Inflammatory Cell Apoptosis Research Articles

Protection of melatonin against long-term radon exposure-caused lung injury.

Radon is one of the major pathogenic factors worldwide. Recently, epidemiological studies have suggested that radon exposure plays an important role in lung injury, which could further cause cancer. However, the toxic effects and underlying mechanism on lung injury are still not clear. Here, we identified the detailed toxic effects of long-term radon exposure. Specifically, the manifestations were inflammatory response and cell apoptosis in dose- and time-dependent manners. In detail, it caused the mitochondrial dysfunction and oxidative stress as determined by the abnormal levels of mitochondrial DNA copy number, adenosine triphosphate, mitochondrial membrane potential, superoxide dismutase, and cycloxygenase-2. Furthermore, we found that melatonin treatment ameliorated mitochondrial dysfunction and attenuated the levels of oxidative stress caused by long-term radon exposure, which could further inhibit the lung tissue apoptosis as determined by the decreased levels of cleaved caspase 3. Our study would provide potential therapeutic application of melatonin on lung tissue injury caused by long-term radon exposure.

Mesenteric Lymph Duct Drainage Attenuates Lung Inflammatory Injury and Inhibits Endothelial Cell Apoptosis in Septic Rats.

The present study was to investigate the effect of mesenteric lymph duct drainage on lung inflammatory response, histological alteration, and endothelial cell apoptosis in septic rats. Animals were randomly assigned into four groups: control, sham surgery, sepsis, and sepsis plus mesenteric lymph drainage. We used the colon ascendens stent peritonitis (CASP) procedure to induce the septic model in rats, and mesenteric lymph drainage was performed with a polyethylene (PE) catheter inserted into mesenteric lymphatic. The animals were sacrificed at the end of CASP in 6 h. The mRNA expression levels of inflammatory mediators were measured by qPCR, and the histologic damage were evaluated by the pathological score method. It was found that mesenteric lymph drainage significantly reduced the expression of TNF-α, IL-1β, and IL-6 mRNA in the lung. Pulmonary interstitial edema and infiltration of inflammatory cells were alleviated by mesenteric lymph drainage. Moreover, increased mRNA levels of TNF-α, IL-1β, IL-6 mRNA, and apoptotic rate were observed in PMVECs treated with septic lymph. These results indicate that mesenteric lymph duct drainage significantly attenuated lung inflammatory injury by decreasing the expression of pivotal inflammatory mediators and inhibiting endothelial apoptosis to preserve the pulmonary barrier function in septic rats.

Comparative efficacy of glucocorticoid receptor agonists on Th2 cell function and attenuation by progesterone

BackgroundCorticosteroids (CS)s suppress cytokine production and induce apoptosis of inflammatory cells. Prednisone and dexamethasone are oral CSs prescribed for treating asthma exacerbations. While prednisone is more commonly prescribed, dexamethasone is long acting and a more potent glucocorticoid receptor (GR) agonist. It can be administered as a one or two dose regime, unlike the five to seven days required for prednisone, a feature that increases compliance. We compared the relative ability of these two oral CSs to suppress type 2 inflammation. Since progesterone has affinity for the GR and women are more likely to relapse following an asthma exacerbation, we assessed its influence on CS action.ResultsDexamethasone suppressed the level of IL-5 and IL-13 mRNA within Th2 cells with ~ 10-fold higher potency than prednisolone (the active form of prednisone). Dexamethasone induced a higher proportion of apoptotic and dying cells than prednisolone, at all concentrations examined. Addition of progesterone reduced the capacity of both CS to drive cell death, though dexamethasone maintained significantly more killing activity. Progesterone blunted dexamethasone-induction of FKBP5 mRNA, indicating that the mechanism of action was by interference of the CS:GR complex.ConclusionsDexamethasone is both more potent and effective than prednisolone in suppressing type 2 cytokine levels and mediating apoptosis. Progesterone attenuated these anti-inflammatory effects, indicating its potential influence on CS responses in vivo. Collectively, our data suggest that when oral CS is required, dexamethasone may be better able to control type 2 inflammation, eliminate Th2 cells and ultimately lead to improved long-term outcomes. Further research in asthmatics is needed.

Z-Ligustilide Ameliorates Diabetic Rat Retinal Dysfunction Through Anti-Apoptosis and an Antioxidation Pathway.

BackgroundDiabetic retinopathy (DR) is one of the major causes of vision impairment. Z-ligustilide (3-butylidene-4,5-dihydrophthalide; Z-LIG) is an important volatile oil from the Chinese herb Angelica sinensis (Oliv.) Diels. It has been extensively studied and reportedly has anti-inflammatory, antioxidant, antitumor, analgesic, vasodilatory, and neuroprotective effects. Its effects on DR, however, remain obscure. In this study, we attempted to explore the protective effects of Z-LIG on retinal dysfunction and the potential underlying mechanisms.Material/MethodsA diabetic rat model was constructed with streptozotocin injection. Three study groups were constituted: control (CON), diabetic model (DM), and DM+Z-LIG. The DM+Z-LIG group was injected intraperitoneally with 10 mg/kg of Z-LIG. The other groups received the same volume of 3% solution of polysorbate 80. After a 12-week intervention, a series of assessments were performed, including tests for retinal function, morphology, and molecular biology.ResultsZ-LIG treatment significantly elevated b-wave and OPs2-wave amplitude and thickened the inner layer of the nucleus of the retina, and the outer plexiform and nuclear layers (INL+OPL+ONL). Moreover, the rate of apoptosis and expression of bcl-2- associated X protein (BAX) and cleaved-Caspase-3 were clearly reduced, and the expression of bcl-2 was raised by Z-LIG in retinas of diabetic mice. In addition, the levels of retinal proinflammatory cytokines interleukin-1 and tumor necrosis factor-α were downregulated by Z-LIG. Furthermore, Z-LIG inhibited expression of vascular endothelial growth factor-α (VEGF-α) at the mRNA and protein levels.ConclusionsZ-LIG can inhibit inflammatory response and cell apoptosis in retinas of diabetic rats by repressing the VEGF-α pathway. Therefore, it may serve as a potential therapeutic agent for DR.

Efficacy of Bunao Fuyuan decoction on cerebral ischemia and reperfusion injury in vitro.

To investigate the protective efficacy of Bunao Fuyuan decoction (BNFY) on cerebral Ischemia/reperfusion (I/R) injury. The mouse PC12 cells were chosen, and the oxidative-glucose deprivation/re-oxygenation (OGD/R) injury model were established to simulate cerebral I/R injury. Atorvastatin was selected as a positive drug, and a gradient dose of BNFY was given for 6, 12 and 24 h. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay were used to detect cell viability at each time point. Cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP-botin nick end labeling (TUNEL) staining. enzyme linked immunosorbent assay was used to detect the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β and platelet activating factor (PAF). Western blot assay were performed to detect the expression of key regulators [toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), p-p38 mitogen-activated protein kinase (MAPK) and p-Akt (also known as protein kinase B, PKB)] of cell survival and inflammatory response. The results of MTT assay and TUNEL staining assay revealed that BNFY significantly increased cell viability and inhibited cell apoptosis of PC12 cells following OGD/R, respectively. Furthermore, the expression of TNF-α, 1L-6, 1L-1 and PAF were decreased after BNFY treatment. And the results of Western blot assay showed that BNFY downregulated TLR4, NF-κB, p-p38 MAPK expression and upregulated p-Akt expression. Our findings suggest that BNFY may play a role in protecting OGD/R injured PC12 cells through inhibiting the inflammatory response and cell apoptosis.

Exploring the role of TREM-1 receptor in experimental Abdominal Aortic Aneurysm

Non-syndromic Abdominal Aortic Aneurysm (AAA) is one of the leading causes of cardiovascular death in elderly men. AAA is characterized by extracellular matrix degradation, smooth muscle cell apoptosis and infiltration of inflammatory cells in the aortic wall. TREM (Triggering Receptor Expressed on Myeloid cells)-1, a receptor expressed by myeloid cells, is a key regulator of innate immune cell activity, and we hypothesized that it might be involved in AAA development. We aim to decipher the role of TREM-1 in the immuno-inflammatory response associated with AAA development and rupture. To study the role of TREM-1 in AAA development, we used an experimental model of Angiotensin-II-induced AAA in ApoE-/-Trem-1-/- and ApoE-/-Trem-1+/+ mice. At day 0, 3, 7 and 28, we analyzed monocyte trafficking (flow cytometry), inflammatory cell infiltration within the aortic wall (immunostaining, qPCR), aortic wall remodeling (histology) and finally AAA development. Angiotensin II infusion increased TREM-1 expression on both classical and non-classical monocytes. TREM-1 deficiency limits Angiotensin II-induced monocytosis at day 3 and limits macrophage infiltration in the aorta at day 7. Trem-1 genetic deletion limits pro-inflammatory response and metalloprotease activity in the aortic wall and protects against elastin degradation. Finally, TREM-1 deficiency significantly reduced AAA rupture and severity. We showed that TREM-1 deficiency reduced AAA development and rupture in an Angiotensin II-induced experimental mouse model.

IL-17A is involved in diabetic inflammatory pathogenesis by its receptor IL-17RA.

The participation of interleukin (IL)-17A in diabetic pathogenesis is suggested in animal models of autoimmune diabetes and in patients with type 1 diabetes (T1D), but with some contradictory results. Particularly, evidence for a direct injury of IL-17A to pancreatic β cells is lacking. We showed that IL-17A deficiency alleviated diabetic signs including hyperglycemia, hypoinsulinemia, and inflammatory response in Ins2Akita (Akita) mice, a T1D model with spontaneous mutation in insulin 2 gene leading to β-cell apoptosis. IL-17A enhanced inflammatory reaction, oxidative stress, and cell apoptosis but attenuated insulin level in mouse insulin-producing MIN6 cells. IL-17A had also a synergistic destruction to MIN6 cells with streptozotocin (STZ), a pancreatic β-cell-specific cytotoxin. Blocking IL-17 receptor A (IL-17RA) reduced all these deleterious effects of IL-17A on MIN6 cells. The results demonstrate the role and the importance of IL-17A in T1D pathogenesis and suggest a potential therapeutic strategy for T1D targeting IL-17A and/or IL-17RA.

The correlations between the serum expression of miR-206 and the severity and prognosis of sepsis.

An accurate assessment of the severity and prognosis of sepsis, especially septic shock, is vital for the tailored treatment of this condition. miRNA participates in the inflammatory response and cell apoptosis and regulates inflammation-related signaling pathways. Immune disorders often accompany sepsis. Since serum miRNA expression is superior to traditional biological markers in terms of sensitivity and specificity, its role in the assessment of sepsis has increasingly been recognized. Serum miRNAs were extracted from septic patients and healthy individuals by using the ultracentrifugation method. The differential expressions of miRNAs in the serum samples were detected by high-throughput sequencing technology. The differentially expressed miRNAs between the two groups were analyzed by bioinformatics. The quantitative polymerase chain reaction real-time polymerase chain reaction (qRT-PCR) was used to amplify the sample size to verify the results and to screen the highly-expressed miR206 in septic patients. Subsequently, serum samples were collected from 63 septic patients, and 30 patients with septic shock and qRT-PCR were performed to analyze the expression of miR-206. These 93 patients were divided into the miR-206 low-expression group and miR-206 high-expression group according to miR206 expression level. The potential correlations between the miR-206 expression and the clinical data were analyzed by using SPSS 25.0. Serum miRNA expression significantly differed between septic patients and healthy individuals. High-throughput sequencing results showed that, compared with those in healthy individuals, 29 miRNA molecules were down-regulated, and 25 molecules were up-regulated in the serum samples of septic patients. qRT-PCR identified the significantly up-regulated miR-206 in septic patients. qRT-PCR also showed significantly higher miR-206 expression levels in patients with septic shock than in septic patients. Furthermore, we observed a significantly longer prothrombin time and activated partial thromboplastin time, and significantly higher SOFA score, APACHE-II score, and in-hospital mortality rate. miR-206 was positively correlated with SOFA sore and APACHE-II score. Serum miR-206 expression is positively correlated with the severity and prognosis of sepsis. Thus, it may be a potential biomarker for assessing the severity and prognosis of sepsis, although the specific mechanism warrants further investigations.

Differentially expressed lnc-NOS2P3-miR-939-5p axis in chronic heart failure inhibits myocardial and endothelial cells apoptosis via iNOS/TNFα pathway.

Inflammatory cytokine‐induced cell apoptosis is important for initiation and progression of chronic heart failure (CHF). Non‐coding RNAs, including long non‐coding RNAs and microRNAs, have emerged as critical regulators of this pathological process. The role in regulating inflammation and induction to cell apoptosis in CHF is not well understood. This study found CHF patients had elevated serum miR‐939‐5p, with greater increase in New York Heart Association (NYHA) I‐II patients than in NYHA III‐IV. Moreover, miR‐939‐5p was positively correlated with B‐type natriuretic peptide (BNP) in NYHA III‐IV patients, while not in NYHA I‐II. Further study showed miR‐939‐5p mimics promoted cell proliferation and inhibited inflammatory cytokine‐induced apoptosis of HUVECs and H9C2, while inhibition of endogenous miR‐939‐5p produced the opposite effects. Induced nitric oxide synthase (iNOS) and tumour necrosis factor α (TNFα) were identified as target genes of miR‐939‐5p. Additionally, lncRNA‐NOS2P3 acted as an endogenous sponge RNA to inhibit miR‐939‐5p expression, regulate the expression of iNOS/TNFα and control inflammation‐induced cells apoptosis. These suggest that CHF patients exhibited elevated serum miR‐939‐5p level especially in NYHA I‐II grades. And lnc‐NOS2P3‐miR‐939‐5p‐iNOS/TNFα pathway regulated inflammatory cytokine‐induced endothelial and myocardial cells apoptosis and provided a promising strategy for diagnosis and treatment of CHF.

Rab27A promotes cellular apoptosis and ROS production by regulating the miRNA-124-3p/STAT3/RelA signalling pathway in ulcerative colitis.

Ulcerative colitis (UC) is a multifactorial inflammatory disease, and increasing evidence has demonstrated that the mechanism of UC pathogenesis is associated with excessive cellular apoptosis and reactive oxygen species (ROS) production. However, their function and molecular mechanisms related to UC remain unknown. In this study, Rab27A mRNA and protein were proven to be overexpressed in intestinal epithelial cells of UC patients and DSS‐induced colitis mice, compared with control (P < 0.05). And Rab27A silencing inhibits inflammatory process in DSS‐induced colitis mice (P < 0.05). Then, it was shown that knockdown of Rab27A suppressed apoptosis and ROS production through modulation of miR‐124‐3p, whereas overexpression of Rab27A promoted apoptosis and ROS production in LPS‑induced colonic cells. In addition, enhanced expression of miR‐124‐3p attenuated apoptosis and ROS production by targeting regulation of STAT3 in LPS‑induced colonic cells. Mechanistically, we found Rab27A reduced the expression and activity of miR‐124‐3p to activate STAT3/RelA signalling pathway and promote apoptosis and ROS production in LPS‑induced colonic cells, whereas overexpression of miR‐124‐3p abrogated these effects of Rab27A. More importantly, animal experiments illustrated that ectopic expression of Rab27A promoted the inflammatory process, whereas overexpression of miR‐124‐3p might interfere with the inflammatory effect in DSS‐induced colitis mice. In summary, Rab27A might modulate the miR‐124‐3p/STAT3/RelA axis to promote apoptosis and ROS production in inflammatory colonic cells, suggesting that Rab27A as a novel therapeutic target for the prevention and treatment of UC patients.

Inhibition of HtrA2 alleviates inflammatory response and cell apoptosis in lipopolysaccharide‑induced acute pneumonia in rats.

Pneumonia is one of the commonest causes of death worldwide. High-temperature requirement A2 (HtrA2) is a proapoptotic mitochondrial serine protease involved in caspase-dependent or caspase-independent cell apoptosis. UCF-101 (5-[5-(2-nitrophenyl) furfuryl iodine]-1,3-diphenyl-2-thiobarbituric acid), an inhibitor of HtrA2, has a protective effect on organs in various diseases by inhibiting cell apoptosis. The aim of the present study was to explore whether UCF-101 has a protective effect on lungs in pneumonia. A lipopolysaccharide (LPS)-induced pneumonia model was established in rats. UCF-101 (2 µmol/kg) was used for treatment. Lung injury was detected by hematoxylin and eosin staining. Pro-inflammatory cytokines and oxidative stress-related factors were detected using corresponding test kits. TUNEL staining was used to measure the amount of cell apoptosis. Apoptosis-associated proteins were detected by western blot assay. The present study indicated pulmonary injury induced by LPS. Treatment with UCF-101 clearly alleviated this pulmonary damage and restored the levels of pro-inflammatory cytokines and oxidative stress-related factors. In addition, UCF-101 significantly reduced LPS-induced cell apoptosis, the release of HtrA2 and cytochrome from mitochondria to the cytoplasm and inhibited the expression of pro-apoptotic proteins. UCF-101 also restored the ATP level. The present results demonstrated that UCF-101 acts as a positive regulator of acute pneumonia by inhibiting inflammatory response, oxidative stress and mitochondrial apoptosis. The present study suggests UCF-101 as a potential candidate for pneumonia therapy.

Neuregulin-1β Protects the Rat Diaphragm during Sepsis against Oxidative Stress and Inflammation by Activating the PI3K/Akt Pathway.

Sepsis-induced diaphragm dysfunction (SIDD) which is mainly characterized by decrease in diaphragmatic contractility has been identified to cause great harms to patients. Therefore, there is an important and pressing need to find effective treatments for improving SIDD. In addition, acetylcholinesterase (AChE) activity is a vital property of the diaphragm, so we evaluated both diaphragmatic contractility and AChE activity. Though neuregulin-1β (NRG-1β) is known to exert organ-protective effects in some inflammatory diseases, little is known about the potential of NRG-1β therapy in the diaphragm during sepsis. Our study was aimed at exploring the effects of NRG-1β application on diaphragmatic contractility and AChE activity during sepsis. Proinflammatory cytokines, muscle injury biomarkers in serum, contractile force, AChE activity, proinflammatory cytokines, oxidative parameters, histological condition, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and expression of phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB/Akt) signaling proteins in the diaphragm were measured and compared between nonseptic and septic groups with or without NRG-1β treatment. In vitro, the effects of NRG-1β on reactive oxygen species (ROS) production in the lipopolysaccharide- (LPS-) stimulated L6 rat muscle skeletal cells with or without the Akt inhibitor MK-2206 were detected. NRG-1β inhibited proinflammatory cytokine release and muscle injury biomarkers soaring in serum and improved the sepsis-induced diaphragm dysfunction and AChE activity decrease significantly during sepsis. Meanwhile, the inflammatory response, oxidative stress, pathological impairment, and cell apoptosis in the diaphragm were mitigated by NRG-1β. And NRG-1β activated the PI3K/Akt signaling in the diaphragm of septic rats. Elevated ROS production in the LPS-stimulated L6 rat skeletal muscle cells was reduced after treatment with NRG-1β, while MK-2206 blocked these effects of NRG-1β. In conclusion, our findings underlined that NRG-1β could reduce circulating levels of proinflammatory cytokines in rats with sepsis, adjust diaphragmatic proinflammatory cytokine level, mitigate diaphragmatic oxidative injury, and lessen diaphragm cell apoptosis, thereby improving diaphragmatic function, and play a role in diaphragmatic protection by activating PI3K/Akt signaling.

Let-7d-5p suppresses inflammatory response in neonatal rats with necrotizing enterocolitis via LGALS3-mediated TLR4/NF-κB signaling pathway.

Necrotizing enterocolitis (NEC) is an acute intestinal condition accounting for severe mortality and morbidity in preterm infants. This study aimed to identify the possible roles of let-7d-5p in neonatal rats with NEC. The differentially expressed genes (DEGs) related to NEC were initially screened in silico. After establishment of NEC rat models, measurement of the expression of let-7d-5p, galectin-3 (LGALS3), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as proinflammatory cytokines (TNF-α, IL-1β, and IL-6) was conducted. The interaction between let-7d-5p and LGALS3 or argonaute-2 (AGO2) was identified. Gain- and loss-of-function approaches were then performed in an attempt to investigate the regulatory roles of let-7d-5p and LGALS3 in inflammation and cell apoptosis in NEC neonatal rats. Let-7d-5p was poorly expressed, whereas LGALS3, TLR4, and NF-κB were highly expressed, in the intestinal tissues of NEC rats. Overexpression of let-7d-5p resulted in decreased levels of proinflammatory factors in the intestinal tissues of NEC rats. Through sequential experimentation, let-7d-5p was identified to target LGALS3 and bind to AGO2. In addition, LGALS3 silencing or LPS treatment blocked the TLR4/NF-κB signaling pathway, thereby suppressing intestinal epithelial cell apoptosis and inflammation in NEC. Collectively, let-7d-5p might exercise its inhibitory properties in the inflammatory response and intestinal epithelial cell apoptosis in NEC neonatal rats via inactivation of the LGALS3-dependent TLR4/NF-κB signaling pathway.

Energy Conversion-Based Nanotherapy for Rheumatoid Arthritis Treatment.

Rheumatoid arthritis (RA) is characterized by synovial hyperplasia and cartilage/bone destruction, which results in a high disability rate on human health and a huge burden on social economy. At present, traditional therapies based on drug therapy still cannot cure RA, in accompany with the potential serious side effects. Based on the development of nanobiotechnology and nanomedicine, energy conversion-based nanotherapy has demonstrated distinctive potential and performance in RA treatment. This strategy employs specific nanoparticles with intrinsic physiochemical properties to target lesions with the following activation by diverse external stimuli, such as light, ultrasound, microwave, and radiation. These nanoagents subsequently produce therapeutic effects or release therapeutic factors to promote necrotic apoptosis of RA inflammatory cells, reduce the concentration of related inflammatory factors, relieve the symptoms of RA, which are expected to ultimately improve the life quality of RA patients. This review highlights and discusses the versatile biomedical applications of energy conversion-based nanotherapy in efficient RA treatment, in together with the deep clarification of the facing challenges and further prospects on the final clinical translations of these energy conversion-based nanotherapies against RA.

MiR-143-3p impacts on pulmonary inflammatory factors and cell apoptosis in mice with mycoplasmal pneumonia by regulating TLR4/MyD88/NF-κB pathway.

miR-143-3p is correlated with inflammatory pain responses, such as hsa-miR-143-3p expression reduction in fibromyalgia. The present study aimed to explore the effects of miR-143-3p and Toll-like receptor (TLR) 4/myeloid differentiation factor 88 (MyD88)/NF-κB signaling pathway on pulmonary inflammatory factors levels and alveolar epithelial cell apoptosis in mycoplasmal pneumonia mice. Twenty mice were selected as normal group. The 120 successfully modeled Mycoplasma pneumoniae (MP) infection mice were randomly divided into model group (without any treatment), negative control (NC) group (injected with NC mimic), miR-143-3p mimic group (injected with miR-143-3p mimic), miR-143-3p inhibitor group (injected with miR-143-3p inhibitor), TAK-242 group (treatment with TAK-242), and miR-143-3p inhibitor + TAK-242 group (treatment with miR-143-3p inhibitor + TAK-242). Compared with model group, model mice had up-regulated miR-143-3p expression and decreased MyD88 and p-NF-κB p50 protein expressions (all P<0.05); Model mice treated with miR-143-3p mimic and TAK-242 had reduced interleukin (IL)-2 and tumor necrosis factor (TNF)-α contents and protein expressions of MyD88, p-NF-κB p50, increased IL-10 content, fewer alveolar epithelial cell apoptosis, lower Bax expression and higher Bcl-2 expression (all P<0.05); however, mice with miR-143-3p inhibitor treatment showed opposite trends in terms of above indicators. The exacerbation of mycoplasmal pneumonia caused by miR-143-3p inhibitor was partly improved by miR-143-3p inhibitor + TAK-242 combination treatment (all P<0.05). Therefore, up-regulation of miR-143-3p expression may ameliorate pulmonary inflammatory factors levels and reduce alveolar epithelial cell apoptosis in mycoplasmal pneumonia mice by inhibiting TLR4/MyD88/NF-κB signaling pathway.

Cytokine regulation of apoptosis-induced apoptosis and apoptosis-induced cell proliferation in vascular smooth muscle cells

Vascular smooth muscle cells (VSMCs) are the main structural cell of blood vessels, and VSMC apoptosis occurs in vascular disease, after injury, and in vessel remodeling during development. Although VSMC apoptosis is viewed as silent, recent studies show that apoptotic cells can promote apoptosis-induced compensatory proliferation (AICP), apoptosis-induced apoptosis (AIA), and migration of both local somatic and infiltrating inflammatory cells. However, the effects of VSMC apoptosis on adjacent VSMCs, and their underlying signaling and mechanisms are unknown. We examined the consequences of VSMC apoptosis after activating extrinsic and intrinsic death pathways. VSMCs undergoing apoptosis through Fas/CD95 or the protein kinase inhibitor staurosporine transcriptionally activated interleukin 6 (IL-6) and granulocyte-macrophage colony stimulating factor (GM-CSF), leading to their secretion. Apoptosis induced activation of p38MAPK, JNK, and Akt, but neither p38 and JNK activation nor IL-6 or GM-CSF induction required caspase cleavage. IL-6 induction depended upon p38 activity, while Fas-induced GM-CSF expression required p38 and JNK. Conditioned media from apoptotic VSMCs induced VSMC apoptosis in vitro, and IL-6 and GM-CSF acted as pro-survival factors for AIA. VSMC apoptosis was studied in vivo using SM22α-DTR mice that express the diphtheria toxin receptor in VSMCs only. DT administration induced VSMC apoptosis and VSMC proliferation, and also signficantly induced IL-6 and GM-CSF. We conclude that VSMC apoptosis activates multiple caspase-independent intracellular signaling cascades, leading to release of soluble cytokines involved in regulation of both cell proliferation and apoptosis. VSMC AICP may ameliorate while AIA may amplify the effects of pro-apoptotic stimuli in vessel remodeling and disease.

Understanding the significance of cytokines and chemokines in the pathogenesis of alopecia areata.

Alopecia areata has basically been understood as a type 1 inflammatory disease. Activated NKG2D+ CD8+ cells produce the Th1 cytokine interferon-γ, which leads to the disruption of immune tolerance of hair follicles and the exposure of self-antigens. This results in dense inflammatory cell infiltration and apoptosis around hair follicles, inducing hair loss. A well-known complication of alopecia areata is atopic dermatitis, a typical type 2 inflammatory disease. Hair scientists have shied away from confronting and understanding how alopecia areata, a type 1 inflammatory disease, and atopic dermatitis, a type 2 inflammatory disease, can occur together. This review summarizes the research on the cytokine balance in alopecia areata and then focuses on the classification of the cytokine balance in alopecia areata, including the classification of atopic dermatitis into extrinsic and intrinsic types. Dupilumab reportedly showed dual efficacy in a patient with concomitant atopic dermatitis and alopecia areata, supporting our own experience. Elevated Th2 cytokine levels have also been reported in patients with alopecia areata, with increased serum IL-4, IL-5, IL-6 levels, high IgE levels and elevated eosinophil levels. Because local immunotherapy is a treatment that induces Th2-type inflammation, it may worsen the condition of alopecia areata patients with extrinsic atopic dermatitis. It is desirable to select appropriate treatments with consideration of the cytokine balance.

Mesenchymal stem cells-derived exosomes ameliorate nucleus pulposus cells apoptosis via delivering miR-142-3p: therapeutic potential for intervertebral disc degenerative diseases

ABSTRACT Intervertebral disc degeneration (IDD) is the main cause of lower back pain (LBP), and puzzles massive individuals worldwide. Mesenchymal stem cells (MSCs) transplantation has been demonstrated to potentially ameliorate IDD progression, while the underlying mechanism has not been fully explained. Interleukin-1β (IL-1β) was used to induce nucleus pulposus cells (NPCs) injury. Bone marrow MSCs-derived exosomes were isolated using the super centrifugation method, and characterized using Transmission electron microscopy (TEM) and western blot. Cell viability was determined by MTT, while apoptosis was measured by Annexin-V staining using flow cytometry. miR-142-3fp and gene expressions were measured by real-time PCR. The protein expressions were determined by western blot. Herein, we found exosomes from bone marrow MSCs are circular vesicles, about 80 nm in diameter, and with robust expression of TSG101 and CD63, but without of Calnexin. MSCs exosomes alleviated NPCs apoptosis by reducing IL-1β-induced inflammatory cytokines secretion and MAPK signaling activation. Additionally, MSCs exosomes inhibited NPCs apoptosis and MAPK signaling by delivering miR-142-3p that targets mixed lineage kinase 3 (MLK3). Overexpression of MLK3 abolished the effects of MSCs exosomes on the inflammatory condition, cell apoptosis, and MAPK signaling activation in NPCs. The results confirmed that bone marrow MSCs-derived exosomes-packaged miR-142-3p alleviates NPCs injury through suppressing MAPK signaling by targeting MLK3. The work highlights the therapeutic effect of MSCs on IDD progression, and bone marrow MSCs exosomes might be apromising therapeutic strategy for IDD.

Silencing of Long Non-Coding RNA (lncRNA) Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) Protects PC-12 Cells from LPS-Induced Injury via Targeting miR-29a.

BackgroundSpinal cord injury (SCI) is a debilitating neuropathological condition that significantly affects the quality of life. The present study is basic research examining the underlying mechanisms of NEAT1 and miR-29a in regulating LPS-induced PC-12 cell injury.Material/MethodsThe model of cell injury was induced by the treatment of PC-12 cells with LPS. The expressions of NEAT1, miR-29a, and inflammatory cytokines were measured by real-time quantitative polymerase chain reactions (RT-qPCR). Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry, respectively. Finally, the target between miR-29a and NEAT1 as well as miR-29a and BCL2L11 was investigated by luciferase and RNA pull-down assays.ResultsKnockdown of NEAT1 can inhibit inflammatory cytokine expression and PC-12 cell apoptosis and promote PC-12 cell proliferation by targeting miR-29a. However, the variation caused by NEAT1 knockdown can be reversed by the silencing of miR-29a and the overexpression of BCL2L11, which is the direct target gene of miR-29a.ConclusionsHigh NEAT1 levels can increase LPS-induced injury in PC-12 cells through the miR-29a/BCL2L11 pathway. lncRNA NEAT1 may, therefore, be a promising target for SCI treatment.

P0966PLACENTAL GROWTH FACTOR DEFICIENCY AGGRAVATES DIABETIC NEPHROPATHY

Abstract Background and Aims Placental growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family. PlGF exerts favorable angiogenetic and lymphangiogenic activity by binding to VEGF-R1 and -R3, respectively. Due to its functional synergy with VEGF-A, it is required for a correct neovascularization during pathological conditions while inactivation of PlGF contributes to decrease of pathological angiogenesis. Because reduced angiogenesis and lymphagiogenesis that contribute to defective lipid drainage are implicated in the progression diabetic kidney disease, we investigated the role of PlGF in the development of diabetic nephropathy by using PlGF-knockout mice. Method Diabetes was induced by a low-dose streptozotocin injection in 9-week-old male C57BL/6J PlGF-KO and wild-type mice and biochemical and morphological parameters were examined at 12 weeks later. Results In diabetic PlGF-KO mice, fasting blood glucose and HbA1c levels increased significantly and the development of glomerular sclerosis and mesangial area expansion were accompanied by albuminuria. Diabetic PlGF-KO mice exhibited increased expression of type IV collagen, transforming growth factor-β1 and glomerular IHC staining for nephrin, PECAM-1 and WT-1-positive cells and VEGF-R1,-R2,-R3 expression decreased, suggesting decreased endothelial cell and podocyte structure. Intrarenal expression of pLKB1, and pAMPK decreased and that of PPARα, PGC1α, ERRα, p-eNOS, and urinary Nox concentration decreased while iNOS increased, indicating disturbed lipid metabolism and endothelial dysfunction in the same group. Increased intrarenal FFA, TG, and cholesterol concentration represents presence of lipid accumulation. F4/80- and TUNEL-positive cells increased, suggesting increased inflammatory cell infiltration and apoptosis. CD68 and arginase-II increased indicating that macrophage subtype M1 polarization is involved in the inflammatory process. Expression of Bcl2/bax decreased and that of SOD1 and 2 decreased, indicating increased apoptosis and oxidative stress, respectively. Increased expression of intrarenal 8-OHdG and urinary isoprostane level indicates increased oxidative stress. Conclusion Impaired angiogenesis and lymphangiogenesis are implicated in PlGF deficiency and this promotes lipotoxicity-induced inflammation, oxidative stress and deteriorates renal functional and phenotypic parameters in the diabetic kidney.