MLL3 Inhibits Apoptosis of Rheumatoid Arthritis Fibroblast-Like Synoviocytes and Promotes Secretion of Inflammatory Factors by Activating CCL2 and the NF-κB Pathway

FNDC4 reduces inflammation, proliferation, invasion and migration of rheumatoid synovial cells by inhibiting CCL2/ERK signaling

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation. Fibronectin type III domain-containing protein 4 (FNDC4) is a secretory factor that can regulate inflammatory diseases. However, the role of FNDC4 in RA has not been reported so far.

METHODS

The expression of FNDC4 in synovial tissues of RA was analyzed by GEO database (GSE55235 dataset). Then, the expression of FNDC4 in RA fibroblast-like synoviocytes (RA-FLSs) was detected by RT-qPCR and western blot. After constructing FNDC4 overexpression plasmid, cell proliferation and apoptosis were detected. Wound healing and transwell assays were used to detect cell migration and invasion. Then we examined the expression of cytokines related to cell inflammation. Subsequently, the regulatory mechanism of FNDC4 was further discussed. We detected the expression of CCL2 and ERK signaling pathway related proteins downstream of FNDC4. Finally, the mechanism was discussed through the overexpression of FNDC4 and CCL2 and the addition of ERK pathway activator tBHQ.

RESULTS

GEO database showed that FNDC4 expression decreased in synovial tissues of RA. FNDC4 expression was also decreased in RA-FLSs. Overexpression of FNDC4 inhibited the proliferation, invasion and migration of RA-FLSs whereas promoted the cellapoptosis. Overexpression of FNDC4 inhibited the release of inflammatory factors in RA-FLSs. The regulatory effect of FNDC4 is achieved by inhibiting the CCL2/ERK signaling pathway.

CONCLUSION

FNDC4 reduces inflammation, proliferation, invasion and migration of RA-FLSs in RA by inhibiting CCL2/ERK signaling.

Biomimetic Epigallocatechin Gallate-Cerium Assemblies for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that is so far incurable with long-term health risks. The high doses and frequent administration for the available RA drug always lead to adverse side effects. Aiming at the obstacles to achieving effective RA treatment, we prepared macrophage cell membrane-camouflaged nanoparticles (M-EC), which were assembled from epigallocatechin gallate (EGCG) and cerium(IV) ions. Due to its geometrical similarity to the active metal sites of a natural antioxidant enzyme, the EC possessed a high scavenge efficiency to various types of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The macrophage cell membrane assisted M-EC in escaping from the immune system, being uptaken by inflammatory cells, and specifically binding IL-1β. After tail vein injection to the collagen-induced arthritis (CIA) mouse model, the M-EC accumulated at inflamed joints and effectively repaired the bone erosion and cartilage damage of rheumatoid arthritis by relieving synovial inflammation and cartilage erosion. It is expected that the M-EC can not only pave a new way for designing metal-phenolic networks with better biological activity but also provide a more biocompatible therapeutic strategy for effective treatment of RA.

Inhibition of Cdc37 Ameliorates Arthritis in Collagen-Induced Arthritis Rats by Inhibiting Synoviocyte Proliferation and Migration Through the ERK Pathway

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to synovial inflammation, pannus formation, cartilage damage, bone destruction, and ultimate disability. Fibroblast-like synoviocytes (FLS) are involved in the pathogenetic mechanism of RA. Cdc37 (cell division cycle protein 37) is regarded as a molecular chaperone involved in various physiological processes such as cell cycle progression, cell proliferation, cell signal transduction, tumorigenesis, and progression. However, the precise role of Cdc37 in the pathogenesis of rheumatoid arthritis (RA) remains uncertain. In our study, we found that Cdc37 expression was upregulated in human rheumatoid synovia in contrast with the normal group. Interestingly, Cdc37 activated the ERK pathway to promote RA-FLS proliferation and migration in vitro. Ultimately, in vivo experiments revealed that silencing of Cdc37 alleviated ankle swelling and cartilage destruction and validated the ERK signaling pathways in vitro findings. Collectively, we demonstrate that Cdc37 promotes the proliferation and migration of RA-FLS by activation of ERK signaling pathways and finally aggravates the progression of RA. These data indicated that Cdc37 may be a novel target for the treatment of RA.

Messenger Nanozyme for Reprogramming the Microenvironment of Rheumatoid Arthritis

Dysregulation of superoxide anion (O₂^-) and hydrogen peroxide (H₂O₂) metabolism in the microenvironment of rheumatoid arthritis (RA) drives the feedback loops of TNF-α and IL-1β thereby inducing an inflammatory storm between immune cells and joint tissue cells. Here, we combine nanoscale manganese dioxide (MnO₂) with microvesicles derived from macrophage (MMV). The former possesses superoxide dismutase (SOD) and catalase (CAT)-like activities that can modulate this imbalance, and we amplify the enzyme-like activities by using the amorphous hollow mesoporous structure and surface modification. The latter is a natural endogenous component with the parent cell-like inflammatory homing ability and a unique function of transmitting information to surrounding and distant cells (″messenger function″), which helps amorphous hollow MnO₂ (H-MnO₂) nanozymes to cloak in the blood and reach the site of inflammation, where they can not only accumulate in activated macrophages but also pretend to be ″messengers″ that are utilized by fibroblast-like synoviocytes (FLS) and chondrocytes. In addition, we also load dexamethasone sodium phosphate (DSP) for helping the nanozymes work. Messenger nanozyme (MMV-MnO₂@DSP) inherits the natural properties of MMV and mimics the enzymatic activity of SOD and CAT. It accumulates in activated macrophages to restore the metabolism of O₂^- and H₂O₂ while promoting repolarization and inhibits the feedback loops of TNF-α and IL-1β among macrophages, fibroblast-like synoviocytes, and chondrocytes, leading to anti-rheumatoid arthritis effects in vitro and in vivo.

KMT2C Induced by FABP5P3 Aggravates Keratinocyte Hyperproliferation and Psoriasiform Skin Inflammation by Upregulating the Transcription of PIK3R3

The extensive involvement of lysine methyltransferase 2C (KMT2C) in the inflammatory response is well-documented. However, little is known about the role of KMT2C in psoriasis. We identified that KMT2C was significantly upregulated in the epidermis of psoriatic skin lesions and the psoriasiform cell model. KMT2C knockdown diminished keratinocyte proliferation and the secretion of IL-6, IL-8, CCL20, and S100A9 in vitro and in vivo. In psoriasiform keratinocytes, KMT2C promoted the transcription of PIK3R3 by regulating the enrichment of histone H3 lysine 4 trimethylation at the PIK3R3 promoter and histone 3 lysine 4 monomethylation at the enhancer. The PIK3R3/protein kinase B/NF-κB pathway is a vital step in KMT2C-mediated alleviation of cytokine-primed inflammation. The long noncoding RNA FABP5P3 sustained KMT2C mRNA stability by recruiting human antigen R. Furthermore, inhibition of KMT2C attenuated epidermal hyperplasia and skin inflammation in mice with psoriasis. Taken together, our findings indicated a link between KMT2C and psoriasis and opened the possibility of using KMT2C as a potential therapeutic target for psoriasis treatment.

Detecting potential mechanism of vitamin D in treating rheumatoid arthritis based on network pharmacology and molecular docking

Aim: Vitamin D plays a vital role in Rheumatoid arthritis (RA). However, the mechanism of vitamin D and rheumatism is still unclear. Therefore, a strategy based on network pharmacology and molecular docking was used to explore the mechanism of vitamin D and RA.

Methods: The targets of RA were obtained from the GeneCards database and Therapeutic Targets Database, and the targets of vitamin D were obtained from the Drugbank database and STITCH database. Next, overlapping genes were identified by Venny, and further Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and molecular docking analyses were performed.

Results: A total of 1,139 targets of RA and 201 targets of vitamin D were obtained. A total of 76 overlapping genes were identified by Venny. The enrichment analysis showed that cell proliferation, immune response, and apoptotic process were the critical biological processes of vitamin D in treating RA. Antifolate resistance, osteoclast differentiation, and the nuclear factor-kappa B (NF-κB) signalling pathway are fundamental mechanisms of vitamin D in treating RA. According to further molecular docking, ALB, TNF, CASP3, and TP53 may be important punctuation points or diagnostic markers for future RA treatment.

Conclusion: By analysing overlapping genes of diseases and drugs, this study confirmed that ALB, TNF, CASP3, and TP53 may be essential markers or diagnostic markers for future RA treatment.

Clinical and Gene Features of SARS-CoV-2-Positive Recurrence in Patients Recovered From COVID-19

There are still frequent reports that a number of recovered coronavirus disease 2019 (COVID-19) patients following discharge have re-detectable positive (RP) results by RT-PCR. Understanding the clinical and molecular characteristics of RP patients may have implications for curbing the COVID-19 pandemic. In this study, 318 COVID-19 convalescent patients, including 59 RP patients and 259 non-RP (NRP) patients, were enrolled. Among RP patients, women accounted for a significantly high proportion (67.8%), and the titers of IgG and IgM antibodies in this group were also significantly high. Differentially expressed genes (DEGs), including 692 upregulated and 383 downregulated genes, overlapped in two public GEO datasets containing RP and NRP blood cell samples. Enrichment analysis indicated that these DEGs were related to several key signaling pathways, such as viral infection, immune activation, and inflammatory responses. Importantly, 59 indicator genes constituting the core network exhibited high diagnostic values and were correlated with markers of different immune cells. Among these, 12 drug-related genes were associated with the RP results. Our work suggests that, in addition to clinically available features, blood cell transcriptome sequencing can be performed to obtain gene signatures for diagnosis of RP patients.