Targeting TBK1 Attenuates LPS-Induced NLRP3 Inflammasome Activation by Regulating of mTORC1 Pathways in Trophoblasts

Crosstalk and Prospects of TBK1 in Inflammation

BACKGROUND

TANK-binding kinase 1 (TBK1) is a pivotal mediator of innate immunity, activated by receptors such as mitochondrial antiviral signaling protein (MAVS), stimulator of interferon genes (STING), and TIR-domain-containing adaptor inducing interferon-β (TRIF). It modulates immune responses by exerting influence on the type I interferons (IFN-Is) signaling and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways, Over the past few years, TBK1 multifaceted role in both immune and inflammatory responses is increasingly recognized.

METHODS AND RESULTS

This review aims to scrutinize how TBK1 operates within the NF-κB pathway and the interferon regulatory transcription factor 3 (IRF3)-dependent IFN-I pathways, highlighting the kinases and other molecules involved in these processes. This analysis reveals the distinctive characteristics of TBK1's involvement in these pathways. Furthermore, it has been observed that the role of TBK1 in exerting anti-inflammatory or pro-inflammatory effects is contingent upon varying pathological conditions, indicating a multifaceted role in immune regulation.

DISCUSSION

TBK1's evolving role in various diseases and the potential of TBK1 inhibitors as therapeutic agents are explored. Targeting TBK1 may provide new strategies for treating inflammatory disorders and autoimmune diseases associated with IFN-Is, warranting further investigation.

Inhibition of BCAT1 expression improves recurrent miscarriage by regulating cellular dysfunction and inflammation of trophoblasts

Sustained or chronic inflammation in the placenta can result in placental insufficiency, leading to adverse reproductive outcomes such as pregnancy loss. Branched-chain amino acid transaminase 1 (BCAT1) expresses in the placenta and is involved in the pathological inflammatory response, but its role in recurrent miscarriage (RM) has not been fully investigated. In the present study, we delved into the effects of BCAT1 on trophoblast inflammation induced by lipopolysaccharide (LPS) and a mouse model of pregnancy loss induced by LPS. In vitro, after the HTR-8/SVneo cells were treated with LPS and BCATc inhibitor 2 (a selective BCAT inhibitor), the cell apoptosis was verified by TUNEL assay, and the activity of caspase-3 and caspase-9 was detected. Real-time PCR, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence (IF) were used to determine the expression of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and inflammasomes (NLRP3 and ASC) in LPS-treated trophoblast cells. Western blot analysis was performed to verify the expression of phospho-IκBα (p-IκBα) in cells and NF-κB p65 in the nuclei. IF staining was used to detect the nuclear translocation of NF-κB p65. The DNA binding activity of NF-κB was detected by an electrophoretic mobility shift assay (EMSA). The results demonstrated that inhibition of BCAT1 reduced trophoblast apoptosis, suppressed the release of proinflammatory cytokines, and prevented NLRP3 inflammasome activation in response to LPS. Additionally, BCAT1 inhibition blocked the activation of the NF-κB pathway in trophoblasts. This study highlights the potential therapeutic role of targeting BCAT1 in preventing adverse reproductive outcomes associated with chronic placental inflammation.

LMWH prevents thromboinflammation in the placenta via HBEGF-AKT signaling

ABSTRACT

Low molecular weight heparins (LMWH) are used to prevent or treat thromboembolic events during pregnancy. Although studies suggest an overall protective effect of LMWH in preeclampsia (PE), their use in PE remains controversial. LMWH may convey beneficial effects in PE independent of their anticoagulant activity, possibly by inhibiting inflammation. Here, we evaluated whether LMWH inhibit placental thromboinflammation and trophoblast NLRP3 inflammasome activation. Using an established procoagulant extracellular vesicle-induced and platelet-dependent PE-like mouse model, we show that LMWH reduces pregnancy loss and trophoblast inflammasome activation, restores altered trophoblast differentiation, and improves trophoblast proliferation in vivo and in vitro. Moreover, LMWH inhibits platelet-independent trophoblast NLRP3 (NLR family pyrin domain containing 3) inflammasome activation. Mechanistically, LMWH activates via heparin-binding epidermal growth factor (HBEGF) signaling the PI3-kinase-AKT pathway in trophoblasts, thus preventing inflammasome activation. In human PE placental explants, inflammasome activation and PI3-kinase-AKT signaling events were reduced with LMWH treatment compared with those without LMWH treatment. Thus, LMWH inhibits sterile inflammation via the HBEGF signaling pathway in trophoblasts and ameliorates PE-associated complications. These findings suggest that drugs targeting the inflammasome may be evaluated in PE and identify a signaling mechanism through which LMWH ameliorates PE, thus providing a rationale for the use of LMWH in PE.

Single-particle rotational microrheology enables pathological staging of macrophage foaming and antiatherosclerotic studies

The formation of macrophage-derived foam cells has been recognized as the pathological hallmark of atherosclerotic diseases. However, the pathological evolution dynamics and underlying regulatory mechanisms remain largely unknown. Herein, we introduce a single-particle rotational microrheology method for pathological staging of macrophage foaming and antiatherosclerotic explorations by probing the dynamic changes of lysosomal viscous feature over the pathological evolution progression. The principle of this method involves continuous monitoring of out-of-plane rotation-caused scattering brightness fluctuations of the gold nanorod (AuNR) probe-based microrheometer and subsequent determination of rotational relaxation time to analyze the viscous feature in macrophage lysosomes. With this method, we demonstrated the lysosomal viscous feature as a robust pathological reporter and uncovered three distinct pathological stages underlying the evolution dynamics, which are highly correlated with a pathological stage-dependent activation of the NLRP3 inflammasome-involved positive feedback loop. We also validated the potential of this positive feedback loop as a promising therapeutic target and revealed the time window-dependent efficacy of NLRP3 inflammasome-targeted drugs against atherosclerotic diseases. To our knowledge, the pathological staging of macrophage foaming and the pathological stage-dependent activation of the NLRP3 inflammasome-involved positive feedback mechanism have not yet been reported. These findings provide insights into in-depth understanding of evolutionary features and regulatory mechanisms of macrophage foaming, which can benefit the analysis of effective therapeutical drugs as well as the time window of drug treatment against atherosclerotic diseases in preclinical studies.

Targeting a mTOR/autophagy axis: a double-edged sword of rapamycin in spontaneous miscarriage

Immune dysfunction is a primary culprit behind spontaneous miscarriage (SM). To address this, immunosuppressive agents have emerged as a novel class of tocolytic drugs, modulating the maternal immune system's tolerance towards the embryo. Rapamycin (PubChem CID:5284616), a dual-purpose compound, functions as an immunosuppressive agent and triggers autophagy by targeting the mTOR pathway. Its efficacy in treating SM has garnered significant research interest in recent times. Autophagy, the cellular process of self-degradation and recycling, plays a pivotal role in numerous health conditions. Research indicates that autophagy is integral to endometrial decidualization, trophoblast invasion, and the proper functioning of decidual immune cells during a healthy pregnancy. Yet, in cases of SM, there is a dysregulation of the mTOR/autophagy axis in decidual stromal cells or immune cells at the maternal-fetal interface. Both in vitro and in vivo studies have highlighted the potential benefits of low-dose rapamycin in managing SM. However, given mTOR's critical role in energy metabolism, inhibiting it could potentially harm the pregnancy. Moreover, while low-dose rapamycin has been deemed safe for treating recurrent implant failure, its potential teratogenic effects remain uncertain due to insufficient data. In summary, rapamycin represents a double-edged sword in the treatment of SM, balancing its impact on autophagy and immune regulation. Further investigation is warranted to fully understand its implications.

Targeting TANK-binding kinase 1 attenuates painful diabetic neuropathy via inhibiting microglia pyroptosis

BACKGROUND

Painful diabetic neuropathy (PDN) is closely linked to inflammation, which has been demonstrated to be associated with pyroptosis. Emerging evidence has implicated TANK-binding kinase 1 (TBK1) in various inflammatory diseases. However, it remains unknown whether activated TBK1 causes hyperalgesia via pyroptosis.

METHODS

PDN mice model of type 1 or type 2 diabetic was induced by C57BL/6J or BKS-DB mice with Lepr gene mutation. For type 2 diabetes PDN model, TBK1-siRNA, Caspase-1 inhibitor Ac-YVAD-cmk or TBK1 inhibitor amlexanox (AMX) were delivered by intrathecal injection or intragastric administration. The pain threshold and plantar skin blood perfusion were evaluated through animal experiments. The assessments of spinal cord, dorsal root ganglion, sciatic nerve, plantar skin and serum included western blotting, immunofluorescence, ELISA, and transmission electron microscopy.

RESULTS

In the PDN mouse model, we found that TBK1 was significantly activated in the spinal dorsal horn (SDH) and mainly located in microglia, and intrathecal injection of chemically modified TBK1-siRNA could improve hyperalgesia. Herein, we described the mechanism that TBK1 could activate the noncanonical nuclear factor κB (NF-κB) pathway, mediate the activation of NLRP3 inflammasome, trigger microglia pyroptosis, and ultimately induce PDN, which could be reversed following TBK1-siRNA injection. We also found that systemic administration of AMX, a TBK1 inhibitor, could effectively improve peripheral nerve injury. These results revealed the key role of TBK1 in PDN and that TBK1 inhibitor AMX could be a potential strategy for treating PDN.

CONCLUSIONS

Our findings revealed a novel causal role of TBK1 in pathogenesis of PDN, which raises the possibility of applying amlexanox to selectively target TBK1 as a potential therapeutic strategy for PDN.

Metabolomic Profiling and In Vivo Antiepileptic Effect of Zygophyllum album Aerial Parts and Roots Crude Extracts against Pentylenetetrazole-Induced Kindling in Mice

The chemical profiles of both Zygophyllum album (Z. album) aerial parts and roots extracts were evaluated with LC-ESI-TOF-MS/MS analysis. Twenty-four compounds were detected. Among them, some are detected in both the aerial parts and the roots extracts, and others were detected in the aerial parts only. The detected compounds were mainly flavonoids, phenolic compounds, triterpenes and other miscellaneous compounds. Such compounds contribute to the diverse pharmacological activities elicited by the Z. album species. This study aimed to elucidate the antiepileptic effect of Z. album aerial parts and roots crude extracts against pentylenetetrazole (PTZ)-induced kindling in mice. Male albino mice were divided into four groups, eight animals each. All groups, except the control group, were kindled with PTZ (35 mg/kg i.p.), once every alternate day for a total of 15 injections. One group was left untreated (PTZ group). The remaining two groups were treated prior to PTZ injection with either Z. album aerial parts or roots crude extract (400 mg/kg, orally). Pretreatment with either extract significantly reduced the seizure scores, partially reversed the histological changes in the cerebral cortex and exerted antioxidant/anti-inflammatory efficacy evinced by elevated hippocampal total antioxidant capacity and SOD and catalase activities, parallel to the decrement in MDA content, iNOS activity and the TXNIB/NLRP3 axis with a subsequent decrease in caspase 1 activation and a release of IL-1β and IL-18. Moreover, both Z. album extracts suppressed neuronal apoptosis via upregulating Bcl-2 expression and downregulating that of Bax, indicating their neuroprotective and antiepileptic potential. Importantly, the aerial parts extract elicited much more antiepileptic potential than the roots extract did.

The NFκB Signaling Pathway Is Involved in the Pathophysiological Process of Preeclampsia

The high prevalence of preeclampsia (PE) is a major cause of maternal and fetal mortality and affects the long-term prognosis of both mother and baby. Termination of pregnancy is currently the only effective treatment for PE, so there is an urgent need for research into its pathogenesis and the development of new therapeutic approaches. The NFκB family of transcription factors has an essential role in inflammation and innate immunity. In this review, we summarize the role of NFκB in normal and preeclampsia pregnancies, the role of NFκB in existing treatment strategies, and potential NFκB treatment strategies.

Pregnancy outcomes in patients with familial Mediterranean fever: systematic review and meta-analysis

OBJECTIVE

The relationship between FMF and pregnancy outcomes remains unclear. This systematic review and meta-analysis aimed to clarify this association.

METHODS

Electronic databases-PubMed, Web of Science, Cochrane, and EMBASE-were searched on 20 December 2022, using specific search terms. Case-control, cohort, and randomized clinical trial studies comparing patients with FMF and healthy controls were considered eligible. We excluded systematic reviews, meta-analyses, case series with fewer than five cases, republished articles without new findings on pregnancy outcomes, studies targeting paternal FMF, and those not published in English. The results were summarized in the form of odds ratios (ORs) and 95% CIs, using a random-effects model. This study was registered in the University hospital Medical Information Network Clinical Trials Registry (Japan) as UMIN000049827.

RESULTS

The initial electronic search identified 611 records, of which 9 were included in this meta-analysis (177 735 pregnancies, 1242 with FMF, and 176 493 healthy controls). FMF was significantly associated with increased odds of preterm deliveries (OR, 1.67; 95% CI, 1.05-2.67; I2 = 22%) and insignificantly associated with increased odds of fetal growth restriction (OR, 1.45; 95% CI, 0.90-2.34; I2 = 0%) and hypertensive disorders during pregnancy (OR, 1.28; 95% CI, 0.87-1.87; I2 = 0%).

CONCLUSION

FMF was significantly associated with preterm delivery and insignificantly associated with fetal growth restriction and hypertensive disorders. All of the included studies were observational studies. Treatment characteristics were not fully collected from the articles, and further analysis of treatments for FMF in pregnancy is still warranted.

Uric acid as a mediator in the correlation between white blood cells and preeclampsia severity: a retrospective cohort study

This study aimed to analyze the independent risk factors for predicting preeclampsia severity and explore its underlying mechanism. Clinical data of patients with preeclampsia were collected from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Univariate and multivariate analyses were employed to assess the significant factors associated with preeclampsia severity. Additionally, we performed multivariate logistic regression analysis and mediation analysis to investigate the potential regulatory path. Based on inclusion and exclusion criteria, 731 participants were enrolled: severe preeclampsia (n = 381) and mild to moderate preeclampsia (n = 350). Age, white blood cells (WBC), platelet, creatinine, albumin, uric acid, aspartate aminotransferase, alanine aminotransferase, international normalized ratio, and prothrombin time were significantly related to preeclampsia severity. Besides, hospital length of stay was significantly higher in the severe group. Notably, age and uric acid were independent predictors for preeclampsia severity. Further, WBC and creatinine were significantly associated with uric acid. Finally, the mediation analysis showed that uric acid was a mediator of the relationship between WBC and preeclampsia severity. In conclusion, WBC might affect preeclampsia severity and progression via the mediation of uric acid. This study might provide novel insight into preventing preeclampsia development.

Identification of key genes in the pathogenesis of preeclampsia via bioinformatic analysis and experimental verification

Background

Preeclampsia (PE) is the primary cause of perinatal maternal-fetal mortality and morbidity. The exact molecular mechanisms of PE pathogenesis are largely unknown. This study aims to identify the hub genes in PE and explore their potential molecular regulatory network.

Methods

We downloaded the GSE148241, GSE190971, GSE74341, and GSE114691 datasets for the placenta and performed a differential expression analysis to identify hub genes. We performed Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Disease Ontology (DO), Gene Set Enrichment Analysis (GSEA), and Protein-Protein Interaction (PPI) Analysis to determine functional roles and regulatory networks of differentially expressed genes (DEGs). We then verified the DEGs at transcriptional and translational levels by analyzing the GSE44711 and GSE177049 datasets and our clinical samples, respectively.

Results

We identified 60 DEGs in the discovery phase, consisting of 7 downregulated genes and 53 upregulated genes. We then identified seven hub genes using Cytoscape software. In the verification phase, 4 and 3 of the seven genes exhibited the same variation patterns at the transcriptional level in the GSE44711 and GSE177049 datasets, respectively. Validation of our clinical samples showed that CADM3 has the best discriminative performance for predicting PE.

Conclusion

These findings may enhance the understanding of PE and provide new insight into identifying potential therapeutic targets for PE.

NLRP3 inflammasome in peripheral blood monocytes as a risk factor for early -onset preeclampsia

INTRODUCTION

As a leading cause of pregnancy and fetal mortality, pre-eclampsia impacts about 5-8% of pregnancies globally. To date, few studies have focused on the role played by (NOD)-like receptors protein 3 (NLRP3) in peripheral blood in early-onset pre-eclampsia (PE). In this study, we investigated whether NLRP3 expression in monocytes before 20 weeks of gestation was associated with an increased risk of early-onset PE.

METHODOLOGY

During the study period from 2019 to 2021, women with singleton pregnancies were enrolled in this prospective study at the General Hospital of Northern Theater Command. A generalized additive model (GAM) and logistic regression models were applied to determine any association between NLRP3 and the risk of early-onset PE.

RESULTS

In total, 571 and 48 subjects were included in the control and pre-eclampsia groups, respectively. The GAM and logistic regression models showed that NLRP3 was a significant factor for PE occurrence. The area under the curve, accuracy, specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.86, 0.82, 0.95, 0.72, 15.17, 0.29, and 52.0, respectively.

CONCLUSION

The monitoring for NLRP3 in peripheral blood may be a potential, prospectively identifying risk factor for preeclampsia.

miR-146a-5p regulates autophagy and NLRP3 inflammasome activation in epithelial barrier damage in the in vitro cell model of ulcerative colitis through the RNF8/Notch1/mTORC1 pathway

Ulcerative colitis (UC) is a chronic inflammatory disease affecting the colon that can be influenced by microRNAs (miRNAs). This study aims to investigate the impact of miR-146a-5p on lipopolysaccharide (LPS)-induced Caco-2/HT-29 cell autophagy and NLRP3 inflammasome activation and the underlying mechanism, with the aim of identifying potential therapeutic targets. We used LPS to establish Caco-2/HT-29 cell models and measured cell viability by CCK-8. The levels of miR-146a-5p, RNF8, markers of NLRP3 inflammasome activation and autophagy, proteins involved in the Notch1/mTORC1 pathway, and inflammatory factors were assessed by RT-qPCR, Western blot, and ELISA. Intestinal epithelial barrier function was evaluated by measuring transepithelial electrical resistance. Autophagic flux was measured using tandem fluorescent-labeled LC3. miR-146a-5p was highly-expressed in LPS-induced Caco-2/HT-29 cells, and autophagy flux was blocked at the autolysosomal stage after LPS induction. Inhibition of miR-146a-5p suppressed NLRP3 inflammasome activation, reduced intestinal epithelial barrier damage, and facilitated autophagy inhibition in LPS-induced Caco-2/HT-29 cells. The autophagy inhibitor NH4Cl partially nullified the inhibitory effects of miR-146a-5p inhibition on NLRP3 inflammation activation. miR-146a-5p targeted RNF8, and silencing RNF8 partly abrogated the action of miR-146a-5p inhibition on promoting autophagy and inhibiting NLRP3 inflammasome activation. miR-146a-5p inhibition suppressed the Notch1/mTORC1 pathway activation by upregulating RNF8. Inhibition of the Notch1/mTORC1 pathway partially nullified the function of silencing RNF8 on inhibiting autophagy and bolstering NLRP3 inflammasome activation. In conclusion, miR-146a-5p inhibition may be a potential therapeutic approach for UC, as it facilitates autophagy of LPS-stimulated Caco-2/HT-29 cells, inhibits NLRP3 inflammasome activation, and reduces intestinal epithelial barrier damage by upregulating RNF8 and suppressing the Notch1/mTORC1 pathway.

A cross-talk between sestrins, chronic inflammation and cellular senescence governs the development of age-associated sarcopenia and obesity

The rapid increase in both the lifespan and proportion of older adults is accompanied by the unprecedented rise in age-associated chronic diseases, including sarcopenia and obesity. Aging is also manifested by increased susceptibility to multiple endogenous and exogenous stresses enabling such chronic conditions to develop. Among the main physiological regulators of cellular adaption to various stress stimuli, such as DNA damage, hypoxia, and oxidative stress, are sestrins (Sesns), a family of three evolutionarily conserved proteins, Sesn1, 2, and 3. Age-associated sarcopenia and obesity are characterized by two key processes: (i) accumulation of senescent cells in the skeletal muscle and adipose tissue and (ii) creation of a systemic, chronic, low-grade inflammation (SCLGI). Presumably, failed SCLGI resolution governs the development of these chronic conditions. Noteworthy, Sesns activate senolytics, which are agents that selectively eliminate senescent cells, as well as specialized pro-resolving mediators, which are factors that physiologically provide inflammation resolution. Sesns reveal clear beneficial effects in pre-clinical models of sarcopenia and obesity. Based on these observations, we propose a novel treatment strategy for age-associated sarcopenia and obesity, complementary to the conventional therapeutic modalities: Sesn activation, SCLGI resolution, and senescent cell elimination.

FGL2 deficiency alleviates maternal inflammation-induced blood-brain barrier damage by blocking PI3K/NF-κB mediated endothelial oxidative stress

Introduction

The impairment of blood-brain barrier (BBB) is one of the key contributors to maternal inflammation induced brain damage in offspring. Our previous studies showed Fibrinogen-like protein 2 (FGL2) deficiency alleviated maternal inflammation induced perinatal brain damage. However, its role in BBB remains undefined.

Methods

Lipopolysaccharide (LPS) was intraperitoneally injected to dams at Embryonic day 17 to establish maternal inflammation model. FGL2 knockout mice and primary brain microvascular endothelial cells (BMECs) were used for the in-vivo and in-vitro experiments. BBB integrity was assessed by sodium fluorescein extravasation and tight junction (TJ) protein expression. Oxidative stress and the activation of PI3K/NF-κB pathway were evaluated to explore the mechanisms underlying.

Results

Upon maternal inflammation, BBB integrity was remarkedly reduced in neonatal mice. Meanwhile, FGL2 expression was consistently increased in BBB-impaired brain as well as in LPS-treated BMECs. Moreover, FGL2 deficiency attenuated the hyperpermeability of BBB, prevented the decline of TJ proteins, and reduced the cytokine expressions in LPS-exposed pups. Mechanistically, the indicators of oxidative stress, as well as the activation of PI3K/NF-κB pathway, were upregulated after LPS exposure in vivo and in vitro. FGL2 deletion decreased the generation of ROS and NO, reduced the endothelial iNOS and NOX2 expressions, and suppressed the PI3K/NF-κB pathway activation. Besides, inhibition of PI3K by LY294002 decreased the oxidative stress in LPS-treated wild-type BMECs. While, overexpression of PI3K by lentivirus reemerged the induction of NOX2 and iNOS as well as NF-κB activation in FGL2-deleted BMECs.

Conclusion

Our findings indicate that FGL2 deficiency alleviates the maternal inflammation-induced BBB disruption by inhibiting PI3K/NF-κB mediated oxidative stress in BMECs. Targeting FGL2 may provide a new therapy for prenatal brain damage of offspring.

The Role of Autophagy in the Female Reproduction System: For Beginners to Experts in This Field

Autophagy is a fundamental process involved in regulating cellular homeostasis. Autophagy has been classically discovered as a cellular process that degrades cytoplasmic components non-selectively to produce energy. Over the past few decades, this process has been shown to work in energy production, as well as in the reduction of excessive proteins, damaged organelles, and membrane trafficking. It contributes to many human diseases, such as neurodegenerative diseases, carcinogenesis, diabetes mellitus, development, longevity, and reproduction. In this review, we provide important information for interpreting results related to autophagic experiments and present the role of autophagy in this field.

TMBIM4 Deficiency Facilitates NLRP3 Inflammasome Activation-Induced Pyroptosis of Trophoblasts: A Potential Pathogenesis of Preeclampsia

Impaired invasion of EVTs results in inadequate remodelling of arteries and poor placentation, leading to PE. TMBIM4 was found to promote the migration and invasion of human osteosarcoma U2-OS and breast cancer MCF7 cell lines. However, the effect of TMBIM4 on trophoblast biological behaviour and its relevance to PE pathophysiology remain unclear. In this study, we confirmed that TMBIM4 was highly expressed in cytotrophoblasts, syncytiotrophoblasts, and EVTs of the human placenta during early pregnancy. By comparing the expression levels of TMBIM4 in the placenta of women with normal-term pregnancy and PE, TMBIM4 was found to be significantly decreased in PE. Thereafter, we determined the expression of TMBIM4 in the LPS-treated first-trimester human trophoblast cell line HTR-8/SVneo (mimicking a PE-like cell model), and determined the effect of TMBIM4 on trophoblast function and its underlying mechanism. LPS treatment reduced the expression of TMBIM4 and induced NLRP3 inflammasome activity in HTR-8/SVneo cells. KO of TMBIM4 in the HTR-8/SVneo cell line impaired cell viability, migration, and invasion, which was more severe in the LPS/ATP-treated TMBIM4-KO cell line. Moreover, TMBIM4 deficiency enhanced NLRP3 inflammasome activity and promoted subsequent pyroptosis, with or without LPS/ATP treatment. The negative relationship between TMBIM4 expression and NLRP3 inflammatory activity was verified in PE placentas. Inhibiting the NLRP3 inflammasome with MCC950 in HTR-8/SVneo cells alleviated LPS/ATP-induced pyroptosis and damaged cell function in the TMBIM4-KO cell line. Overall, this study revealed a new PE-associated protein, TMBIM4, and its biological significance in trophoblast pyroptosis mediated by the NLRP3 inflammasome. TMBIM4 may serve as a potential target for the treatment of placental inflammation-associated PE.

Verapamil-loaded supramolecular hydrogel patch attenuates metabolic dysfunction-associated fatty liver disease via restoration of autophagic clearance of aggregated proteins and inhibition of NLRP3

BACKGROUND

Obesity, a serious threat to public health, is linked to chronic metabolic complications including insulin resistance, type-2 diabetes, and metabolic dysfunction-associated fatty liver disease (MAFLD). Current obesity medications are challenged by poor effectiveness, poor patient compliance, and potential side effects. Verapamil is an inhibitor of L-type calcium channels, FDA-approved for the treatment of hypertension. We previously investigated the effect of verapamil on modulating autophagy to treat obesity-associated lipotoxicity. This study aims to develop a verapamil transdermal patch and to evaluate its anti-obesity effects.

METHODS

Verapamil is loaded in biomimetic vascular bundle-like carboxymethyl pullulan-based supramolecular hydrogel patches cross-linked with citric acid and glycerol linkages (CLCMP). The investigation was then carried out to determine the therapeutic effect of verapamil-loaded CLCMP (Vera@CLCMP) on diet-induced obese mice.

RESULTS

Vera@CLCMP hydrogel patches with hierarchically organized and anisotropic pore structures not only improved verapamil bioavailability without modifying its chemical structure but also enhanced verapamil release through the stratum corneum barrier. Vera@CLCMP patches exhibit low toxicity and high effectiveness at delivering verapamil into the systemic circulation through the dermis in a sustained manner. Specifically, transdermal administration of this patch into diet-induced obese mice drastically improved glucose tolerance and insulin sensitivity and alleviated metabolic derangements associated with MAFLD. Furthermore, we uncovered a distinct molecular mechanism underlying the anti-obesity effects associated with the hepatic NLR family pyrin domain-containing 3 (NLRP3) inflammasome and autophagic clearance by the vera@CLCMP hydrogel patches.

CONCLUSION

The current study provides promising drug delivery platforms for long-term family treatment of chronic diseases, including obesity and metabolic dysfunctions.

NLRP3 mediates trophoblastic inflammasome activation and protects against Listeria monocytogenes infection during pregnancy

Background

Intrauterine Listeria monocytogenes (L. monocytogenes) infections pose a major threat during pregnancy via affecting placental immune responses. However, the underlying mechanisms of placental defense against this pathogen remain ill-defined. Therefore, this study aims to investigate the function and the mechanism of inflammasomes on against L. monocytogenes infection during pregnancy.

Methods

A listeriosis murine model and cell culture system was used to investigate the role of trophoblastic nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) in orchestrating innate immune responses to L. monocytogenes infection. Caspase-1 activity was determined using a caspase-1 activity colorimetric kit. NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) in placental tissue was detected by immunohistochemistry. NLRP3 in HTR-8/SVneo cells was also detected by immunofluorescence. The expression of interleukin 1β (IL-1β), NLRP3, ASC, and caspase-1 was detected by Western blot. We characterized the NLRP3 inflammasome in trophoblast cells according to whether L. monocytogenes infection increased the activation of caspase-1 and the release of IL-1β. For human or mouse IL-1β in the culture supernatants and mouse tissue lysates were analyzed using ELISA Kits.

Results

Trophoblast cells constitutively expressed the components of the NLRP3 inflammasome. In vitro, L. monocytogenes triggers NLRP3 inflammasome activation in trophoblast cells by inducing caspase-1 activation, increasing the NLRP3 protein levels, IL-1β maturation and secretion in HTR-8/SVneo cells. In vivo, L. monocytogenes induces fetal resorption and IL-1β processing in pregnant mice. In addition, NLRP3-deficient mice were more prone to fetal loss than their wild-type counterparts following infection with L. monocytogenes at a lower infective dose.

Conclusions

We conclude that trophoblast cells respond to L. monocytogenes infection through the NLRP3 receptor, resulting in inflammasome activation and IL-1β production, which prevents listeriosis during pregnancy.

Inflammation in Preeclampsia: Genetic Biomarkers, Mechanisms, and Therapeutic Strategies

Objective

Preeclampsia is a common and serious complication of pregnancy, posing a threat to maternal and fetal safety due to the lack of effective biomarkers and treatment strategies. This study aimed to identify potential biomarkers that can be used to predict preeclampsia and identify the molecular mechanisms of preeclampsia pathogenesis and drug prediction at the transcriptome level.

Methods

We analyzed differential expression genes (DEGs) in preeclampsia and non-preeclampsia groups in the GSE75010 dataset, cross-linking with extracted inflammatory response-related genes to obtain differentially expressed inflammation-related genes (DINRGs). Enrichment analysis and protein-protein interaction (PPI) networks were constructed to understand the functions and enrichment pathways. Machine learning models were used to identify key genes associated with preeclampsia and build a nomogram in the training set, which was validated in the validation set. The R package RcisTarget was used to predict transcription factors, and Cytoscape was used to construct miRNA-mRNA pathways, which could identify the molecular mechanisms. Then, we conducted molecular docking of the obtained key genes INHBA (inhibin subunit beta A), OPRK1 (opioid receptor kappa 1), and TPBG (trophoblast glycoprotein), as well as predicted transcription factors with drug molecules. Additionally, the CIBERSORT method explored the differences in immune cell infiltration between preeclampsia and non-preeclampsia samples based on the GSE75010 dataset.

Results

A total of 69 DINRGs associated with preeclampsia patients were screened. INHBA, OPRK1, and TPBG were the key genes based on machine learning models. A nomogram for prediction was further constructed, and the receiver operating curves (ROCs) showed good performance. Based on the transcriptome level of key genes, we proposed that RELA-miR-548K/miR-1206-TPBG may be a potential RNA regulatory pathway regulating the progression of early preeclampsia. Molecular docking suggested the effectiveness of curcumin in the treatment of preeclampsia. Additionally, regulatory T cells (Tregs) and resting mast cells were significantly different between the two groups.

Conclusion

In summary, we identified three key inflammation-associated genes, namely INHBA, OPRK1, and TPBG, which can be used as potential genetic biomarkers for preeclampsia prediction and treatment, and established a nomogram as a predictive model. Additionally, we provided insights into the mechanisms of preeclampsia development at the transcriptome level and performed corresponding drug predictions.

Salicornia herbacea Aqueous Extracts Regulate NLRP3 Inflammasome Activation in Macrophages and Trophoblasts

Salicornia herbacea L. (Chenopodiaceae), an edible salt marsh plant with anti-inflammatory effects, was examined in macrophages and trophoblasts whether it modulates NLRP3 inflammasome activity. Pretreatment and delayed treatment of S. herbacea extract (SHE) in bone marrow-derived macrophages (BMDMs) reduced the activity of NLRP3 inflammasome induced by lipopolysaccharide (LPS) and adenosine triphosphate stimulation and downregulated interleukin (IL)-1β production. SHE also inhibited pyroptotic cell death, the adaptor molecule apoptosis-associated speck-like protein containing a CARD (ASC), oligomerization, and speck by NLRP3 inflammasome activity in BMDM. Similarly, SHE decreased the mRNA expression of NLRP3, ASC, IL-1β, and IL-6 in the LPS-stimulated human trophoblast cell line, Swan 71 cells. In addition, SHE inhibited the production of IL-6 and IL-1β and decreased the expression of cyclooxygenase-2 and prostaglandin E2 in stimulated Swan 71 cells. Finally, 3,5-dicaffeoylquinic acid (3,5-DCQA), one of the components of S. herbacea, inhibited IL-1β produced by NLRP3 inflammasome activity. In conclusion, SHE downregulated the activity of the NLRP3 inflammasome in macrophages and trophoblasts.

A Tug of War: Pseudorabies Virus and Host Antiviral Innate Immunity

The non-specific innate immunity can initiate host antiviral innate immune responses within minutes to hours after the invasion of pathogenic microorganisms. Therefore, the natural immune response is the first line of defense for the host to resist the invaders, including viruses, bacteria, fungi. Host pattern recognition receptors (PRRs) in the infected cells or bystander cells recognize pathogen-associated molecular patterns (PAMPs) of invading pathogens and initiate a series of signal cascades, resulting in the expression of type I interferons (IFN-I) and inflammatory cytokines to antagonize the infection of microorganisms. In contrast, the invading pathogens take a variety of mechanisms to inhibit the induction of IFN-I production from avoiding being cleared. Pseudorabies virus (PRV) belongs to the family Herpesviridae, subfamily Alphaherpesvirinae, genus Varicellovirus. PRV is the causative agent of Aujeszky’s disease (AD, pseudorabies). Although the natural host of PRV is swine, it can infect a wide variety of mammals, such as cattle, sheep, cats, and dogs. The disease is usually fatal to these hosts. PRV mainly infects the peripheral nervous system (PNS) in swine. For other species, PRV mainly invades the PNS first and then progresses to the central nervous system (CNS), which leads to acute death of the host with serious clinical and neurological symptoms. In recent years, new PRV variant strains have appeared in some areas, and sporadic cases of PRV infection in humans have also been reported, suggesting that PRV is still an important emerging and re-emerging infectious disease. This review summarizes the strategies of PRV evading host innate immunity and new targets for inhibition of PRV replication, which will provide more information for the development of effective inactivated vaccines and drugs for PRV.