miR-125b is downregulated in systemic lupus erythematosus patients and inhibits autophagy by targeting UVRAG

American College of Rheumatology White Paper: The Effects of Climate Change on Rheumatic Conditions-An Evolving Landscape and a Path Forward

OBJECTIVE

Increases in global temperatures and extreme weather events associated with climate change have complex yet poorly understood detrimental impacts on human health. We reviewed the current published literature on climate change-related effects and rheumatic conditions.

METHODS

To summarize our current understanding of the likely effects of climate change, including increased air pollution, on rheumatic disease, we searched the published, peer-reviewed English-language literature from January 2000 to December 2022. Articles were reviewed by a team of rheumatologists and clinical and translational science researchers. Systematic review articles were not included but informed additional literature searches.

RESULTS

After extensive examination and adjudication, 88 articles met inclusion criteria and were selected for review. Much of the epidemiologic investigations assessed associations between air pollution and increased risk of development of rheumatoid arthritis, anti-citrullinated protein antibodies, flares of gout, and hospitalizations for systemic lupus erythematosus. Increased heat vulnerability was associated with higher odds of recurrent hospitalizations across rheumatic conditions. Mechanisms for observed associations are poorly understood but could include the effects of epigenetic changes, oxidative stress, and inflammatory cytokines. Studies had limitations, including restricted geography and populations studied without focus on historically marginalized communities at highest risk for adverse effects from pollution and climate change, the relative lack of mechanistic evaluations, and most with only indirect links to climate change.

CONCLUSION

To date, the published literature lacks studies that directly examine effects of climate change on rheumatic diseases. Collaborative translational and epidemiologic research is needed to enhance our understanding and awareness in this area.

Exosomes in Action: Unraveling Their Role in Autoimmune Diseases and Exploring Potential Therapeutic Applications

Exosomes are double phospholipid membrane vesicles that are synthesized and secreted by a variety of cells, including T cells, B cells, dendritic cells, immune cells, are extracellular vesicles. Recent studies have revealed that exosomes can play a significant role in under both physiological and pathological conditions. They have been implicated in regulation of inflammatory responses, immune response, angiogenesis, tissue repair, and antioxidant activities, particularly in modulating immunity in autoimmune diseases (AIDs). Moreover, variations in the expression of exosome-related substances, such as miRNA and proteins, may not only offer valuable perspectives for the early warning, and prognostic assessment of various AIDs, but may also serve as novel markers for disease diagnosis. This article examines the impact of exosomes on the development of AIDs and explores their potential for therapeutic application.

Effects of ambient UVB light on Pacific oyster Crassostrea gigas mantle tissue based on multivariate data

Ambient ultraviolet radiation (UVB) from solar and artificial light presents serious environmental risks to aquatic ecosystems. The Pacific oyster, Crassostrea gigas, perceives changes in the external environment primarily through its mantle tissue, which contains many nerve fibers and tentacles. Changes within the mantles can typically illustrate the injury of ambient UVB. In this study, a comprehensive analysis of phenotypic, behavioral, and physiological changes demonstrated that extreme UVB radiation (10 W/m²) directly suppressed the behavioral activities of C. gigas. Conversely, under ambient UVB radiation (5 W/m²), various physiological processes exhibited significant alterations in C. gigas, despite the behavior remaining relatively unaffected. Using mathematical model analysis, the integrated analysis of the full-length transcriptome, proteome, and metabolome showed that ambient UVB significantly affected the metabolic processes (saccharide, lipid, and protein metabolism) and cellular biology processes (autophagy, apoptosis, oxidative stress) of the C. gigas mantle. Subsequently, using Procrustes analysis and Pearson correlation analysis, the association between multi-omics data and physiological changes, as well as their biomarkers, revealed the effect of UVB on three crucial biological processes: activation of autophagy signaling (key factors: Ca2+, LC3B, BECN1, caspase-7), response to oxidative stress (reactive oxygen species, heat shock 70, cytochrome c oxidase), and recalibration of energy metabolism (saccharide, succinic acid, translation initiation factor IF-2). These findings offer a fresh perspective on the integration of multi-data from non-model animals in ambient UVB risk assessment.

MicroRNA-125b mediates Interferon-γ-induced downregulation of the vitamin D receptor in systemic lupus erythematosus

BACKGROUND

The inflammatory factor interferon (IFN)-γ is related to the occurrence and development of systemic lupus erythematosus (SLE). The vitamin D receptor (VDR) has an anti-inflammatory effect and its downregulation is involved in the onset of SLE. Our previous studies have confirmed that the expression of VDR in SLE peripheral blood mononuclear cells (PBMCs) is downregulated, which is negatively correlated with disease activity and inflammation. However, the mechanism underlying VDR downregulation in SLE is unknown.

METHODS

Based on the results of computer simulation analysis, the expression of VDR and four microRNAs (miR-17-3p, miR-34a, miR-346, and miR-125b) in SLE PBMC cells was analyzed under proinflammatory cytokine IFN‑γ treatment, and miR-125b was identified as the target miRNA. The relationship between IFN‑γ, miR-125b, and VDR was further assessed in THP‑1 cells.

RESULTS

We showed that IFN‑γ inhibited the expression of VDR and miR-125b. Further study revealed that VDR mRNA was positively correlated with miR-125b in THP‑1 cells after IFN‑γ intervention. After transfection of miR-125b mimic or inhibitor, the expression of VDR in the miR-125b inhibitor group was lower than in the control group and miR-125b mimic group, while expression in the control group was lower than in miR-125b mimic group. Transfection of miR-125b inhibitor into THP‑1 cells could further promote the ability of IFN‑γ to inhibit VDR.

CONCLUSION

The decrease in VDR expression promotes development of inflammation and SLE. These data suggest that miR-125b may mediate inflammatory factor IFN-γ-induced downregulation of VDR in the pathogenesis of SLE.

Systemic lupus erythematosus: From non-coding RNAs to exosomal non-coding RNAs

Systemic lupus erythematosus (SLE), as an immunological illness, frequently impacts young females. Both vulnerabilities to SLE and the course of the illness's clinical symptoms have been demonstrated to be affected by individual differences in non-coding RNA expression. Many non-coding RNAs (ncRNAs) are out of whack in patients with SLE. Because of the dysregulation of several ncRNAs in peripheral blood of patients suffering from SLE, these ncRNAs to be showed valuable as biomarkers for medication response, diagnosis, and activity. NcRNAs have also been demonstrated to influence immune cell activity and apoptosis. Altogether, these facts highlight the need of investigating the roles of both families of ncRNAs in the progress of SLE. Being aware of the significance of these transcripts perhaps elucidates the molecular pathogenesis of SLE and could open up promising avenues to create tailored treatments during this condition. In this review we summarized various non-coding RNAs and Exosomal non-coding RNAs in SLE.

The emerging role of noncoding RNAs in systemic lupus erythematosus: new insights into the master regulators of disease pathogenesis

Auto-immune diseases are a form of chronic disorders in which the immune system destroys the body's cells due to a loss of tolerance to self-antigens. Systemic lupus erythematosus (SLE), identified by the production of autoantibodies in different body parts, is one of the most well-known examples of these diseases. Although the etiology of SLE is unclear, the disease's progression may be affected by genetic and environmental factors. As studies in twins provide adequate evidence for genetic involvement in the SLE, other phenomena such as metallization, histone modifications, and alterations in the expression of noncoding RNAs (ncRNAs) also indicate the involvement of epigenetic factors in this disease. Among all the epigenetic alterations, ncRNAs appear to have the most crucial contribution to the pathogenesis of SLE. The ncRNAs' length and size are divided into three main classes: micro RNAs, long noncoding RNAs (LncRNA), and circular RNAs (circRNAs). Accumulating evidence suggests that dysregulations in these ncRNAs contributed to the pathogenesis of SLE. Hence, clarifying the function of these groups of ncRNAs in the pathophysiology of SLE provides a deeper understanding of the disease. It also opens up new opportunities to develop targeted therapies for this disease.

miR-125b Promotes the Proliferation, Migration and Invasion of Oral Squamous Cell Carcinoma (OSCC)

miR-125b is involved in several tumors. However, miR-125b’s role in oral squamous cell carcinoma (OSCC) is unclear. Tumor tissues and oral normal mucosa tissues of OSCC patients were collected to measure miR-125b level. Oral cancer Tca8113 cells were separated into control group, miR-125b inhibitor group, and miR-125b mimics group, followed by measuring miR-125b level by real time PCR, cell survival, migration and invasion, PI3K/mTOR signaling protein level by Western blot. miR-125b was upregulated in OSCC tumor tissues and related to clinical/TNM stage, metastasis and overall survival (P < 0.05). miR-125b overexpression significantly promoted tumor cell behaviors and increased PI3K/mTOR phosphorylation (P < 0.05); while inhibiting miR-125b expression significantly inhibited tumor cell biological behaviors, and decreased PI3K/mTOR phosphorylation (P < 0.05). miR-125b level is increased in OSCC tumor tissues, which is related to clinicopathological characteristics. miR-125b overexpression promotes OSCC cell behaviors by regulating PI3K/mTOR signaling.

Expression of the miR-9-5p, miR-125b-5p and its target gene NFKB1 and TRAF6 in childhood-onset systemic lupus erythematosus (cSLE)

Childhood- onset systemic lupus erythematosus (cSLE) is a multisystem inflammatory disease that can lead to severe clinical conditions resulting in early comorbidities. Several genetic, environmental, and immunological factors are known to influence the onset of the disease. MiRNAs have been already considered as potential actors involved in the development and activity of the SLE. Thus, understanding the behavior of these regulators can contribute to clarify the inflammatory process affecting SLE patients. Among miRNAs, miR-125b-5p and miR-9-5p targeting NFKB1 and TRAF6 genes can be involved in the etio-pathogenesis of the disease by modulating inflammation. In this study we evaluated miR-9-5p and miR-125b-5p expression and its target genes NFKB1 and TRAF6 in peripheral blood samples (PBMC) from the 35 cSLE patients and 35 healthy controls. MiRNAs and gene target expression have been evaluated by using RT-PCR with specific TaqMan® probes. Both miR-9-5p [Fold Change (FC) = -2.21; p = 0.002] and miR-125b-5p (FC= -3.30; p < 0.0001) and NFKB1 (FC = -1.84; p < 0.001) were downregulated in cSLE patients, while TRAF6 was upregulated (FC = 1.80; p = 0.006) in cSLE patients when compared to controls. A significant correlation was found between miR-125b-5p and its target gene NFKB1 [Spearman (r) = 0.47; p = 0.023]. Our results showed miR-125b-5p and miR-9-5p differential expression in cSLE patients, possibly contributing to better understanding the role of these regulators in cSLE development and disease pathogenesis.

Gypenosides regulate autophagy through Sirt1 pathway and the anti-inflammatory mechanism of mitochondrial autophagy in systemic lupus erythematosus

To study the mechanism of gynostemma pentaphyllum saponins (GpS) regulating mitochondrial autophagy and anti-inflammatory through Sirtuin 1 (Sirt1) pathway in systemic lupus erythematosus (SLE). JURKAT cells were cultured in vitro, RT-PCR and western blotting (WB) were utilized to identify the expression of related-proteins in Sirt1 pathway and global autophagy and mitochondrial autophagy markers in JURKAT before and after GpS treatment induced by ultraviolet B (UVB), and the related-mechanism of GpS regulation of autophagy was analyzed. The SLE model was established to analyze the alleviating effects of GpS on various symptoms of lupus mice. Sirt1/AMPK/mTOR pathway was activated in UVB induced JURKAT cells. After the addition of GpS, WB revealed that the phosphorylation of AMPK decreased, the phosphorylation of mTOR increased, the expression of Sirt1 protein decreased, and the activation of the pathway was inhibited. Moreover, autophagy of JURKAT cells wasinhibited. In order to further verify the role of Sirt1 pathway, we activated Sirt1 expression in cells by constructing lentiviral vectors, and the therapeutic effect of GpS was significantly reduced. These results indicate GpS can exert autophagy regulation by inhibiting the activity of Sirt1 pathway. To treat SLE. GpS can significantly reduce the level of autoantibodies, kidney inflammation, immune complex deposition and urinary protein excretion, improve kidney function in lupus-prone mice. GpS can regulate autophagy and mitochondrial autophagy through Sirt1 pathway, which may be a potential mechanism for GpS to reduce the level of autoantibodies, kidney inflammation, immune complex deposition and urinary protein excretion, improve kidney function in lupus-prone mice.

Decreased miR-4512 Levels in Monocytes and Macrophages of Individuals With Systemic Lupus Erythematosus Contribute to Innate Immune Activation and Neutrsophil NETosis by Targeting TLR4 and CXCL2

Objective

Systemic lupus erythematosus (SLE) is an autoimmune disease with complex etiology that is not yet entirely understood. We aimed to elucidate the mechanisms and therapeutic potential of microRNAs (miRNAs) in SLE in a Tibetan population.

Methods

Peripheral blood mononuclear cells from SLE patients (n = 5) and healthy controls (n = 5) were used for miRNA–mRNA co-sequencing to detect miRNAs related to immune abnormalities associated with SLE. Luciferase reporter assay was used to identify potential targets of candidate miRNA. The target genes were verified in miRNA-agomir/antagomir transfection assays with multiple cells lines and by expression analysis. The effects of candidate miRNA on monocyte and macrophage activation were evaluated by multiple cytokine profiling. Neutrophil extracellular traps (NETs) formation was analyzed in vitro by cell stimulation with supernatants of monocytes and macrophages transfected with candidate miRNA. The rodent MRL/lpr lupus model was used to evaluate the therapeutic effect of CXCL2Ab on SLE and the regulation effect of immune disorders.

Results

Integrated miRNA and mRNA expression profiling identified miRNA-4512 as a candidate miRNA involved in the regulation of neutrophil activation and chemokine-related pathways. MiR-4512 expression was significantly reduced in monocytes and macrophages from SLE patients. MiR-4512 suppressed the TLR4 pathway by targeting TLR4 and CXCL2. Decreased monocyte and macrophage miR-4512 levels led to the expression of multiple proinflammatory cytokines in vitro. Supernatants of miR-4512 antagomir-transfected monocytes and macrophages significantly promoted NETs formation (P < 0.05). Blocking of CXCL2 alleviated various pathogenic manifestations in MRL/lpr mice, including kidney damage and expression of immunological markers of SLE.

Conclusions

We here demonstrated the role of miR-4512 in innate immunity regulation in SLE. The effect of miR-4512 involves the regulation of monocytes, macrophages, and NETs formation by direct targeting of TLR4 and CXCL2, indicating the miR-4512-TLR4-CXCL2 axis as a potential novel therapeutic target in SLE.

Targeting of EIF4EBP1 by miR-99a-3p affects the functions of B lymphocytes via autophagy and aggravates SLE disease progression

Excessive activation of immune cells plays a key role in the pathogenesis of systemic lupus erythematosus (SLE). The regulation of immune cells by miRNAs is a research hotspot. In this study, second-generation high-throughput sequencing revealed a reduction in miR-99a-3p expression in patients with SLE; however, the specific mechanism underlying this phenomenon remains unclear. After transfection with an miR-99a-3p agomir, the proliferation of Ball-1 cells decreased and the levels of their apoptosis increased. The opposite effects were observed in cells transfected with the miR-99a-3p antagomir. Luciferase reporter assay indicated that miR-99a-3p directly targeted EIF4EBP1. Rescue experiments confirmed the proposed interaction between miR-99a-3p and EIF4EBP1. In vitro, in vivo and clinical investigations further confirmed that the miR-99a-3p agomir reduced the expression of EIF4EBP1, LC3B and LAMP-2A. In the in vivo experiments, serum levels of anti-nuclear antibodies, double-stranded DNA, IgE, IgM, IL-6, IL-10 and B lymphocyte stimulator were higher in mice from the antagomir group than those in mice from the MRL/lpr group. Furthermore, the protein and mRNA levels of EIF4EBP1, LC3B and LAMP-2A, the intensity of immunohistochemical staining of EIF4EBP1, LC3B and LAMP-2A, the urinary protein levels, and the C3 immunofluorescence deposition increased in mice from the antagomir group. The upregulation of miR-99a-3p expression protected B cells from EIF4EBP1-mediated autophagy, whilst the downregulation of miR-99a-3p expression induced autophagy via the EIF4EBP1-mediated regulation of the autophagy signalling pathway in B cells isolated from individuals with SLE. Based on these results, miR-99a-3p and EIF4EBP1 may be considered potential targets for SLE treatment.

Optimization of BCG Therapy Targeting Neutrophil Extracellular Traps, Autophagy, and miRNAs in Bladder Cancer: Implications for Personalized Medicine

Bladder cancer (BC) is the ninth most common cancer and the thirteenth most common cause of mortality worldwide. Bacillus Calmette Guerin (BCG) instillation is a common treatment option for BC. BCG therapy is associated with the less adversary effects, compared to chemotherapy, radiotherapy, and other conventional treatments. BCG could inhibit the progression and recurrence of BC by triggering apoptosis pathways, arrest cell cycle, autophagy, and neutrophil extracellular traps (NETs) formation. However, BCG therapy is not efficient for metastatic cancer. NETs and autophagy were induced by BCG and help to suppress the growth of tumor cells especially in the primary stages of BC. Activated neutrophils can stimulate autophagy pathway and release NETs in the presence of microbial pathogenesis, inflammatory agents, and tumor cells. Autophagy can also regulate NETs formation and induce production of reactive oxygen species (ROS) and NETs. Moreover, miRNAs are important regulator of gene expression. These small non-coding RNAs are also considered as an essential factor to control the levels of tumor development. However, the interaction between BCG and miRNAs has not been well-understood yet. Therefore, the present study discusses the roles of miRNAs in regulations of autophagy and NETs formation in BCG therapy in the treatment of BC. The roles of autophagy and NETs formation in BC treatment and efficiency of BCG are also discussed.

MiR-125b inhibits cardiomyocyte apoptosis by targeting BAK1 in heart failure

Background

Although miR-125b plays a crucial role in many human cancers. However, its function in heart failure (HF) remains unclear. Our study aimed to investigate its involvement in heart failure.

Methods

In this study, the mouse HF model was successfully constructed through transverse aortic constriction (TAC) operation. Changes in mRNA and protein levels in isolated myocytes and heart tissues were examined using qRT-PCR, Western blot and Immunohistochemical staining and immunofluorescent staining. Changes in cardiac functions were examined using ultrasound. Interactions between miR-125b and BAK1 was analyzed using the luciferase reporter assay. Cardiomyocyte apoptosis was evaluated using the TUNEL staining.

Results

We found that miR-125b expression was significantly downregulated in myocardial tissues of HF mice. Moreover, miR-125b upregulation in HF mice injected with agomir-125b efficiently ameliorated cardiac function. Further, miR-125b upregulation significantly decreased the protein levels of apoptosis-related makers c-caspase 3 and Bax, while increased Bcl-2 expression. In addition, BAK1 was identified as a direct target of miR-125b. As expected, BAK1 overexpression observably reversed the effect of agomir-125b on cardiac function and on the expression of apoptosis-related makers in the heart tissues of HF mice.

Conclusions

Taken together, miR-125b overexpression efficiently attenuated cardiac function injury of HF mice by targeting BAK1 through inhibiting cardiomyocyte apoptosis, suggesting that miR-125b/BAK1 axis might be a potential target for the diagnosis or treatment of HF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00328-w.

The role of miRNAs in the regulation of autophagy in autoimmune diseases

Autoimmune diseases (AD), which are classified as chronic injuries, are caused by a specific auto-reactive reaction. The etiology of most ADs is not well understood. Meanwhile, Autophagy is a protective response defining as a catabolic method by lysosomes tending to maintain homeostasis acts by recycling and discrediting cell compartments. Autophagy plays a crucial role in controlling immune homeostasis by eliminating intracellular pathogens and presenting antigens to immune cognition. MicroRNAs are commonly known as endogenous non-coding small RNAs, which span 18-25 nt and take part in the gene expression at the post-transcriptional level regulation. miRNAs play important roles in different processes like, cell differentiation, duplicating, and apoptosis. Moreover, miRNAs are the critical molecules for the regular function of the immune system by modulating immune tolerance mechanisms and autoimmunity. Recent findings support the role of dysregulated miRNAs in the pathogenesis of ADs and in the regulation of autophagy. In this review, we will focus on the role of the miRNAs in the regulation of autophagy and then will explain the role of dysregulated miRNAs in the initiation of the ADs by modulating autophagy.

Protective effects of miR-155-5p silencing on IFN-γ-induced apoptosis and inflammation in salivary gland epithelial cells

Previous studies have demonstrated that microRNAs (miRNAs/miRs) serve a vital role in the pathogenesis of Sjögren's syndrome (SS). The present study aimed to investigate the role of miR-155-5p in SS and determine its underlying molecular mechanism. An inflammatory lesion model was established by stimulating salivary gland epithelial cells (SGECs) with interferon-γ (IFN-γ). The apoptosis of SGECs was measured by using flow cytometry. Levels of proinflammatory factors were detected by reverse transcription-quantitative PCR and ELISA, respectively. Immunofluorescence was used for p65 staining. Dual-luciferase reporter assay was performed to verify the interaction between miR-155-5p and arrestin β2 (ARRB2). The protein levels in the NF-κB signaling pathway were assessed by western blotting. The results of the present study demonstrated that treatment with IFN-γ increased miR-155-5p expression, in addition to inducing apoptosis and inflammation in SGECs. Furthermore, overexpression of miR-155-5p promoted IFN-γ-induced apoptosis and inflammation in SGECs. Overexpression of miR-155-5p also increased Bax protein expression, enzyme activities of caspase 3 and caspase 9, release of inflammatory cytokines interleukin-6 and tumor necrosis factor-α, and decreased Bcl-2 protein expression in IFN-γ-treated SGECs. By contrast, all of the effects aforementioned were reversed following miR-155-5p knockdown. These results demonstrated that miR-155-5p activated the NF-κB signaling pathway, where treatment with the NF-κB inhibitor, pyrrolidine dithiocarbamate, reversed the effects of miR-155-5p overexpression on the inflammatory factors in IFN-γ-induced SGECs. miR-155-5p was demonstrated to target ARRB2 and negatively regulated its expression levels, such that overexpression of ARRB2 reversed the effects of miR-155-5p overexpression on the inflammatory response, apoptosis and the NF-κB signaling pathway in IFN-γ-treated SGECs. Collectively, results from the present study suggest that miR-155-5p may activate the NF-κB signaling pathway by negatively regulating ARRB2 to promote salivary gland damage during SS pathogenesis. This suggests that miR-155-5p may serve to be a potential target for the treatment of SS.

The high expression of miR-564 in patients with systemic lupus erythematosus promotes differentiation and maturation of DC cells by negatively regulating TP53 expression in vitro

BACKGROUND

miRNA is involved in the occurrence and progression of systemic lupus erythematosus (SLE), but the regulatory effect of miRNA on dendritic cells in SLE patients is still unclear.

MATERIAL AND METHODS

Bioinformatics methods were used to analyze the differentially expressed miRNA and its target genes in SLE patients. In vitro experiments were conducted to explore the effects and mechanisms of differentially expressed miRNAs in SLE patients on the differentiation and maturation of monocyte-derived dendritic cells.

RESULTS

Bioinformatics analysis showed that miR-564 was up-regulated in SLE patients, and TP53 was the core target gene of miR-564. The expression level of miR-564 showed a rising trend during the differentiation and maturation of monocytes into Mo-DC cells. The differentiation, maturation and proliferation of Mo-DC cells were significantly inhibited by transfection with miR-564 antagomir. The expression of TP53 is negatively regulated by miR-564. In rescue experiments, the proliferation and migration of DC cells were significantly restored by co-transfection of miR-564 antagomir and TP53 si-RNA.

CONCLUSION

Highly expressed miR-564 promotes the maturation, proliferation of Mo-DC cells by negatively regulating the expression of TP53.

Hsa_circ_0010957 level is increased and sponges microRNA‑125b in CD4+ T cells of patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe autoimmune disorder, the pathogenesis of which remains largely unknown. The present study aimed to investigate the role and mechanism of circular RNAs in the etiopathogenesis of SLE. CD4⁺ T cells in patients with SLE expressed higher levels of hsa_circ_0010957 compared with healthy individuals and was a good differentiator of the active from inactive SLE disease. It was also determined that hsa_circ_0010957 mediated microRNA (miR)-125b/STAT3 signaling and subsequent secretion of inflammatory cytokines interleukin (IL)-18, IL-6 and IL-17, which are important factors in the process of SLE. Hsa_circ_0010957 abrogated the proinflammatory effect of IL-6 via the blockade of STAT3 signaling. In conclusion, increased hsa_circ_0010957 may be involved in SLE pathogenesis via miR-125b/STAT3 signaling. Hsa_circ_0010957 promises to be a potential biomarker and therapeutic target for SLE.

Therapeutic prospects of MicroRNAs carried by mesenchymal stem cells-derived extracellular vesicles in autoimmune diseases

Autoimmune diseases (ADs) are a class of chronic disease conditions with impaired tolerance to autoantigens. Currently, there is no effective treatment for ADs, and the existing medications have limitations due to non-specific targets and side effects. Accumulating evidence has shown that mesenchymal stem cells (MSCs) play a role in ADs treatment. These beneficial effects mainly rely on cell-to-cell communication through the secretion of extracellular vesicles (EVs) and soluble factors. MSC-derived EVs (MSC-EVs) could modulate adjacent and distinct cells by transferring various DNA, mRNA, non-coding RNAs, proteins, and lipids from parent cells to recipient cells. MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate multiple target genes at the post-transcriptional level and are involved in chronic inflammatory and immune processes. Compared to fluid, MSC-EVs delivery can protect miRNAs from the degradation of ribonucleases, ensuring that miRNAs are able to perform their respective crucial roles in AD recipient cells. In this review, we discussed the therapeutic prospects and challenges of miRNAs secreted by MSC-EVs (MSC-EV-miRNAs) by reviewing the experimentally verified therapeutic outcomes of MSC-EV-miRNAs for several ADs, including rheumatoid arthritis (RA), autoimmune hepatitis (AIH), asthma, colitis, systemic sclerosis (SSc) and graft-versus-host disease (GVHD).

Cytotoxin-Associated Gene A-Positive Helicobacter pylori Promotes Autophagy in Colon Cancer Cells by Inhibiting miR-125b-5p

Objectives

To investigate the effects of cytotoxin-associated gene A- (CagA-) positive Helicobacter pylori on proliferation, invasion, autophagy, and expression of miR-125b-5p in colon cancer cells.

Methods

Colon cancer cells were cocultured with H. pylori (CagA+) to analyze the effects of H. pylori on miR-125b-5p and autophagy. Colon cancer cells infected with H. pylori (CagA+) were mimicked by transfection of CagA plasmid. The effects of CagA on the proliferation, invasion, and autophagy of colon cancer cells were analyzed. Cell counting kit-8 (CCK-8), clone formation, and Transwell assays were used to detect cell viability, proliferation, and invasion ability, respectively. Proteins and miRNAs were detected by western blotting and qPCR, respectively.

Results

H. pylori (CagA+) inhibited expression of miR-125b-5p and promoted autophagy in colon cancer cells. MiR-125 b-5p was underexpressed in colon cancer cells after CagA overexpression. CagA promoted colon cancer cell proliferation, invasion, and autophagy. Overexpression of miR-125b-5p inhibited the proliferation, invasion, and autophagy of colon cancer cells and reversed the effects of CagA.

Conclusion

H. pylori (CagA+) infection may promote the development and invasion of colon cancer by inhibiting miR-125b-5p.

Abnormal expression of autophagy-related proteins in immune thrombocytopenia

Autophagy is a highly conserved protein degradation pathway that is essential for affecting some autoimmune diseases. Immune thrombocytopenia (ITP) is a common autoimmune disorder, and the complex dysregulation of cellular immunity has been observed; however, the relationship between autophagy-related proteins and immune responses in ITP remains unclear. Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression levels of Beclin-1, SQSTM1/p62 and LC3 were measured in the peripheral blood mononuclear cells (PBMCs) of 20 newly diagnosed patients with active ITP, 16 ITP patients in remission and 21 healthy volunteers. The stained Beclin-1 and SQSTM1/p62 proteins were also observed in the bone marrow of active ITP patients and normal controls by immunofluorescence. SQSTM1/p62 mRNA expression in PBMCs in newly diagnosed patients was significantly decreased. At the same time, Beclin-1 mRNA was increased significantly. During the remission stages, the levels of these autophagy-related proteins were comparable with those observed in healthy controls. Taken together, these results suggest that the aberrant expression of autophagy-related proteins might be involved in the pathogenesis of ITP. Further study of the autophagy pathway may provide a new strategy and direction for the treatment of ITP.

Regulation of Apoptosis and Inflammatory Response in Interleukin-1β-Induced Nucleus Pulposus Cells by miR-125b-5p Via Targeting TRIAP1

The aim of the present study was to determine the function of microRNA (miR)-125b-5p in lumbar disc degeneration (LDD). Nucleus pulposus (NP) cells were stimulated with 10 ng/ml IL-1β for 24 h to establish an LDD model. Reverse transcription-quantitative PCR was used to assess miR-125b-5p levels in human lumbar degenerative NP samples and IL-1β-treated NP cells. An interaction between miR-125b-5p and TP53-regulated inhibitor of apoptosis 1 (TRIAP1) was revealed by TargetScan 7.1 and dual-luciferase reporter assay. Protein levels of pro-inflammatory factors were determined using ELISA. Cell viability and apoptosis were evaluated by MTT and flow cytometry analysis, respectively. miR-125b-5p was markedly upregulated in both human lumbar degenerative NP specimens and IL-1β-treated NP cells. TRIAP1, which directly targets miR-125b-5p, was markedly downregulated in human lumbar degenerative NP specimens and IL-1β-treated NP cells. The levels of TNF-α and IL-6 were inhibited in IL-1β-treated NP cells transfected with miR-125b-5p inhibitor. Moreover, miR-125b-5p inhibitor increased NP cell viability, prevented apoptosis and repressed the apoptotic peptidase activating factor 1/caspase 9 pathway in IL-1β-treated NP cells. Thus, the present findings suggested that miR-125b-5p could regulate LDD by adjusting NP cell apoptosis and inflammatory responses via TRIAP1.

Programmed Cell Death Pathways in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by excessive inflammatory and immune responses and tissue damage. Increasing evidence has demonstrated the important role of programmed cell death in SLE pathogenesis. When apoptosis encounters with defective clearance, accumulated apoptotic cells lead to secondary necrosis. Different forms of lytic cell death, including secondary necrosis after apoptosis, NETosis, necroptosis, and pyroptosis, contribute to the release of damage-associated molecular patterns (DAMPs) and autoantigens, resulting in triggering immunity and tissue damage in SLE. However, the role of autophagy in SLE pathogenesis is in dispute. This review briefly discusses different forms of programmed cell death pathways and lay particular emphasis on inflammatory cell death pathways such as NETosis, pyroptosis, and necroptosis and their roles in the inflammatory and immune responses in SLE.

Non-coding RNAs regulate autophagy process via influencing the expression of associated protein

Autophagy is a tightly-regulated multi-step process involving the lysosomal degradation of proteins and cytoplasmic organelles. Central to this process is the formation of the autophagosome, a double membrane-bound vesicle, which is fuse with lysosomes or endosomes, and then deliver its cytoplasmic cargo to the lysosomes. Here, we summarize the recent process of autophagy, focusing on protein molecules, their complexes, and its essential roles of autophagy in various phases. Emerging evidence has revealed that miRNAs, lncRNAs, and circRNAs play an indispensable role in autophagy regulation by modulating targeting gene expression. This review we will summarize the main features of ncRNAs and point to gaps in our current knowledge of the connection between ncRNAs and autophagy, as well as their potential utilization in various disease phenotypes. Also, we highlight recent advances in ncRNAs and autophagy-associated protein interaction and how they regulate the autophagy process.

Modulated Autophagy by MicroRNAs in Osteoarthritis Chondrocytes

Osteoarthritis (OA) is a chronic joint disease characterized by articular cartilage regression. The etiology of OA is diverse, the exact pathogenesis of which remains unclear. Autophagy is a conserved maintenance mechanism in eukaryotic cells. Dysfunction of chondrocyte autophagy is regarded as a crucial pathogenesis of cartilage degradation in OA. MircoRNAs (miRNAs) are a category of small noncoding RNAs, acting as posttranscriptional modulators that regulate biological processes and cell signaling pathways via target genes. A series of miRNAs are involved in the progression of chondrocyte autophagy and are connected with numerous factors and pathways. This article focuses on the mechanisms of chondrocyte autophagy in OA and reviews the role of miRNA in their modulation. Potentially relevant miRNAs are also discussed in order to provide new directions for future research and improve our understanding of the autophagic network of miRNAs.

Extracellular Vesicles as Transmitters of Hypoxia Tolerance in Solid Cancers

Tumour hypoxia is a common feature of solid tumours that contributes to poor prognosis after treatment. This is mainly due to increased resistance of hypoxic cells to radio- and chemotherapy and the association of hypoxic cells with increased metastasis development. It is therefore not surprising that an increased hypoxic tumour fraction is associated with poor patient survival. The extent of hypoxia within a tumour is influenced by the tolerance of individual tumor cells to hypoxia, a feature that differs considerably between tumors. High numbers of hypoxic cells may, therefore, be a direct consequence of enhanced cellular capability inactivation of hypoxia tolerance mechanisms. These include HIF-1α signaling, the unfolded protein response (UPR) and autophagy to prevent hypoxia-induced cell death. Recent evidence shows hypoxia tolerance can be modulated by distant cells that have experienced episodes of hypoxia and is mediated by the systemic release of factors, such as extracellular vesicles (EV). In this review, the evidence for transfer of a hypoxia tolerance phenotype between tumour cells via EV is discussed. In particular, proteins, mRNA and microRNA enriched in EV, derived from hypoxic cells, that impact HIF-1α-, UPR-, angiogenesis- and autophagy signalling cascades are listed.