Dupilumab therapy improves gut microbiome dysbiosis and tryptophan metabolism in Chinese patients with atopic dermatitis.

BACKGROUND: Dupilumab has demonstrate its potential to orchestrate inflammatory skin microenvironment, enhance skin barrier and shift skin microbiome dysbiosis, collectively contributing to clinical improvement in patients with atopic dermatitis (AD). As the second genome of human body, growing evidence suggests that the gut microbiome might relate to the host response to treatments. Little is known about the association between dupilumab treatment and gut microbiome in AD patients. OBJECTIVE: We aimed to characterize the gut microbiome among Chinese subjects with or without AD and determine the potential effect of dupilumab on the gut microbiome. RESULTS: The 16 s rRNA gene sequencing was conducted on 48 healthy controls (HC), 44 AD patients and 27 AD patients who received dupilumab for 16 weeks. Prior to treatment, we identified the changed beta-diversity, increased Firmicutes/Bacteroidetes ratio, decreased Bifidobacterium and expanded Faecalibacterium among the AD patients compared to HC. After 16 weeks of dupilumab treatment, gut microbiome dysbiosis of the AD patients improved with reversed beta-diversity, closer bacterial connections, increased colonization of Bifidobacterium, Ruminococcus gnavus, and Coprococcus, which were negatively correlated with disease severity indicators. This shift was largely independent of the degree of clinical improvement. Bacterial function analysis revealed further metabolic alterations following dupilumab treatment, including up-regulated expression of genes involved in the indole pathway of tryptophan metabolism, corroborated by quantitative UHPLC-MS/MS analysis. CONCLUSION: Dupilumab treatment tends to help shift the gut microbial dysbiosis in AD patients to a healthier state, along with improved intestinal tryptophan metabolism, suggesting the gut flora and its metabolites may mediate part of the synergistic therapeutic effects on the host.

GRP78 Downregulation in Keratinocytes Promotes Skin Inflammation through the Recruitment and Activation of CCR6+ IL-17A-Producing γδ T Cells.

The migration of γδ T lymphocytes toward skin lesions and their concomitant pathogenic IL-17A production play a crucial role in the pathogenesis of psoriasis. However, the regulatory mechanisms of IL-17A production by γδ T cells and their migration remain to be fully explored. Intracellular GRP78 is a molecular chaperone that regulates endoplasmic reticulum stress, whereas secretory GRP78, as a member of the resolution-associated molecular patterns, exerts immunoregulatory effects. In this study, we reported that both the intracellular GRP78 in skin lesions and secretory GRP78 in the serum were significantly decreased in patients with psoriasis. A GRP78 knockdown exacerbated imiquimod-induced skin inflammation, whereas the application of recombinant GRP78 protein or BIP inducer X (a GRP78 inducer) attenuated the dermatitis. Mechanistically, the GRP78 knockdown in keratinocytes enhanced the production of chemokines, specifically CCL20, which regulates γδ T-cell migration. Moreover, recombinant GRP78 was found to directly bind to γδ T cells to suppress its migration ability and proinflammatory capacities by downregulating the CCR6 and IL-17A expression. Collectively, our results uncovered a pivotal role of GRP78 in the pathogenesis of psoriasis, which was mainly exerted by regulating the interaction between keratinocytes and γδ T cells, and might provide a promising target for psoriasis therapy.

LINC01224 promotes colorectal cancer progression through targeting miR-485-5p/MYO6 axis.

BACKGROUND: Long noncoding RNAs (lncRNAs) are related to colorectal cancer (CRC) development. However, the role and mechanism of lncRNA LINC01224 in CRC development are largely unknown. METHODS: LINC01224, Yin Yang 1 (YY1), microRNA (miR)-485-5p, and myosins of class VI (MYO6) levels were examined using quantitative reverse transcription polymerase chain reaction and western blotting. Functional analyses were processed through CCK-8, colony formation, flow cytometry, transwell, and xenograft analyses. Dual-luciferase reporter, chromatin immunoprecipitation (ChIP), RNA immunoprecipitation, and pull-down assays were conducted to analyze the binding interaction. RESULTS: LINC01224 abundance was elevated in CRC tissue samples and cell lines. Elevated LINC01224 might indicate the lower 5-year overall survival in 52 CRC patients. LINC01224 was upregulated via the transcription factor YY1. LINC01224 knockdown restrained CRC cell proliferation, migration, and invasion and increased apoptosis. MiR-485-5p was sponged by LINC01224, and miR-485-5p downregulation relieved the influence of LINC01224 interference on CRC progression. MYO6 was targeted via miR-485-5p and regulated via LINC01224/miR-485-5p axis. MiR-485-5p overexpression suppressed CRC cell proliferation, migration, and invasion and facilitated apoptosis. MYO6 upregulation mitigated the role of miR-485-5p. LINC01224 knockdown decreased xenograft tumor growth. CONCLUSION: YY1-induced LINC01224 regulates CRC development via modulating miR-485-5p/MYO6 axis.

A curcumin analog GL63 inhibits the malignant behaviors of hepatocellular carcinoma by inactivating the JAK2/STAT3 signaling pathway via the circular RNA zinc finger protein 83/microRNA-324-5p/cyclin-dependent kinase 16 axis.

BACKGROUND AND AIM: (1E,4E)-1,5-bis(2-bromophenyl) penta-1,4-dien-3-one (GL63) is a curcumin analog that can protect against carcinogenesis in hepatocellular carcinoma (HCC). The aim of this study was to explore the molecular mechanism of GL63 in HCC. METHODS: Cell viability was examined by cell counting kit-8 (CCK-8) assay. Circular RNA zinc finger protein 83 (circZNF83), microRNA-324-5p (miR-324-5p), and cyclin-dependent kinase 16 (CDK16) levels were measured via the quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed using colony formation assay. Flow cytometry was performed for detecting cell cycle and apoptosis. Protein analysis was conducted by western blot. Cell migration and invasion were determined using transwell assay. Target relation was analyzed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The function of GL63 in vivo was researched by xenograft model in mice. RESULTS: GL63 inhibited the circZNF83 expression in HCC cells. CircZNF83 overexpression attenuated the inhibitory effects of GL63 on HCC cell growth, cell cycle progression, migration, and invasion but the promoting effect on cell apoptosis. CircZNF83 served as a sponge of miR-324-5p and circZNF83/miR-324-5p axis was involved in the functional regulation of GL63 in HCC progression. Moreover, CDK16 was a downstream target of miR-324-5p and circZNF83 could regulate the CDK16 expression by sponging miR-324-5p. The anti-tumor function of GL63 was also related to the miR-324-5p/CDK16 axis. In addition, GL63 inactivated the JAK2/STAT3 pathway via downregulating circZNF83 to mediate the miR-324-5p/CDK16 axis. GL63 also repressed tumor growth in vivo through the circZNF83/miR-324-5p/CDK16-mediated JAK2/STAT3 signal inhibition. CONCLUSION: This study suggested GL63 impeded the HCC development by blocking the JAK2/STAT3 signaling pathway via mediating the circZNF83/miR-324-5p/CDK16 axis.

Human amniotic mesenchymal stem cells and their paracrine factors promote wound healing by inhibiting heat stress-induced skin cell apoptosis and enhancing their proliferation through activating PI3K/AKT signaling pathway.

BACKGROUND: Increasing evidence has shown that mesenchymal stem cells (MSCs) yield a favorable therapeutic benefit for thermal burn skin wounds. Human amniotic MSCs (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating skin wounds. However, the exact effects of hAMSCs on the healing of thermal burn skin wounds and their potential mechanisms are not explored. METHODS: hAMSCs were isolated from amniotic membrane and characterized by RT-PCR, flow cytometry, immunofluorescence, and tumorigenicity test. We assessed the effects of hAMSCs and hAMSC conditional medium (CM) on wound healing in a deep second-degree burn injury model of mice. We then investigated the biological effects of hAMSCs and hAMSC-CM on the apoptosis and proliferation of heat stress-injured human keratinocytes HaCAT and dermal fibroblasts (DFL) both in vivo and in vitro. Next, we explored the underlying mechanisms by assessing PI3K/AKT and GSK3ß/ß-catenin signaling pathways in heat injured HaCAT and DFL cells after hAMSCs and hAMSC-CM treatments using PI3K inhibitor LY294002 and ß-catenin inhibitor ICG001. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may activate PI3K/AKT signaling pathway. RESULTS: Our results showed that hAMSCs expressed various markers of embryonic stem cells and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAMSC and hAMSC-CM transplantation significantly promoted thermal burn wound healing by accelerating re-epithelialization with increased expression of CK19 and PCNA in vivo. hAMSCs and hAMSC-CM markedly inhibited heat stress-induced apoptosis in HaCAT and DFL cells in vitro through activation of PI3K/AKT signaling and promoted their proliferation by activating GSK3ß/ß-catenin signaling. Furthermore, we demonstrated that hAMSC-mediated activation of GSK3ß/ß-catenin signaling was dependent on PI3K/AKT signaling pathway. Antibody array assay showed that a panel of cytokines including PAI-1, C-GSF, periostin, and TIMP-1 delivered from hAMSCs may contribute to the improvement of the wound healing through activating PI3K/AKT signaling pathway. CONCLUSION: Our results demonstrated that hAMSCs and hAMSC-CM efficiently cure heat stress-induced skin injury by inhibiting apoptosis of skin cells and promoting their proliferation through activating PI3K/AKT signaling pathway, suggesting that hAMSCs and hAMSC-CM may provide an alternative therapeutic approach for the treatment of skin injury.

[Interferon-ß combined with all-trans retinoic acid supresses proliferation and promote apoptosis by inhibiting JAK2/STAT3 pathway in HepG2 human hepatocellular carcinoma cells].

Objective To investigate the effect of interferon-ß (IFN-ß) combined with all-trans retinoic acid (ATRA) on the proliferation and apoptosis of HepG2 human hepatocarcinoma cells and the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signal pathway in the process. Methods HepG2 cells were randomly divided intro three groups and treated with 1000 U/mL IFN-ß, 10 µmol/L ATRA and 1000 U/mL IFN-ß combined with 10 µmol/L ATRA, respectively for 24 hours. Cell viability was measured by MTT assay and apoptosis rate was detected by flow cytometry. Western blotting was applied to detect the protein levels of p-JAK2, p-STAT3, gene associated with retinoid-interferon-induced mortality-19 (GRIM-19), Bcl-2, Bcl-xl and Bax. Results IFN-ß or ATRA inhibited the proliferation and induced the apoptosis of HepG2 cells. The effect was enhanced when IFN-ß was combined with ATRA. The expressions of p-JAK2 and p-STAT3 were down-regulated while the expressions of GRIM-19 and Bax were up-regulated after treated with IFN-ß or ATRA on HepG2 cells, especially the combination of IFN-ß and ATRA. Conclusion Combination of IFN-ß and ATRA could suppress the proliferation and induced the apoptosis of HepG2 hepatocarcinoma cells by inhibiting JAK2/STAT3 signal pathway.