PSTPIP2 Inhibits the Inflammatory Response and Proliferation of Fibroblast-Like Synoviocytes in vitro

m6A epitranscriptomic and epigenetic crosstalk in liver fibrosis: Special emphasis on DNA methylation and non-coding RNAs

Liver fibrosis is a pathological process caused by a variety of chronic liver diseases. Currently, therapeutic options for liver fibrosis are very limited, highlighting the urgent need to explore new treatment approaches. Epigenetic modifications and epitranscriptomic modifications, as reversible regulatory mechanisms, are involved in the development of liver fibrosis. In recent years, researches in epitranscriptomics and epigenetics have opened new perspectives for understanding the pathogenesis of liver fibrosis. Exploring the epigenetic mechanisms of liver fibrosis may provide valuable insights into the development of new therapies for chronic liver diseases. This review primarily focus on the regulatory mechanisms of N6-methyladenosine (m6A) modification, non-coding RNA, and DNA methylation in organ fibrosis. It discusses the interactions between m6A modification and DNA methylation, as well as between m6A modification and non-coding RNA, providing a reference for understanding the interplay between epitranscriptomics and epigenetics.

PSTPIP2 protects against alcoholic liver injury and invokes STAT3-mediated suppression of apoptosis

Alcoholic liver injury (ALI) stands as a prevalent affliction within the spectrum of complex liver diseases. Prolonged and excessive alcohol consumption can pave the way for liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Recent findings have unveiled the protective role of proline serine-threonine phosphatase interacting protein 2 (PSTPIP2) in combating liver ailments. However, the role of PSTPIP2 in ALI remains mostly unknown. This study aimed to determine the expression profile of PSTPIP2 in ALI and to uncover the mechanism through which PSTPIP2 affects the survival and apoptosis of hepatocytes in ALI, using both ethyl alcohol (EtOH)-fed mice and an EtOH-induced AML-12 cell model. We observed a consistent decrease in PSTPIP2 expression both in vivo and in vitro. Functionally, we assessed the impact of PSTPIP2 overexpression on ALI by administering adeno-associated virus 9 (AAV9)-PSTPIP2 into mice. The results demonstrated that augmenting PSTPIP2 expression significantly shielded against liver parenchymal distortion and curbed caspase-dependent hepatocyte apoptosis in EtOH-induced ALI mice. Furthermore, enforcing PSTPIP2 expression reduced hepatocyte apoptosis in a stable PSTPIP2-overexpressing AML-12 cell line established through lentivirus-PSTPIP2 transfection in vitro. Mechanistically, this study also identified signal transducer and activator of transcription 3 (STAT3) as a direct signaling pathway regulated by PSTPIP2 in ALI. In conclusion, our findings provide compelling evidence that PSTPIP2 has a regulatory role in hepatocyte apoptosis via the STAT3 pathway in ALI, suggesting PSTPIP2 as a promising therapeutic target for ALI.

PSTPIP2 is associated with disease severity in patients with pressure ulcer sepsis and has anti-inflammatory effects

BACKGROUND

One of the common adverse reactions in patients with pressure ulcers (PU) is sepsis, which is mainly related to microbial infections caused by pathogenic organisms. The activation of nuclear factor kappa-B (NF-κB) frequently occurs in conjunction with pathogenic microbial infections. Proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) is closely related to inflammatory disorders. The role and mechanism of PSTPIP2 in sepsis because of pressure ulcers is unclear. In this study, we discovered that PSTPIP2 was lowly expressed in peripheral blood of patients with sepsis induced by pressure ulcers.

METHODS

Peripheral blood was collected from 20 patients with sepsis due to pressure ulcers and 10 healthy controls, and the expression of PSTPIP2 in peripheral blood was discovered by polymerase chain reaction and Western blot analysis. Information on the clinical characteristics of patients was summarized, and the expression data of PSTPIP2 were correlated with the patients' acute physiology and chronic health evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score, and C-reactive protein (CRP) and procalcitonin (PCT) scores by Spearman's correlation analysis. One of the main mediators of Gram-negative sepsis is lipopolysaccharide (LPS). In order to establish an in vitro sepsis model, THP-1 cells were treated with LPS, and the cells were transfected with PSTPIP2. Contents of interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor-α (TNF-α) in each group of cells were detected by enzyme-linked--immunosorbent serologic assay, and NF-κB-related proteins were detected by Western blot analysis.

RESULTS

When compared to healthy controls, the peripheral blood of patients with pressure sepsis had lower PSTPIP2 expression, which had a negative correlation with the APACHE II, SOFA, CRP, and PCT scores. LPS-induced THP-1 cells expressed less PSTPIP2 than the untreated control cells, and PSTPIP2 transfection decreased IL-6, IL-1β, and TNF-α levels and inhibited the activation of NF-κB pathway.

CONCLUSION

PSTPIP2 is associated with disease severity in patients with pressure ulcer sepsis and has anti-inflammatory effects.

PSTPIP2 alleviates obesity associated adipose tissue inflammation and insulin resistance in diabetes mice through promoting M2 macrophage polarization via activation of PPARγ

BACKGROUND

Proline-serine-threonine phosphatase-interacting protein 2 (PSTPIP2) plays a role in inflammatory disease. In diabetes, very little is known about PSTPIP2 until now. Hence, this study aimed to determine PSTPIP2 functional role in diabetes.

METHODS

Diabetes mouse model was constructed by feeding high fat diet (HFD). Intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test were examined the glucose and insulin tolerance. The expression of genes and proteins was detected by quantitative real time PCR, immunohistochemistry and western blotting. The pathological changes of epididymal adipose tissues were examined by hematoxylin-eosin staining. RAW264.7 macrophages were treated with GW9662 (PPARγ antagonist). Flow cytometry examined the proportion of M1/M2 macrophages.

RESULTS

HFD enhanced the body weight, glucose and insulin tolerance, and inhibited PSTPIP2 expression in mice. PSTPIP2 overexpression alleviated glucose and insulin tolerance, reduced inflammation and macrophage accumulation in the epididymal adipose tissues of diabetic mice. The expression of iNOS and TNF-α was increased, the expression of IL-10 and Arg-1 was decreased in diabetic mice, which was abrogated by PSTPIP2 overexpression. In vitro, PSTPIP2 overexpression reduced the proportions of iNOS-positive cells and enhanced the proportions of CD206-positive cells in RAW264.7 cells. PPARγ and p-STAT6 were up-regulated, STAT6 was down-regulated in RAW264.7 cells. GW9662 impaired PSTPIP2 overexpression-mediated up-regulation of Arg-1, YM-1 and FIZZ1 in RAW264.7 cells.

CONCLUSION

PSTPIP2 alleviates obesity associated adipose tissue inflammation and insulin resistance in diabetic mice through promoting M2 macrophage polarization via activation of PPARγ, suggesting that PSTPIP2 is a prospective target for diabetes treatment.

Secretory phosphoprotein 1 secreted by fibroblast-like synoviocytes promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis

Synovial tissue hyperplasia is a major cause of bone damage in rheumatoid arthritis (RA). Over-proliferation and secretion of cytokines of fibroblast-like synoviocytes (FLSs) are key contributors to bone damage in the joint microenvironment. Therefore, inhibition of FLSs-mediated bone damage is of great significance in RA patients. The aim of this study was to investigate the molecular mechanisms by which FLSs-mediated bone damage in the joint microenvironment. The results of whole transcriptome sequencing showed that Spp1 gene expression was significantly upregulated in collagen-induced arthritis FLSs compared to Normal FLSs. KEGG enrichment analysis revealed up-regulated Spp1 gene expression, associated with PI3K/AKT signaling. Animal and cellular experiments were designed to validate and explore the results of sequencing. Briefly, the data demonstrated secretory phosphoprotein 1 (SPP1) (encoded by Spp1 gene) secreted by FLSs promotes osteoclasts differentiation in vivo and in vitro and exacerbates articular bone damage in collagen-induced arthritis mice. Interestingly, SPP1 secreted by FLSs does not affect its own proliferation and apoptosis. The results of co-culture of FLSs with bone marrow-derived monocytes indicated the level of SPP1 secreted by FLSs positively correlates with the frequency of p-PI3K⁺PI3K⁺ osteoclasts, whereas not with the frequency of p-AKT⁺AKT⁺ osteoclasts. This may suggest that SPP1 secreted by FLSs acts directly on PI3K while indirectly on AKT. Together, the results revealed SPP1 secreted by FLSs promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis. Regulation of Spp1 gene expression in FLSs may be a potential approach to treat RA bone damage in the joint microenvironment.

Short-chain fatty acids regulate B cells differentiation via FFAR2 to alleviate rheumatoid arthritis

BACKGROUND AND PURPOSE

Short-chain fatty acids (SCFAs) are metabolites of gut microbes involved in the host's inflammatory response and immunity. The aim of this study was to investigate the role of SCFAs in RA and the possible mechanisms.

EXPERIMENTAL APPROACH

Gut microbiota diversity in mice was analysed by 16S rDNA sequencing. SCFAs levels were analysed by gas chromatography mass spectrometry. T cells and B cells were analysed by flow cytometry. Bone damage was analysed by micro-CT and x-ray. Histopathological status was analysed by HE staining. The protein in tissues were analysed by immunohistochemistry and PCR. Mice with CD19⁺ B cells specifically deficient in FFAR2 were used to explore the molecular mechanisms involved.

KEY RESULTS

Levels of acetate, propionate, butyrate, and valerate were decreased in RA patients, and the first three levels correlated positively with the frequency of Bregs in peripheral blood but not with Tregs. Administration of the three SCFAs prior to the onset of collagen-induced arthritis in mice improved arthritic symptoms, increased the Bregs frequency, and decreased transitional B cells and follicular B cells frequency. However, the preceding phenomena could not be observed in mice with CD19⁺ B cells deficient in FFAR2. The effects of the three SCFAs in RA were dependent on FFAR2 while were independent of the other five B cell receptors (FFAR3, GPR109A, PPARγ, Olfr-78, and AhR).

CONCLUSIONS AND IMPLICATIONS

SCFAs regulate B cells differentiation via FFAR2 to alleviate RA. This will provide new insights into the treatment of RA from an immunological and microbiological perspective.

New advances of DNA/RNA methylation modification in liver fibrosis

Liver fibrosis is a complex pathological process caused by multiple pathogenic factors，such as ethanol, viruses, toxins, drugs or cholestasis, and it can eventually develop into liver cirrhosis without effective treatment. Activation of hepatic stellate cells (HSCs) is a pivotal cellular event in the pathogenesis of liver fibrosis. However, the pathogenesis of liver fibrosis has not been fully elucidated. DNA/RNA methylation can regulate gene expression without alteration in its sequence, and numerous studies have shown the involvement of DNA methylation in the activation of HSCs and then promote the progression of liver fibrosis. In addition, RNA methylation has recently been reported to play a regulatory role in this process. In this review, we focus on the aberrant DNA/RNA methylation of selected genes and explore their functional mechanism in regulating HSCs activation and liver fibrogenesis. All of these findings will enhance our understanding of DNA/RNA methylation and their roles in liver fibrosis and provide the basis to identify effective therapeutic targets.

Experimental Babesia rossi infection induces hemolytic, metabolic, and viral response pathways in the canine host

Background

Babesia rossi is a leading cause of morbidity and mortality among the canine population of sub-Saharan Africa, but pathogenesis remains poorly understood. Previous studies of B. rossi infection were derived from clinical cases, in which neither the onset of infection nor the infectious inoculum was known. Here, we performed controlled B. rossi inoculations in canines and evaluated disease progression through clinical tests and whole blood transcriptomic profiling.

Results

Two subjects were administered a low inoculum (10⁴ parasites) while three received a high (10⁸ parasites). Subjects were monitored for 8 consecutive days; anti-parasite treatment with diminazene aceturate was administered on day 4. Blood was drawn prior to inoculation as well as every experimental day for assessment of clinical parameters and transcriptomic profiles. The model recapitulated natural disease manifestations including anemia, acidosis, inflammation and behavioral changes. Rate of disease onset and clinical severity were proportional to the inoculum. To analyze the temporal dynamics of the transcriptomic host response, we sequenced mRNA extracted from whole blood drawn on days 0, 1, 3, 4, 6, and 8. Differential gene expression, hierarchical clustering, and pathway enrichment analyses identified genes and pathways involved in response to hemolysis, metabolic changes, and several arms of the immune response including innate immunity, adaptive immunity, and response to viral infection.

Conclusions

This work comprehensively characterizes the clinical and transcriptomic progression of B. rossi infection in canines, thus establishing a large mammalian model of severe hemoprotozoal disease to facilitate the study of host-parasite biology and in which to test novel anti-disease therapeutics. The knowledge gained from the study of B. rossi in canines will not only improve our understanding of this emerging infectious disease threat in domestic dogs, but also provide insight into the pathobiology of human diseases caused by Babesia and Plasmodium species.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07889-4.

METTL3 Promotes Activation and Inflammation of FLSs Through the NF-κB Signaling Pathway in Rheumatoid Arthritis

Rheumatoid arthritis (RA), a common autoimmune disease, is extremely damaging to human health. Fibroblast-like synoviocytes (FLSs) have a vital role in the occurrence and development of RA. Methyltransferase-like 3 (METTL3), which is a crucial component of the N⁶-methyladenosine (m⁶A) methyltransferase complex, is involved in the progression of many diseases. In this study, we explored the role of METTL3 in the inflammatory response and proliferation, invasion, and migration of FLSs. We used human RA synovial tissues and the adjuvant-induced arthritis (AIA) animal model of RA. Experimental results revealed that METTL3 expression was significantly upregulated in human RA synovial tissues and in the rat AIA model. METTL3 knockdown suppressed interleukin (IL)-6, matrix metalloproteinase (MMP)-3, and MMP-9 levels in human RA-FLSs and rat AIA-FLSs. In contrast, they were increased by METTL3 overexpression. Additionally, we found that, in FLSs, METTL3 may activate the nuclear factor (NF)-κB signaling pathway. The experimental results showed that METTL3 may promote FLS activation and inflammatory response via the NF-κB signaling pathway.

Pyrrolizidine alkaloid-induced transcriptomic changes in rat lungs in a 28-day subacute feeding study

Pyrrolizidine alkaloids (PAs) are secondary plant metabolites synthesized by a wide range of plants as protection against herbivores. These toxins are found worldwide and pose a threat to human health. PAs induce acute effects like hepatic sinusoidal obstruction syndrome and pulmonary arterial hypertension. Moreover, chronic exposure to low doses can induce cancer and liver cirrhosis in laboratory animals. The mechanisms causing hepatotoxicity have been investigated previously. However, toxic effects in the lung are less well understood, and especially data on the correlation effects with individual chemical structures of different PAs are lacking. The present study focuses on the identification of gene expression changes in vivo in rat lungs after exposure to six structurally different PAs (echimidine, heliotrine, lasiocarpine, senecionine, senkirkine, and platyphylline). Rats were treated by gavage with daily doses of 3.3 mg PA/kg bodyweight for 28 days and transcriptional changes in the lung and kidney were investigated by whole-genome microarray analysis. The results were compared with recently published data on gene regulation in the liver. Using bioinformatics data mining, we identified inflammatory responses as a predominant feature in rat lungs. By comparison, in liver, early molecular consequences to PAs were characterized by alterations in cell-cycle regulation and DNA damage response. Our results provide, for the first time, information about early molecular effects in lung tissue after subacute exposure to PAs, and demonstrates tissue-specificity of PA-induced molecular effects.

Proline-Serine-Threonine Phosphatase-Interacting Protein 2 Alleviates Diabetes Mellitus-Osteoarthritis in Rats through Attenuating Synovial Inflammation and Cartilage Injury

Objective

To explore the possible way of proline‐serine–threonine phosphatase‐interacting protein 2 (PSTPIP2) influencing diabetes mellitus‐osteoarthritis (DM‐OA) progression.

Methods

In vivo, eight‐week‐old male Sprague Dawley rats were induced with DM‐OA by intraperitoneal injection of streptozotocin with high‐fat diet feeding and intra‐articular injection of monoiodoacetate. PSTPIP2 overexpression was achieved by intra‐articular injection of lentivirus vectors. PSTPIP2 expression was verified by real‐time polymerase chain reaction and Western blotting. Histological changes were examined by hematoxylin/eosin and safranin‐O/fast‐green staining. In vitro, rat synovial fibroblasts were induced DM‐OA by stimulation of high glucose (HG) and interleukin (IL)‐1β. PSTPIP2 overexpression was achieved by lentivirus infection. U0126 was added as an ERK inhibitor. Levels of tumor necrosis factor (TNF)‐α, IL‐6, and IL‐1β were detected using enzyme‐linked immunosorbent assay. Expression of matrix metalloproteinase (MMP)‐3, MMP‐13, aggrecanase‐2 (ADAMTS‐5), intercellular cell adhesion molecule (ICAM)‐1, extracellular regulated protein kinase (ERK) and phospho‐ERK (p‐ERK) was detected by Western blotting.

Results

In DM‐OA rats, PSTPIP2 relative messenger RNA (mRNA) level was significantly decreased compared to control rats. The protein expression was also decreased obviously. Inflammation score in synovium was dramatically increased, accompanying with increased TNF‐α, IL‐6, and IL‐1β levels. Osteoarthritis research society international (OARSI) score in cartilage was markedly increased, along with increased MMP‐3, MMP‐13, ADAMTS‐5, ICAM‐1, ERK and p‐ERK expression. In PSTPIP2‐overexpressed DM‐OA rats, PSTPIP2 mRNA level and protein expression was increased compared to DM‐OA rats received negative‐control lentivirus vectors. The inflammation score, as well as TNF‐α, IL‐6, and IL‐1β levels were dramatically decreased. Also, the OARSI score and protein expression of MMP‐3, MMP‐13, ADAMTS‐5, ICAM‐1, ERK and p‐ERK were decreased. In HG+IL‐1β‐treated rat synovial fibroblasts, PSTPIP2 protein expression was decreased compared to normal glucose (NG)‐treated cells. Levels of TNF‐α, IL‐6, and IL‐1β, as well as expression of MMP‐3, MMP‐13, ADAMTS‐5, ICAM‐1, ERK and p‐ERK were increased. After cells were infected with PSTPIP2‐overexpressed lentivirus, levels of TNF‐α, IL‐6, and IL‐1β, and expression of MMP‐3, MMP‐13, ADAMTS‐5, ICAM‐1, ERK and p‐ERK were obviously decreased compared to cells infected with NC lentivirus. In addition, ERK inhibitor U0126 treatment also decreased the TNF‐α, IL‐6, and IL‐1βlevels and MMP‐3, MMP‐13, ADAMTS‐5, ICAM‐1, ERK and p‐ERK expression in HG + IL‐1β treated rat synovial fibroblasts.

Conclusion

Overexpression of PSTPIP2 alleviates synovial inflammation and cartilage injury during DM‐OA progression via inhibiting ERK phosphorylation.

The Macrophage-Osteoclast Axis in Osteoimmunity and Osteo-Related Diseases

Osteoimmunity is involved in regulating the balance of bone remodeling and resorption, and is essential for maintaining normal bone morphology. The interaction between immune cells and osteoclasts in the bone marrow or joint cavity is the basis of osteoimmunity, in which the macrophage-osteoclast axis plays a vital role. Monocytes or tissue-specific macrophages (macrophages resident in tissues) are an important origin of osteoclasts in inflammatory and immune environment. Although there are many reports on macrophages and osteoclasts, there is still a lack of systematic reviews on the macrophage-osteoclast axis in osteoimmunity. Elucidating the role of the macrophage-osteoclast axis in osteoimmunity is of great significance for the research or treatment of bone damage caused by inflammation and immune diseases. In this article, we introduced in detail the concept of osteoimmunity and the mechanism and regulators of the differentiation of macrophages into osteoclasts. Furthermore, we described the role of the macrophage-osteoclast axis in typical bone damage caused by inflammation and immune diseases. These provide a clear knowledge framework for studying macrophages and osteoclasts in inflammatory and immune environments. And targeting the macrophage-osteoclast axis may be an effective strategy to treat bone damage caused by inflammation and immune diseases.

Regulating Gut Microbiome: Therapeutic Strategy for Rheumatoid Arthritis During Pregnancy and Lactation

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation and bone destruction. Microbial infection is considered to be the most important inducement of RA. The pregnancy planning of women in childbearing age is seriously affected by the disease activity of RA. Gut microbiome, related to immunity and inflammatory response of the host. At present, emerging evidence suggested there are significant differences in the diversity and abundance of gut microbiome during pregnancy and lactation, which may be associated with the fluctuation of RA disease activity. Based on these research foundations, we pioneer the idea of regulating gut microbiome for the treatment of RA during pregnancy and lactation. In this review, we mainly introduce the potential treatment strategies for controlling the disease activity of RA based on gut microbiome during pregnancy and lactation. Besides, we also briefly generalize the effects of conventional anti-rheumatic drugs on gut microbiome, the effects of metabolic changes during pregnancy on gut microbiome, alteration of gut microbiome during pregnancy and lactation, and the effects of anti-rheumatic drugs commonly used during pregnancy and lactation on gut microbiome. These will provide a clear knowledge framework for researchers in immune-related diseases during pregnancy. Regulating gut microbiome may be a potential and effective treatment to control the disease activity of RA during pregnancy and lactation.

Paeoniflorin-6'-o-benzene sulfonate (CP-25) improves vasculitis through inhibiting IL-17A/JAK/STAT3 signaling pathway in endothelial cells of HFD CIA rats

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects not only joints but also multiple organ systems including cardiovascular system. Endothelial dysfunction plays an important role in cardiovascular diseases (CVD). In RA, endothelial dysfunction exists at both the macrovascular and the microvascular levels, which is a precursor to vasculitis. This study aimed to investigate the pathogenesis of vasculitis and the therapeutic effect of CP-25 on vasculitis in high-fat diet (HFD) collagen-induced arthritis (CIA) rats. Experimental groups were divided into normal group, HFD group, CIA group, HFD CIA group, CP-25 group and MTX group. In vitro, IL-17A was used to stimulate human umbilical vein endothelial cells (HUVECs), and then CP-25 was used to intervene. Results showed that CP-25 reduced global scoring (GS), arthritis index (AI), and swollen joint count (SJC) scores, improved histopathological score, reduced T cells percentage, and decreased IL-17A and ICAM-1 levels. Besides, CP-25 reduced the expression of p-STAT3 to normal levels in vascular of HFD CIA rats. In vitro, IL-17A promoted the expression of p-JAK1, p-JAK2, p-JAK3, pSTAT3, and ICAM-1, and CP-25 inhibited the expression of p-JAK1, p-JAK2, p-JAK3, p-STAT3, and ICAM-1. In conclusion, CP-25 might inhibit endothelial cell activation through inhibiting IL-17A/JAK/STAT3 signaling pathway, which improves vasculitis in HFD CIA rats.

Etanercept Inhibits B Cell Differentiation by Regulating TNFRII/TRAF2/NF-κB Signaling Pathway in Rheumatoid Arthritis

Objective

To explore the role of B cells in rheumatoid arthritis (RA) and the potential effects and mechanisms of etanercept on B cells.

Methods

In RA patients, the levels of tumor necrosis factor-α (TNF-α) and B cell activating factor (BAFF) were detected by ELISA. The percentage of B cell subsets was measured by flow cytometry. Laboratory indicators (rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate) and clinical indicators (disease activity score in 28 joints, health assessment questionnaire score, swollen joint counts, tender joint counts) were measured. The correlation between B cell subsets and laboratory indicators or clinical indicators was analyzed. In mice, B cells proliferation was detected by CCK-8 kit. The expression of TNFRII and the percentage of B cell subsets in spleen were detected by flow cytometry. The expressions of TRAF2, p38, P-p38, p65, P-p65 in B cells were detected by WB.

Results

The percentage of CD19⁻CD27⁺CD138⁺ plasma B cells was positively correlated with ESR or RF. Etanercept could decrease the percentage of CD19⁺ total B cells, CD19⁺CD27⁺ memory B cells and CD19⁻CD27⁺CD138⁺ plasma B cells, reduce the levels of TNF-α, BAFF, relieve clinical and laboratory indicators in RA patients. In addition, etanercept could inhibit the proliferation of B cells, bate the differentiation of transitional B cells to mature B cells, down-regulate the expression of TNFRII, TRAF2, P-p38, P-p65 in B cells.

Conclusion

B cells act a key role in the pathogenesis of RA. Etanercept inhibits B cells differentiation by down-regulating TNFRII/TRAF2/NF-κB signaling pathway.

The Role of Microbiomes in Pregnant Women and Offspring: Research Progress of Recent Years

Pregnancy is a complicated and delicate process, the maternal body undergoes changes on hormones, immunity, and metabolism during pregnancy to support fetal development. Microbiomes in the human body mainly live in the intestine, and the human gut microbiomes are complex, which composed of more than 500 to 1500 different bacteria, archaea, fungi, and viruses. Studies have shown that these microbiomes are not only involved in the digestion and absorption of food but also indispensable in regulating host health. In recent years, there has been increasing evidence that microbiomes are important for pregnant women and fetuses. During pregnancy, there will be great changes in gut microbiomes. Regulating gut microbiomes is beneficial to the health of the mother and the fetus. In addition, many complications during pregnancy are related to gut microbiomes, such as gestational diabetes, obesity, preeclampsia, digestive disorders, and autoimmune diseases. Moreover, the microbiomes in mother's milk and vagina are closely related to the colonization of microbiomes in the early life of infants. In this review, we systematically review the role of maternal microbiomes in different gestational complications, and elucidate the function and mechanism of maternal microbiomes in the neural development and immune system of offspring. These will provide a clear knowledge framework or potential research direction for researchers in related fields.

PSTPIP2 attenuates joint damage and suppresses inflammation in adjuvant-induced arthritis

Proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) is related to inflammation. In this study, we investigated the function of PSTPIP2 in adjuvant-induced arthritis (AIA) by using adeno-associated virus (AAV) to overexpress PSTPIP2 in rat. AIA rats were developed by injecting Lewis rats with complete Freund's adjuvant (CFA) on day 0. AAV-empty or AAV-PSTPIP2, or PBS was administered intraarticularly into each knee joint on day 8 postinduction. All animals were killed at day 18 after adjuvant injection. WB was used to detect the expression of PSTPIP2 in rat synovial tissues. Fluorescence microscopy showed the transduction efficiency in synovial tissue. The morphology of arthritic joints was examined by HE, safranin O/fast green, or Toluidine blue staining. The bone destruction was examined via X-ray and micro-CT analysis. Immunohistochemical analysis or TRAP staining were used to investigate the role of PSTPIP2 in osteoclasts and the expression of PSTPIP2 in synovial tissue. RT-qPCR and ELISA were used to examine the expression of pro-inflammatory cytokines in synovial tissue or serum. AIA rats were found to have decreased PSTPIP2 expression and AIA-associated bone loss and inflammatory infiltration. We showed that administration of AAV-PSTPIP2 before arthritis onset significantly reduces the severity of AIA. PSTPIP2 was highly expressed in synovial cells. In addition, inflammatory responses and the number of osteoclasts were reduced with AAV-PSTPIP2 treatment. These findings demonstrate that PSTPIP2 may improve the severity of AIA by inhibiting the function of fibroblast-like synoviocytes, suppressing inflammation and reducing the number of osteoclasts.