Pigment epithelium‑derived factor facilitates NLRP3 inflammasome activation through downregulating cytidine monophosphate kinase 2: A potential treatment strategy for missed abortion

The role of pyroptosis in the occurrence and development of pregnancy-related diseases

Pyroptosis is a form of programmed cell death that is crucial in the development of various diseases, including autoimmune diseases, atherosclerotic diseases, cancer, and pregnancy complications. In recent years, it has gained significant attention in national and international research due to its association with inflammatory immune overactivation and its involvement in pregnancy complications such as miscarriage and preeclampsia (PE). The mechanisms discussed include the canonical pyroptosis pathway of gasdermin activation and pore formation (caspase-1-dependent pyroptosis) and the non-canonical pyroptosis pathway (cysteoaspartic enzymes other than caspase-1). These pathways work on various cellular and factorial levels to influence normal pregnancy. This review aims to summarize and analyze the pyroptosis pathways associated with abnormal pregnancies and pregnancy complications. The objective is to enhance pregnancy outcomes by identifying various targets to prevent the onset of pyroptosis.

LincRNA-p21/AIF-1/CMPK2/NLRP3 pathway promoted inflammation, autophagy and apoptosis of human tubular epithelial cell induced by urate via exosomes

Urate nephropathy, a common complication of hyperuricemia, has garnered increasing attention worldwide. However, the exact pathogenesis of this condition remains unclear. Currently, inflammation is widely accepted as the key factor in urate nephropathy. Therefore, the aim of this study was to elucidate the interaction of lincRNA-p21/AIF-1/CMPK2/NLRP3 via exosomes in urate nephropathy. This study evaluated the effect of lincRNA-p21/AIF-1/CMPK2/NLRP3 using clinical data collected from patients with urate nephropathy and human renal tubular epithelial cells (HK2) cultured with different concentrations of urate. In clinical research section, the level of lincRNA-p21/AIF-1 in exosomes of urine in patients with hyperuricemia or urate nephropathy was found to be increased, particularly in patients with urate nephropathy. In vitro study section, the level of exosomes, inflammation, autophagy, and apoptosis was increased in HK2 cells induced by urate. Additionally, the expression of lincRNA-p21, AIF-1, CMPK2, and NLRP3 was upregulated in exosomes and HK2 cells. Furthermore, manipulating the activity of lincRNA-p21, AIF-1, CMPK2, and NLRP3 through overexpression or interference vectors regulated the level of inflammation, autophagy, and apoptosis in HK2 cells. In conclusion, the pathway of lincRNA-p21/AIF-1/CMPK2/NLRP3 contributed to inflammation, autophagy, and apoptosis of human renal tubular epithelial cell induced by urate via exosomes. Additionally, the specific exosomes in urine might serve as novel biomarkers for urate nephropathy.

Maternal prenatal systemic inflammation indexes predicts premature neonatal respiratory distress syndrome

Neonatal respiratory distress syndrome (NRDS) is one of the leading causes of neonatal mortality in low-income countries. It is caused by a lack of surface-active substances in the lungs, and the maternal inflammatory response plays an important role in the formation of surface-active substances in the fetal lungs. We aimed to investigate the correlation between maternal prenatal systemic inflammatory indices and respiratory distress syndrome in preterm neonates. This is a retrospective case-control study that collected data from all patients who delivered between 28 and 36 weeks of gestation at Longhua District People's Hospital in Shenzhen City and whose infants were admitted to the neonatal unit, newborns with respiratory distress syndrome were in the experimental group (NRDS group), and newborns without NRDS were in the control group (non-NRDS group). To minimize the effect of confounders on the results, propensity score matching was performed on baseline characteristics. Totally, 524 patients were included (93 in the NRDS group and 431 in the non-NRDS group), and 71 matched pairs (142 patients). The neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI) and neutrophil lymphocyte to platelet ratio (NLPR) were higher in the NRDS group than in the non-NRDS group (p < 0.05). The ROC curves of NLR, dNLR, SII, SIRI, AISI and NLPR for the diagnosis of NRDS were plotted, and it was found that the combined diagnostic efficacy of these six systemic inflammatory markers was better (AUC: 0.643, P = 0.003). Patients were divided into two groups based on the cut-off values determined from the ROC curves, and analysis using binary regression models revealed that SII ≥ 1199.94 (OR, 2.554; 95% CI 1.245-5.239, P = 0.011) and NLPR ≥ 0.0239 (OR, 2.175; 95% CI 1.061-4.459, P = 0.034) were independent risk factors predicting NRDS. Maternal prenatal SII ≥ 1199.94 and NLPR ≥ 0.0239 are independent risk factors for NRDS, and clinicians may be used to prevent neonatal respiratory distress in advance to reduce the incidence of NRDS.

CXC chemokine receptor type 5 may induce trophoblast dysfunction and participate in the processes of unexplained missed abortion, wherein p-ERK and interleukin-6 may be involved

Chemokines regulate the trophoblast dysfunction involved in the occurrence and development of pathological pregnancy, including missed abortions. In particular, CXC chemokine receptor type 5 mediates cell proliferation, migration, and inflammation; nonetheless, its role in missed abortions remains unclear. This study aimed to examine the expression of CXC chemokine receptor type 5 in missed abortions and to investigate the effects of CXC chemokine receptor type 5 on the biological behaviour of trophoblasts, as well as the underlying mechanisms. Our results indicated that CXC chemokine receptor type 5 was upregulated in the villi of women who experienced unexplained missed abortions, as compared with those who had normal pregnancies. CXC chemokine receptor type 5 inhibited the proliferation and migration of human first-trimester trophoblast/simian virus cells but promoted cell apoptosis. With respect to its mechanisms, CXC chemokine receptor type 5 activated the extracellular signal-regulated protein kinase 1/2 signalling pathway and upregulated the secretion of interleukin-6; however, it had no effect on the secretion of tumour necrosis factor-α. In conclusion, our findings suggest that CXC chemokine receptor type 5 induces trophoblast dysfunction and participates in the processes of unexplained missed abortions, wherein p-ERK and interleukin-6 may be involved.

Knockdown of DAPK1 inhibits IL-1β-induced inflammation and cartilage degradation in human chondrocytes by modulating the PEDF-mediated NF-κB and NLRP3 inflammasome pathway

Osteoarthritis (OA) is a common joint disease that is characterized by inflammation and cartilage degradation. Death-associated protein kinase 1 (DAPK1) is a multi-domain serine/threonine kinase and has been reported to be involved in the progression of OA. However, its role and mechanism in OA remain unclear. Here, we found the expression of DAPK1 in OA cartilage tissues was higher than that in normal cartilage tissues. The expression of DAPK1 in chondrocytes was up-regulated by IL-1β. Knockdown of DAPK1 promoted cell viability and anti-apoptotic protein expression, while it inhibited the apoptosis rate and pro-apoptotic protein expressions in IL-1β-induced chondrocytes. In addition, DAPK1 inhibition reduced the levels of inflammatory cytokines and expressions of matrix metalloproteinases (MMPs), and increased the expressions of collagen II and aggrecan. The data of mechanistic investigation indicated that the expression of pigment epithelium-derived factor (PEDF) was positively regulated by DAPK1. Overexpression of PEDF attenuated the effects of DAPK1 knockdown on IL-1β-induced cell viability, apoptosis, inflammation, and cartilage degradation. Furthermore, PEDF overexpression restored the activity of the NF-κB pathway and NLRP3 inflammasome after DAPK1 knockdown. Collectively, down-regulation of DAPK1 inhibited IL-1β-induced inflammation and cartilage degradation via the PEDF-mediated NF-κB and NLRP3 inflammasome pathways.

Functional Variants Associated With CMPK2 and in ASB16 Influence Bovine Digital Dermatitis

Bovine digital dermatitis (BDD) is an infectious disease of the hoof in cattle with multifactorial etiology and a polygenic influence on susceptibility. With our study, we identified genomic regions with the impact on occurrence and development of BDD. We used 5,040 genotyped animals with phenotype information based on the M-stage system for genome-wide association. Significant associations for single-nucleotide polymorphisms were found near genes CMPK2 (chromosome 11) and ASB16 (chromosome 19) both being implicated in immunological processes. A sequence analysis of the chromosomal regions revealed rs208894039 and rs109521151 polymorphisms as having significant influence on susceptibility to the disease. Specific genotypes were significantly more likely to be affected by BDD and developed chronic lesions. Our study provides an insight into the genomic background for a genetic predisposition related to the pathogenesis of BDD. Results might be implemented in cattle-breeding programs and could pave the way for the establishment of a BDD prescreening test.

Electroacupuncture Inhibits NLRP3 Activation by Regulating CMPK2 After Spinal Cord Injury

Objectives

This study aimed to evaluate the expression of cytosine monophosphate kinase 2 (CMPK2) and activation of the NLRP3 inflammasome in rats with spinal cord injury (SCI) and to characterize the effects of electroacupuncture on CMPK2-associated regulation of the NLRP3 inflammasome.

Methods

An SCI model was established in Sprague–Dawley (SD) rats. The expression levels of NLRP3 and CMPK2 were measured at different time points following induction of SCI. The rats were randomly divided into a sham group (Sham), a model group (Model), an electroacupuncture group (EA), an adeno-associated virus (AAV) CMPK2 group, and an AAV NC group. Electroacupuncture was performed at jiaji points on both sides of T9 and T11 for 20 min each day for 3 consecutive days. In the AAV CMPK2 and AAV NC groups, the viruses were injected into the T9 spinal cord via a microneedle using a microscope and a stereotactic syringe. The Basso–Beattie–Bresnahan (BBB) score was used to evaluate the motor function of rats in each group. Histopathological changes in spinal cord tissue were detected using H&E staining, and the expression levels of NLRP3, CMPK2, ASC, caspase-1, IL-18, and IL-1β were quantified using Western blotting (WB), immunofluorescence (IF), and RT-PCR.

Results

The expression levels of NLRP3 and CMPK2 in the spinal cords of the model group were significantly increased at day 1 compared with those in the sham group (p < 0.05). The expression levels of NLRP3 and CMPK2 decreased gradually over time and remained low at 14 days post-SCI. We successfully constructed AAV CMPK2 and showed that CMPK2 was significantly knocked down following 2 dilutions. Finally, treatment with EA or AAV CMPK2 resulted in significantly increased BBB scores compared to those in the model group and the AAV NC group (p < 0.05). The histomorphology of the spinal cord in the EA and AAV CMPK2 groups was significantly different than that in the model and AAV NC groups. WB, IF, and PCR analyses showed that the expression levels of CMPK2, NLRP3, ASC, caspase-1, IL-18, and IL-1β were significantly lower in the EA and AAV CMPK2 groups compared with those in the model and AAV NC groups (p < 0.05).

Conclusion

Our study showed that CMPK2 regulated NLRP3 expression in rats with SCI. Activation of NLRP3 is a critical mechanism of inflammasome activation and the inflammatory response following SCI. Electroacupuncture downregulated the expression of CMPK2 and inhibited activation of NLRP3, which could improve motor function in rats with SCI.

Inhibition of HMGB1 Ameliorates the Maternal-Fetal Interface Destruction in Unexplained Recurrent Spontaneous Abortion by Suppressing Pyroptosis Activation

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy that affects the physical and mental health of pregnant women, and approximately 50% of the mechanisms are unclear. Our previous studies have found that high mobility group box 1 (HMGB1) molecules are highly expressed at the maternal-fetal interface of unexplained recurrent spontaneous abortion (URSA) patients. The purpose of this study was to further detect the expression of HMGB1 and pyroptosis in decidual tissue of URSA patients, and explore the potential mechanism of the protective role of HMGB1 in URSA patients and mouse model. The decidua tissues of 75 URSA patients and 75 women who actively terminated pregnancy were collected, and URSA mouse models were established and treated with HMGB1 inhibitor-aspirin. The expression of HMGB1, and their receptors (RAGE, TLR2, TLR4), pyroptosis-associated proteins (NLRP-3, caspase-1, GSDMD) and NF-κB was examined at the maternal-fetal interface of human and mouse. Our study found that HMGB1, NLRP-3, Caspase-1, GSDMD, RAGE, TLR2 and TLR4 were highly expressed and NF-κB signaling pathway were activated in the decidua tissue of URSA group. Moreover, immune cell disorder and co-localization of HMGB1 and macrophages were found at the maternal-fetal interface of URSA mice. However, HMGB1, TLR2, TLR4, NF-κB, and pyroptosis-associated proteins can be down-regulated by administering low-dose aspirin. These data may indicate that highly expressed HMGB1 was actively secreted by macrophages and then activated pyroptosis through the TLR2/TLR4-NF-κB pathway to cause aseptic inflammation, leading to the occurrence and development of URSA. Moreover, low-dose aspirin can reduce HMGB1 protein levels of serum and decidual in URSA.

Metformin Corrects Glucose Metabolism Reprogramming and NLRP3 Inflammasome-Induced Pyroptosis via Inhibiting the TLR4/NF-κB/PFKFB3 Signaling in Trophoblasts: Implication for a Potential Therapy of Preeclampsia

NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome-mediated pyroptosis is a crucial event in the preeclamptic pathogenesis, tightly linked with the uteroplacental TLR4/NF-κB signaling. Trophoblastic glycometabolism reprogramming has now been noticed in the preeclampsia pathogenesis, plausibly modulated by the TLR4/NF-κB signaling as well. Intriguingly, cellular pyroptosis and metabolic phenotypes may be inextricably linked and interacted. Metformin (MET), a widely accepted NF-κB signaling inhibitor, may have therapeutic potential in preeclampsia while the underlying mechanisms remain unclear. Herein, we investigated the role of MET on trophoblastic pyroptosis and its relevant metabolism reprogramming. The safety of pharmacologic MET concentration to trophoblasts was verified at first, which had no adverse effects on trophoblastic viability. Pharmacological MET concentration suppressed NLRP3 inflammasome-induced pyroptosis partly through inhibiting the TLR4/NF-κB signaling in preeclamptic trophoblast models induced via low-dose lipopolysaccharide. Besides, MET corrected the glycometabolic reprogramming and oxidative stress partly via suppressing the TLR4/NF-κB signaling and blocking transcription factor NF-κB1 binding on the promoter PFKFB3, a potent glycolytic accelerator. Furthermore, PFKFB3 can also enhance the NF-κB signaling, reduce NLRP3 ubiquitination, and aggravate pyroptosis. However, MET suppressed pyroptosis partly via inhibiting PFKFB3 as well. These results provided that the TLR4/NF-κB/PFKFB3 pathway may be a novel link between metabolism reprogramming and NLRP3 inflammasome-induced pyroptosis in trophoblasts. Further, MET alleviates the NLRP3 inflammasome-induced pyroptosis, which partly relies on the regulation of TLR4/NF-κB/PFKFB3-dependent glycometabolism reprogramming and redox disorders. Hence, our results provide novel insights into the pathogenesis of preeclampsia and propose MET as a potential therapy.

Clinical Efficacy and Safety Study of Mifepristone with Misoprostol Treatment in Patients with Missed Abortion

Currently, medication abortion is widely used in clinical practice in China. The aim of this study was to investigate the effect of mifepristone with misoprostol treatment on the efficacy of patients with missed abortion (MA) and the safety of this drug regimen. 95 patients with MA treated in our hospital from February 2019 to April 2021 were collected as the subjects of this study, and the patients were divided into the control and the research groups according to different treatment modalities. Among them, 46 cases in the control group were treated by diethylstilbestrol combined with oxytocin and 49 cases in the research group were treated by mifepristone combined with misoprostol, and both groups underwent curettage after medication. The rates of complete abortion, time of embryo expulsion, time of operation, intraoperative bleeding, time of postoperative vaginal bleeding, amount of vaginal bleeding, rate of one-time curettage, the levels of serum estradiol (E2), progesterone (P), β-chorionic gonadotropin (β-hCG), and interleukin-18 (IL-18), and the incidence of adverse effects in the two groups were examined and compared. Alanine transaminase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and serum creatinine (Scr) were used as indicators to evaluate the safety of the drug. The results showed that the rates of complete abortion and one-time curettage were significantly higher in the study group than in the control group, while the time of embryo expulsion, operation time, intraoperative bleeding, postoperative vaginal bleeding time, and vaginal bleeding were significantly lower than in the control group. The serum E2, P, and β-hCG levels before curettage in both groups were significantly higher, and IL-18 levels were significantly lower than those at the time of admission, with E2, P, and β-hCG levels increasing more and IL-18 levels decreasing more in the research group. After drug treatment, no abnormal changes in liver and kidney functions were observed in both groups, and the incidence of adverse reactions was at a similar and lower level in both groups. This shows that mifepristone with misoprostol is a safer and more effective drug regimen for the treatment of MA, which can regulate the levels of serum sex hormones and inflammatory factors in the body, promote the shedding of placental tissue, and create conditions for improving the rate of curettage.

MiR-494-3p alleviates acute lung injury through regulating NLRP3 activation by targeting CMPK2

Acute lung injury (ALI) is a severe respiratory disorder with a high rate of mortality, and is characterized by excessive cell apoptosis and inflammation. MicroRNAs (miRNAs) play pivotal roles in ALI. This study examined the biological function of miR-494-3p in cell apoptosis and inflammatory response in ALI. For this, mice were injected with lipopolysaccharide (LPS) to generate an in-vivo model of ALI (ALI mice), and WI-38 cells were stimulated with lipopolysaccharide (LPS) to generate an in-vitro model of ALI. We found that miR-494-3p was significantly downregulated in the ALI mice and in the in-vitro model. Overexpression of miR-494-3p inhibited inflammation and cell apoptosis in the LPS-induced WI-38 cells, and improved the symptoms of lung injury in the ALI mice. We then identified cytidine/uridine monophosphate kinase 2 (CMPK2) as a novel target of miR-494-3p in the WI-38 cells. Furthermore, miR-494-3p suppressed cell apoptosis and the inflammatory response in LPS-treated WI-38 cells through targeting CMPK2. The NLRP3 inflammasome is reportedly responsible for the activation of inflammatory processes. In our study, CMPK2 was confirmed to activate the NLRP3 inflammasome in LPS-treated WI-38 cells. In conclusion, miR-494-3p attenuates ALI through inhibiting cell apoptosis and the inflammatory response by targeting CMPK2, which suggests the value of miR-494-3p as a target for the treatment for ALI.

Evaluation of diagnosis and prognosis with anti-mullerian hormone level in early missed abortion

OBJECTIVE

This research was designed to probe into the clinical significance of anti-mullerian hormone (AMH) levels in early missed abortion.

METHODS

Forty-six women with early missed abortions treated in our hospital from October 2018 to June 2019 were collected as the research subjects and included in the observation group (OG), while 51 normal pregnant women were included in the control group (CG) during the same period. The levels of AMH, human follicle stimulating hormone (FSH) and human luteinizing hormone (LH) in the serum of women of both groups were tested by enzyme-linked immunosorbent assay (ELISA). The diagnostic value of AMH in early missed abortion was analyzed by receiver operating characteristic (ROC). The correlation between AMH and FSH, LH was assessed via Pearson correlation. According to the median expression of AMH before treatment, patients were divided into high and low expression groups (HEG, LEG, respectively), and time of vaginal bleeding and menstrual resurgence, and the incidence of coagulation dysfunction were compared after operation.

RESULTS

The AMH and FSH levels in serum of patients in the OG were obviously lower than those in the CG, and the LH level was markedly higher. The area under the curve of serum AMH was 0.867. AMH was positively correlated with FSH and negatively correlated with LH. The time of vaginal bleeding and menstruation resurgence of the HEG patients were remarkably lower than those of the LEG (All P < 0.05).

CONCLUSION

Serum AMH level is expected to be a good prognostic indicator in diagnosing early missed abortion.