Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis.

JOURNAL/nrgr/04.03/01300535-202504000-00027/figure1/v/2024-07-06T104127Z/r/image-tiff Cardiac arrest can lead to severe neurological impairment as a result of inflammation, mitochondrial dysfunction, and post-cardiopulmonary resuscitation neurological damage. Hypoxic preconditioning has been shown to improve migration and survival of bone marrow-derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest, but the specific mechanisms by which hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown. To this end, we established an in vitro co-culture model of bone marrow-derived mesenchymal stem cells and oxygen-glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis, possibly through inhibition of the MAPK and nuclear factor κB pathways. Subsequently, we transplanted hypoxia-preconditioned bone marrow-derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia. The results showed that hypoxia-preconditioned bone marrow-derived mesenchymal stem cells significantly reduced cardiac arrest-induced neuronal pyroptosis, oxidative stress, and mitochondrial damage, whereas knockdown of the liver isoform of phosphofructokinase in bone marrow-derived mesenchymal stem cells inhibited these effects. To conclude, hypoxia-preconditioned bone marrow-derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest, and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Deep mucosal healing in ulcerative colitis: how deep is better?

Ulcerative colitis (UC), characterized by its recurrent nature, imposes a significant disease burden and compromises the quality of life. Emerging evidence suggests that achieving clinical remission is not sufficient for long-term remission. In pursuit of a favorable prognosis, mucosal healing (MH) has been defined as the target of therapies in UC. This paradigm shift has given rise to the formulation of diverse endoscopic and histological scoring systems, providing distinct definitions for MH. Endoscopic remission (ER) has been widely employed in clinical practice, but it is susceptible to subjective factors related to endoscopists. And there's growing evidence that histological remission (HR) might be associated with a lower risk of disease flares, but the incorporation of HR as a routine therapeutic endpoint remains a debate. The integration of advanced technology has further enriched the definition of deep MH. Up to now, a universal standardized definition for deep MH in clinical practice is currently lacking. This review will focus on the definition of deep MH, from different dimensions, and analyze strengths and limitations, respectively. Subsequent multiple large-scale trials are needed to validate the concept of deep MH, offering valuable insights into potential benefits for UC patients.

Identification of the histone acetyltransferase gene family in the Artemisia annua genome.

As the most effective therapeutic drug for malaria, artemisinin can only be extracted from Artemisia annua L., which is sensitive to the surrounding growing habitat. Histone acetyltransferases (HATs) contain acetyl groups, which modulate mRNA transcription and thereby regulate plant environmental adaptation. Comprehensive analyses of HATs have been performed in many plants, but systematic identification of HATs in medicinal plants is lacking. In the present study, we identified 11 AaHATs and characterized these genes into four classes according to their conserved protein structures. According to the phylogenetic analysis results, potential functions of HAT genes from Arabidopsis thaliana, Oryza sativa, and A. annua were found. According to our results, AaHAT has a highly conserved evolutionary history and is rich in highly variable regions; thus, AaHAT has become a comparatively ideal object of medical plant identification and systematic study. Moreover, motifs commonly present in histone acetyltransferases in the A. annua genome may be associated with functional AaHATs. AaHATs appear to be related to gene-specific functions. AaHATs are regulated by cis-elements, and these genes may affect phytohormone responsiveness, adaptability to stress, and developmental growth. We performed expression analyses to determine the potential roles of AaHATs in response to three environmental stresses. Our results revealed a cluster of AaHATs that potentially plays a role in the response of plants to dynamic environments.

Substrate Characterization for Hydrolysis of Multiple Types of Aromatic Esters by Promiscuous Aminopeptidases.

Synthetic aromatic esters, widely employed in agriculture, food, and chemical industries, have become emerging environmental pollutants due to their strong hydrophobicity and poor bioavailability. This study attempted to address this issue by extracellularly expressing the promiscuous aminopeptidase (Aps) from Pseudomonas aeruginosa GF31 in B. subtilis, achieving an impressive enzyme activity of 13.7 U/mg. Notably, we have demonstrated, for the first time, the Aps-mediated degradation of diverse aromatic esters, including but not limited to pyrethroids, phthalates, and parabens. A biochemical characterization of Aps reveals its esterase properties and a broader spectrum of substrate profiles. The degradation rates of p-nitrobenzene esters (p-NB) with different side chain structures vary under the action of Aps, showing a preference for substrates with relatively longer alkyl side chains. The structure-dependent degradability aligns well with the binding energies between Aps and p-NB. Molecular docking and enzyme-substrate interaction elucidate that hydrogen bonding, hydrophobic interactions, and π-π stacking collectively stabilize the enzyme-substrate conformation, promoting substrate hydrolysis. These findings provide new insights into the enzymatic degradation of aromatic ester pollutants, laying a foundation for the further development and modification of promiscuous enzymes.

Effect of metformin on gut microbiota imbalance in patients with T2DM, and the value of probiotic supplementation.

PURPOSE: To investigate the effect of metformin on gut microbiota imbalance in patients with type 2 diabetes mellitus (T2DM), and the value of probiotic supplementation. METHODS: A total of 84 newly diagnosed T2DM patients were randomly divided into probiotics group, metformin group, and control group, with 28 patients in each group. The blood glucose control, islet function, gut microbiota, and inflammatory factors were compared between three groups. RESULTS: After 3 months of treatment, fasting plasma glucose (FPG), 2-h postprandial plasma glucose (2-h PG), and glycosylated hemoglobin A1c (HbA1c) were evidently decreased in both probiotics and metformin groups (P < 0.05) and were lower than that in the control group prior to treatment. Besides, FPG, 2-h PG, and HbA1c were lower in the metformin group than that in the control group. FPG, 2-h PG, and HbA1c were further lower in the probiotic group than in the metformin group (P < 0.05). Fasting insulin (FINS) and islet ß cell (HOMA-ß) -function were dramatically increased in the same group (P < 0.05), while insulin-resistant islet ß cells (HOMA-IR) were significantly lower in the same group (P < 0.05); FINS and HOMA-ß were significantly higher, while HOMA-IR was significantly lower (P < 0.05) in both groups than in the control group prior to treatment. HOMA-IR was also lower in the probiotic group than in the metformin group after treatment (P < 0.05); the number of lactobacilli and bifidobacteria increased (P < 0.05) in both probiotic and metformin groups than in the control group prior to treatment, and the number of Enterobacteriaceae and Enterococcus was lower in the control group prior to treatment (P < 0.05). In addition, the number of lactobacilli and bifidobacteria was higher and the number of enterobacteria and enterococci was lower in the probiotic group than that in the metformin group after treatment, and the differences were statistically significant (P < 0.05). Lipopolysaccharide (LPS), interleukin 6 (IL-6), and C-reactive protein (CRP) levels were lower in both probiotic and metformin groups (P < 0.05). The serum LPS, IL-6, and CRP levels were lower in both probiotic and metformin groups, compared to the control group prior to the treatment (P < 0.05). CONCLUSION: Metformin while treating T2DM assists in improving the imbalance of gut microbiota.

Characterization of on-road nitrogen oxides and black carbon emissions from high emitters of heavy-duty diesel vehicles in China.

Heavy-duty diesel vehicles (HDDVs) significantly contribute to atmospheric nitrogen oxides (NOX) and black carbon (BC), with high emitters within the HDDV fleet impacting the total emissions. However, emission patterns and contributions of high emitters are rarely explored from a fleet-perspective. We investigated NOX and BC emission factors (EFs) from 1925 HDDVs in Shenzhen by the plume-chasing method, and found that the fleet-average EFs decreased with stricter emission standards. Unexpectedly, the average NOX EF for the China IV fleet was comparable with that for the China III fleet due to possible ineffective aftertreatment in high-emitter sectors of China IV HDDVs. Decreasing trend in average NOX EF since 2017 reflected the effective emission controls by the implementation of China V standard. Besides, semi-trailer tractors exhibited a higher incidence of NOX over-emissions, whereas BC high emitters were more pronounced in box trucks. Total NOX and BC emissions from HDDVs in Shenzhen were revisited, reaching 54.0 and 1.1 Gg·yr-1, with updated NOX EF correcting a 26.2 % underestimation in national guidelines. Notably, eliminating high emitters yields greater emission reduction benefits than merely retiring old HDDVs, with BC reduction outpacing NOX. This study provides new insights into the implementation of targeted emission reduction measures for HDDVs.

Characteristics of atypical Pulmonary Tuberculosis without typical clinical features diagnosed by pathology.

PURPOSE: Some patients with pulmonary tuberculosis (PTB) do not display typical clinical features, leading to delays in diagnosis and treatment. METHODS: We retrospectively analyzed PTB patients admitted to the Second Affiliated Hospital of Chongqing Medical University between 2017 and 2020. They are divided into pathological group (diagnosed through pathological biopsy) and control group (diagnosed via sputum or lavage fluid). Clinical data of both groups were compared. Based on radiographic features, the pathological group was further divided into the inflammation group, peripheral nodule group, and central occupancy group. We then statistically analyzed the computed tomography (CT) signs, bronchoscopic manifestations and results of pathological biopsy for each subgroup. RESULTS: The pathological group consisted of 75 patients, while the control group had 338 patients. Multivariate logistic regression analysis showed that the pathological group had more diabetes (OR = 3.266, 95% CI = 1.609-6.630, P = 0.001), lower ESR (OR = 0.984, 95% CI = 0.971-0.998, P = 0.022), and lower CRP (OR = 0.990, 95% CI = 0.980-0.999, P = 0.036). In the three subgroups, the exudative lesions in the inflammation group were mostly located in atypical areas of PTB. The lobulation sign and spiculation sign were frequently observed in the peripheral nodule group. All presented with significant hilar mediastinal lymphadenopathy in the central occupancy group. In the pathological group, bronchoscopic manifestations typically included mucosal edema and bronchial stenosis. CONCLUSION: Diabetes is an independent risk factor for atypical PTB. Expression of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in atypical PTB is low. Radiologically, it is most easily misdiagnosed when presented as peripheral solid nodules or masses, so a biopsy is recommended.

Treatment of primary epididymal adenocarcinoma: a case report and review of the literature.

BACKGROUND: Epididymal tumors, especially malignant tumors, have low incidence and are rare in our clinical work. However, they may progress quickly and have poor prognosis. For such rare clinical cases with extremely low incidence rates, and as they are prone to misdiagnosis and missed diagnosis and have a very poor prognosis, clinical workers need to pay special attention and consider the possibility of primary epididymal malignant tumors. CASE REPORT: A 63-year-old Chinese male patient from Asia was admitted due to scrotal pain. Upon examination, an abnormal lesion was found in the right epididymal region. After thorough evaluation, surgical resection was performed, and the postoperative pathological result confirmed the presence of epididymal adenocarcinoma. After further ruling out secondary lesions, primary epididymal adenocarcinoma was considered. Right retroperitoneal lymph node dissection was performed under laparoscopic for treatment, and 1/11 lymph node metastasis was detected after surgery. The patient is currently under close follow-up. CONCLUSIONS: The number of clinical cases of primary epididymal malignant tumors is very limited, there is currently no standardized diagnosis and treatment process, and there is a lack of systematic evaluation methods regarding the effectiveness of different treatment options such as chemotherapy, radiotherapy, immunotherapy, and targeted therapy. In addition, the outcome is difficult to predict. In this article, we reviewed relevant literature and systematically elaborated on the diagnosis and treatment of epididymal malignant tumors, hoping to provide useful information for relevant experts.

Serum IgA as a Prognostic Beacon: Anticipating Systemic Therapy Efficacy in Metastatic Clear Cell Renal Cell Carcinoma.

OBJECTIVE: Immunotherapy-tyrosine kinase inhibitor (IO-TKI) therapy has revolutionized the treatment landscape for metastatic clear cell renal cell carcinoma (mccRCC); however, the absence of effective biomarkers poses a challenge in predicting the efficacy of these regimens. This study aims to explore the predictive and prognostic value of serum immunoglobulin A (IgA) in mccRCC patients undergoing IO-TKI therapy. METHODS: Ninety-six mccRCC patients treated with IO-TKI therapy from 2019 to 2023 were enrolled and serum IgA levels were assessed at the pretreatment baseline and after 3 months of treatment. RESULTS: Notably, baseline levels of IgA showed no correlation with the objective response rate. However, patients achieving complete or partial responses exhibited a remarkable decrease in IgA levels, while those with stable or progressive disease displayed an increase in IgA levels after 3 months of treatment. Furthermore, the dynamic alteration in IgA levels after 3 months of treatment demonstrated predictive value for both progression-free survival (PFS) and overall survival (OS). The time-dependent receiver operating characteristic curves exhibited outstanding performance in predicting PFS (AUC 0.793) and OS (AUC 0.738). CONCLUSION: Taken together, this study demonstrates that dynamic alteration of serum IgA after 3 months of treatment was significantly correlated with prognosis and therapeutic efficacy in mccRCC patients.

Ursolic acid alleviates lupus nephritis by suppressing SUMO1-mediated stabilization of NLRP3.

BACKGROUND: Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease that affects multiple organs and cause a wide range of severe clinical manifestations, including lupus nephritis (LN), which is a major risk factor for morbidity and mortality in individual with SLE. Ursolic acid (UA) is a natural compound with favorable anti-inflammatory properties and has been employed to treat multiple disease, including inflammatory diseases, diabetes, and Parkinson's disease. However, its therapeutic potential on LN and the underlying mechanisms remains unclear. PURPOSE: This aim of this study was to investigate the impact of UA on LN and its underlying mechanism. METHODS: MRL/lpr lupus-prone mouse model was used and UA was administered orally for 8 weeks. Dexamethasone was used as a positive control. After 8 weeks of administration, the spleen-to-body-weight ratio, renal function, urine albumin excretion, cytokines levels, and the deposition of immune complex were measured. The primary mouse glomerular mesangial cells (GMCs) and SV40-MES-13 were stimulated by lipopolysaccharide (LPS), either alone or in combination with nigericin, to establish an in vitro model. The activation of NLRP3 inflammasome were investigated both in vivo and in vitro using qRT-PCR, immunoblotting, and immunofluorescence. RESULTS: Our results revealed that UA prominently alleviated LN in MRL/lpr lupus-prone mice, leading to a significant reduction in proteinuria production, infiltration of immune cells infiltration, and histopathological damage in the renal tissue. In addition, UA exerted inhibitory effects on the secretion of IL-1ß, IL-18, and caspase-1, pyroptosis, and ASC speck formation in primary mouse GMCs and SV40-MES-13 cells. Furthermore, UA facilitated the degradation of NLRP3 by suppressing SUMO1-mediated SUMOylation of NLRP3. CONCLUSION: UA possess a therapeutical effect on LN in MRL/lpr mice by enhancing the degradation of NLRP3 through inhibition of SUMO1-mediated SUMOylation of NLRP3. Our findings provide a basis for proposing UA as a potential candidate for the treatment of LN.

IL-37 ameliorates myocardial fibrosis by regulating mtDNA-enriched vesicle release in diabetic cardiomyopathy mice.

BACKGROUND: Diabetic cardiomyopathy (DCM), a serious complication of diabetes, leads to structural and functional abnormalities of the heart and ultimately evolves to heart failure. IL-37 exerts a substantial influence on the regulation of inflammation and metabolism. Whether IL-37 is involved in DCM is unknown. METHODS: The plasma samples were collected from healthy controls, diabetic patients and DCM patients, and the level of IL-37 and its relationship with heart function were observed. The changes in cardiac function, myocardial fibrosis and mitochondrial injury in DCM mice with or without IL-37 intervention were investigated in vivo. By an in vitro co-culture approach involving HG challenge of cardiomyocytes and fibroblasts, the interaction carried out by cardiomyocytes on fibroblast profibrotic activation was studied. Finally, the possible interactive mediator between cardiomyocytes and fibroblasts was explored, and the intervention role of IL-37 and its relevant molecular mechanisms. RESULTS: We showed that the level of plasma IL-37 in DCM patients was upregulated compared to that in healthy controls and diabetic patients. Both recombinant IL-37 administration or inducing IL-37 expression alleviated cardiac dysfunction and myocardial fibrosis in DCM mice. Mechanically, hyperglycemia impaired mitochondria through SIRT1/AMPK/PGC1α signaling, resulting in significant cardiomyocyte apoptosis and the release of extracellular vesicles containing mtDNA. Fibroblasts then engulfed these mtDNA-enriched vesicles, thereby activating TLR9 signaling and the cGAS-STING pathway to initiate pro-fibrotic process and adverse remodeling. However, the presence of IL-37 ameliorated mitochondrial injury by preserving the activity of SIRT1-AMPK-PGC1α axis, resulting in a reduction in release of mtDNA-enriched vesicle and ultimately attenuating the progression of DCM. CONCLUSIONS: Collectively, our study demonstrates a protective role of IL-37 in DCM, offering a promising therapeutic agent for this disease.

A Current Understanding of FXR in NAFLD: The multifaceted regulatory role of FXR and novel lead discovery for drug development.

The global prevalence of nonalcoholic fatty liver disease (NAFLD) has reached 30 %, with an annual increase. The incidence of NAFLD-induced cirrhosis is rapidly rising and has become the leading indicator for liver transplantation in the US. However, there are currently no US Food and Drug Administration-approved drugs for NAFLD. Increasing evidence underscores the close association between NAFLD and bile acid metabolism disorder, highlighting the feasibility of targeting the bile acid signaling pathway for NAFLD treatment. The farnesoid X receptor (FXR) is an endogenous receptor for bile acids that exhibits favorable effects in ameliorating the metabolic imbalance of bile acids, lipid disorders, and disruption of intestinal homeostasis, all of which are key characteristics of NAFLD, making FXR a promising therapeutic target for NAFLD. The present review provides a comprehensive overview of the diverse mechanisms through which FXR improves NAFLD, with particular emphasis on its involvement in regulating bile acid homeostasis and the recent advancements in drug development targeting FXR for NAFLD treatment.

Complete mitochondrial genome of Angelica dahurica and its implications on evolutionary analysis of complex mitochondrial genome architecture in Apiaceae.

Angelica dahurica is a kind of Chinese traditional herbs with economic and ornament value, widely distributed in China. Despite its significance, there have been limited comprehensive investigations on the genome of A. dahurica, particularly regarding mitochondrial genomes. To investigate the conversion between mitochondrial genome and chloroplast genome, a complete and circular mitochondrial genome was assembled using Oxford Nanopore Technologies (ONT) long reads. The mitochondrial genome of A. dahurica had a length of 228,315 base pairs (bp) with 45.06% GC content. The mitochondrial genome encodes 56 genes, including 34 protein-coding genes, 19 tRNA genes and 3 rRNA genes. Moreover, we discovered that 9 homologous large fragments between chloroplast genome and mitochondrial genome based on sequence similarity. This is the first report for A. dahurica mitochondrial genome, which could provide an insight for communication between plastid genome, and also give a reference genome for medicinal plants within the Angelica family.

Metabolomics reveals the importance of metabolites in Mussaenda pubescens for antioxidant properties and quality traits.

Mussaenda pubescens (Mp) is a valuable medicinal plant that has traditionally been used for medicinal purposes or as a tea substitute. However, there are few studies on the comprehensive and dynamic evaluation of Mp metabolites. This study used an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach and biochemical analysis to investigate substance changes in leaves at three different stages and elucidate the relationship between metabolites and antioxidant capacity. The findings showed that Mp leaves contained 957 metabolites, the majority of which were phenolic acids, lipids, and terpenoids. The metabolite profiling of Mp leaves was significantly influenced by their growth and development at different stages. A total of 317 differentially accumulated metabolites (DAMs) were screened, including 150 primary metabolites and 167 secondary metabolites, with 202 DAMs found in bud leaf vs. tender leaf, 54 DAMs in tender leaf vs. mature leaf, and 254 DAMs in bud leaf vs. mature leaf. Total phenolics, flavonoids, and anthocyanin concentrations decreased as Mp leaves grew and developed, whereas terpenoids increased significantly. The secondary metabolites also demonstrated a positive correlation with antioxidant activity. Phenolics, flavonoids, terpenoids, and anthocyanins were the primary factors influencing the antioxidant activity of leaves. These findings provide new insights into the metabolite formation mechanism, as well as the development and utilization of Mp tea.

Observation of the effect of hypothermia therapy combined with optimized nursing on brain protection after cardiopulmonary resuscitation: A retrospective case-control study.

This study aimed to investigate the impact of optimized emergency nursing in conjunction with mild hypothermia nursing on neurological prognosis, hemodynamics, and complications in patients with cardiac arrest. A retrospective analysis was conducted on the medical records of 124 patients who received successful cardiopulmonary resuscitation (CPR) at Fujian Provincial Hospital South Branch. The patients were divided into control and observation groups, each consisting of 62 cases. The brain function of both groups was assessed using the Glasgow Coma Scale and the National Institutes of Health Stroke Scale. Additionally, serum neuron-specific enolase level was measured in both groups. The vital signs and hemodynamics of both groups were analyzed, and the complications and satisfaction experienced by the 2 groups were compared. The experimental group exhibited significantly improved neurological function than the control group (P < .05). Furthermore, the heart rate in the experimental group was significantly lower than the control group (P < .05). However, no significant differences were observed in blood oxygen saturation, mean arterial pressure, central venous pressure, and systolic blood pressure between the 2 groups (P > 0.05). Moreover, the implementation of optimized nursing practices significantly reduced complications and improved the quality of life and satisfaction of post-CPR patients (P < .05). The integration of optimized emergency nursing practices in conjunction with CPR improves neurological outcomes in patients with cardiac arrest.

Supramolecular salicylic acid combined with niacinamide in chloasma: A randomized controlled trial.

BACKGROUND: No trial of supramolecular salicylic acid (SSA) for chloasma is available yet. OBJECTIVE: The purpose of this study was to assess the efficacy and safety of Bole DA 30% supramolecular salicylic acid (SSA) combined with 10% niacinamide in treating chloasma. METHODS: This multicenter (n=15), randomized, double-blind, parallel placebo-controlled trial randomized the subjects (1:1) to Bole DA 30% SSA or placebo. The primary endpoint was the effective rate after 16 weeks using the modified melasma area severity index (mMASI) [(pretreatment-posttreatment)/pretreatment×100%]. RESULTS: This study randomized 300 subjects (150/group in the full analysis set, 144 and 147 in the per-protocol set). The total mMASI score, overall Griffiths 10 score, left Griffiths 10 score, and right Griffiths 10 score were significantly lower in the Bole DA 30% SSA group than in the placebo group (all P<0.001). One study drug-related AE and one study drug-unrelated adverse events (AE) were reported in the Bole DA 30% SSA group. No AE was reported in the placebo group. CONCLUSION: Bole DA 30% SSA combined with 10% niacinamide is effective and safe for treating chloasma. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR2200065346.

ERK signaling expands mammalian cortical radial glial cells and extends the neurogenic period.

The molecular basis for cortical expansion during evolution remains largely unknown. Here, we report that fibroblast growth factor (FGF)-extracellular signal-regulated kinase (ERK) signaling promotes the self-renewal and expansion of cortical radial glial (RG) cells. Furthermore, FGF-ERK signaling induces bone morphogenic protein 7 (Bmp7) expression in cortical RG cells, which increases the length of the neurogenic period. We demonstrate that ERK signaling and Sonic Hedgehog (SHH) signaling mutually inhibit each other in cortical RG cells. We provide evidence that ERK signaling is elevated in cortical RG cells during development and evolution. We propose that the expansion of the mammalian cortex, notably in human, is driven by the ERK-BMP7-GLI3R signaling pathway in cortical RG cells, which participates in a positive feedback loop through antagonizing SHH signaling. We also propose that the relatively short cortical neurogenic period in mice is partly due to mouse cortical RG cells receiving higher SHH signaling that antagonizes ERK signaling.

Protective Effect of Silibinin on Lipopolysaccharide-Induced Endotoxemia by Inhibiting Caspase-11-Dependent Cell Pyroptosis.

OBJECTIVE: To explore the protective effect and the underlying mechanism of silibinin (SIB), one of the active compounds from Silybum marianum (L.) Gaertn in endotoxemia. METHODS: Mouse peritoneal macrophage were isolated via intraperitoneally injection of BALB/c mice with thioglycolate medium. Cell viability was assessed using the cell counting kit-8, while cytotoxicity was determined through lactate dehydrogenase cytotoxicity assay. The protein expressions of interleukin (IL)-1 α, IL-1 ß, and IL-18 were determined by enzyme-linked immunosorbent assay. Intracellular lipopolysaccharide (LPS) levels were measured by employing both the limulus amoebocyte lysate assay and flow cytometry. Additionally, proximity ligation assay was employed for the LPS and caspase-11 interaction. Mice were divided into 4 groups: the control, LPS, high-dose-SIB (100 mg/kg), and low-dose-SIB (100 mg/kg) groups (n=8). Zebrafish were divided into 4 groups: the control, LPS, high-dose-SIB (200 εmol/L), and low-dose-SIB (100 εmol/L) groups (n=30 for survival experiment and n=10 for gene expression analysis). The expression of caspase-11, gasdermin D (GSDMD), and N-GSDMD was determined by Western blot and the expressions of caspy2, gsdmeb, and IL-1 ß were detected using quantitative real-time PCR. Histopathological observation was performed through hematoxylineosin staining, and protein levels in bronchoalveolar lavage fluid were quantified using the bicinchoninicacid protein assay. RESULTS: SIB noticeably decreased caspase-11 and GSDMD-mediated pyroptosis and suppressed the secretion of IL-1 α, IL-1 ß, and IL-18 induced by LPS (P<0.05). Moreover, SIB inhibited the translocation of LPS into the cytoplasm and the binding of caspase-11 and intracellular LPS (P<0.05). SIB also attenuated the expression of caspase-11 and N-terminal fragments of GSDMD, inhibited the relative cytokines, prolonged the survival time, and up-regulated the survival rate in the endotoxemia models (P<0.05). CONCLUSIONS: SIB can inhibit pyroptosis in the LPS-mediated endotoxemia model, at least in part, by inhibiting the caspase-11-mediated cleavage of GSDMD. Additionally, SIB inhibits the interaction of LPS and caspase-11 and inhibits the LPS-mediated up-regulation of caspase-11 expression, which relieves caspase-11-dependent cell pyroptosis and consequently attenuates LPS-mediated lethality.