SMURF2-mediated ubiquitin signaling plays an essential role in the regulation of PARP1 PARylating activity, molecular interactions, and functions in mammalian cells.

Poly(ADP-ribose) polymerase 1 (PARP1) is a key molecular stress sensor and response mediator implicated in multiple cellular functions in health and diseases. Despite its importance and intrinsic involvement in pivotal molecular and cellular processes, including DNA repair, transcription regulation, chromatin organization, and cell death, the regulatory mechanisms of PARP1 are poorly understood. In this study, we show that SMURF2, a HECT-type E3 ubiquitin ligase and suggested tumor suppressor, physically interacts with PARP1 in different cellular settings, directly ubiquitinates it in vitro and stimulates its PARylation activity in cells, the phenomenon that required SMURF2 E3 ubiquitin ligase function. Intriguingly, in the cellular environment SMURF2 was found to regulate the dynamic exchange of ubiquitin moieties on PARP1, mostly decreasing its monoubiquitination. Through the set of systematic mass spectrometry analyses conducted on SMURF2-modified cells, we identified on PARP1 18 lysine residues (out of 126 present in PARP1) as sites which ubiquitination was considerably affected by SMURF2. Subsequent site-directed mutagenesis coupled with in cellula ubiquitination and PARylation assays unveiled K222 as a critical site enabling a cross talk between SMURF2-modulated monoubiquitination of PARP1 and its activity, and pointed to K498, S507, and a KTR triad (K498/K521/K524) as the main auto-PARylation sites affected by SMURF2. The results also uncovered that SMURF2 controls PARP1 interactome, influencing its functions and expression in a context-dependent manner. Taken together, these findings suggest that SMURF2-mediated ubiquitin signaling plays an essential role in PARP1 regulation, beyond the regulation of its protein expression.

Targeting SMOX for the treatment of hepatocellular carcinoma?

Dysregulation of the polyamine metabolism is common in different cancer types. SMOX is upregulated in hepatocellular carcinoma (HCC) but the relationship between SMOX and liver inflammation and fibrosis, remains unclear. In this issue of Clin Res Hepatol Gastroenterol, Hu and colleagues find targeting SMOX can alleviate liver cancer progression.

A bibliometric analysis of insomnia in adolescent.

Background: The negative effects of insomnia on adolescents' development, academic performance, and quality of life place a burden on families, schools, and society. As one of the most important research directions for insomnia, adolescent insomnia has significant research value, social value, and practical significance. Unfortunately, there is no bibliometric analysis in this field of study. This study aims to analyze published articles using bibliometrics, summarize the current research progress and hot topics in this field systematically and exhaustively, and predict the future direction and trend of research. Methods: For this study, the Web of Science Core Collection (WoSCC) database was searched between 2002 and 2022 for publications related to adolescent insomnia. The R-bibliometrix, VOSViewer, and CiteSpace software were utilized for bibliometric analysis. Results: This investigation included 2468 publications from 3102 institutions in 87 countries, led by China and the United States. This field of research has entered a period of rapid development since 2017. The journal with the most publications on adolescent insomnia is Sleep, which is also the most co-cited journal. American Journal of Psychology has the highest impact factor among the top 10 journals. These papers were written by 10605 authors; notably, Liu Xianchen emerged as the author with the highest frequency of publications, while Mary A. Carskadon was the most frequently co-cited author. Mental health and comorbid diseases were the main research directions in this field. "Depression," "anxiety," "mental health," "COVID-19," "stress," "quality of life," "heart rate variability," and "attention-deficit hyperactivity disorder" were hot spots and trends in this field at the current moment. Conclusion: The research on adolescent insomnia has social value, research value, and research potential; its development is accelerating, and an increasing number of researchers are focusing on it. This study summarized and analyzed the development process, hot spots, and trends of adolescent insomnia research using bibliometric analysis, which identified the current hot topics in this field and predicted the development trend for the future.

Identification of biomarkers related to sepsis diagnosis based on bioinformatics and machine learning and experimental verification.

Sepsis is a systemic inflammatory response syndrome caused by bacteria and other pathogenic microorganisms. Every year, approximately 31.5 million patients are diagnosed with sepsis, and approximately 5.3 million patients succumb to the disease. In this study, we identified biomarkers for diagnosing sepsis analyzed the relationships between genes and Immune cells that were differentially expressed in specimens from patients with sepsis compared to normal controls. Finally, We verified its effectiveness through animal experiments. Specifically, we analyzed datasets from four microarrays(GSE11755、GSE12624、GSE28750、GSE48080) that included 106 blood specimens from patients with sepsis and 69 normal human blood samples. SVM-RFE analysis and LASSO regression model were carried out to screen possible markers. The composition of 22 immune cell components in patients with sepsis were also determined using CIBERSORT. The expression level of the biomarkers in Sepsis was examined by the use of qRT-PCR and Western Blot (WB). We identified 50 differentially expressed genes between the cohorts, including 2 significantly upregulated and 48 significantly downregulated genes, and KEGG pathway analysis identified Salmonella infection, human T cell leukemia virus 1 infection, Epstein-Barr virus infection, hepatitis B, lysosome and other pathways that were significantly enriched in blood from patients with sepsis. Ultimately, we identified COMMD9, CSF3R, and NUB1 as genes that could potentially be used as biomarkers to predict sepsis, which we confirmed by ROC analysis. Further, we identified a correlation between the expression of these three genes and immune infiltrate composition. Immune cell infiltration analysis revealed that COMMD9 was correlated with T cells regulatory (Tregs), T cells follicular helper, T cells CD8, et al. CSF3R was correlated with T cells regulatory (Tregs), T cells follicular helper, T cells CD8, et al. NUB1 was correlated with T cells regulatory (Tregs), T cells gamma delta, T cells follicular helper, et al. Taken together, our findings identify potential new diagnostic markers for sepsis that shed light on novel mechanisms of disease pathogenesis and, therefore, may offer opportunities for therapeutic intervention.

Experimental verification and identifying biomarkers related to insomnia.

Introduction: Insomnia is the most common form of sleep deprivation (SD) observed in clinics. Although there are differences between insomnia and SD, they have similar symptoms and the same animal model. Currently, there is a lack of microarray data on insomnia. Therefore, for now, we are going to apply the SD data to insomnia. Although many studies have explained the possible mechanisms associated with insomnia, no previous studies have considered the key genes associated with insomnia or the relationship between insomnia and immune cells. In this study, we analyzed the relationship between key genes and immune cells by identifying biomarkers for the diagnosis of insomnia. Next, we verified the efficacy of these biomarkers experimentally. Methods: First, we downloaded four microarrays (GSE11755, GSE12624, GSE28750, and GSE48080) from the Gene Expression Omnibus (GEO) database, which included data from 239 normal human blood samples and 365 blood specimens from patients with SD. Then, we analyzed two groups of differentially expressed genes (DEGs) and used Support Vector Machine Recursive Feature Elimination (SVM-RFE) analysis and the Least Absolute Shrinkage and Selection Operator (LASSO) regression model to investigate these key genes. Next, we used CIBERSORT to investigate the composition of 22 immune cell components of key genes in SD patients. Finally, the expression levels of key biomarkers in sleep-deprived patients were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Results: A total of 50 DEGs were identified: six genes were significantly upregulated, and 44 genes were significantly downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that Salmonella infection, NOD-like receptor (NLR) signaling pathway, Kaposi sarcoma-associated herpesvirus infection, and Th17 cell differentiation were significant. Based on machine learning, we identified C2CD2L, SPINT2, APOL3, PKNOX1, and A2M as key genes for SD; these were confirmed by receiver operating characteristic (ROC) analysis. Immune cell infiltration analysis showed that C2CD2L, SPINT2, APOL3, PKNOX1, and A2M were related in different degrees to regulatory T cells (Tregs), follicular T helper cells, CD8 cells, and other immune cells. The qRT-PCR experiments confirmed that the expression levels of C2CD2L concurred with the results derived from machine learning, but PKNOX1 and APOL3 did not. Discussion: In summary, we identified a key gene (C2CD2L) that may facilitate the development of biomarkers for insomnia.

Fructus gardeniae ameliorates anxiety-like behaviors induced by sleep deprivation via regulating hippocampal metabolomics and gut microbiota.

Fructus gardeniae (FG) is a traditional Chinese medicine and health food for thousands of years of application throughout Chinese history and is still widely used in clinical Chinese medicine. FG has a beneficial impact on anxiety, depression, insomnia, and psychiatric disorders; however, its mechanism of action requires further investigation. This study aimed to investigate the effects and mechanisms of FG on sleep deprivation (SD)-induced anxiety-like behavior in rats. A model of SD-induced anxiety-like behavior in rats was established by intraperitoneal injection of p-chlorophenylalanine (PCPA). This was accompanied by neuroinflammation and metabolic abnormalities in the hippocampus and disturbance of intestinal microbiota. However reduced SD-induced anxiety-like behavior and decreased levels of pro-inflammatory cytokines including TNF-α and IL-1ß were observed in the hippocampus of rats after 7 days of FG intervention. In addition, metabolomic analysis demonstrated that FG was able to modulate levels of phosphatidylserine 18, Phosphatidylinositol 18, sn-glycero-3-phosphocholine, deoxyguanylic acid, xylose, betaine and other metabolites in the hippocampus. The main metabolic pathways of hippocampal metabolites after FG intervention involve carbon metabolism, glycolysis/gluconeogenesis, pentose phosphate, and glycerophospholipid metabolism. 16S rRNA sequencing illustrated that FG ameliorated the dysbiosis of gut microbiota in anxious rats, mainly increased the abundance of Muribaculaceae and Lactobacillus, and decreased the abundance of Lachnospiraceae_NK4A136_group. In addition, the correlation analysis demonstrated that there was a close relationship between hippocampal metabolites and intestinal microbiota. In conclusion, FG improved the anxiety behavior and inhibited of neuroinflammation in sleep-deprived rats, and the mechanism may be related to the FG regulation of hippocampal metabolites and intestinal microflora composition.

Therapeutic potential of ReACp53 targeting mutant p53 protein in CRPC.

BACKGROUNDS: p53 is a tumor suppressor that prevents cancer onset and progression, and mutations in the p53 gene cause loss of the tumor suppressor function of the protein. The mutant p53 protein in tumor cells can form aggregates which contribute to the dominant-negative effect over the wild-type p53 protein, causing loss of p53 tumor suppression or gain of novel oncogenic functions. Mutations in p53 have been implicated in the pathogenesis of primary prostate cancer (PCa), and are often detected in recurrent and metastatic disease. Thus, targeting mutant p53 may constitute an alternative therapeutic strategy for advanced PCa for which there are no other viable options. METHODS: In this study, we used immunoprecipitation, immunofluorescence, clonogenic survival, and cell proliferation assays, flow cytometric analysis and in vivo xenograft to investigate the biological effects of ReACp53, a cell-permeable peptide inhibitor of p53 aggregation, on mutant p53-carrying PCa cells. RESULTS: Our results show that ReACp53 targets amyloid aggregates of mutant p53 protein and restores the p53 nuclear function as transcriptional factor, induces mitochondrial cell death and reduces DNA synthesis of mutant p53-carrying PCa cells; ReACp53 also inhibits xenograft tumor growth in vivo. CONCLUSIONS: The data presented here suggest a therapeutic potential of targeting mutant p53 protein in advanced PCa setting, which has a clinical impact for aggressive PCa with transforming how such tumors are managed.

ATM deficiency promotes progression of CRPC by enhancing Warburg effect.

ATM is a well-known master regulator of double strand break (DSB) DNA repair and the defective DNA repair has been therapeutically exploited to develop PARP inhibitors based on the synthetic lethality strategy. ATM mutation is found with increased prevalence in advanced metastatic castration-resistant prostate cancer (mCRPC). However, the molecular mechanisms underlying ATM mutation-driving disease progression are still largely unknown. Here, we report that ATM mutation contributes to the CRPC progression through a metabolic rather than DNA repair mechanism. We showed that ATM deficiency generated by CRISPR/Cas9 editing promoted CRPC cell proliferation and xenograft tumor growth. ATM deficiency altered cellular metabolism and enhanced Warburg effect in CRPC cells. We demonstrated that ATM deficiency shunted the glucose flux to aerobic glycolysis by upregulating LDHA expression, which generated more lactate and produced less mitochondrial ROS to promote CRPC cell growth. Inhibition of LDHA by siRNA or inhibitor FX11 generated less lactate and accumulated more ROS in ATM-deficient CRPC cells and therefore potentiated the cell death of ATM-deficient CRPC cells. These findings suggest a new therapeutic strategy for ATM-mutant CRPC patients by targeting LDHA-mediated glycolysis metabolism, which might be effective for the PARP inhibitor resistant mCRPC tumors.

Leukemia Inhibitory Factor Promotes Castration-resistant Prostate Cancer and Neuroendocrine Differentiation by Activated ZBTB46.

PURPOSE: The molecular targets for castration-resistant prostate cancer (CRPC) are unknown because the disease inevitably recurs, and therapeutic approaches for patients with CRPC remain less well understood. We sought to investigate regulatory mechanisms that result in increased therapeutic resistance, which is associated with neuroendocrine differentiation of prostate cancer and linked to dysregulation of the androgen-responsive pathway. EXPERIMENTAL DESIGN: The underlying intracellular mechanism that sustains the oncogenic network involved in neuroendocrine differentiation and therapeutic resistance of prostate cancer was evaluated to investigate and identify effectors. Multiple sets of samples with prostate adenocarcinomas and CRPC were assessed via IHC and other assays. RESULTS: We demonstrated that leukemia inhibitory factor (LIF) was induced by androgen deprivation therapy (ADT) and was upregulated by ZBTB46 in prostate cancer to promote CRPC and neuroendocrine differentiation. LIF was found to be induced in patients with prostate cancer after ADT and was associated with enriched nuclear ZBTB46 staining in high-grade prostate tumors. In prostate cancer cells, high ZBTB46 output was responsible for the activation of LIF-STAT3 signaling and neuroendocrine-like features. The abundance of LIF was mediated by ADT-induced ZBTB46 through a physical interaction with the regulatory sequence of LIF. Analysis of serum from patients showed that cases of higher tumor grade and metastatic prostate cancer exhibited higher LIF titers. CONCLUSIONS: Our findings suggest that LIF is a potent serum biomarker for diagnosing advanced prostate cancer and that targeting the ZBTB46-LIF axis may therefore inhibit CRPC development and neuroendocrine differentiation after ADT.

Mutant allele quantification reveals a genetic basis for TP53 mutation-driven castration resistance in prostate cancer cells.

The concept that human cancer is in essence a genetic disease driven by gene mutations has been well established, yet its utilization in functional studies of cancer genes has not been fully explored. Here, we describe a simple genetics-based approach that can quickly and sensitively reveal the effect of the alteration of a gene of interest on the fate of its host cells within a heterogeneous population, essentially monitoring the genetic selection that is associated with and powers the tumorigenesis. Using this approach, we discovered that loss-of-function of TP53 can promote the development of resistance of castration in prostate cancer cells via both transiently potentiating androgen-independent cell growth and facilitating the occurrence of genome instability. The study thus reveals a novel genetic basis underlying the development of castration resistance in prostate cancer cells and provides a facile genetic approach for studying a cancer gene of interest in versatile experimental conditions.

Expression and correlation of matrix metalloproteinase-7 and interleukin-15 in human osteoarthritis.

OBJECTIVES: To investigate the expression and correlation of matrix metalloproteinase (MMP)-7 and interleukin (IL)-15 in human osteoarthritis (OA). METHODS: From October 2013 to December 2014, 30 patients with OA were enrolled. In addition, anther 30 patients with simple meniscus injury were collected as a control group. There were no significant differences in age and gender between the two groups. Articular cartilage tissue was obtained from both OA patients and control group patients. Protein, mRNA, and serum expression levels of MMP-7 and IL-15 in the both two groups were determined by immunohistochemical (IHC), in situ hybridization, and enzyme-linked immunosorbent assay (ELISA) assay, respectively. Additionally, correlation between MMP-7 and IL-15 expression level in cartilage tissue and serum was assessed using Pearson correlation analysis. RESULTS: Protein, mRNA, and serum expression levels of MMP-7 and IL-15 in patients with OA were all significantly increased in OA patients compared with the control group. Besides, there were strong positive relationships between articular MMP-7 level and serum MMP-7 level (R(2) = 0.573, P = 0.018), between articular IL-15 level and serum IL-15 level (R(2) = 0.861, P = 0.023), and between serum IL-15 level and serum MMP-7 level (R(2) = 0.602, P = 0.012). CONCLUSION: These results suggest that MMP-7 and IL-15 might play important roles in the pathogenesis of OA, and IL-15 and MMP-7 has positive correlation in OA.

17ß-estradiol activates mTOR in chondrocytes by AKT-dependent and AKT-independent signaling pathways.

To confirm whether 17ß-estradiol (E2) activates mammalian target of rapamycin (mTOR) signaling pathway in chondrocytes and in what way activates mTOR. Human immortalized chondrocytes cell lines TC28a2 and C28/I2 were subjected to incubate with or without E2, LY294002 (the inhibitor of PI3K), rapamycin (the inhibitor of mTOR), or E2 in combination with LY294002 or rapamycin. Thereafter, protein levels of S6K1, p-S6K1, protein kinase B (AKT), and p-AKT were determined by Western blot analysis. Matrix metallopeptidase (MMP) 3 or MMP13 mRNA levels were evaluated by quantitative real-time PCR (qRT-PCR). Co-immunoprecipitation and Western blot analysis were performed to verify the interaction between ERα and mTOR. Both p-S6K1 and p-AKT protein levels in TC28a2 and C28/I2E2 cells were significantly increased by incubation with E2 (0.5 h and 1 h) (P < 0.05). Rapamycin did not affect the levels of p-AKT, but were significantly reduced by LY294002 or E2 in combination with LY294002. The levels of p-S6K1 were significantly decreased by incubation with LY294002, but the effect could be reversed by E2 in combination with LY294002. Rabbit anti-mTOR antibody was able to immunoprecipitate ERα after incubation with E2. Moreover, E2 inhibited the mRNA levels of MMP3 and MMP13 by mTOR pathway. E2 actives mTOR in chondrocytes through AKT-dependent and independent ways.