NLRP3 inflammasome signaling as an early molecular response is negatively controlled by miR-186 in CFA-induced prosopalgia mice

Circulating microRNA Profiles Identify a Patient Subgroup with High Inflammation and Severe Symptoms in Schizophrenia Experiencing Acute Psychosis

Schizophrenia is a complex and heterogenous psychiatric disorder. This study aimed to demonstrate the potential of circulating microRNAs (miRNAs) as a clinical biomarker to stratify schizophrenia patients and to enhance understandings of their heterogenous pathophysiology. We measured levels of 179 miRNA and 378 proteins in plasma samples of schizophrenia patients experiencing acute psychosis and obtained their Positive and Negative Syndrome Scale (PANSS) scores. The plasma miRNA profile revealed three subgroups of schizophrenia patients, where one subgroup tended to have higher scores of all the PANSS subscales compared to the other subgroups. The subgroup with high PANSS scores had four distinctively downregulated miRNAs, which enriched 'Immune Response' according to miRNA set enrichment analysis and were reported to negatively regulate IL-1β, IL-6, and TNFα. The same subgroup had 22 distinctively upregulated proteins, which enriched 'Cytokine-cytokine receptor interaction' according to protein set enrichment analysis, and all the mapped proteins were pro-inflammatory cytokines. Hence, the subgroup is inferred to have comparatively high inflammation within schizophrenia. In conclusion, miRNAs are a potential biomarker that reflects both disease symptoms and molecular pathophysiology, and identify a patient subgroup with high inflammation. These findings provide insights for the precision medicinal strategies for anti-inflammatory treatments in the high-inflammation subgroup of schizophrenia.

Three Main SCFAs Mitigate Lung Inflammation and Tissue Remodeling Nlrp3-Dependent in Murine HDM-Induced Neutrophilic Asthma

Neutrophilic asthma is generally defined by poorly controlled symptoms and high levels of neutrophils in the lungs. Short-chain fatty acids (SCFAs) are proposed as nonpharmacological therapy for allergic asthma, but their impact on the neutrophilic asthma lacks evidence. SCFAs regulate immune cell responses and impact the inflammasome NLRP3, a potential pharmacological target for neutrophilic asthma. Here, we explored the capacity of SCFAs to mitigate murine-induced neutrophilic asthma and the contribution of NLRP3 to this asthma. The objective of this study is to analyze whether SCFAs can attenuate lung inflammation and tissue remodeling in murine neutrophilic asthma and NLRP3 contribution to this endotype. Wild-type (WT) C57BL6 mice orotracheally received 10 μg of HDM (house dust mite) in 80 μL of saline on days 0, 6-10. To explore SCFAs, each HDM group received 200 mM acetate, propionate, or butyrate. To explore NLRP3, Nlrp3 KO mice received the same protocol of HDM. On the 14th day, after euthanasia, bronchoalveolar lavage fluid (BALF) and lungs were collected to evaluate cellularity, inflammatory cytokines, and tissue remodeling. HDM group had increased BALF neutrophil influx, TNF-α, IFN-γ, IL-17A, collagen deposition, and mucus secretion compared to control. SCFAs distinctively attenuate lung inflammation. Only features of tissue remodeling were Nlrp3-dependent such as collagen deposition, mucus secretion, active TGF-β cytokine, and IMs CD206+. SCFAs greatly decreased inflammatory cytokines and tissue remodeling. Only tissue remodeling was dependent on NLRP3. It reveals the potential of SCFAs to act as an additional therapy to mitigate neutrophilic asthma and the NLRP3 contribution to asthma.

Heightened presence of inflammatory mediators in the cerebrospinal fluid of patients with trigeminal neuralgia

Introduction

Trigeminal neuralgia (TN) is a chronic, debilitating facial pain disease causing stabbing pain attacks in the sensory distribution of the trigeminal nerve. The underlying pathophysiology of TN is incompletely understood, although microstructural abnormalities consistent with focal demyelination of the trigeminal nerve root have been shown in patients with TN. Studies of the cerebrospinal fluid (CSF) in patients with TN suggest an increased prevalence of inflammatory mediators, potentially implicating neuroinflammation in the pathophysiology of TN, as it has been implicated in other chronic pain conditions.

Objectives

This study aimed to further assess the inflammatory profile of CSF in TN.

Methods

Cerebrospinal fluid was collected from 8 medically refractory patients with TN undergoing microvascular decompression surgery and 4 pain-free controls (2 with hemifacial spasm; 2 with normal pressure hydrocephalus). Cerebrospinal fluid was collected from the cerebellopontine angle cistern intraoperatively in the patients with TN. Inflammatory profiles of CSF samples were analyzed using a 71-plex cytokine and chemokine multiplex assay.

Results

Ten inflammatory markers were found to be significantly higher in TN CSF, and no analytes were significantly lower. Elevated factors can be classified into pro-inflammatory cytokines (IL-9, IL-18, and IL-33), chemokines (RANTES and ENA-78), the tumor necrosis factor superfamily (TRAIL and sCD40L), and growth factors (EGF, PDGF-AB/BB, and FGF-2).

Conclusion

This study further supports the notion that neuroinflammation is present in TN, and that multiple molecular pathways are implicated.

Effect of lidocaine on expression of P2X7, p-p38 and IL-Iβ in the thalamus of rats with trigeminal neuralgia

We investigated whether lidocaine can increase the pain threshold of rats with trigeminal neuralgia by affecting the expression of P2X7, p-p38 and IL-Iβ proteins in the thalamus. Thirty-three male Sprague-Dawley (SD) rats were randomly divided into three groups (n = 11): Sham group, Ion-CCI (infraorbital nerve chronic constriction injury) group and Ion-CCI+L group(Ion-CCI+lidocaine 10 mg/kg/day, i.p.). The mechanical pain threshold of rats was measured preoperatively and at 1, 3, 5, 7, 9, 11 and 14days after operation with the von Frey filament sensor tester. Fourteen days after operation, the rats were dissected to collect their whole brain, thalamus and trigeminal ganglion to detect IL-1β, P2X7, p38, and p-p38 protein expression. The pain threshold of rats in Ion-CCI+L group was lower than that in Sham group (p < 0.01) and higher than that in Ion-CCI group (p < 0.01).ELISA showed that IL-1β in the thalamus and trigeminal ganglion in Ion-CCI+L group were lower than those in ion-CCI group (p < 0.05) but higher than those in Sham group (p < 0.05). Western blot showed that the expression levels of P2X7 and p-p38 in the thalamus of rats in Ion-CCI+L group were lower than those in Ion-CCI group (p < 0.01) and higher than thaose in Sham group (p < 0.01),while the expression levels of IL-1β in the thalamus in Ion-CCI+L group were lower than those in Ion-CCI group (p < 0.05) and higher than those in Sham group (p < 0.01). Immunofluorescence showed that p-p38 in the thalamus in Ion-CCI+L group was lower than that in Ion-CCI group (p < 0.05) and higher than that in Sham group (p < 0.05). Lidocaine can reduce the inflammatory response of the central nervous system and increase the pain threshold of trigeminal neuralgia rats by inhibiting p2x7-p38-IL-1β signaling pathway.This pathway play an important role in the pathogenesis of trigeminal neuralgia, and it may be one of the targets for the treatment of trigeminal neuralgia.

Pathophysiology of Post-Traumatic Trigeminal Neuropathic Pain

Trigeminal nerve injury is one of the causes of chronic orofacial pain. Patients suffering from this condition have a significantly reduced quality of life. The currently available management modalities are associated with limited success. This article reviews some of the common causes and clinical features associated with post-traumatic trigeminal neuropathic pain (PTNP). A cascade of events in the peripheral and central nervous system function is involved in the pathophysiology of pain following nerve injuries. Central and peripheral processes occur in tandem and may often be co-dependent. Due to the complexity of central mechanisms, only peripheral events contributing to the pathophysiology have been reviewed in this article. Future investigations will hopefully help gain insight into trigeminal-specific events in the pathophysiology of the development and maintenance of neuropathic pain secondary to nerve injury and enable the development of new therapeutic modalities.

The Underlying Pathogenesis of Neurovascular Compression Syndromes: A Systematic Review

Neurovascular compression syndromes (NVC) are challenging disorders resulting from the compression of cranial nerves at the root entry/exit zone. Clinically, we can distinguish the following NVC conditions: trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. Also, rare cases of geniculate neuralgia and superior laryngeal neuralgia are reported. Other syndromes, e.g., disabling positional vertigo, arterial hypertension in the course of NVC at the CN IX-X REZ and torticollis, have insufficient clinical evidence for microvascular decompression. The exact pathomechanism leading to characteristic NVC-related symptoms remains unclear. Proposed etiologies have limited explanatory scope. Therefore, we have examined the underlying pathomechanisms stated in the medical literature. To achieve our goal, we systematically reviewed original English language papers available in Pubmed and Web of Science databases before 2 October 2021. We obtained 1694 papers after eliminating duplicates. Only 357 original papers potentially pertaining to the pathogenesis of NVC were enrolled in full-text assessment for eligibility. Of these, 63 were included in the final analysis. The systematic review suggests that the anatomical and/or hemodynamical changes described are insufficient to account for NVC-related symptoms by themselves. They must coexist with additional changes such as factors associated with the affected nerve (e.g., demyelination, REZ modeling, vasculature pathology), nucleus hyperexcitability, white and/or gray matter changes in the brain, or disturbances in ion channels. Moreover, the effects of inflammatory background, altered proteome, and biochemical parameters on symptomatic NVC cannot be ignored. Further studies are needed to gain better insight into NVC pathophysiology.

MiR-223-3p alleviates trigeminal neuropathic pain in the male mouse by targeting MKNK2 and MAPK/ERK signaling

BACKGROUND

Trigeminal neuralgia (TN) is a neuropathic pain that occurs in branches of the trigeminal nerve. MicroRNAs (miRNAs) have been considered key mediators of neuropathic pain. This study was aimed to elucidate the pathophysiological function and mechanisms of miR-223-3p in mouse models of TN.

METHODS

Infraorbital nerve chronic constriction injury (CCI-ION) was applied in male C57BL/6J mice to establish mouse models of TN. Pain responses were assessed utilizing Von Frey method. The expression of miR-223-3p, MKNK2, and MAPK/ERK pathway protein in trigeminal ganglions (TGs) of CCI-ION mice was measured using RT-qPCR and Western blotting. The concentrations of inflammatory cytokines were evaluated using Western blotting. The relationship between miR-223-3p and MKNK2 was tested by a luciferase reporter assay.

RESULTS

We found that miR-223-3p was downregulated, while MKNK2 was upregulated in TGs of CCI-ION mice. MiR-223-3p overexpression by an intracerebroventricular injection of Lv-miR-223-3p attenuated trigeminal neuropathic pain in CCI-ION mice, as well as reduced the protein levels of pro-inflammatory cytokines in TGs of CCI-ION mice. MKNK2 was verified to be targeted by miR-223-3p. Additionally, miR-223-3p overexpression decreased the phosphorylation levels of ERK1/2, JNK, and p38 protein in TGs of CCI-ION mice to inhibit MAPK/ERK signaling.

CONCLUSIONS

Overall, miR-223-3p attenuates the development of TN by targeting MKNK2 to suppress MAPK/ERK signaling.

The NLRP3 Inflammasome Pathway: A Review of Mechanisms and Inhibitors for the Treatment of Inflammatory Diseases

The NLRP3 inflammasome is a multiprotein complex that plays a pivotal role in regulating the innate immune system and inflammatory signaling. Upon activation by PAMPs and DAMPs, NLRP3 oligomerizes and activates caspase-1 which initiates the processing and release of pro-inflammatory cytokines IL-1β and IL-18. NLRP3 is the most extensively studied inflammasome to date due to its array of activators and aberrant activation in several inflammatory diseases. Studies using small molecules and biologics targeting the NLRP3 inflammasome pathway have shown positive outcomes in treating various disease pathologies by blocking chronic inflammation. In this review, we discuss the recent advances in understanding the NLRP3 mechanism, its role in disease pathology, and provide a broad review of therapeutics discovered to target the NLRP3 pathway and their challenges.

The Protective Effect of Picroside II on Isoflurane-Induced Neuronal Injury in Rats via Downregulating miR-195

INTRODUCTION

Numerous pieces of evidence demonstrated that isoflurane induces hippocampal cell injury and cognitive impairments. Picroside II has been investigated for its anti-apoptosis and antioxidant neuroprotective effects. We aimed to explore the protective effects of picroside II and the role of microRNA-195 (miR-195) on isoflurane-induced neuronal injury in rats.

METHODS

The Morris water maze test was used to evaluate the effects of isoflurane on rats regarding escape latency and time in quadrant parameters. Real-time quantitative PCR was used to detect the expression levels of miR-195 and pro-inflammatory cytokines, including inter-leukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) mRNA, in the hippocampal tissues and neuronal cells.

RESULTS

The picroside II significantly improves isoflurane-induced higher escape latency and lower time spent in the quadrant compared with the control rats. Picroside II also promotes cell viability and suppresses cell apoptosis of isoflurane-induced neuronal cells. Besides, picroside II suppresses the expression of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and miR-195 in vivo and in vitro. Furthermore, overexpression of miR-195 abrogates the effects of picroside II on the expression of pro-inflammatory cytokines. The appropriate dose of picroside II is 20 mg/kg.

CONCLUSION

Picroside II could protect the nervous system possibly through inhibiting the inflammatory response in the isoflurane-induced neuronal injury of rats. The protective effect of picroside II may be achieved by downregulating the expression of miR-195 and then inhibiting the inflammatory response.

Non-coding RNAs: The key regulators in NLRP3 inflammasome-mediated inflammatory diseases

Inflammasomes are multiprotein complexes responding to various microbes and endogenous danger signals, contributing to initiating the innate protective response of inflammatory diseases. NLRP3 inflammasome is a crucial regulator of pro-inflammatory cytokines (IL-1β and IL-18) production through activating caspase-1. Non-coding RNAs (ncRNAs) are a class of RNA transcripts lacking the ability to encode peptides or proteins. Its dysregulation leads to the development and progression of inflammation in diseases. Recently, accumulating evidence has indicated that NLRP3 inflammasome activation could be modulated by ncRNAs (lncRNAs, miRNAs, and circRNAs) in a variety of inflammatory diseases. This review focuses on the substantial role and function of ncRNAs in the NLRP3 inflammasome activation, providing novel insight for the future therapeutic approach of inflammatory diseases.

Puerarin Attenuates Complete Freund's Adjuvant-Induced Trigeminal Neuralgia and Inflammation in a Mouse Model via Sirt1-Mediated TGF-β1/Smad3 Inhibition

Background

Puerarin, an active compound of radix puerariae, is a major compound used in Chinese herbal medicines and it has been well known for its pharmacological effects, including antioxidant, anti‑inflammatory, neuroprotective and cardioprotective properties. The aim of the present study was to determine the role of puerarin (Pue) in complete Freund’s adjuvant (CFA)-induced trigeminal neuralgia (TN) and the effects of this compound on Sirt1 activity and on the progression of CFA-induced TN.

Methods

Mice were injected with CFA on the unilateral face to induce TN. A cell model of inflammation-associated TN was established by interleukin-1β (IL-1β; 10 ng/mL) and tumor necrosis factor-α (TNF-α; 50 ng/mL) stimulation of neurons. Reverse transcription-quantitative PCR and Western blot analyses were performed to analyze mRNA and protein expression levels in trigeminal ganglion and nerve cells. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was used to determine nerve cell apoptosis following IL-1β/TNF-α or Pue treatment.

Results

Pue is a conceivable Sirtuin1 (Sirt1) activator used for the prevention of trigeminal nerve injury that attenuates CFA-induced TN and inflammatory cytokine-evoked overactivation of neuronal inflammation and apoptosis. Treatment of mice with inflammatory cytokines induced upregulation of cleaved caspase-3 protein expression, which was neutralized by Pue supplementation. Both in vivo and in vitro experiments led to the conclusion that Pue modulated Sirt1 activation and repressed transforming growth factor-β1 (TGF-β1) protein expression and drosophila mothers against decapentaplegic homolog3 (Smad3) phosphorylation in order to exert neuroprotection.

Conclusion

The findings suggested that Pue functioned as a potential Sirt1 activator to improve neuroinflammation-induced TN and neuronal apoptosis via the suppression of TGF-β1/Smad3 activity. The pharmacological activity of Pue provides a new perspective for the effective prevention and treatment of TN.

Trigeminal neuralgia and genetics: A systematic review

Trigeminal neuralgia (TN) is a severe facial pain disease of unknown cause and unclear genetic background. To examine the existing knowledge about genetics in TN, we performed a systematic study asking about the prevalence of familial trigeminal neuralgia, and which genes that have been identified in human TN studies and in animal models of trigeminal pain. MedLine, Embase, Cochrane Library and Web of Science were searched from inception to January 2021. 71 studies were included in the systematic review. Currently, few studies provide information about the prevalence of familial TN; the available evidence indicates that about 1–2% of TN cases have the familial form. The available human studies propose the following genes to be possible contributors to development of TN: CACNA1A, CACNA1H, CACNA1F, KCNK1, TRAK1, SCN9A, SCN8A, SCN3A, SCN10A, SCN5A, NTRK1, GABRG1, MPZ gene, MAOA gene and SLC6A4. Their role in familial TN still needs to be addressed. The experimental animal studies suggest an emerging role of genetics in trigeminal pain, though the animal models may be more relevant for trigeminal neuropathic pain than TN per se. In summary, this systematic review suggests a more important role of genetic factors in TN pathogenesis than previously assumed.

The NLRP3-related inflammasome modulates pain behavior in a rat model of trigeminal neuropathic pain

AIMS

Nod-like receptor family pyrin domain containing 3 (NLRP3) may play an important role in neuropathic pain. Treatment for trigeminal neuropathic pain remains a challenge, as common drugs either do not demonstrate beneficial therapeutic effects or induce intolerance in patients.

MAIN METHODS

In a rat model of trigeminal neuropathic pain, pain caused by the malpositioning of dental implants is similar to that experienced by humans. We used masculine Sprague-Dawley rats with inferior alveolar nerve damage as a model to investigate the differential regulation of NLRP3. First, we confirmed the level of NLRP3 in the medullary dorsal horn and variation of pain response behavior after silencing the expression of NLRP3 inflammasome bodies in rats with trigeminal neuropathic pain. Second, under localized anesthesia, we extracted the lower left second molar, implanted a micro-dental implant, and deliberately injured the inferior alveolar nerve.

KEY FINDINGS

After nerve damage, the level of NLRP3-related inflammasomes was upregulated in microglia and the expression of a component of the inflammasome gradually increased during postoperative days 3-21. The suppression of adenovirus-shRNA-NLRP3 on postoperative day 1 markedly inhibited the expression of pro-inflammatory cytokines and the activation of the inflammasome and mechanical allodynia. Furthermore, it attenuated cell death in microglia, as evidenced by increased Bcl-2, Bcl-xL, Bax, and Bik expression.

SIGNIFICANCE

The level of NLRP3 in the dorsal horn is a pivotal factor in trigeminal neuropathic pain, and inhibition of the early expression of NLRP3 might serve as a potential therapeutic approach.

Modulatory mechanisms of NLRP3: Potential roles in inflammasome activation

The NLRP3 inflammasome regulates innate immune and inflammatory responses by promoting pro-inflammatory cytokines such as IL-18 and IL-1β. NLRP3 is one of the main factors restricting the activation of the inflammasome, which is closely related to the abundance and localization of NLRP3. A substantial number of studies have focused on specifically targeting NLRP3 to develop inhibitors against NLRP3 inflammasome. Here, we succinctly review the regulation of NLRP3 expression at DNA/chromosome, transcriptional, post-transcriptional, and translation levels. These are critical for the fine regulation of the NLRP3 inflammasome.

NLRP3 sparks the Greek fire in the war against lipid-related diseases

In recent years, the obesity rate worldwide has reached epidemic proportions and contributed to the growing prevalence of lipid-related diseases. A strong link between inflammation and metabolism is becoming increasingly evident. Compelling evidence has indicated the activation of the nucleotide-binding and oligomerization domain-like receptor, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome, a cytoplasmic complex containing multiple proteins, in a variety of lipid-related diseases including obesity, atherosclerosis, liver diseases, and type 2 diabetes. Recent studies have further clarified the regulatory mechanisms and the optional therapeutic agents that target NLRP3 inflammasomes. In this study, we review the recent progress in the research on NLRP3 inflammasomes and discuss their implications for a better understanding of inflammation in lipid-related disease and the prospects of targeting the NLRP3 inflammasome for therapeutic intervention.

Sinomenine Attenuates Acetaminophen-Induced Acute Liver Injury by Decreasing Oxidative Stress and Inflammatory Response via Regulating TGF-β/Smad Pathway in vitro and in vivo

Introduction

Liver disease is common and often life-threatening. Sinomenine (SIN) is an active ingredient extracted from  Sinomenium acutum. This study investigated the protective effect and mechanism of sinomenine (SIN) on acetaminophen (APAP)-induced liver injury from in vitro and in vivo.

Methods

In vivo experiments, mice were randomly divided into six groups (n=10): control group, model group, SIN (25 mg/kg) group, SIN (50 mg/kg) group, SIN (100 mg/kg) group and SIN (100 mg/kg) + SRI-011381 group. Alanine transaminases (ALT), aspartate transaminases (AST) and alkaline phosphatase (ALP) were detected. The pathological lesion was measured by HE staining. Apoptosis was measured by TUNEL staining. In vitro experiments, BRL-3A cells were treated with APAP (7.5 mM) and then subjected to various doses of SIN (10, 50 and 100 μg/mL) at 37°C for 24 h. Inflammatory factors and oxidative stress index were measured by ELISA. The expression of proteins was detected by Western blot.

Results

The results showed that compared with the control group, the levels of ALT, AST and ALP in the serum of APAP-induced mice were significantly increased, followed by liver histological damage and hepatocyte apoptosis. Besides, APAP reduced the activity of SOD and GSH-Px, while increasing the content of MDA and LDH. Notably, APAP also promoted the expression of NLRP3, ASC, caspase-1 and IL-1β. Interestingly, SIN treatment dose-dependently reduced APAP-induced liver injury and oxidative stress, inhibited the activation of NLRP3 inflammasomes, and reduced the levels of inflammatory cytokines. In vitro studies have shown that SIN treatment significantly reduced the viability of BRL-3A cells and oxidative stress and inflammation. In addition, the Western blotting analysis showed that SIN inhibited the activation of TGF-β/Smad pathway in a dose-dependent manner in vitro and in vivo. These effects were significantly reversed by TGF-β/Smad activator SRI-011381 or TGF-β overexpression.

Discussion

The study indicates that SIN attenuates APAP-induced acute liver injury by decreasing oxidative stress and inflammatory response via TGF-β/Smad pathway in vitro and in vivo.

The Role of P2X7 Purinergic Receptors in the Renal Inflammation Associated with Angiotensin II-induced Hypertension

Purinergic receptors play a central role in the renal pathophysiology of angiotensin II-induced hypertension, since elevated ATP chronically activates P2X7 receptors in this model. The changes induced by the P2X antagonist Brilliant blue G (BBG) in glomerular hemodynamics and in tubulointerstitial inflammation resulting from angiotensin II infusion were studied. Rats received angiotensin II (435 ng·kg^-1·min^-1, 2 weeks) alone or in combination with BBG (50 mg/kg/day intraperitoneally). BBG did not modify hypertension (214.5 ± 1.4 vs. 212.7 ± 0.5 mmHg), but restored to near normal values afferent (7.03 ± 1.00 to 2.97 ± 0.27 dyn.s.cm^-5) and efferent (2.62 ± 0.03 to 1.29 ± 0.09 dyn.s.cm^-5) arteriolar resistances, glomerular plasma flow (79.23 ± 3.15 to 134.30 ± 1.11 nl/min), ultrafiltration coefficient (0.020 ± 0.002 to 0.036 ± 0.003 nl/min/mmHg) and single nephron glomerular filtration rate (22.28 ± 2.04 to 34.46 ± 1.54 nl/min). Angiotensin II induced overexpression of P2X7 receptors in renal tubular cells and in infiltrating T and B lymphocytes and macrophages. All inflammatory cells were increased by angiotensin II infusion and reduced by 20% to 50% (p < 0.05) by BBG administration. Increased IL-2, IL-6, TNFα, IL-1β, IL-18 and overexpression of NLRP3 inflammasome were induced by angiotensin II and suppressed by BBG. These studies suggest that P2X7 receptor-mediated renal vasoconstriction, tubulointerstitial inflammation and activation of NLRP3 inflammasome are associated with angiotensin II-induced hypertension.

Thymic stromal lymphopoietin is a key cytokine for the immunomodulation of atherogenesis with Freund's adjuvant

Adaptive immune responses regulate the development of atherosclerosis, with a detrimental effect of type 1 but a protective role of type 2 immune responses. Immunization of Apolipoprotein E‐deficient (ApoE^−/−) mice with Freund's adjuvant inhibits the development of atherosclerosis. However, the underlying mechanisms are not fully understood. Thymic stromal lymphopoietin (TSLP) is an IL7‐like cytokine with essential impact on type 2 immune responses (Th2). Thymic stromal lymphopoietin is strongly expressed in epithelial cells of the skin, but also in various immune cells following appropriate stimulation. In this study, we investigated whether TSLP may be crucial for the anti‐atherogenic effect of Freund's adjuvant. Subcutaneous injection of complete Freund's adjuvant (CFA) rapidly led to the expression of TSLP and IL1β at the site of injection. In male mice, CFA‐induced TSLP occurred in immigrated monocytes—and not epithelial cells—and was dependent on NLRP3 inflammasome activation and IL1β‐signalling. In females, CFA‐induced TSLP was independent of IL1β and upon ovariectomy. CFA/OVA led to a more pronounced imbalance of the T cell response in TSLPR^−/− mice, with increased INFγ/IL4 ratio compared with wild‐type controls. To test whether TSLP contributes to the anti‐atherogenic effects of Freund's adjuvant, we treated ApoE^−/− and ApoE^−/−/TSLPR^−/− mice with either CFA/IFA or PBS. ApoE^−/− mice showed less atherogenesis upon CFA/IFA compared with PBS injections. ApoE^−/−/TSLPR^−/− mice had no attenuation of atherogenesis upon CFA/IFA treatment. Freund's adjuvant executes significant immune‐modulating effects via TSLP induction. TSLP‐TSLPR signalling is critical for CFA/IFA‐mediated attenuation of atherosclerosis.

lncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through miR-135b suppression to promote CLDN11 expression

BACKGROUND

Gastric cancer is a severe disease with a high occurrence rate worldwide. And lncRNAs are demonstrated to be responsible for cancer growth and metastasis. So, it is of great importance to explore the lncRNAs involved mechanism of gastric cancer occurrence and development deeply.

METHODS

Transfection was conducted to build over-expression and down-expression models. Moreover, RT-qPCR and western blot were used to detect the transcriptional and translational levels. The biological functions such as proliferation, migration and invasion of AGS cells were evaluated by MTT analysis, colony formation assay, scarification detection and transwell assay, respectively. The potential binding of miR-135b and its downstream and upstream molecules was validated by dual luciferase reporter gene assay or RIP. Also, the in-vivo mice model was further used to demonstrate the role of lncRNA PCAT18 in gastric cancer.

RESULTS

PCAT18 down-expression promoted proliferation, migration and invasion of gastric cancer cells. Furtherly, over-expression of miR-135b also promoted these biological characteristics of AGS cells. Importantly, we found that PCAT18 could bind miR-135b which also was bound with CLDN11. We found that miR-135b is negatively correlated with CLDN11; PCAT18 and CLDN11 are positively correlated. Moreover, miR-135b mimics could down-regulate protein level of CLDN11, whereas CLDN11 could reverse this effect. In in-vivo experiment, PCAT18 over-expression restrained tumor growth and metastasis.

CONCLUSIONS

Over-expressed lncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through regulation of miR-135b/CLDN11.

Clinical Value of Serum and Exhaled Breath Condensate miR-186 and IL-1β Levels in Non-Small Cell Lung Cancer

OBJECTIVE

Our study aimed to investigate the expression level and clinical significance of serum and exhaled breath condensate miR-186 and IL-1β in non-small cell lung cancer patients.

METHODS

The serum and exhaled breath condensate specimens of 62 non-small cell lung cancer patients and 60 healthy controls were collected to detect miR-186 expression levels by real-time fluorescent quantitative PCR. Enzyme linked immunosorbent assay was applied to examine IL-1β concentration. Statistical analyses were used to evaluate the correlation between miR-186 and IL-1β in serum and clinicopathological features, traditional serum tumor markers, and inflammatory markers. The diagnostic efficacy of miR-186 and IL-1β for non-small cell lung cancer was evaluated by receiver operating characteristic curve analysis. The correlation between miR-186 and IL-1β was determined.

RESULTS

① The relative expression level of miR-186 was greatly reduced in the serum and EBC of patients with non-small cell lung cancer, and the miR-186 expression level was reduced in different TNM stages of non-small cell lung cancer, from the early to later stages. ② The IL-1β concentration in serum and exhaled breath condensate of patients with non-small cell lung cancer was increased. ③ Serum miR-186 and IL-1β levels were closely related to lymph node metastasis, and the low expression of serum miR-186 and the high concentration of IL-1β were associated with higher serum carcinoembryonic antigen, C-reactive protein, and erythrocyte sedimentation rate levels. ④ ROC curve analysis showed that exhaled breath condensate miR-186 had higher area under the curve than serum miR-186, and the combined detection showed higher diagnostic efficacy than the separate detection. In addition, the combined detection of IL-1β and miR-186 has a larger AUC than the separate detection of both. ⑤ The correlation between serum miR-186 and IL-1β was negative.

CONCLUSION

miR-186 and IL-1β are expected to be potential diagnostic biomarkers for non-small cell lung cancer.

Dysregulation of Inflammasome Priming and Activation by MicroRNAs in Human Immune-Mediated Diseases

Inflammasomes are protein complexes that respond to a wide range of pathogens and cellular damage signals. Their activation prompts the caspase-1-mediated cleavage of the proinflammatory cytokines IL-1β and IL-18. Inflammasome dysregulation has been demonstrated to play a role in a range of diseases involving the adaptive immune system like multiple sclerosis, rheumatic diseases, and type 1 diabetes. Priming and activation of inflammasomes can be modulated by microRNAs (miRNAs), small noncoding RNAs that regulate gene expression posttranscriptionally. miRNAs, such as miR-223-3p, have been demonstrated to directly target the inflammasome components NLRP3, caspase-1, and caspase-8. Other miRNAs like miR-155-5p modulate TLR-, IL-1R-, TNFR-, and IFNAR-mediated signaling pathways upstream of the inflammasomes. In this study, we discuss how a more detailed elucidation of miRNA-driven inflammasome regulation helps in understanding the molecular processes underlying immune-mediated human diseases, holds potential for the identification of biomarkers and may offer novel targets for the development of future therapeutics.

Tissue Specific Reference Genes for MicroRNA Expression Analysis in a Mouse Model of Peripheral Nerve Injury

MicroRNAs (miRNAs) have emerged as master switch regulators in many biological processes in health and disease, including neuropathy. miRNAs are commonly quantified by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), usually estimated as relative expression through reference genes normalization. Different non-coding RNAs (ncRNAs) are used for miRNA normalization; however, there is no study identifying the optimal reference genes in animal models for peripheral nerve injury. We evaluated the stability of eleven ncRNAs, commonly used for miRNA normalization, in dorsal root ganglia (DRG), dorsal horn of the spinal cord (dhSC), and medial prefrontal cortex (mPFC) in the mouse spared nerve injury (SNI) model. After RT-qPCR, the stability of each ncRNA was determined by using four different methods: BestKeeper, the comparative delta-Cq method, geNorm, and NormFinder. The candidates were rated according to their performance in each method and an overall ranking list was compiled. The most stable ncRNAs were: sno420, sno429, and sno202 in DRG; sno429, sno202, and U6 in dhSC; sno202, sno420, and sno142 in mPFC. We provide the first reference genes' evaluation for miRNA normalization in different neuronal tissues in an animal model of peripheral nerve injury. Our results underline the need for careful selection of reference genes for miRNA normalization in different tissues and experimental conditions. We further anticipate that our findings can be used in a broad range of nerve injury related studies, to ensure validity and promote reproducibility in miRNA quantification.