The role of TLR4/NF-κB signaling pathway in activated microglia of rats with chronic high intraocular pressure and vitro scratch injury-induced microglia

Acute ocular hypertension in the living human eye: Model description and initial cellular responses to elevated intraocular pressure

This initial methods study presents the initial immunohistochemical and transcriptomic changes in the optic nerve head and retina from three research-consented brain-dead organ donors following prolonged and transient intraocular pressure (IOP) elevation. In this initial study, research-consented brain-dead organ donors were exposed to unilateral elevation of IOP for 7.5 h (Donor 1), 30 h (Donor 2), and 1 h (Donor 3) prior to organ procurement. Optic nerve tissue and retinal tissue was obtained following organ procurement for immunohistological and transcriptomic analysis. Optic nerve sections in Donor 1 exposed to 7.5-hours of unilateral sub-ischemic IOP elevation demonstrated higher levels of protein expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), within the lamina cribrosa with greatest expression inferior temporally in the treated eye compared to control. Spatial transcriptomic analysis performed on optic nerve head tissues from Donor 2 exposed to 30 h of unilateral IOP elevation demonstrated differential transcription of mRNA across laminar and scleral regions. Immunohistochemistry of retinal sections from Donor 2 exhibited higher GFAP and IBA1 expression in the treated eye compared with control, but this was not observed in Donor 3, which was exposed to only 1-hour of IOP elevation. While there were no differences in GFAP protein expression in the retina following the 1-hour IOP elevation in Donor 3, there were higher levels of transcription of GFAP in the inner nuclear layer, and CD44 in the retinal ganglion cell layer, indicative of astrocytic and Müller glial reactivity as well as an early inflammatory response, respectively. We found that transcriptomic differences can be observed across treated and control eyes following unilateral elevation of IOP in brain dead organ donors. The continued development of this model affords the unique opportunity to define the acute mechanotranscriptomic response of the optic nerve head, evaluate the injury and repair mechanisms in the retina in response to IOP elevation, and enable correlation of in vivo imaging and functional testing with ex vivo cellular responses for the first time in the living human eye.

Vitamin D3 improves glucose metabolism and attenuates inflammation in prediabetic human and mice

Prediabetes is a crucial stage for prevention and treatment of diabetes, and vitamin D (VD) has been found to be linked to the development of prediabetes and diabetes. Thus, we aimed to identify the effect of VD supplementation on glucose metabolism in prediabetic participants and mice. A 1:1 paired design of randomized, placebo-controlled trial with 1600 IU/day VD3 or placebo was administered to individuals with prediabetes, two-way repeated-measures ANCOVA was used to analyze glycolipid and inflammatory factors. A high-fat diet induced prediabetic KKay mice were utilized to evaluate the effects of VD3 with 16 weeks supplementation. Generalized estimation equation, one way ANOVA were used to analyze continuous monitoring indexes and terminal indexes, respectively. Exercise capacity, skeletal muscle pathological features and relevant proteins were examined. The clinical results showed that VD3 could improve insulin secretion and decrease inflammation. Results of KKay mice exhibited that VD3 not only ameliorate glycolipid metabolism and inflammatory indicators, but also regulated pathological changes of skeletal muscle and exercise capacity. Mechanistically, our results demonstrated that VD3 could inhibit the TLR4/NFκB and activate PI3K/AKT signaling pathway. Collectively, the study indicated that VD3 exerts its beneficial effects by inhibiting TLR4/NFκB to decrease inflammatory response, and activating PI3K/AKT signaling pathway to regulate glucose homeostasis.

Enhancing gut barrier integrity: Upregulation of tight junction proteins by chitosan oligosaccharide through the ERK1/2 signaling pathway

OBJECTIVES

This study aimed to explore the protective mechanism of chitosan oligosaccharide (COS) against lipopolysaccharide (LPS)-induced inflammatory responses in IEC-6 cells and dextran sodium sulfate (DSS)-induced colitis in mice.

METHODS

The cell inflammation model was constructed by LPS in vitro and enteritis model by DSS in vivo.

RESULTS

Following LPS exposure, IEC-6 cell proliferation significantly decreased, epithelial cell integrity was compromised, and TNF-α and IL-1β levels were increased. However, COS pretreatment reversed these changes. In vivo, DSS-treated mice exhibited evident pathological alterations, including heightened inflammatory levels and significantly decreased expression of tight junction proteins and critical proteins in the Mitogen activated proteins kinase signaling pathway. Nevertheless, COS administration notably reduced inflammatory levels and increased the expression of tight junction proteins and key proteins in the Mitogen activated proteins kinase signaling pathway.

CONCLUSIONS

Our findings suggest that COS safeguards gut barrier integrity by upregulating tight junction proteins through the ERK1/2 signaling pathway. Therefore, COS has emerged as a promising candidate for novel drug interventions against inflammatory bowel disease.

Role of APOE in glaucoma

Glaucoma is a chronic blinding eye disease caused by the progressive loss of retinal ganglion cells (RGCs). Currently, no clinically approved treatment can directly improve the survival rate of RGCs. The Apolipoprotein E (APOE) gene is closely related to the genetic risk of numerous neurodegenerative diseases and has become a hot topic in the field of neurodegenerative disease research in recent years. The optic nerve and retina are extensions of the brain's nervous system. The pathogenesis of retinal degenerative diseases is closely related to the degenerative diseases of the nerves in the brain. APOE consists of three alleles, ε4, ε3, and ε2, in a single locus. They have varying degrees of risk for glaucoma. APOE4 and the APOE gene deletion (APOE-/-) can reduce RGC loss. By contrast, APOE3 and the overall presence of APOE genes (APOE+/+) result in significant loss of RGC bodies and axons, increasing the risk of glaucoma RGCs death. Currently, there is no clear literature indicating that APOE2 is beneficial or harmful to glaucoma. This study summarises the mechanism of different APOE genes in glaucoma and speculates that APOE targeted intervention may be a promising method for protecting against RGCs loss in glaucoma.

The Molecular Mechanisms Involved in Axonal Degeneration and Retrograde Retinal Ganglion Cell Death

Axonal degeneration is a pathologic change common to multiple retinopathies and optic neuropathies. Various pathologic factors, such as mechanical injury, inflammation, and ischemia, can damage retinal ganglion cell (RGC) somas and axons, eventually triggering axonal degeneration and RGC death. The molecular mechanisms of somal and axonal degeneration are distinct but also overlap, and axonal degeneration can result in retrograde somal degeneration. While the mitogen-activated protein kinase pathway acts as a central node in RGC axon degeneration, several newly discovered molecules, such as sterile alpha and Toll/interleukin-1 receptor motif-containing protein 1 and nicotinamide mononucleotide adenylyltransferase 2, also play a critical role in this pathological process following different types of injury. Therefore, we summarize the types of injury that cause RGC axon degeneration and retrograde RGC death and important underlying molecular mechanisms, providing a reference for the identification of targets for protecting axons and RGCs.

Cerebrospinal Fluid Pressure Reduction Induces Glia-Mediated Retinal Inflammation and Leads to Retinal Ganglion Cell Injury in Rats

Low intracranial pressure (LICP)-induced translaminar cribrosa pressure difference (TLCPD) elevation has been proven as a risk factor in glaucomatous neurodegeneration, whereas the underlying retinal immune features of LICP-induced retinal ganglion cells (RGC) injury remain elusive. Here, we identified the retinal immune characteristics of LICP rats, and minocycline (Mino) treatment was utilized to analyze its inhibitory role in glia-mediated retinal inflammation of LICP rats. The results showed that retrograde axonal transport was decreased in LICP rats without significant RGC loss, indicating the RGC injury was at an early stage before the morphological loss. The activation of retinal microglia and astrocytes with morphologic and M1 or A1-marker alternations was detected in TLCPD elevation rats, the activation level is more dramatic in HIOP rats than in the LICP rats (P<0.05). Besides, we detected reduced retinal tight junction protein expressions, accompanied by specific imbalance patterns of T lymphocytes in the retina of both LICP and HIOP rats (P<0.05). Further Mino treatment showed an effective inhibitory role in glia-driven inflammatory responses in LICP rats, including improving retrograde axonal transport, inhibiting retinal glial activation and proinflammatory subtype polarization, and alleviating the blood-retina barrier compromise. This study identified the glia-mediated retinal inflammation features triggered by LICP stimulus, and Mino application exhibited an effective role in the inhibition of retinal glia-mediated inflammation in LICP-induced TLCPD elevation rats.

TRIM9 promotes Müller cell-derived retinal stem cells to differentiate into retinal ganglion cells by regulating Atoh7

Glaucoma is a multifactorial, irreversible blinding eye disease characterized by a large number of retinal ganglion cell (RGC) deaths. Müller cell-derived retinal stem cells (RSCs) can be induced to differentiate into RGCs under certain conditions. This study aimed to explore the regulatory effect and mechanism of TRIM9 on the differentiation of Müller cell-derived stem cells into RGCs. First, episcleral vein cauterization was used to induce high intraocular pressure (IOP) rat model. Next, Müller cells were isolated from rat retina, identified and induced to dedifferentiate into RSCs. Finally, RSCs were intervened with lentivirus PGC-FU-TRIM9-GFP transfection or siRNA Atoh7 and induced to redifferentiate into RGCs. In vivo, TRIM9 was highly expressed and Müller cells proliferated abnormally in the high IOP rat model. In vitro, S-100, GFAP, vimentin, and GS were positively expressed in Müller cells isolated from rat retina, and the purity of cells was 97.17%. Under the stimulation of cytokines, the proliferative capacity of the cells and the expression of Nestin and Ki67 gradually increased with the prolongation of culture time. Furthermore, RSCs transfected with the lentiviral vector PGC-FU-TRIM9-GFP displayed a striking morphological feature of long neurites. Additionally, there was a remarkable increase in the fluorescence intensity of Brn-3b and Thy1.1, accompanied by elevated mRNA and protein expression levels of Brn-3b, Thy1.1, and Atoh7. After knocking down Atoh7, the effect of TRIM9 on the above indicators was reversed. TRIM9 might promote the differentiation of Müller cells into RGCs by regulating the expression of Atoh7.

Rapamycin suppresses neuroinflammation and protects retinal ganglion cell loss after optic nerve crush

Pyroptosis, an inflammasome-mediated mode of death, plays an important role in glaucoma. It has been shown that regulating the mTOR pathway can inhibit pyroptosis. Unfortunately, whether rapamycin (RAPA), a specific inhibitor of the mTOR pathway, can inhibit optic nerve crush (ONC)-induced pyroptosis to protect retinal ganglion cells (RGCs) has not been investigated. Our research aimed to confirm the effect of intravitreal injection of RAPA on RGCs. Furthermore, we used the ONC model to explore the underlying mechanisms. First, we observed that intravitreal injection of RAPA alleviated RGC damage induced by various types of injury. We then used the ONC model to further explore the potential mechanism of RAPA. Mechanistically, RAPA not only reduced the activation of glial cells in the retina but also inhibited retinal pyroptosis-induced expression of inflammatory factors such as nucleotide-binding oligomeric domain-like receptor 3 (NLRP3), apoptosis-associated speckle-like protein containing a CARD (ASC), N-terminal of gasdermin-D (GSDMD-N), IL-18 and IL-1β. Moreover, RAPA exerted protective effects on RGC axons, possibly by inhibiting glial activation and regulating the mTOR/ROCK pathway. Therefore, this study demonstrates a novel mechanism by which RAPA protects against glaucoma and provides further evidence for its application in preclinical studies.

Retinal protection by fungal product theissenolactone B in a sodium iodate-induced AMD model through targeting retinal pigment epithelial matrix metalloproteinase-9 and microglia activity

Age-related macular degeneration (AMD) is the leading cause of low vision and blindness for which there is currently no cure. Increased matrix metalloproteinase-9 (MMP-9) was found in AMD and potently contributes to its pathogenesis. Resident microglia also promote the processes of chronic neuroinflammation, accelerating the progression of AMD. The present study investigates the effects and mechanisms of the natural compound theissenolactone B (LB53), isolated from Theissenia cinerea, on the effects of RPE dysregulation and microglia hyperactivation and its retinal protective ability in a sodium iodate (NaIO₃)-induced retinal degeneration model of AMD. The fungal component LB53 significantly reduces MMP-9 gelatinolysis in TNF-α-stimulated human RPE cells (ARPE-19). Similarly, LB53 abolishes MMP-9 protein and mRNA expression in ARPE-19 cells. Moreover, LB53 efficiently suppresses nitric oxide (NO) production, iNOS expression, and intracellular ROS levels in LPS-stimulated TLR 4-activated microglial BV-2 cells. According to signaling studies, LB53 specifically targets canonical NF-κB signaling in both ARPE-19 and BV-2 microglia. In an RPE-BV-2 interaction assay, LB53 ameliorates LPS-activated BV-2 conditioned medium-induced MMP-9 activation and expression in the RPE. In NaIO₃-induced AMD mouse model, LB53 restores photoreceptor and bipolar cell dysfunction as assessed by electroretinography (ERG). Additionally, LB53 prevents retinal thinning, primarily the photoreceptor, and reduces retinal blood flow from NaIO₃ damage evaluated by optic coherence tomography (OCT) and laser speckle flowgraphy (LSFG), respectively. Our results demonstrate that LB53 exerts neuroprotection in a mouse model of AMD, which can be attributed to its anti-retinal inflammatory effects by impeding RPE-mediated MMP-9 activation and anti-microglia.

Nanoparticles for the treatment of glaucoma-associated neuroinflammation

Recently, a considerable amount of literature has emerged around the theme of neuroinflammation linked to neurodegeneration. Glaucoma is a neurodegenerative disease characterized by visual impairment. Understanding the complex neuroinflammatory processes underlying retinal ganglion cell loss has the potential to improve conventional therapeutic approaches in glaucoma. Due to the presence of multiple barriers that a systemically administered drug has to cross to reach the intraocular space, ocular drug delivery has always been a challenge. Nowadays, studies are focused on improving the current therapies for glaucoma by utilizing nanoparticles as the modes of drug transport across the ocular anatomical and physiological barriers. This review offers some important insights on the therapeutic advancements made in this direction, focusing on the use of nanoparticles loaded with anti-inflammatory and neuroprotective agents in the treatment of glaucoma. The prospect of these novel therapies is discussed in relation to the current therapies to alleviate inflammation in glaucoma, which are being reviewed as well, along with the detailed molecular and cellular mechanisms governing the onset and the progression of the disease.

Artemisinin Attenuates Amyloid-Induced Brain Inflammation and Memory Impairments by Modulating TLR4/NF-κB Signaling

The abnormal immune response is an early change in the pathogenesis of Alzheimer’s disease (AD). Microglial activation is a crucial regulator of the immune response, which contributes to progressive neuronal injury by releasing neurotoxic products. Therefore, finding effective drugs to regulate microglial homeostasis and neuroinflammation has become a new AD treatment strategy. Artemisinin has potent anti-inflammatory and immune activities. However, it is unclear whether Artemisinin contributes to the regulation of microglial activation, thereby improving AD pathology. This study found that Artemisinin significantly reduced amyloid beta-peptide 1–42 (Aβ_1–42)-induced increases in nitric oxide and reactive oxygen species and inflammatory factors in BV2 cells. In addition, Artemisinin inhibited the migration of microglia and prevented the expansion of the inflammatory cascade. The mechanical studies showed Artemisinin inhibited neuroinflammation and exerted neuroprotective effects by regulating the Toll-like receptor 4 (TLR4)/Nuclear factor-kappa B (NF-κB) signaling pathway. Similar results were obtained in AD model mice, in which Artemisinin administration attenuated Aβ_1–42-induced neuroinflammation and neuronal injury, reversing spatial learning and memory deficits. The anti-inflammatory effect of Artemisinin is also accompanied by the activation of the TLR4/NF-κB signaling pathway in the animal model. Our results indicate that Artemisinin attenuated Aβ_1–42-induced neuroinflammation and neuronal injury by stimulating the TLR4/NF-κB signaling pathway. These findings suggest that Artemisinin is a potential therapeutic agent for AD.

Effect of TLR4/MyD88/NF-kB axis in paraventricular nucleus on ventricular arrhythmias induced by sympathetic hyperexcitation in post-myocardial infarction rats

Sympathetic activation after myocardial infarction (MI) leads to ventricular arrhythmias (VAs), which can result in sudden cardiac death (SCD). The toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor-kappa B (NF-kB) axis within the hypothalamic paraventricular nucleus (PVN), a cardiac-neural sympathetic nerve centre, plays an important role in causing VAs. An MI rat model and a PVN-TLR4 knockdown model were constructed. The levels of protein were detected by Western blotting and immunofluorescence, and localizations were visualized by multiple immunofluorescence staining. Central and peripheral sympathetic activation was visualized by immunohistochemistry for c-fos protein, renal sympathetic nerve activity (RSNA) measurement, heart rate variability (HRV) analysis and norepinephrine (NE) level detection in serum and myocardial tissue measured by ELISA. The arrhythmia scores were measured by programmed electrical stimulation (PES), and cardiac function was detected by the pressure-volume loop (P-V loop). The levels of TLR4 and MyD88 and the nuclear translocation of NF-kB within the PVN were increased after MI, while sympathetic activation and arrhythmia scores were increased and cardiac function was decreased. However, inhibition of TLR4 significantly reversed these conditions. PVN-mediated sympathetic activation via the TLR4/MyD88/NF-kB axis ultimately leads to the development of VAs after MI.

RGFP966 is protective against lipopolysaccharide-induced depressive-like behaviors in mice by inhibiting neuroinflammation and microglial activation

Depression is a prevalent mental disorder. However, its pathophysiological mechanism has still remained elusive, and a limited number of effective treatments have been presented. Recent studies have shown that neuroinflammation and microglial activation are involved in the pathogenesis of depression. Histone deacetylase 3 (HDAC3) has neurotoxic effects on several neuropathological conditions. The inhibition of HDAC3 has been reported to induce anti-inflammatory and antioxidant effects. RGFP966 is a highly selective inhibitor of HDAC3. This study aimed to investigate the antidepressant effect of RGFP966 on lipopolysaccharide (LPS)-induced depressive-like behaviors in mice and to explore its possible mechanism. Adult male C57BL/6J mice were utilized in this study. The LPS and RGFP966 were injected intraperitoneally daily for 5 days. The behavior tests were performed to elucidate the depression-like behaviors. Western blot, ELISA and immunofluorescence staining were used to study the HDAC3/TLR4/NLRP3 pathway-related proteins. The results of behavioral tests showed that RGFP966 could improve the LPS-induced depressive-like behaviors in mice. The results of Western blotting showed that RGFP966 treatment downregulated the expression levels of toll-like receptor 4 (TLR4), nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3), caspase-1, and interleukin-1β (IL-1β) (P < 0.05). Furthermore, the results of immunofluorescence staining showed that RGFP966 treatment inhibited microglial activation in the hippocampus of mice (P < 0.01). These findings suggested that RGFP966 could effectively ameliorate LPS-induced depressive-like behaviors in mice by inhibiting neuroinflammation and microglial activation. The anti-inflammatory mechanism of RGFP966 might be related to the inhibition of the HDAC3/TLR4/NLRP3 signaling pathway. Therefore, inhibition of HDAC3 using RGFP966 could serve as a potential treatment strategy for depression.

Lactobacillus acidophilus and vitamin C attenuate ethanol-induced intestinal and liver injury in mice

Ethanol exposure frequently induces intestinal and liver injury, dysbiosis of the gut microbiota and vitamin C (VC) deficiency. Gut microbiota-targeted therapy is emerging as an important adjuvant method for protecting the body against ethanol-induced injury, particularly probiotics containing Lactobacillus acidophilus (LA). However, the feasibility and efficiency of using synbiotics containing LA and VC against ethanol-induced injury remained largely undetermined. To examine the advantages of LA+VC, their effect was evaluated in an ethanol-fed mouse model. The results suggested that LA+VC restored gut microbiota homeostasis and reinstated the immune balance of colonic T-regulatory cells (CD4⁺CD45⁺forkhead box p3⁺). In addition, intestinal barrier disorders were improved via upregulating tight junction proteins (claudin-2, zona occludens-1 and occludin) and mucus secretion, which prevented the translocation of lipopolysaccharide into circulatory systems and subsequently reduced the expression of Toll-like receptor 4 in liver tissues. In this context, LA+VC treatment reduced the inflammatory response in the liver, which was likely responsible for the improved liver function in ethanol-challenged mice. Collectively, these results indicated that LA+VC treatment significantly protected the intestine and liver from ethanol damage by enhancing intestinal barrier function and reducing systemic inflammation. The present study paved the way for further exploration of synbiotics based on Lactobacillus species and VC.

Commonalities of optic nerve injury and glaucoma-induced neurodegeneration: Insights from transcriptome-wide studies

Glaucoma is a collection of diseases that lead to an irreversible vision loss due to damage of retinal ganglion cells (RGCs). Although the underlying events leading to RGC death are not fully understood, recent research efforts are beginning to define the genetic changes that play a critical role in the initiation and progression of glaucomatous injury and RGC death. Several genetic and experimental animal models have been developed to mimic glaucomatous neurodegeneration. These models differ in many respects but all result in the loss of RGCs. Assessing transcriptional changes across different models could provide a more complete perspective on the molecular drivers of RGC degeneration. For the past several decades, changes in the retinal transcriptome during neurodegeneration process were defined using microarray methods, RNA sequencing and now single cell RNA sequencing. It is understood that these methods have strengths and weaknesses due to technical differences and variations in the analytical tools used. In this review, we focus on the use of transcriptome-wide expression profiling of the changes occurring as RGCs are lost across different glaucoma models. Commonalities of optic nerve crush and glaucoma-induced neurodegeneration are identified and discussed.

Crosstalk between MicroRNA and Oxidative Stress in Primary Open-Angle Glaucoma

Reactive oxygen species (ROS) plays a key role in the pathogenesis of primary open-angle glaucoma (POAG), a chronic neurodegenerative disease that damages the trabecular meshwork (TM) cells, inducing apoptosis of the retinal ganglion cells (RGC), deteriorating the optic nerve head, and leading to blindness. Aqueous humor (AH) outflow resistance and intraocular pressure (IOP) elevation contribute to disease progression. Nevertheless, despite the existence of pharmacological and surgical treatments, there is room for the development of additional treatment approaches. The following review is aimed at investigating the role of different microRNAs (miRNAs) in the expression of genes and proteins involved in the regulation of inflammatory and degenerative processes, focusing on the delicate balance of synthesis and deposition of extracellular matrix (ECM) regulated by chronic oxidative stress in POAG related tissues. The neutralizing activity of a couple of miRNAs was described, suggesting effective downregulation of pro-inflammatory and pro-fibrotic signaling pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), transforming growth factor-beta 2 (TGF-β2), Wnt/β-Catenin, and PI3K/AKT. In addition, with regards to the elevated IOP in many POAG patients due to increased outflow resistance, Collagen type I degradation was stimulated by some miRNAs and prevented ECM deposition in TM cells. Mitochondrial dysfunction as a consequence of oxidative stress was suppressed following exposure to different miRNAs. In contrast, increased oxidative damage by inhibiting the mTOR signaling pathway was described as part of the action of selected miRNAs. Summarizing, specific miRNAs may be promising therapeutic targets for lowering or preventing oxidative stress injury in POAG patients.

An update: mechanisms of microRNA in primary open-angle glaucoma

Glaucoma is a disease with characteristic optic neuropathy and loss of vision, leading to blindness, and primary open-angle glaucoma (POAG) is the most common glaucoma type throughout the world. Genetic susceptibility is the main factor in POAG, and most susceptibility genes cause changes in microRNA expression and function, thereby leading to POAG occurrence and development. Increasing evidence indicates that many microRNAs are involved in the regulation of intraocular pressure (IOP) and play an important role in the increase in IOP in POAG. Additionally, microRNA is closely related to optic nerve damage factors (mechanical stress, hypoxia and inflammation). This review discusses the effect of single-nucleotide polymorphisms in POAG-related genes on microRNA and the value of microRNA in the diagnosis and treatment of POAG.

Ursolic acid protects chondrocytes, exhibits anti-inflammatory properties via regulation of the NF-κB/NLRP3 inflammasome pathway and ameliorates osteoarthritis

Inflammation and poor viability of chondrocytes result in the degradation of cartilage as osteoarthritis (OA) progresses. The purpose of the present study was to investigate whether ursolic acid (UA) can protect chondrocytes and alleviate OA. Following stimulation with tumor necrosis factor-α (TNF-α), 5 μM UA displayed no cytotoxicity and reversed the up-regulation of the inflammatory factors MMP13, IL-1β, IL-6 and PTGS2, and down-regulation of the cartilaginous genes/proteins type II collagen and Aggrecan. RNA sequencing identified 533 common deferentially expressed genes (DEGs) of which TNF, PI3K-AKT, NOD-like receptor, cytokine receptor interaction and NF-κB pathways were of potential importance. Further notable DEGs in the most-highly expressed 10 pathways contributed to maintenance of cartilaginous ECM homeostasis and were involved in an inflammatory response. The expression of these most-enriched DEGs was reversed by UA following stimulation with TNF-α. Additional investigation demonstrated that treatment with UA inhibited TNF-α-induced nuclear translocation of p65 and phosphorylation of IκBα and AKT, and reversed TNF-α-induced up-regulation of P20, ACS and NLRP3. Furthermore, rat anterior cruciate ligament transection (ACLT) induced-OA was ameliorated by treatment with UA. In conclusion, these results suggest that UA activates chondrocytes through the NF-κB/NLRP3 inflammasome pathway, thus preventing cartilage degeneration in osteoarthritis.

Neuroinflammation in Primary Open-Angle Glaucoma

Primary open-angle glaucoma (POAG) is the second leading cause of irreversible blindness worldwide. Increasing evidence suggests oxidative damage and immune response defects are key factors contributing to glaucoma onset. Indeed, both the failure of the trabecular meshwork tissue in the conventional outflow pathway and the neuroinflammation process, which drives the neurodegeneration, seem to be linked to the age-related over-production of free radicals (i.e., mitochondrial dysfunction) and to oxidative stress-linked immunostimulatory signaling. Several previous studies have described a wide range of oxidative stress-related makers which are found in glaucomatous patients, including low levels of antioxidant defences, dysfunction/activation of glial cells, the activation of the NF-κB pathway and the up-regulation of pro-inflammatory cytokines, and so on. However, the intraocular pressure is still currently the only risk factor modifiable by medication or glaucoma surgery. This present review aims to summarize the multiple cellular processes, which promote different risk factors in glaucoma including aging, oxidative stress, trabecular meshwork defects, glial activation response, neurodegenerative insults, and the altered regulation of immune response.

Laquinimod exerts anti-inflammatory and antiapoptotic effects in retinal ischemia/reperfusion injury

Retinal ischemia/reperfusion (I/R) occurs in various vision disabled ocular diseases, involved in acute glaucoma, diabetic retinopathy, ischemic optic neuropathy, hypertensive retinopathy and retinal vascular occlusion. Laquinimod (LQ), a new type of immunosuppressant, has been reported to exert anti-inflammatory effects on autoimmune diseases. This research aims to investigate the protective effect of LQ on I/R damage by focusing on inhibiting dysregulated neuroinflammation and neuronal apoptosis. In our study, mice were treated with LQ after high intraocular pressure (IOP)-induced retinal I/R injury. The data showed that LQ significantly attenuated high IOP-induced retinal ganglion cell (RGC) death and inner plexiform layer (IPL) thinning and inhibited microglial activation. The results of qRT-PCR, flow cytometry and Luminex multiplex assays demonstrated the anti-inflammatory action of LQ in BV2 cells stimulated with lipopolysaccharide (LPS). In addition, primary RGC apoptosis induced by oxygen-glucose deprivation/reperfusion (OGD/R) was also directly suppressed by LQ. Importantly, LQ inhibited the expression of cleaved caspase-8 and the downstream NLRP3 inflammasome and IL-1β. In conclusion, our findings offer the first evidence that LQ treatment prevents retinal I/R damage. Furthermore, LQ could directly inhibit RGC apoptosis. Caspase-8 activation and subsequent inflammation can also be suppressed by LQ, which suggests that LQ may act through inhibiting the caspase-8 pathway. This study demonstrates a new mechanism of LQ and provides beneficial preclinical data for the clinical application of LQ.

NF-κB interaction long non-coding RNA inhibits migration, invasion and epithelial-mesenchymal transition of cervical cancer cells through inhibiting NF-κB signaling pathways

The long non-coding RNA (lncRNA) NF-κB interaction lncRNA (NKILA) has been found to exert tumor suppressive effects in numerous types of carcinoma; however, the relationship between NKILA and cervical cancer (CC) remains largely unclear. The present study aimed to investigate the effects of NKILA on the proliferation and metastasis of CC cell lines, in addition to the related molecular mechanisms. Reverse transcription-quantitative PCR was used to detect the expression levels of NKILA in cancer tissues and cell lines. The constructed overexpression vector, pcDNA3.1NKILA, and its corresponding negative control sequence were transfected into CaSki cells and short hairpin RNA targeting NKILA and the corresponding negative control sequence were transfected into C-33A cells. Subsequently, the proliferative, migratory and invasive ability, as well as the process of epithelial-mesenchymal transition (EMT) of C-33 A and CaSki cells were analyzed by performing Cell Counting Kit-8, wound healing, Matrigel invasion and western blot assays, respectively. The expression levels of proteins were detected using western blot analysis. The expression levels of NKILA were decreased in CC tissues and CC cell lines (SiHa, C-33A, CaSki and HeLa) and the downregulation of NKILA expression using shRNA was observed to significantly increase the proliferation of CC cells. Conversely, the upregulation of NKILA inhibited the proliferation of CC cells, in addition to significantly inhibiting the migration and invasion of CaSki cells, whereas the knockdown of NKILA promoted the invasion of C-33A cells. Thus, it was hypothesized that NKILA may inhibit the migration and invasion of CC cells via regulation of EMT processes, which was reflected by the expression of ZO-1, E-cadherin, N-cadherin and Vimentin. Furthermore, the overexpression of NKILA significantly inhibited the activation of NF-κB in CaSki cells, whereas the knockdown of NKILA expression promoted the degradation of inhibitory protein-κB and promoted the transfer of p65 into the nucleus in C-33A cells. In conclusion, the results from the present study suggested that NKILA may be involved in the inhibition of migration and invasion in CC cells through regulating EMT processes, which may be related to its inhibition of NF-κB activation.