Down-regulation of miR-10a-5p in synoviocytes contributes to TBX5-controlled joint inflammation

The Transcription Factor Tbx5-Dependent Epigenetic Modification Contributes to Neuropathic Allodynia by Activating TRPV1 Expression in the Dorsal Horn

Nerve injury can induce aberrant changes in the spine; these changes are due to, or at least partly governed by, transcription factors that contribute to the genesis of neuropathic allodynia. Here, we showed that spinal nerve ligation (SNL, a clinical neuropathic allodynia model) increased the expression of the transcription factor Tbx5 in the injured dorsal horn in male Sprague Dawley rats. In contrast, blocking this upregulation alleviated SNL-induced mechanical allodynia, and there was no apparent effect on locomotor function. Moreover, SNL-induced Tbx5 upregulation promoted the recruitment and interaction of GATA4 and Brd4 by enhancing its binding activity to H3K9Ac, which was enriched at the Trpv1 promotor, leading to an increase in TRPV1 transcription and the development of neuropathic allodynia. In addition, nerve injury-induced expression of Fbxo3, which abates Fbxl2-dependent Tbx5 ubiquitination, promoted the subsequent Tbx5-dependent epigenetic modification of TRPV1 expression during SNL-induced neuropathic allodynia. Collectively, our findings indicated that spinal Tbx5-dependent TRPV1 transcription signaling contributes to the development of neuropathic allodynia via Fbxo3-dependent Fbxl2 ubiquitination and degradation. Thus, we propose a potential medical treatment strategy for neuropathic allodynia by targeting Tbx5.

Secretome profiling of human epithelial cells exposed to cigarette smoke extract and their effect on human lung microvascular endothelial cells

Cigarette smoke (CS) is one of the leading causes of pulmonary diseases and can induce lung secretome alteration. CS exposure-induced damages to human pulmonary epithelial cells and microvascular endothelial cells have been extensively demonstrated; however, the effects of the secretome of lung epithelial cells exposed to CS extracts (CSE) on lung microvascular endothelial cells are not fully understood. In this study, we aimed to determine the effects of the secretome of lung epithelial cells exposed to CSE on lung microvascular endothelial cells. Human lung epithelial cells, A549, were exposed to CSE, and the secretome was collected. Human lung microvascular endothelial cells, HULEC-5a, were used to evaluate the effect of the secretome of A549 exposed to CSE. Secretome profile, endothelial cell death, inflammation, and permeability markers were determined. CSE altered the secretome expression of A549 cells, and secretome derived from CSE-exposed A549 cells caused respiratory endothelial cell death, inflammation, and moderately enhanced endothelial permeability. This study demonstrates the potential role of cellular interaction between endothelial and epithelial cells during exposure to CSE and provides novel therapeutic targets or beneficial biomarkers using secretome analysis for CSE-related respiratory diseases.

Ocu-miR-10a-5p promotes the chondrogenic differentiation of rabbit BMSCs by targeting BTRC-mediated Wnt/β-catenin signaling pathway

MicroRNAs (miRNAs) play an important role in articular cartilage damage in osteoarthritis (OA). However, the biological role of miRNAs in the chondrogenic differentiation of bone marrow mesenchymal stem cell (BMSC) remains largely unclear. Rabbit bone marrow mesenchymal stem cells (rBMSCs) were isolated, cultured, and identified. Afterwards, rBMSCs were induced to chondrogenic differentiation, examined by Alcian Blue staining. Differentially expressed miRNAs were identified in rBMSCs between induced and non-induced groups by miRNA sequencing analysis, part of which was validated via PCR assay. Cell viability and apoptosis were assessed by CCK-8 assay and Hoechst staining. Saffron O staining was utilized to assess chondrocyte hyperplasia. The expression of specific chondrogenic markers, including COL2A1, SOX9, Runx2, MMP-13, Aggrecan, and BMP-2, were measured at mRNA and protein levels. The association between beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) and miR-10a-5p in the miRNA family from rabbit (ocu-miR-10a-5p) was determined by luciferase reporter assay. A total of 76 differentially expressed miRNAs, including 52 downregulated and 24 upregulated miRNAs, were identified in rBMSCs from the induced group. Inhibition of ocu-miR-10a-5p suppressed rBMSC viability and chondrogenic differentiation, as well as downregulated the expression of β-catenin, SOX9, COL2A1, MMP-13, and Runx2. BTRC was predicted and confirmed as a target of ocu-miR-10a-5p. Overexpression of BTRC rescued the promoting impacts of overexpressed ocu-miR-10a-5p on chondrogenic differentiation of rBMSCs and β-catenin expression. Taken together, our data suggested that ocu-miR-10a-5p facilitated rabbit BMSC survival and chondrogenic differentiation by activating Wnt/β-catenin signaling through BTRC.

The Killer's Web: Interconnection between Inflammation, Epigenetics and Nutrition in Cancer

Inflammation is a key contributor to both the initiation and progression of tumors, and it can be triggered by genetic instability within tumors, as well as by lifestyle and dietary factors. The inflammatory response plays a critical role in the genetic and epigenetic reprogramming of tumor cells, as well as in the cells that comprise the tumor microenvironment. Cells in the microenvironment acquire a phenotype that promotes immune evasion, progression, and metastasis. We will review the mechanisms and pathways involved in the interaction between tumors, inflammation, and nutrition, the limitations of current therapies, and discuss potential future therapeutic approaches.

Epigenetic regulation of inflammation: The metabolomics connection

Epigenetic factors are considered the regulator of complex machinery behind inflammatory disorders and significantly contributed to the expression of inflammation-associated genes. Epigenetic modifications modulate variation in the expression pattern of target genes without affecting the DNA sequence. The current knowledge of epigenetic research focused on their role in the pathogenesis of various inflammatory diseases that causes morbidity and mortality worldwide. Inflammatory diseases are categorized as acute and chronic based on the disease severity and are regulated by the expression pattern of various genes. Hence, understanding the role of epigenetic modifications during inflammation progression will contribute to the disease outcomes and therapeutic approaches. This review also focuses on the metabolomics approach associated with the study of inflammatory disorders. Inflammatory responses and metabolic regulation are highly integrated and various advanced techniques are adopted to study the metabolic signature molecules. Here we discuss several metabolomics approaches used to link inflammatory disorders and epigenetic changes. We proposed that deciphering the mechanism behind the inflammation-metabolism loop may have immense importance in biomarkers research and may act as a principal component in drug discovery as well as therapeutic applications.

miR-10a induces inflammatory responses in epileptic hippocampal neurons of rats via PI3K/Akt/mTOR signaling pathway

Epilepsy is a common chronic neurological disorder worldwide. MicroRNAs (miRNAs) play an important role in the pathogenesis of epilepsy. However, the mechanism of the regulatory effect of miR-10a on epilepsy is unclear. In this study, we investigated the effect of miR-10a expression on the PI3K/Akt/mTOR signaling pathway and inflammatory cytokines in epileptic hippocampal neurons of rats. The miRNA differential expression profile of rat epileptic brain was analyzed using bioinformatic approaches. Neonatal Sprague-Dawley rat hippocampal neurons were prepared as epileptic neuron models in vitro by replacing culture medium with magnesium-free extracellular solution. The hippocampal neurons were transfected with miR-10a mimics, and transcript levels of miR-10a, PI3K, Akt and mTOR were detected by quantitative reverse transcription-PCR, and PI3K, mTOR, Akt, TNF-α, IL-1β, IL-6 protein expression levels were detected by Western blot. Cytokines secretory levels were detected by ELISA. Sixty up-regulated miRNAs were identified in the hippocampal tissue of epileptic rats and might affect the PI3K-Akt signaling pathway. In the epileptic hippocampal neurons model, the expression levels of miR-10a were significantly increased, with decreasing levels of PI3K, Akt and mTOR, and increasing levels of TNF-α, IL-1β and IL-6. The miR-10a mimics promoted the expression of TNF-α, IL-1β and IL-6. Meanwhile, miR-10a inhibitor activated PI3K/Akt/mTOR pathway and inhibited cytokines secretion. Finally, cytokine secretion was increased by treated with PI3K inhibitor and miR-10a inhibitor. The miR-10a may promote inflammatory responses in rat hippocampal neurons by inhibiting the PI3K/Akt/mTOR pathway, suggesting that miR-10a may be one of the target therapeutic molecules for epilepsy treatment.

Saliva microRNA Profile in Children with and without Severe SARS-CoV-2 Infection

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) may impair immune modulating host microRNAs, causing severe disease. Our objectives were to determine the salivary miRNA profile in children with SARS-CoV-2 infection at presentation and compare the expression in those with and without severe outcomes. Children <18 years with SARS-CoV-2 infection evaluated at two hospitals between March 2021 and February 2022 were prospectively enrolled. Severe outcomes included respiratory failure, shock or death. Saliva microRNAs were quantified with RNA sequencing. Data on 197 infected children (severe = 45) were analyzed. Of the known human miRNAs, 1606 (60%) were measured and compared across saliva samples. There were 43 miRNAs with ≥2-fold difference between severe and non-severe cases (adjusted p-value < 0.05). The majority (31/43) were downregulated in severe cases. The largest between-group differences involved miR-4495, miR-296-5p, miR-548ao-3p and miR-1273c. These microRNAs displayed enrichment for 32 gene ontology pathways including viral processing and transforming growth factor beta and Fc-gamma receptor signaling. In conclusion, salivary miRNA levels are perturbed in children with severe COVID-19, with the majority of miRNAs being down regulated. Further studies are required to validate and determine the utility of salivary miRNAs as biomarkers of severe COVID-19.

USP25 UPREGULATION BOOSTS GSDMD -MEDIATED PYROPTOSIS OF ACINAR CELLS IN ACUTE PANCREATITIS

ABSTRACT

Acute pancreatitis (AP) is an inflammation-associated disorder in the digestive system. Ubiquitin-specific peptidase 25 ( USP25 ) can modulate inflammation in diseases. This study expounded on the role of USP25 in pyroptosis of acinar cells in AP. Acinar cells were treated with lipopolysaccharide (LPS) and caerulein (CRE) to induce AP. Afterward, the expression patterns of USP25 , microRNA (miR)-10a-5p, and Krüppel-like factor 4 ( KLF4 ) in acinar cells were examined. Then, acinar cell viability and levels of NLR family pyrin-domain containing 3 (NLRP3), cleaved caspase-1, cleaved N -terminal gasdermin D ( GSDMD - N ), interleukin (IL)-1β, and IL-18 were determined. We observed that USP25 was highly expressed in AP models, and silencing USP25 increased cell viability and inhibited pyroptosis of AP acinar cells. The bindings of USP25 to KLF4 and miR-10a-5p to KLF4 and the GSDMD 3'UTR sequence were validated. We found that USP25 binding to KLF4 inhibited ubiquitination degradation of KLF4 , KLF4 transcriptionally decreased miR-10a-5p expression, and miR-10a-5p targeted GSDMD expression. Finally, rescue experiments proved that KLF4 overexpression or miR-10a-5p suppression enhanced pyroptosis of AP acinar cells. Overall, USP25 stabilized KLF4 expression through deubiquitination, limited miR-10a-5p expression, and increased GSDMD expression, finally promoting pyroptosis of acinar cells in AP.

Circ_0000284 Promoted Acute Pancreatitis Progression through the Regulation of miR-10a-5p/Wnt/β-Catenin Pathway

Circular RNAs (circRNAs) have been found to be involved in the progression of acute pancreatitis (AP). The objective of our study was to investigate the effects of circ_0000284 on caerulein-induced AR42J cell injury. To mimic AP in vitro, rat pancreatic acinar AR42J cells were treated with caerulein. The expression of circ_0000284 and miR-10a-5p was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Enzyme-linked immunosorbent assay (ELISA) was employed to determine the content of inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor α (TNF-α). Western blotting was applied to analyze the levels of Wnt/β-catenin pathway-related and apoptosis-related proteins. Cell viability and apoptosis were monitored by Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. The target connection between circ_0000284 and miR-10a-5p was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. AP induced inflammation in patients, and caerulein treatment increased apoptosis and inflammation in AR42J cells. Circ_0000284 was upregulated in serum of AP patients and caerulein-induced AR42J cells, while Wnt/β-catenin pathway was inactivated. Knockdown of circ_0000284 could decrease apoptosis and inflammation in caerulein-induced AR42J cells, which was attenuated by miR-10a-5p inhibition or Wnt signaling pathway antagonist Dickkopf-related protein 1 (DKK1). MiR-10a-5p was sponged by circ_000028 and was downregulated in caerulein-induced AR42J cells. Circ_0000284 depletion could protect caerulein-induced AR42J cells from apoptosis and inflammation by upregulating miR-10a-5p expression and activating Wnt/β-catenin pathway, underscoring a potential target for AP therapy.

Protective effects of the notoginsenoside R1 on acute lung injury by regulating the miR-128-2-5p/Tollip signaling pathway in rats with severe acute pancreatitis

Notoginsenoside R1 (NG-R1), the extract and the main ingredient of Panax notoginseng, has anti-inflammatory effects and can be used in treating acute lung injury (ALI). In this study, we explored the pulmonary protective effect and the underlying mechanism of the NG-R1 on rats with ALI induced by severe acute pancreatitis (SAP). MiR-128-2-5p, ERK1, Tollip, HMGB1, TLR4, IκB, and NF-κB mRNA expression levels were measured using real-time qPCR, and TLR4, Tollip, HMGB1, IRAK1, MyD88, ERK1, NF-κB65, and P-IκB-α protein expression levels using Western blot. The NF-κB and the TLR4 activities were determined using immunohistochemistry, and TNF-α, IL-6, IL-1β, and ICAM-1 levels in the bronchoalveolar lavage fluid (BALF) using ELISA. Lung histopathological changes were observed in each group. NG-R1 treatment reduced miR-128-2-5p expression in the lung tissue, increased Tollip expression, inhibited HMGB1, TLR4, TRAF6, IRAK1, MyD88, NF-κB65, and p-IκB-α expression levels, suppressed NF-κB65 and the TLR4 expression levels, reduced MPO activity, reduced TNF-α, IL-1β, IL-6, and ICAM-1 levels in BALF, and alleviated SAP-induced ALI. NG-R1 can attenuate SAP-induced ALI. The mechanism of action may be due to a decreased expression of miR-128-2-5p, increased activity of the Tollip signaling pathway, decreased activity of HMGB1/TLR4 and ERK1 signaling pathways, and decreased inflammatory response to SAP-induced ALI. Tollip was the regulatory target of miR-128-2-5p.

Downregulation of LncRNA OIP5-AS1 Induced by IL-1β Aggravates Osteoarthritis via Regulating miR-29b-3p/PGRN

BACKGROUND

Long noncoding RNA (lncRNA) OIP5 antisense RNA 1 (OIP5-AS1) is an oncogenic lncRNA; however, its role in osteoarthritis (OA) pathology still remains unknown.

MATERIALS AND METHODS

qRT-PCR was performed to measure the expressions of OIP5-AS1, miR-29b-3p and progranulin (PGRN) mRNA in OA cartilage tissues and normal cartilage tissues. Chondrocyte cell lines, CHON-001 and ATDC5, were treated with different doses of interleukin-1β (IL-1β) to induce the inflammatory response. Overexpression plasmids, microRNA mimics, microRNA inhibitors and small interfering RNAs were constructed and transfected into CHON-001 and ATDC5 cells. CCK-8 assay was used for determining the cell viability and Transwell assay was used for monitoring cell migration. Western blot was applied to measure the expressions of apoptosis-related proteins. Enzyme-linked immunosorbent assay (ELISA) was adopted to measure the contents of inflammatory factors. StarBase and TargetScan were used to predict the binding sites between OIP5-AS1 and miR-29b-3p, miR-29b-3p and 3'-UTR of PGRN respectively, which were verified by dual luciferase reporter assay.

RESULTS

OIP5-AS1 and PGRN mRNA were downregulated while miR-29b-3p was upregulated in OA tissues and models. The up-regulated OIP5-AS1 facilitated the proliferation and migration of CHON-001 and ATDC5 cells, while ameliorated the apoptosis and inflammatory response. However, miR-29b-3p had opposite effects. PGRN was identified as a target gene of miR-29b-3p, which could be indirectly suppressed by OIP5-AS1 knockdown.

CONCLUSION

Downregulation of OIP5-AS1 induced by IL-1β could inhibit the proliferation and migration abilities of CHON-001 and ATDC5 cells and facilitate the apoptosis and inflammation response via regulating miR-29b-3p/PGRN axis.

MicroRNA-106b Overexpression Suppresses Synovial Inflammation and Alleviates Synovial Damage in Patients with Rheumatoid Arthritis

OBJECTIVES

To explore the effect of miR-106b on synovial inflammation and damage in rheumatoid arthritis (RA) patients, and further to investigate its possible mechanism.

METHODS

: Quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence, in situ hybridization and immunohistochemistry assay were separately used to verify the levels of miR-106b and cytokines in the synovial tissues of patients with RA or osteoarthritis (OA). Pearson correlation analysis was conducted to examine the bivariate relationship between miR-106b and cytokines or RANKL. Following the isolation and culture of fibroblast-like synoviocytes (FLS), the cells were transfected with lentivirus-mediated miR-106b mimic, miR-106b inhibitor, and negative control miR-106b mimic, respectively. Thereafter, cell proliferation was measured by Cell Counting Kit-8 assay, and cell invasion and migration capacity was assessed by Transwell assay. Furthermore, concentration and expression of cytokines were separately detected by Enzyme linked immunosorbent assay and Western blot.

RESULTS

Compared with osteoarthritis, validation by qRT-PCR showed that RA patients had a lower level of miR-106b and higher levels of receptor activator of nuclear factor-κ B ligand (RANKL), tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6). Additionally, the scatter plot showed that the relative transcription of miR-106b level was negatively correlated to the level of TNF-a, IL-6, and RNKAL in the synovial tissues of both RA and OA patients (All P<0.05). Furthermore, miR-106b overexpression suppressed cell proliferation, migration and invasion capacity of human RA-FLS.

CONCLUSIONS

miR-106b overexpression suppresses synovial inflammation and alleviates synovial damage, thus it may be served as a potential therapeutic target for RA patients.

LncRNA SNHG5 promotes chondrocyte proliferation and inhibits apoptosis in osteoarthritis by regulating miR-10a-5p/H3F3B axis

BACKGROUND

Osteoarthritis (OA) is a common degenerative joint disease in the elderly. Increasing evidence suggested that long non-coding RNAs (lncRNAs) played vital roles in OA progression. This study aimed to explore the role and mechanism of lncRNA small nucleolar RNA host gene 5 (SNHG5) in OA development.

METHODS

Chondrocytes were stimulated with interleukin-1β (IL-1β) in vitro. The levels of SNHG5, miR-10a-5p, and H3 histone family 3B (H3F3B) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and colony formation assay. Cell apoptosis was tested by flow cytometry. The levels of apoptosis-related and cartilage-related markers were detected by western blot. The interaction among SNHG5, miR-10a-5p, and H3F3B was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

RESULTS

SNHG5 and H3F3B were downregulated, while miR-10a-5p was upregulated in OA cartilage tissues. Knockdown of SNHG5 enhanced IL-1β-induced apoptosis in chondrocytes. Rescue experiments verified that SNHG5 hindered apoptosis in IL-1β-stimulated chondrocytes by sponging miR-10a-5p. Moreover, H3F3B was a target of miR-10a-5p, and miR-10a-5p promoted IL-1β-induced chondrocyte apoptosis by regulating H3F3B. In addition, SNHG5 regulated H3F3B expression via sponging miR-10a-5p in IL-1β-treated chondrocytes.

CONCLUSION

SNHG5 suppressed chondrocytes apoptosis in OA by regulating the miR-10a-5p/H3F3B axis, which provided a promising biomarker for OA treatment.

miR-205 and HMGB1 expressions in chronic periodontitis patients and their associations with the inflammatory factors

OBJECTIVE

This paper sets out to investigate the miR-205 and HMGB1 expressions in chronic periodontitis (PO) patients and their associations with the inflammatory factors.

METHODS

From February 2016 to May 2018, 68 PO patients treated in our hospital were recruited for the study and placed in a patient group (PG), and 60 healthy volunteers were also recruited and placed in a healthy group (HG). Serum samples were collected from both groups for the identification of miR-205 using qPCR, as well as to determine the HMGB1 and inflammatory factor (IL-1β, IL-6, TNF-α) expression levels using ELISA. The correlations of the miR-205 and HMGB1 expression levels with the periodontal clinical indicators and the inflammatory factors were analyzed using a correlation analysis.

RESULTS

In comparison with the HG expression, the serum miR-205 expression was lower, and the HMGB1 was elevated in PG (P < 0.05). An ROC curve analysis showed that the areas under the curve (AUCs) of the serum miR-205 and HMGB1 expressions in diagnosing PO were 0.936 and 0.955 respectively. However, the serum miR-205 expression in PG increased while the HMGB1 expression decreased post treatment (P < 0.05). A correlation analysis revealed an inverse association between the serum miR-205 expression levels and the periodontal clinical indicators [bleeding index (BI), probing depth (PD), plaque index (PLI), and attachment loss (AL)], and the inflammatory factors [interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α)], but there was a positive association between the HMGB1 expression level and these parameters.

CONCLUSIONS

miR-205 and HMGB1 are closely related to the progression of PO, and may be candidate biomarkers for the diagnosis and treatment of PO.

Differential Spatio-Temporal Regulation of T-Box Gene Expression by microRNAs during Cardiac Development

Cardiovascular development is a complex process that starts with the formation of symmetrically located precardiac mesodermal precursors soon after gastrulation and is completed with the formation of a four-chambered heart with distinct inlet and outlet connections. Multiple transcriptional inputs are required to provide adequate regional identity to the forming atrial and ventricular chambers as well as their flanking regions; i.e., inflow tract, atrioventricular canal, and outflow tract. In this context, regional chamber identity is widely governed by regional activation of distinct T-box family members. Over the last decade, novel layers of gene regulatory mechanisms have been discovered with the identification of non-coding RNAs. microRNAs represent the most well-studied subcategory among short non-coding RNAs. In this study, we sought to investigate the functional role of distinct microRNAs that are predicted to target T-box family members. Our data demonstrated a highly dynamic expression of distinct microRNAs and T-box family members during cardiogenesis, revealing a relatively large subset of complementary and similar microRNA-mRNA expression profiles. Over-expression analyses demonstrated that a given microRNA can distinctly regulate the same T-box family member in distinct cardiac regions and within distinct temporal frameworks, supporting the notion of indirect regulatory mechanisms, and dual luciferase assays on Tbx2, Tbx3 and Tbx5 3' UTR further supported this notion. Overall, our data demonstrated a highly dynamic microRNA and T-box family members expression during cardiogenesis and supported the notion that such microRNAs indirectly regulate the T-box family members in a tissue- and time-dependent manner.

Loss of microRNA-147 function alleviates synovial inflammation through ZNF148 in rheumatoid and experimental arthritis

MicroRNA-147 (miR-147) had been previously found induced in synoviocytes by inflammatory stimuli derived from T cells in experimental arthritis. This study was designed to verify whether loss of its function might alleviate inflammatory events in joints of experimental and rheumatoid arthritis (RA). Dark Agouti (DA) rats were injected intradermally with pristane to induce arthritis, and rno-miR-147 antagomir was locally administrated into individual ankle compared with negative control or rno-miR-155-5p antagomir (potential positive control). Arthritis onset, macroscopic severity, and pathological changes were monitored. While in vitro, gain or loss function of hsa-miR-147b-3p/hsa-miR-155-5p and ZNF148 was achieved in human synovial fibroblast cell line SW982 and RA synovial fibroblasts (RASF). The expression of miRNAs and mRNAs was detected by using RT-quantitative PCR, and protein expression was detected by using Western blotting. Anti-miR-147 therapy could alleviate the severity, especially for the synovitis and joint destruction in experimental arthritis. Gain of hsa-miR-147b-3p/hsa-miR-155-5p function in TNF-α stimulated SW982 and RASF cells could upregulate, in contrast, loss of hsa-miR-147b-3p/hsa-miR-155-5p function could downregulate the gene expression of TNF-α, IL-6, MMP3, and MMP13. Hence, such alteration could participate in synovial inflammation and joint destruction. RNAi of ZNF148, a miR-147's target, increased gene expression of TNF-α, IL-6, MMP3, and MMP13 in SW982 and RASF cells. Also, mRNA sequencing data showed that hsa-miR-147b-3p mimic and ZNF148 siRNA commonly regulated the gene expression of CCL3 and DEPTOR as well as some arthritis and inflammation-related pathways. Taken together, miR-147b-3p contributes to synovial inflammation through repressing ZNF148 in RA and experimental arthritis.

Mog1 knockout causes cardiac hypertrophy and heart failure by downregulating tbx5-cryab-hspb2 signalling in zebrafish

AIMS

MOG1 is a small protein that can bind to small GTPase RAN and regulate transport of RNA and proteins between the cytoplasm and nucleus. However, the in vivo physiological role of mog1 in the heart needs to be fully defined.

METHODS

Mog1 knockout zebrafish was generated by TALEN. Echocardiography, histological analysis, and electrocardiograms were used to examine cardiac structure and function. RNA sequencing and real-time RT-PCR were used to elucidate the molecular mechanism and to analyse the gene expression. Isoproterenol was used to induce cardiac hypertrophy. Whole-mount in situ hybridization was used to observe cardiac morphogenesis.

RESULTS

Mog1 knockout zebrafish developed cardiac hypertrophy and heart failure (enlarged pericardium, increased nppa and nppb expression and ventricular wall thickness, and reduced ejection fraction), which was aggravated by isoproterenol. RNAseq and KEGG pathway analyses revealed the effect of mog1 knockout on the pathways of cardiac hypertrophy, dilatation and contraction. Mechanistic studies revealed that mog1 knockout decreased expression of tbx5, which reduced expression of cryab and hspb2, resulting in cardiac hypertrophy and heart failure. Overexpression of cryab, hspb2 and tbx5 rescued the cardiac oedema phenotype of mog1 KO zebrafish. Telemetry electrocardiogram monitoring showed QRS and QTc prolongation and a reduced heart rate in mog1 knockout zebrafish, which was associated with reduced scn1b expression. Moreover, mog1 knockout resulted in abnormal cardiac looping during embryogenesis because of the reduced expression of nkx2.5, gata4 and hand2.

CONCLUSION

Our data identified an important molecular determinant for cardiac hypertrophy and heart failure, and rhythm maintenance of the heart.

Transformation of fibroblast-like synoviocytes in rheumatoid arthritis; from a friend to foe

Swelling and the progressive destruction of articular cartilage are major characteristics of rheumatoid arthritis (RA), a systemic autoimmune disease that directly affects the synovial joints and often causes severe disability in the affected positions. Recent studies have shown that type B synoviocytes, which are also called fibroblast-like synoviocytes (FLSs), as the most commonly and chiefly resident cells, play a crucial role in early-onset and disease progression by producing various mediators. During the pathogenesis of RA, the FLSs' phenotype is altered, and represent invasive behavior similar to that observed in tumor conditions. Modified and stressful microenvironment by FLSs leads to the recruitment of other immune cells and, eventually, pannus formation. The origins of this cancerous phenotype stem fundamentally from the significant metabolic changes in glucose, lipids, and oxygen metabolism pathways. Moreover, the genetic abnormalities and epigenetic alterations have recently been implicated in cancer-like behaviors of RA FLSs. In this review, we will focus on the mechanisms underlying the transformation of FLSs to a cancer-like phenotype during RA. A comprehensive understanding of these mechanisms may lead to devising more effective and targeted treatment strategies.

T-2 Toxin Induces Epiphyseal Plate Lesions via Decreased SECISBP2-Mediated Selenoprotein Expression in DA Rats, Exacerbated by Selenium Deficiency

OBJECTIVE

Both selenium (Se) deficiency and mycotoxin T2 lead to epiphyseal plate lesions, similar to Kashin-Beck disease (KBD). However, regulation of selenoproteins synthesis mediated by SECISBP2, in response to these 2 environmental factors, remained unclear. The present study proposed to explore the mechanism behind the cartilage degradation resulting from Se deficiency and mycotoxin T2 exposure.

DESIGN

Deep chondrocyte necrosis and epiphyseal plate lesions were replicated in Dark Agouti (DA) rats by feeding them T2 toxin/Se deficiency artificial synthetic diet for 2 months.

RESULTS

Se deficiency led to decreased expression of COL2α1, while T2 treatment reduced the heparan sulfate 6-O-sulfotransferase 2 (HS6ST2) expression, both of which affected the cartilage extracellular matrix metabolism in the rat models. The expression of Col2α1, Acan, Hs6st2, Secisbp2, Gpx1, and Gpx4 were all significantly decreased in cartilage tissues from DA rats, fed a Se-deficient diet or exposed to T2 toxin, contrary to Adamts4, whose expression was increased in both conditions. In addition, T2 treatment led to the decreased expression of SBP2, GPX1, GPX4, and total GPXs activity in C28/I2 cells.

CONCLUSION

DA rats exposed to T2 toxin and/or Se-deficient conditions serve as the perfect model of KBD. The 2 environmental risk factors of KBD, which serve as a "double whammy," can intensify the extracellular matrix metabolic imbalance and the antioxidant activity of chondrocytes, leading to articular cartilage degradation and epiphyseal plate abnormalities similar to those observed in KBD.

Extracellular vesicles-encapsulated microRNA-10a-5p shed from cancer-associated fibroblast facilitates cervical squamous cell carcinoma cell angiogenesis and tumorigenicity via Hedgehog signaling pathway

Cancer-associated fibroblast (CAF) secretes extracellular vesicle (EV)-encapsulated microRNAs (miRNAs) which have been underlined great promise for therapeutic target for diseases and cancers. Our study aimed to explore the role of EV-encapsulated miR-10a-5p from CAFs in angiogenesis in cervical cancer. Expression of miR-10a-5p in clinical samples of cervical cancer and cancer cells was detected by in situ hybridization and RT-qPCR. Results demonstrated that miR-10a-5p expression was upregulated in both cancer tissues and cells. CAFs and normal fibroblasts (NFs) from cervical cancer patient tissues were characterized under transmission electron microscopy, followed by EV isolation from CAFs. The EVs labeled with PKH67 were cultured with cervical squamous cell carcinoma (CSCC) cell line (SiHa) and HUVECs. Data indicated that CAF-EVs were internalized by cancer cells and promoted cell proliferation and tube formation. CAF-EVs then were transfected with miR-10a-5p inhibitor and then injected into nude mice. While injection of CAF-EVs promoted tumor growth and increased VEGFR and CD31 expression level, miR-10a-5p inhibitor-treated CAF-EVs resulted in decreased tumor volume and amount of vessel around tumor. Of note, dual-luciferase reporter gene assay and bioinformatic analysis indicated TBX5 as a target gene of miR-10a-5p. Moreover, EV-derived miR-10a-5p promoted angiogenesis in vivo and in vitro through activation of Hedgehog signaling via downregulation of TBX5. Taken altogether, miR-10a-5p in CAF-EVs promoted CSCC cell angiogenesis and tumorigenicity via activation of Hh signaling by inhibition of TBX5, providing insight into novel treatment based on miR-10a-5p against CSCC.

Long noncoding RNA LEF1-AS1 acts as a microRNA-10a-5p regulator to enhance MSI1 expression and promote chemoresistance in hepatocellular carcinoma cells through activating AKT signaling pathway

Long noncoding RNAs (lncRNAs) contribute to the development of hepatocellular carcinoma (HCC), which could regulate various HCC biological characteristics. Here, the study seeks to investigate the role of lncRNA LEF1-AS1 in HCC cell chemoresistance by regulating microRNA (miR)-10a-5p and Musashi1 (MSI1). The microarray-based analysis was employed to identify the HCC-related lncRNA-miRNA-gene regulatory network. Expression patterns of LEF1-AS1, miR-10a-5p, and MSI1 in the HCC cell lines, tissues were accessed by means of reverse transcription-quantitative polymerase chain reaction. Next, the interaction among LEF1-AS1, miR-10a-5p, and MSI1 in HCC was accessed by bioinformatics and dual-luciferase reporter gene assay. Then, the cell line resistant to cisplatin was established, which was then treated with sh/oe-lncRNA LEF1-AS1, miR-10a-5p-mimic, and oe/sh-MSI1 vectors alone or in combination. Afterward, the effect of LEF1-AS1, miR-10a-5p, and MSI1 on HCC cell chemoresistance, proliferation, and apoptosis was assessed. At last, in vivo experiments confirmed the role of MSI1 in tumor growth and chemoresistance in HCC. LEF1-AS1 might potentially affect the growth and chemoresistance of HCC cells by regulating miR-10a-5p and MSI1. LEF1-AS1 and MSI1 expression patterns were elevated, while miR-10a-5p was repressed in HCC tissues and cell lines. LEF1-AS1 combined to miR-10a-5p and regulated MSI1, thereby activating the protein kinase B (AKT) signaling pathway. Knockdown of LEF1-AS1 and MSI1 or elevation of miR-10a-5p compromised the proliferation of Huh7 cell line resistant to DDP and promoted its chemosensitivity and apoptosis. At last, these in vitro findings were also confirmed in vivo. Our results unraveled LEF1-AS1 acts as a miR-10a-5p modulator to promote chemoresistance of HCC cells by stimulating MSI1 and activating the AKT signaling pathway, which might provide a novel therapeutic target for HCC.

MiR-655-3p inhibits the progression of osteoporosis by targeting LSD1 and activating BMP-2/Smad signaling pathway

Osteoporosis (OP) is one of the most common chronic metabolic bone diseases in the seniors and postmenopausal women. Plenty of microRNAs (miRNAs) have been confirmed to be involved in OP progression. However, the role of miR-655-3p in osteogenic differentiation and bone formation was still unclear. In this study, we aimed to investigate the cellular function of miR-655-3p and its underlying mechanism in OP. We found that miR-655-3p expression was downregulated in both ovariectomized (OVX) mice bone tissues and MC3T3-E1 cells treated with simulated microgravity (MG). MiR-655-3p overexpression facilitated cell differentiation but suppressed cell apoptosis of MC3T3-E1 cells induced by simulated MG. Mechanistically, we confirmed that lysine-specific histone demethylase 1 (LSD1) is a downstream target gene of miR-655-3p. Furthermore, overexpression of miR-655-3p activated the bone morphogenetic protein 2 (BMP-2)/decapentaplegic homolog (Smad) signaling pathway by suppressing LSD1 expression. Moreover, LSD1 knockdown accelerated osteogenic differentiation and inhibited apoptosis in MC3T3-E1 cells under simulated MG. Additionally, the OVX mouse model was established to investigate the role of miR-655-3p/LSD1 axis in vivo. The results demonstrated that LSD1 could reverse the effects triggered by the injection of adeno-associated virus-miR-655-3p on OP development. Further investigations revealed that miR-655-3p boosted osteogenic differentiation through LSD1/BMP-2/Smad signaling pathway. In summary, these findings implied a potential value of miR-655-3p in OP therapy.

Overexpression of miR-10a-5p facilitates the progression of osteoarthritis

The current study was aimed at exploring the potential roles and possible mechanisms of miR-10a-5p in osteoarthritis (OA). We performed RT-qPCR, Western blot, CCK8, EdU Assay, and flow cytometry assay to clarify the roles of miR-10a-5p in OA. Furthermore, the whole transcriptome sequencing together with integrated bioinformatics analyses were conducted to elucidate the underlying mechanisms of miR-10a-5p involving in OA. Our results demonstrated that miR-10a-5p was upregulated in OA and acted as a significant contributing factor for OA. A large number of circRNAs, lncRNAs, miRNAs, and mRNAs were identified by overexpressing miR-10a-5p. Functional enrichment analyses indicated that these differentially-expressed genes were enriched in some important terms including PPAR signaling pathway, PI3K-Akt signaling pathway, and p53 signaling pathway. A total of 42 hub genes were identified in the protein-protein interaction network including SERPINA1, TTR, APOA1, and A2M. Also, we constructed the network regulatory interactions across coding and noncoding RNAs triggered by miR-10a-5p, which revealed the powerful regulating effects of miR-10a-5p. Moreover, we found that HOXA3 acted as the targeted genes of miR-10a-5p and miR-10a-5p contributed to the progression of OA by suppressing HOXA3 expression. Our findings shed insight on regulatory mechanisms of miR-10a-5p, which might provide novel therapeutic targets for OA.

Clinical significance of miRNAs in autoimmunity

MicroRNAs (miRNAs) are evolutionally conserved, single-stranded RNAs that regulate gene expression at the posttranscriptional level by disrupting translation. MiRNAs are key players in variety of biological processes that regulate the differentiation, development and activation of immune cells in both innate and adaptive immunity. The disruption and dysfunction of miRNAs can perturb the immune response, stimulate the release of inflammatory cytokines and initiate the production of autoantibodies, and contribute to the pathogenesis of autoimmune diseases, including systemic lupus erythmatosus (SLE), rheumatoid arthritis (RA), primary biliary cholangitis (PBC), and multiple sclerosis (MS). Accumulating studies demonstrate that miRNAs, which can be collected by noninvasive methods, have the potential to be developed as diagnostic and therapeutic biomarkers, the discovery and validation of which is essential for the improvement of disease diagnosis and clinical monitoring. Recently, with the development of detection tools, such as microarrays and NGS (Next Generation Sequencing), large amounts of miRNAs have been identified and suggest a critical role in the pathogenesis of autoimmune diseases. Several miRNAs associated diagnostic biomarkers have been developed and applied clinically, though the pharmaceutical industry is still facing challenges in commercialization and drug delivery. The development of miRNAs is less advanced for autoimmune diseases compared with cancer. However, drugs that target miRNAs have been introduced as candidates and adopted in clinical trials. This review comprehensively summarizes the differentially expressed miRNAs in several types of autoimmune diseases and discusses the role and the significance of miRNAs in clinical management. The study of miRNAs in autoimmunity promises to provide novel and broad diagnostic and therapeutic strategies for a clinical market that is still in its infancy.

PCV2 Regulates Cellular Inflammatory Responses through Dysregulating Cellular miRNA-mRNA Networks

Porcine circovirus type 2 (PCV2) is closely linked to postweaning multisystemic wasting syndrome (PMWS) and other PCV-associated diseases (PCVADs), which influence the global pig industry. MicroRNAs (miRNAs) are evolutionarily conserved classes of endogenous small non-coding RNA that regulate almost every cellular process. According to our previous transcription study, PCV2 infection causes up-regulation of genes related to inflammation. To reveal the function of miRNAs in PCV2 infection and PCV2-encoded miRNAs, next generation sequencing and data analysis was performed to explore miRNA expression in PCV2-infected cells and non-infected cells. Data analysis found some small RNAs matched the PCV2 genome but PCV2 does not express miRNAs in an in vitro infection (PK-15 cells). More than 297 known and 427 novel miRNAs were identified, of which 44 miRNAs were differently expressed (DE). The pathways of inflammation mediated by chemokine and cytokine signaling pathway (P00031), were more perturbed in PCV2-infected cells than in mock controls. DE miRNAs and DE mRNA interaction network clearly revealed that PCV2 regulates the cellular inflammatory response through dysregulating the cellular miRNA-mRNA network. MiRNA overexpression and down-expression results demonstrated that miRNA dysregulation could affect PCV2 infection-induced cellular inflammatory responses. Our study revealed that host miRNA can be dysregulated by PCV2 infection and play an important role in PCV2-modulated inflammation.

CircINHA resists granulosa cell apoptosis by upregulating CTGF as a ceRNA of miR-10a-5p in pig ovarian follicles

Mammalian ovarian follicular atresia is a complex and fine-regulated biological process with active involvement of connective tissue growth factor (CTGF). The emergence of studies of endogenous non-coding RNAs has raised a new aspect for exploration of the regulatory mechanisms involved in follicular atresia. Here, we aimed to illustrate a circRNA involved in the CTGF regulatory pathway during the apoptosis and follicular atresia of pig granulosa cells (GCs). We first detected a decreased expression pattern of CTGF during follicular atresia using IHC, FISH and qRT-PCR and confirmed the anti-apoptosis effect of CTGF in GCs in vitro by CTGF siRNA knockdown. Then, we used a dual luciferase activity assay to demonstrate CTGF as a direct functional target of miR-10a-5p, which was upregulated in atresic follicles and promoted the apoptosis of GCs in vitro. The negative effect of miR-10a-5p on GC viability was confirmed by cell cycle assays, cell proliferation/apoptosis assays and the WB detection of marker proteins. More importantly, we identified a novel circRNA, termed circINHA, that was downregulated during atresia in ovarian follicles, and we confirmed a direct interaction between miR-10a-5p and circINHA. Finally, we demonstrated that circINHA promoted GCs proliferation and inhibited GCs apoptosis via CTGF as a competing endogenous RNA (ceRNA) that directly bound to miR-10a-5p. Taken together, this study provides evidence for the circINHA/miR-10a-5p/CTGF regulatory pathway in follicular GC apoptosis and provides novel insights into the role of circRNAs in the modulation of ovarian physiological functions.

Epigenetic Changes in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease that affects about 1% of the world’s population. The etiology of RA remains unknown. It is considered to occur in the presence of genetic and environmental factors. An increasing body of evidence pinpoints that epigenetic modifications play an important role in the regulation of RA pathogenesis. Epigenetics causes heritable phenotype changes that are not determined by changes in the DNA sequence. The major epigenetic mechanisms include DNA methylation, histone proteins modifications and changes in gene expression caused by microRNAs and other non-coding RNAs. These modifications are reversible and could be modulated by diet, drugs, and other environmental factors. Specific changes in DNA methylation, histone modifications and abnormal expression of non-coding RNAs associated with RA have already been identified. This review focuses on the role of these multiple epigenetic factors in the pathogenesis and progression of the disease, not only in synovial fibroblasts, immune cells, but also in the peripheral blood of patients with RA, which clearly shows their high diagnostic potential and promising targets for therapy in the future.

miR-449a inhibits cell proliferation, migration, and inflammation by regulating high-mobility group box protein 1 and forms a mutual inhibition loop with Yin Yang 1 in rheumatoid arthritis fibroblast-like synoviocytes

Background

We previously found that high-mobility group box protein 1 (HMGB1) promoted cell proliferation, migration, invasion, and autophagy in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS), but little is known about its regulatory mechanism. The aim of this study was to investigate the regulatory mechanism of HMGB1 at the posttranscription level.

Methods

Real-time qPCR, CCK-8 cell proliferation assay, transwell cell migration assay, enzyme-linked immunosorbent assay (ELISA), and western blotting were used in this study. The targeting relationship between miRNA and mRNA was presented by the luciferase reporter assay.

Results

MiR-449a was downregulated in RA synovial tissue and inhibited RA-FLS proliferation, migration, and IL-6 production. MiR-449a directly targeted HMGB1 and inhibited its expression. Yin Yang 1(YY1) negatively regulated miR-449a expression and formed a mutual inhibition loop in RA-FLS. MiR-449a inhibited TNFα-mediated HMGB1 and YY1 overexpression and IL-6 production.

Conclusions

Our results reveal the regulatory mechanism of HMGB1 in RA and demonstrate that miR-449a is a crucial molecule in RA pathogenesis and a suitable candidate for miRNA replacement therapies in RA.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1920-0) contains supplementary material, which is available to authorized users.

The role of DNA methylation and hydroxymethylation in immunosenescence

A healthy functioning immune system is critical to stave off infectious diseases, but as humans and other organisms age, their immune systems decline. As a result, diseases that were readily thwarted in early life pose nontrivial harm and can even be deadly in late life. Immunosenescence is defined as the general deterioration of the immune system with age, and it is characterized by functional changes in hematopoietic stem cells (HSCs) and specific blood cell types as well as changes in levels of numerous factors, particularly those involved in inflammation. Potential mechanisms underlying immunosenescence include epigenetic changes such as changes in DNA methylation (DNAm) and DNA hydroxymethylation (DNAhm) that occur with age. The purpose of this review is to describe what is currently known about the relationship between immunosenescence and the age-related changes to DNAm and DNAhm, and to discuss experimental approaches best suited to fill gaps in our understanding.

Identification of key genes, pathways, and miRNA/mRNA regulatory networks of CUMS-induced depression in nucleus accumbens by integrated bioinformatics analysis

INTRODUCTION

Major depressive disorder (MDD) is a recurrent, devastating mental disorder, which affects >350 million people worldwide, and exerts substantial public health and financial costs to society. Thus, there is a significant need to discover innovative therapeutics to treat depression efficiently. Stress-induced dysfunction in the subtype of neuronal cells and the change of synaptic plasticity and structural plasticity of nucleus accumbens (NAc) are implicated in depression symptomology. However, the molecular and epigenetic mechanisms and stresses to the NAc pathological changes in depression remain elusive.

MATERIALS AND METHODS

In this study, treatment group mice were treated continually with the chronic unpredictable mild stress (CUMS) until expression of depression-like behaviors were found. Depression was confirmed with sucrose preference, novelty-suppressed feeding, forced swimming, and tail suspension tests. We applied high-throughput RNA sequencing to assess microRNA expression and transcriptional profiles in the NAc tissue from depression-like behaviors mice and control mice. The regulatory network of miRNAs/mRNAs was constructed based on the high-throughput RNA sequence and bioinformatics software predictions.

RESULTS

A total of 17 miRNAs and 10 mRNAs were significantly upregulated in the NAc of CUMS-induced mice with depression-like behaviors, and 12 miRNAs and 29 mRNAs were downregulated. A series of bioinformatics analyses showed that these altered miRNAs predicted target mRNA and differentially expressed mRNAs were significantly enriched in the MAPK signaling pathway, GABAergic synapse, dopaminergic synapse, cytokine-cytokine receptor interaction, axon guidance, regulation of autophagy, and so on. Furthermore, dual luciferase report assay and qRT-PCR results validated the miRNA/mRNA regulatory network.

CONCLUSION

The deteriorations of GABAergic synapses, dopaminergic synapses, neurotransmitter synthesis, as well as autophagy-associated apoptotic pathway are associated with the molecular pathological mechanism of CUMS-induced depression.

Cytokine Targeting by miRNAs in Autoimmune Diseases

Persistent and excessive cytokine production is a hallmark of autoimmune diseases and may play a role in disease pathogenesis and amplification. Therefore, cytokine neutralization is a useful therapeutic strategy to treat immune-mediated conditions. MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression in diverse biological processes. Altered miRNA levels are observed in most autoimmune diseases and are recognized to influence autoimmunity through different mechanisms. Here, we review the impact of altered miRNA levels on the expression of cytokines that play a relevant pathogenic role in autoimmunity, namely primary pro-inflammatory cytokines, the IL-17/IL-23 axis, type I interferons and IL-10. Regulation can be either “direct” on the target cytokine, or “indirect,” meaning that one given miRNA post-transcriptionally regulates the expression of a protein that in turn influences the level of the cytokine. In addition, miRNAs associated with extracellular vesicles can regulate cytokine production in neighboring cells, either post-transcriptionally or via the stimulation of innate immune RNA-sensors, such as Toll-like receptors. Because of their tremendous potential as physiological and pathological regulators, miRNAs are in the limelight as promising future biopharmaceuticals. Thus, these studies may lead in the near future to the design and testing of therapeutic miRNAs as next generation drugs to target pathogenic cytokines in autoimmunity.

Epigenetics of inflammatory arthritis

PURPOSE OF REVIEW

Aberrant epigenetic changes in DNA methylation, histone marks, and noncoding RNA expression regulate the pathogenesis of many rheumatic diseases. The present article will review the recent advances in the epigenetic profile of inflammatory arthritis and discuss diagnostic biomarkers and potential therapeutic targets.

RECENT FINDINGS

Methylation signatures of fibroblast-like synoviocytes not only distinguish rheumatoid arthritis (RA) and osteoarthritis (OA), but also early RA from late RA or juvenile idiopathic arthritis. Methylation patterns are also specific to individual joint locations, which might explain the distribution of joint involvement in some rheumatic diseases. Hypomethylation in systemic lupus erythematosus (SLE) T cells is, in part, because of active demethylation and 5-hydroxymethylation. The methylation status of some genes in SLE is associated with disease severity and has potential as a diagnostic marker. An integrative analysis of OA methylome, transcriptome, and proteome in chondrocytes has identified multiple-evidence genes that might be evaluated for therapeutic potential. Class-specific histone deacetylase inhibitors are being evaluated for therapy in inflammatory arthritis.

SUMMARY

Disease pathogenesis is regulated by the interplay of genetics, environment, and epigenetics. Understanding how these mechanisms regulate cell function in health and disease has implications for individualized therapy.

MicroRNAs in Autoimmunity and Hematological Malignancies

Autoimmunity and hematological malignancies are often concomitant in patients. A causal bidirectional relationship exists between them. Loss of immunological tolerance with inappropriate activation of the immune system, likely due to environmental and genetic factors, can represent a breeding ground for the appearance of cancer cells and, on the other hand, blood cancers are characterized by imbalanced immune cell subsets that could support the development of the autoimmune clone. Considerable effort has been made for understanding the proteins that have a relevant role in both processes; however, literature advances demonstrate that microRNAs (miRNAs) surface as the epigenetic regulators of those proteins and control networks linked to both autoimmunity and hematological malignancies. Here we review the most up-to-date findings regarding the miRNA-based molecular mechanisms that underpin autoimmunity and hematological malignancies.

miR-145 eliminates lipopolysaccharides-induced inflammatory injury in human fibroblast-like synoviocyte MH7A cells

Recently, it has been accepted that miR-based therapy may be beneficial for rheumatoid arthritis (RA). This study aimed to evaluate the potential involvement of miR-145 in RA in vitro. The expression of miR-145 in the human fibroblast-like synoviocyte line MH7A was overexpressed by miR-mimic transfection, after which cells were subjected to lipopolysaccharides (LPS). Cell viability, apoptosis, and the release of pro-inflammatory cytokines were measured. The result showed that the apoptosis and the release of IL-1β, IL-6, IL-8, and TNF-α were significantly induced by LPS. Meanwhile, LPS treatment led to downregulation of miR-145. miR-145 overexpression in LPS-untreated MH7A cells had no impacts on cell apoptosis and inflammation. But, restoring miR-145 expression in LPS-stimulated cells by supplementation of a miR-145 mimic protected MH7A cells against LPS-induced apoptosis and inflammation. Furthermore, miR-145 overexpression in LPS-untreated MH7A cells slightly blocked the PI3K/ATK and mTOR pathways, whereas miR-145 overexpression in LPS-stimulated cells notably repressed the LPS-induced activation of PI3K/ATK and MAPK/mTOR pathways. Our study suggested that miR-145 protected MH7A cells against LPS-induced apoptosis and inflammation by inhibiting the PI3K/AKT and MAPK/mTOR pathways.

Decreased MiR-128-3p alleviates the progression of rheumatoid arthritis by up-regulating the expression of TNFAIP3

Background: Rheumatoid arthritis (RA) is a inflammatory disease that characterized with the destruction of synovial joint, which could induce disability. Inflammatory response mediated the RA. It has been reported that MiR-128-3p is significantly increased in RA, while the potential role was still unclear.

Methods: T cells in peripheral blood mononuclear cell (PBMC) were isolated from the peripheral blood from people of RA and normal person were used. Real-time PCR was performed to detect the expression of MiR-128-3p, while the protein expression of tumor necrosis factor-α-induced protein 3 (TNFAIP3) was determined using Western blot. The levels of IL-6 and IL-17 were measured using enzyme-linked immunosorbent assay (ELISA). The expression of CD69 and CD25 was detected using flow cytometry. The RA mouse model was constructed for verification of the role of MiR-128-3p.

Results: The expression of MiR-128-3p was significantly increased, while TNFAIP3 was decreased, the levels of IL-6 and IL-17 were also increased in the T cells of RA patients. Down-regulated MiR-128-3p significantly suppressed the expression of p-IkBα and CD69, and CD25in T cells. MiR-128-3p targets TNFAIP3 to regulate its expression. MiR-128-3p knockdown significantly suppressed the activity of nuclear factor κB (NF-κB) and T cells by up-regulating TNFAIP3, while cells co-transfected with si-TNFAIP3 abolished the effects of MiR-128-3p knockdown. The in vivo experiments verified the potential role of MiR-128-3p on RA.

Conclusion: Down-regulated MiR-128-3p significantly suppressed the inflammation response of RA through suppressing the activity of NF-κB pathway, which was mediated by TNFAIP3.

MicroRNA-mediated immune regulation in rheumatic diseases

MicroRNAs (miRNAs) are endogenous small, non-coding RNAs that regulate genome expression at the post-transcriptional level. They are involved in a wide range of physiological processes including the maintenance of immune homeostasis and normal function. Accumulating evidence from animal studies show that alterations in pan or specific miRNA expression would break immunological tolerance, leading to autoimmunity. Differential miRNA expressions have also been documented in patients of many autoimmune disorders. In this review, we highlight the evidence that signifies the critical role of miRNAs in autoimmunity, specifically on their regulatory roles in the pathogenesis of several rheumatic diseases including systemic lupus erythematosus, rheumatoid arthritis and spondyloarthritis. The potential of miRNAs as biomarkers and therapeutic targets is also discussed. Manipulation of dysregulated miRNAs in vivo through miRNA delivery or inhibition offers promise for new therapeutic strategies in treating rheumatic diseases.

miR-10a-5p, miR-99a-5p and miR-21-5p are steroid-responsive circulating microRNAs

Steroid-induced osteonecrosis of the femoral head (ONFH) is a common orthopedic disease. The lack of specific manifestations and effective diagnostic methods make it difficult for this disease to be diagnosed at early stages. Recent studies have shown that microRNAs (miRNA) participate in the development of steroid-induced ONFH, but there is limited research into the diagnostic use of circulating miRNAs. Blood samples from 23 human subjects (7 systemic lupus erythematosus (SLE) patients with steroid-induced ONFH; 7 SLE controls without ONFH; and 9 healthy controls) and 71 rats (19 with steroid-induced ONFH; 28 receiving steroids without ONFH; and 24 untreated controls) were collected to verify the abundance of changes of 6 previously identified ONFH-associated plasma miRNAs (miR-423-5p, miR-99a-5p, miR-10a-5p, miR-21-5p, miR-130a-3p and miR-6787-5p) by quantitative RT-PCR (Reverse Transcription-Polymerase Chain Reaction). In humans, the circulating levels of miR-10a-5p, miR-99a-5p and miR-21-5p were increased in SLE patients treated with cortico steroid regardless of ONFH status when compared with healthy controls. However, miR-423-5p, miR-6787-5p and miR-130a-3p showed no significant differences between the three groups. In the rat model, the success rate of steroid-induced ONFH was 40.4% (19/47) based on pathological examination and confirmation by micro-CT scan. Similar to human plasma, the circulating levels of miR-10a-5p, miR-99a-5p and miR-21-5p were increased in steroid-treated rats independent of ONFH development. The serum levels of miR-10a-5p, miR-99a-5p and miR-21-5p were increased by steroid treatment regardless of ONFH development in both humans and rats. These data suggested that miR-10a-5p, miR-99a-5p and miR-21-5p are steroid-responsive circulating miRNAs, but they are not specific for diagnosing steroid-induced ONFH.

Dysregulation of microRNAs in autoimmune diseases: Pathogenesis, biomarkers and potential therapeutic targets

MicroRNAs (miRNAs) are small, single-stranded, endogenous non-coding RNAs that repress the expression of target genes via post-transcriptional mechanisms. Due to their broad regulatory effects, the precisely regulated, spatial-specific and temporal-specific expression of miRNAs is fundamentally important to various biological processes including the immune homeostasis and normal function of both innate and adaptive immune response. Aberrance of miRNAs is implicated in the development of various human diseases, especially cancers. Increasing evidence has revealed a dysregulated expression pattern of miRNAs in autoimmune diseases, among which many play key roles in the pathogenesis. In this review we summarize these findings on miRNA dysregulation implicated in autoimmune diseases, focusing on four representative systemic autoimmune diseases, i.e. systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis and dermatomyositis. The causes of the dysregulation of miRNA expression in autoimmune diseases may include genetic and epigenetic variants, and various environmental factors. Further understanding of miRNA dysregulation and its mechanisms during the development of different autoimmune diseases holds enormous potential to bring about novel therapeutic targets or strategies for these complex human disorders, as well as novel circulating or exosomal miRNA biomarkers.

Down-regulation of miR-10a-5p promotes proliferation and restricts apoptosis via targeting T-box transcription factor 5 in inflamed synoviocytes

Synoviocytes from rheumatoid arthritis (RA) patients share certain features with tumor cells, such as over proliferation and invasion. Anomalous microRNA (miRNA) expression may participate in the pathogenesis of RA in different ways. The objective of the present study was to observe the role of miR-10a-5p targeting T-box transcription factor 5 (TBX5) gene on synoviocyte proliferation and apoptosis in RA. Human synovial sarcoma cell line, SW982 cells stimulating with interleukin-1β (IL-1β) were transfected with miR-10a-5p mimic and siRNA of TBX5. The real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis were used to evaluate the expression level of miR-10a-5p and TBX5 in SW982 cells respectively. Further, the proliferation and apoptosis of SW982 cells after treatment were determined by cell counting kit (CCK-8) and flow cytometry analysis respectively. We found that the miR-10a-5p showed down-regulated while TBX5 showed up-regulated expression in synoviocytes after stimulation with IL-1β. The miR-10a-5p mimic treatment showed a decline in cell proliferation while the increased rate of cell apoptosis as compared with control. Moreover, knockdown of TBX5 favored the apoptosis and reduced the cell proliferation as compared with control group. We conclude that down-regulation of miR-10a-5p promotes proliferation and restricts apoptosis via targeting TBX5 in inflamed synoviocytes.