uMSCs) could alleviate PF; however, the underlying mechanism remains to be elucidated. METHODS: The therapeutic effects of uMSC-derived extracellular vesicles (uMSC-EVs) on PF were evaluated using bleomycin (BLM)-induced mouse models. Then, the role and mechanism of uMSC-EVs in inhibiting myofibroblast differentiation were investigated in vivo and in vitro. RESULTS: Treatment with uMSC-EVs alleviated the PF and enhanced the proliferation of alveolar epithelial cells in BLM-induced mice, thus improved the life quality, including the survival rate, body weight, fibrosis degree, and myofibroblast over differentiation of lung tissue. Moreover, these effects of uMSC-EVs on PF are likely achieved by inhibiting the transforming growth factor-ß (TGF-ß) signaling pathway, evidenced by decreased expression levels of TGF-ß2 and TGF-ßR2. Using mimics of uMSC-EV-specific miRNAs, we found that miR-21 and miR-23, which are highly enriched in uMSC-EVs, played a critical role in inhibiting TGF-ß2 and TGF-ßR2, respectively. CONCLUSION: The effects of uMSCs on PF alleviation are likely achieved via EVs, which reveals a new role of uMSC-EV-derived miRNAs, opening a novel strategy for PF treatment in the clinical setting.