Cathelicidin LL37 Promotes Epithelial and Smooth-Muscle-Like Differentiation of Adipose-Derived Stem Cells through the Wnt/β-Catenin and NF-κB Pathways

Adipose stem cells in tissue regeneration and repair: From bench to bedside

ADSCs are a large number of mesenchymal stem cells in Adipose tissue, which can be applied to tissue engineering. ADSCs have the potential of multi-directional differentiation, and can differentiate into bone tissue, cardiac tissue, urothelial cells, skin tissue, etc. Compared with other mesenchymal stem cells, ADSCs have a multitude of promising advantages, such as abundant number, accessibility in cell culture, stable function, and less immune rejection. There are two main methods to use ADSCs for tissue repair and regeneration. One is to implant the "ADSCs-scaffold composite" into the injured site to promote tissue regeneration. The other is cell-free therapy: using ADSC-exos or ADSC-CM alone to release a large number of miRNAs, cytokines and other bioactive substances to promote tissue regeneration. The tissue regeneration potential of ADSCs is regulated by a variety of cytokines, signaling molecules, and external environment. The differentiation of ADSCs into different tissues is also induced by growth factors, ions, hormones, scaffold materials, physical stimulation, and other factors. The specific mechanisms are complex, and most of the signaling pathways need to be further explored. This article reviews and summarizes the mechanism and clinical application of ADSCs in tissue injury repair so far, and puts forward further problems that need to be solved in this field, hoping to provide directions for further research in this field.

Cathelicidin antimicrobial peptide (CAMP) gene promoter methylation induces chondrocyte apoptosis

Objective

The occurrence of osteoarthritis is related to genetic and environmental factors. Among them, the change of chondrocyte gene expression pattern regulated by epigenetic modification is an important participant. This study analyzed the effect of CAMP gene methylation on the level of oxidative stress and inflammation of chondrocytes.

Methods

We analyzed the changes of the transcriptome in the articular cartilage tissue of osteoarthritis (OA) patients from the GSE117999 dataset. The GSE48422 dataset was used to analyze the changes in the methylation level of osteoarthritis cells. Cell Counting Kit-8 (CCK-8) and flow cytometry analysis of short hairpin RNA (shRNA) silencing CAMP gene and 5-μM 5-Aza-2’-Deoxycytidine (AZA) treatment on the proliferation and apoptosis of Human chondrocytes osteoarthritis (HC-OA) cells. The Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was used to detect the level of reactive oxygen species (ROS), and the expression level of inflammatory factors was analyzed by Western Blot.

Results

The expression of CAMP in cartilage tissue of OA patients was upregulated, and the level of methylation was downregulated. CAMP was highly expressed in osteoarthritis articular cartilage cells. Silencing CAMP inhibited the proliferation of HC-OA cells and promoted their apoptosis. CAMP gene methylation inhibited ROS levels and tumor necrosis factor-α (TNF-α) expression levels in HC-OA cells, and promoted transforming growth factor beta (TGF-β) expression. CAMP gene methylation inhibited the proliferation of HC-OA cells and promoted their apoptosis.

Conclusion

CAMP gene promoter methylation inhibits ROS levels and inflammation and induces chondrocyte apoptosis.

Hypoxia Promotes Vascular Smooth Muscle Cell (VSMC) Differentiation of Adipose-Derived Stem Cell (ADSC) by Regulating Mettl3 and Paracrine Factors

Adipose-derived stem cell (ADSC) is an alternative and less invasive source of mesenchymal stem cells which can be used to develop biological treatment strategies for tissue regeneration, and their therapeutic applications hinge on an understanding of their physiological characteristics. N6-Methyladenosine (m6A) is the most common chemical modification of mRNAs and has recently been revealed to play important roles in cell lineage differentiation and development. However, the role of m6A modification in the vascular smooth muscle cell (VSMC) differentiation of ADSCs remains unclear. Herein, we investigated the expression of N6-adenosine methyltransferases (Mettl3) and demethylases (Fto and Alkbh5) and found that Mettl3 was upregulated in ADSCs undergoing vascular smooth muscle differentiation induction. Moreover, silence of Mettle3 reduced the expression level of VSMC-specific markers, including α-SMA, SM22α, calponin, and SM-MHC. Meanwhile, Mettl3 knockdown also decreased the expression of paracrine factors, including VEGF, HGF, TGF-β, GM-CSF, bFGF, and SDF-1. In addition, our results suggested that hypoxia stress promotes the ADSC differentiate into VMSCs and regulates the secretion of VEGF, HGF, TGF-β, GM-CSF, bFGF, and SDF-1 by mediating Mettl3 gene expression. These observations might contribute to novel progress in understanding the role of epitranscriptomic regulation in the VSMC differentiation of ADSCs and provide a promising perspective for new therapeutic strategies for tissue regeneration.

From Antimicrobial to Anticancer Peptides: The Transformation of Peptides

BACKGROUND

Antimicrobial peptides play an important role in the innate immune system. Possessing broad-spectrum antibacterial activity, antimicrobial peptides can quickly treat and kill various targets, including gram-negative bacteria, gram-positive bacteria, fungi, and tumor cells.

OBJECTIVE

An overview of the state of play with regard to the research trend of antimicrobial peptides in recent years and the situation of targeting tumor cells, and to make statistical analysis of the patents related to anticancer peptides published in recent years, is important both from toxicological and medical tumor therapy point of view.

METHODS

Based on the Science Citation Index Expanded version, the Derwent Innovation Index and Innography as data sources, the relevant literature and patents concerning antimicrobial peptides and anticancer peptides were analyzed through the Thomson Data Analyzer. Results of toxicologic and pharmacologic studies that brought to the development of patents for methods to novel tumor drugs were analyzed and sub-divided according to the specific synthesis of anticancer peptides.

RESULTS

The literature and patent search data show that the research and development of global antimicrobial peptides and anticancer peptides has been in an incremental mode. Growing patent evidence indicate that bioinformatics technology is a valuable strategy to modify, synthesize or recombine existing antimicrobial peptides to obtain tumor drugs with high activity, low toxicity and multiple targets.

CONCLUSION

These findings may have important clinical implications for cancer treatment, especially in patients with conditions that are not currently treatable by other drugs, or that are resistant to existing cancer drugs.

Nuclear Factor Kappa-B Is Enriched in Eyelid Specimens of Rosacea: Implications for Pathogenesis and Therapy

PURPOSE

To assess the role of nuclear factor kappa-B (NFKB) in cutaneous specimens of rosacea and unaffected tissue.

METHODS

Immunohistochemical staining was performed for the activated, phosphorylated variant of NFKB (pNFKB) in eyelid specimens of rosacea (n = 12) and normal, healthy tissue (n = 12). The numbers of positively staining cells/40× microscopic field were counted across 5 consecutive fields. Additionally, quantitative Western blotting was carried out for pNFKB and NFKB in specimens of rosacea (n = 15) and normal controls (n = 14). Statistical comparisons were performed via a dedicated software package.

RESULTS

The mean number of cells/40× microscopic field that stained positively for pNFKB was 18.4 (standard deviation = 15.3) for control patients and 39.3 (standard deviation = 16.9) for rosacea patients, and the difference between the 2 groups was statistically significant (P = .0024). On Western blotting, the mean ratios of pNFKB:NFKB for control and rosacea patients measured 0.58 (standard deviation = 0.81) and 3.11 (standard deviation = 3.53), respectively. The 2 groups were statistically significantly different (P = .0002).

CONCLUSIONS

The activated form of NFKB is enriched in rosacea, indicating a role for this pathway in the pathogenesis of this disease. Interference with NFKB signaling may represent a novel therapy for rosacea as clinical agents become available. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Inhibitory Effects of Antimicrobial Peptide JH-3 on Salmonella enterica Serovar Typhimurium Strain CVCC541 Infection-Induced Inflammatory Cytokine Release and Apoptosis in RAW264.7 Cells

The antibiotic resistance of Salmonella has become increasingly serious due to the increased use of antibiotics, and antimicrobial peptides have been considered as an ideal antibiotic alternative. Salmonella can induce macrophage apoptosis and thus further damage the immune system. The antimicrobial peptide JH-3 has been shown to have a satisfactory anti-Salmonella effect in previous research, but its mechanism of action remains unknown. In this study, the effects of JH-3 on macrophages infected with Salmonella Typhimurium CVCC541 were evaluated at the cellular level. The results showed that JH-3 significantly alleviated the damage to macrophages caused by S. Typhi infection, reduced the release of lactic dehydrogenase (LDH), and killed the bacteria in macrophages. In addition, JH-3 decreased the phosphorylation level of p65 and the expression and secretion of interleukin 2 (IL-2), IL-6, and tumor necrosis factor-α (TNF-α) by inhibiting the activation of the mitogen-activated protein kinase (MAPK) (p38) signaling pathway and alleviating the cellular inflammatory response. From confocal laser scanning microscopy and flow cytometry assays, JH-3 was observed to inhibit the release of cytochrome c in the cytoplasm; the expression of TNF-αR2, caspase-9, and caspase-8; to further weaken caspase-3 activation; and to reduce the S.-Typhi-induced apoptosis of macrophages. In summary, the mechanism by which JH-3 inhibits Salmonella infection was systematically explored at the cellular level, laying the foundation for the development and utilization of JH-3 as a therapeutic alternative to antibiotics.