Hammerhead-type FXR agonists induce an enhancer RNA Fincor that ameliorates nonalcoholic steatohepatitis in mice.

The nuclear receptor, farnesoid X receptor (FXR/NR1H4), is increasingly recognized as a promising drug target for metabolic diseases, including nonalcoholic steatohepatitis (NASH). Protein-coding genes regulated by FXR are well known, but whether FXR also acts through regulation of long non-coding RNAs (lncRNAs), which vastly outnumber protein-coding genes, remains unknown. Utilizing RNA-seq and global run-on sequencing (GRO-seq) analyses in mouse liver, we found that FXR activation affects the expression of many RNA transcripts from chromatin regions bearing enhancer features. Among these we discovered a previously unannotated liver-enriched enhancer-derived lncRNA (eRNA), termed FXR-induced non-coding RNA (Fincor). We show that Fincor is specifically induced by the hammerhead-type FXR agonists, including GW4064 and tropifexor. CRISPR/Cas9-mediated liver-specific knockdown of Fincor in dietary NASH mice reduced the beneficial effects of tropifexor, an FXR agonist currently in clinical trials for NASH and primary biliary cholangitis (PBC), indicating that amelioration of liver fibrosis and inflammation in NASH treatment by tropifexor is mediated in part by Fincor. Overall, our findings highlight that pharmacological activation of FXR by hammerhead-type agonists induces a novel eRNA, Fincor, contributing to the amelioration of NASH in mice. Fincor may represent a new drug target for addressing metabolic disorders, including NASH.

Non-alcoholic steatohepatitis, also known as NASH, is a severe condition whereby fat deposits around the liver lead to inflammation, swelling, scarring and lasting damage to the organ. Despite being one of the leading causes of liver-related deaths worldwide, the disease has no approved treatment. A protein known as Farnesoid X receptor (or FXR) is increasingly being recognized as a promising drug target for non-alcoholic steatohepatitis. Once activated, FXR helps to regulate the activity of DNA regions which are coding for proteins important for liver health. However, less is known about how FXR may act on non-coding regions, the DNA sequences that do not generate proteins but can be transcribed into RNA molecules with important biological roles. In response, Chen et al. investigated whether FXR activation of non-coding RNAs could be linked to the clinical benefits of hammerhead FXR agonists, a type of synthetic compounds that activates this receptor. To do so, genetic analyses of mouse livers were performed to identify non-coding RNAs generated when FXR was activated by the agonist. These experiments revealed that agonist-activated FXR induced a range of non-coding RNAs transcribed from DNA sequences known as enhancers, which help to regulate gene expression. In particular, hammerhead FXR agonists led to the production of a liver-specific enhancer RNA called Fincor. Additional experiments using tropifexor, a hammerhead FXR agonist currently into clinical trials, showed that this investigational new drug had reduced benefits in a mouse model of non-alcoholic steatohepatitis with low Fincor levels. This suggested that this enhancer RNA may play a key role in mediating the clinical benefits of hammerhead FXR agonists, encouraging further research into its role and therapeutic value.

Efficacy and safety of antibiotics for treatment of leptospirosis: a systematic review and network meta-analysis.

BACKGROUND: Leptospirosis, an important zoonotic bacterial disease, commonly affects resource-poor populations and results in significant morbidity and mortality worldwide. The value of antibiotics in leptospirosis remains unclear, as evidenced by the conflicting opinions published. METHODS: We conducted a search in the PubMed, Web of Science, and Cochrane Library databases for studies. These studies included clinical trials and retrospective studies that evaluated the efficacy or safety of antibiotics for leptospirosis treatment. The primary outcomes assessed were defervescence time, mortality rate, and hospital stays. Subgroup analyses were performed based on whether there were cases involving children and whether there were cases of severe jaundice. Safety was defined as the prevalence of adverse events associated with the use of antibiotics. p scores were utilized to rank the efficacy of the antibiotics. RESULTS: There are included 9 randomized controlled trials (RCTs), 1 control trial (CT), and 3 retrospective studies (RS) involving 920 patients and 8 antibiotics. Six antibiotics resulted in significantly shorter defervescence times compared to the control, namely cefotaxime (MD, - 1.88; 95% CI = - 2.60 to - 1.15), azithromycin (MD, - 1.74; 95% CI = - 2.52 to - 0.95), doxycycline (MD, - 1.53; 95% CI = - 2.05 to - 1.00), ceftriaxone (MD, - 1.22; 95% CI = - 1.89 to - 0.55), penicillin (MD, - 1.22; 95% CI = - 1.80 to - 0.64), and penicillin or ampicillin (MD, - 0.08; 95% CI = - 1.01 to - 0.59). The antibiotics were not effective in reducing the mortality and hospital stays. Common adverse reactions to antibiotics included Jarisch-Herxheimer reaction, rash, headache, and digestive reactions (nausea, vomiting, diarrhea, abdominal pain, and others). CONCLUSIONS: Findings recommend that leptospirosis patients be treated with antibiotics, which significantly reduced the leptospirosis defervescence time. Cephalosporins, doxycycline, and penicillin are suggested, and azithromycin may be a suitable alternative for drug-resistant cases. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022354938.

Hammerhead-type FXR agonists induce an eRNA FincoR that ameliorates nonalcoholic steatohepatitis in mice.

The nuclear receptor, Farnesoid X Receptor (FXR/NR1H4), is increasingly recognized as a promising drug target for metabolic diseases, including nonalcoholic steatohepatitis (NASH). Protein coding genes regulated by FXR are well known, but whether FXR also acts through regulation of long non-coding RNAs (lncRNAs), which vastly outnumber protein-coding genes, remains unknown. Utilizing RNA-seq and GRO-seq analyses in mouse liver, we found that FXR activation affects the expression of many RNA transcripts from chromatin regions bearing enhancer features. Among these we discovered a previously unannotated liver-enriched enhancer-derived lncRNA (eRNA), termed FincoR. We show that FincoR is specifically induced by the hammerhead-type FXR agonists, including GW4064 and tropifexor. CRISPR/Cas9-mediated liver-specific knockdown of FincoR in dietary NASH mice reduced the beneficial effects of tropifexor, an FXR agonist currently in clinical trials for NASH and primary biliary cholangitis (PBC), indicating that that amelioration of liver fibrosis and inflammation in NASH treatment by tropifexor is mediated in part by FincoR. Overall, our findings highlight that pharmacological activation of FXR by hammerhead-type agonists induces a novel eRNA, FincoR, contributing to the amelioration of NASH in mice. FincoR may represent a new drug target for addressing metabolic disorders, including NASH.

The dark side of NRF2 in arsenic carcinogenesis.

Arsenic is an environmental toxicant that significantly enhances the risk of developing disease, including several cancers. While the epidemiological evidence supporting increased cancer risk due to chronic arsenic exposure is strong, therapies tailored to treat exposed populations are lacking. This can be accredited in large part to the chronic nature and pleiotropic pathological effects associated with prolonged arsenic exposure. Despite this fact, several putative mediators of arsenic promotion of cancer have been identified. Among these, the critical transcription factor NRF2 has been shown to be a key mediator of arsenic's pro-carcinogenic effects. Importantly, the dependence of arsenic-transformed cancer cells on NRF2 upregulation exposes a targetable liability that could be utilized to treat arsenic-promoted cancers. In this chapter, we briefly introduce the "light" vs "dark" side of the NRF2 pathway. We then give a brief overview of arsenic metabolism, and discuss the epidemiological and experimental evidence that support arsenic promotion of different cancers, with a specific emphasis on mechanisms mediated by chronic, non-canonical activation of NRF2 (i.e., the "dark" side). Finally, we briefly highlight how the non-canonical NRF2 pathway plays a role in other arsenic-promoted diseases, as well as research directions that warrant further investigation.

NRF2 controls iron homeostasis and ferroptosis through HERC2 and VAMP8.

Enhancing the intracellular labile iron pool (LIP) represents a powerful, yet untapped strategy for driving ferroptotic death of cancer cells. Here, we show that NRF2 maintains iron homeostasis by controlling HERC2 (E3 ubiquitin ligase for NCOA4 and FBXL5) and VAMP8 (mediates autophagosome-lysosome fusion). NFE2L2/NRF2 knockout cells have low HERC2 expression, leading to a simultaneous increase in ferritin and NCOA4 and recruitment of apoferritin into the autophagosome. NFE2L2/NRF2 knockout cells also have low VAMP8 expression, which leads to ferritinophagy blockage. Therefore, deletion of NFE2L2/NRF2 results in apoferritin accumulation in the autophagosome, an elevated LIP, and enhanced sensitivity to ferroptosis. Concordantly, NRF2 levels correlate with HERC2 and VAMP8 in human ovarian cancer tissues, as well as ferroptosis resistance in a panel of ovarian cancer cell lines. Last, the feasibility of inhibiting NRF2 to increase the LIP and kill cancer cells via ferroptosis was demonstrated in preclinical models, signifying the impact of NRF2 inhibition in cancer treatment.

Decreased autophagosome biogenesis, reduced NRF2, and enhanced ferroptotic cell death are underlying molecular mechanisms of non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Caloric excess and sedentary lifestyles have led to an epidemic of obesity, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD). The objective of this study was to investigate the mechanisms underlying high fat diet (HFD)-induced NAFLD, and to explore NRF2 activation as a strategy to alleviate NAFLD. APPROACH AND RESULTS: Herein, we demonstrated that high fat diet (HFD) induced lipid peroxidation and ferroptosis, both of which could be alleviated by NRF2 upregulation. Mechanistically, HFD suppressed autophagosome biogenesis through AMPK- and AKT-mediated mTOR activation and decreased ATG7, resulting in KEAP1 stabilization and decreased NRF2 levels in mouse liver. Furthermore, ATG7 is required for HFD-induced NRF2 downregulation, as ATG7 deletion in Cre-inducible ATG7 knockout mice decreased NRF2 levels and enhanced ferroptosis, which was not further exacerbated by HFD. This finding was recapitulated in mouse hepatocytes, which showed a similar phenotype upon treatment with saturated fatty acids (SFAs) but not monounsaturated fatty acids (MUFAs). Finally, NRF2 activation blocked fatty acid (FA)-mediated NRF2 downregulation, lipid peroxidation, and ferroptosis. Importantly, the HFD-induced alterations were also observed in human fatty liver tissue samples. CONCLUSIONS: HFD-mediated autophagy inhibition, NRF2 suppression, and ferroptosis promotion are important molecular mechanisms of obesity-driven metabolic diseases. NRF2 activation counteracts HFD-mediated NRF2 suppression and ferroptotic cell death. In addition, SFA vs. MUFA regulation of NRF2 may underlie their harmful vs. beneficial effects. Our study reveals NRF2 as a key player in the development and progression of fatty liver disease and that NRF2 activation could serve as a potential therapeutic strategy.

NRF2 and Diabetes: The Good, the Bad, and the Complex.

Despite decades of scientific effort, diabetes continues to represent an incredibly complex and difficult disease to treat. This is due in large part to the multifactorial nature of disease onset and progression and the multiple organ systems affected. An increasing body of scientific evidence indicates that a key mediator of diabetes progression is NRF2, a critical transcription factor that regulates redox, protein, and metabolic homeostasis. Importantly, while experimental studies have confirmed the critical nature of proper NRF2 function in preventing the onset of diabetic outcomes, we have only just begun to scratch the surface of understanding the mechanisms by which NRF2 modulates diabetes progression, particularly across different causative contexts. One reason for this is the contradictory nature of the current literature, which can often be accredited to model discrepancies, as well as whether NRF2 is activated in an acute or chronic manner. Furthermore, despite therapeutic promise, there are no current NRF2 activators in clinical trials for the treatment of patients with diabetes. In this review, we briefly introduce the transcriptional programs regulated by NRF2 as well as how NRF2 itself is regulated. We also review the current literature regarding NRF2 modulation of diabetic phenotypes across the different diabetes subtypes, including a brief discussion of contradictory results, as well as what is needed to progress the NRF2 diabetes field forward.

Brd4 modulates diet-induced obesity via PPARγ-dependent Gdf3 expression in adipose tissue macrophages.

Macrophage-mediated inflammatory response has been implicated in the pathogenesis of obesity and insulin resistance. Brd4 has emerged as a key regulator in the innate immune response. However, the role of Brd4 in obesity-associated inflammation and insulin resistance remains uncharacterized. Here, we demonstrated that myeloid lineage-specific Brd4 knockout (Brd4-CKO) mice were protected from high-fat diet-induced (HFD-induced) obesity with less fat accumulation, higher energy expenditure, and increased lipolysis in adipose tissue. Brd4-CKO mice fed a HFD also displayed reduced local and systemic inflammation with improved insulin sensitivity. RNA-Seq of adipose tissue macrophages (ATMs) from HFD-fed WT and Brd4-CKO mice revealed that expression of antilipolytic factor Gdf3 was significantly decreased in ATMs of Brd4-CKO mice. We also found that Brd4 bound to the promoter and enhancers of Gdf3 to facilitate PPARγ-dependent Gdf3 expression in macrophages. Furthermore, Brd4-mediated expression of Gdf3 acted as a paracrine signal targeting adipocytes to suppress the expression of lipases and the associated lipolysis in cultured cells and mice. Controlling the expression of Gdf3 in ATMs could be one of the mechanisms by which Brd4 modulates lipid metabolism and diet-induced obesity. This study suggests that Brd4 could be a potential therapeutic target for obesity and insulin resistance.

BRD4 inhibition and FXR activation, individually beneficial in cholestasis, are antagonistic in combination.

Activation of farnesoid X receptor (FXR) by obeticholic acid (OCA) reduces hepatic inflammation and fibrosis in patients with primary biliary cholangitis (PBC), a life-threatening cholestatic liver failure. Inhibition of bromodomain-containing protein 4 (BRD4) also has antiinflammatory, antifibrotic effects in mice. We determined the role of BRD4 in FXR function in bile acid (BA) regulation and examined whether the known beneficial effects of OCA are enhanced by inhibiting BRD4 in cholestatic mice. Liver-specific downregulation of BRD4 disrupted BA homeostasis in mice, and FXR-mediated regulation of BA-related genes, including small heterodimer partner and cholesterol 7 alpha-hydroxylase, was BRD4 dependent. In cholestatic mice, JQ1 or OCA treatment ameliorated hepatotoxicity, inflammation, and fibrosis, but surprisingly, was antagonistic in combination. Mechanistically, OCA increased binding of FXR, and the corepressor silencing mediator of retinoid and thyroid hormone receptor (SMRT) decreased NF-κB binding at inflammatory genes and repressed the genes in a BRD4-dependent manner. In patients with PBC, hepatic expression of FXR and BRD4 was significantly reduced. In conclusion, BRD4 is a potentially novel cofactor of FXR for maintaining BA homeostasis and hepatoprotection. Although BRD4 promotes hepatic inflammation and fibrosis in cholestasis, paradoxically, BRD4 is required for the antiinflammatory, antifibrotic actions of OCA-activated FXR. Cotreatment with OCA and JQ1, individually beneficial, may be antagonistic in treatment of liver disease patients with inflammation and fibrosis complications.

MiR-455-5p Attenuates Cerebral Ischemic Reperfusion Injury by Targeting FLT3.

Cerebral ischemia-reperfusion (I/R) injury is a terrible disease which results in the dysfunction and structural damage of brain tissues. Growing evidence implies that miR-455-5p is implicated in the regulation of pathogenesis of several diseases. The aim of this study is to reveal the role of miR-455-5p in cerebral I/R injury and the regulatory mechanism. We established a vitro model by inducing SH-SY5Y and PC-12 cells with oxygen-glucose deprivation and reoxygenation. The experimental cerebral I/R rat model was established by middle cerebral artery occlusion operation. The findings indicated that miR-455-5p expression was downregulated in oxygen-glucose deprivation and reoxygenation induced cells and I/R rat model. In addition, miR-455-5p upregulation inhibited SH-SY5Y cell apoptosis and cerebral damage, whereas miR-455-5p silencing promoted SH-SY5Y cell apoptosis and cerebral damage. Mechanistically, luciferase reporter assay corroborated that miR-455-5p could bind with feline mcDonough sarcoma-like tyrosine kinase 3 (FLT3) mRNA. However, the role of FLT3 in cerebral I/R injury was rarely investigated. Real-time polymerase chain reaction revealed that FTL3 expression was negatively regulated by miR-455-5p. FTL3 upregulation reversed the inhibitory effects of miR-455-5p upregulation on PC-12 and SH-SY5Y cell apoptosis. Therefore, our study verified that miR-455-5p improved cerebral I/R injury by targeting FLT3, which suggests a potential new target for the prevention of cerebral I/R injury.

Phosphorylation of hepatic farnesoid X receptor by FGF19 signaling-activated Src maintains cholesterol levels and protects from atherosclerosis.

The bile acid (BA) nuclear receptor, farnesoid X receptor (FXR/NR1H4), maintains metabolic homeostasis by transcriptional control of numerous genes, including an intestinal hormone, fibroblast growth factor-19 (FGF19; FGF15 in mice). Besides activation by BAs, the gene-regulatory function of FXR is also modulated by hormone or nutrient signaling-induced post-translational modifications. Recently, phosphorylation at Tyr-67 by the FGF15/19 signaling-activated nonreceptor tyrosine kinase Src was shown to be important for FXR function in BA homeostasis. Here, we examined the role of this FXR phosphorylation in cholesterol regulation. In both hepatic FXR-knockout and FXR-knockdown mice, reconstitution of FXR expression up-regulated cholesterol transport genes for its biliary excretion, including scavenger receptor class B member 1 (Scarb1) and ABC subfamily G member 8 (Abcg5/8), decreased hepatic and plasma cholesterol levels, and increased biliary and fecal cholesterol levels. Of note, these sterol-lowering effects were blunted by substitution of Phe for Tyr-67 in FXR. Moreover, consistent with Src's role in phosphorylating FXR, Src knockdown impaired cholesterol regulation in mice. In hypercholesterolemic apolipoprotein E-deficient mice, expression of FXR, but not Y67F-FXR, ameliorated atherosclerosis, whereas Src down-regulation exacerbated it. Feeding or treatment with an FXR agonist induced Abcg5/8 and Scarb1 expression in WT, but not FGF15-knockout, mice. Furthermore, FGF19 treatment increased occupancy of FXR at Abcg5/8 and Scarb1, expression of these genes, and cholesterol efflux from hepatocytes. These FGF19-mediated effects were blunted by the Y67F-FXR substitution or Src down-regulation or inhibition. We conclude that phosphorylation of hepatic FXR by FGF15/19-induced Src maintains cholesterol homeostasis and protects against atherosclerosis.

T63 inhibits osteoclast differentiation through regulating MAPKs and Akt signaling pathways.

Inhibition of excessive osteoclast differentiation and activity is a valid approach for the treatment of osteoporosis. T63 is a small-molecule compound identified from a high throughput screening based on RUNX2 transcriptional activity, and has been reported to stimulate osteoblast formation. However, whether the compound has any effect on osteoclast differentiation remains unknown. Here, we examined the in vitro effect of T63 on osteoclastogenesis. T63 was found to inhibit the number of TRAP-positive cells in an osteoblast-osteoclast co-culture system, and inhibited Rankl expression in the preosteoblast MC3T3-E1 cells. The compound also directly suppressed RANKL-induced osteoclast differentiation in both dose- and time-dependent manner, as evidenced by the decrease of TRAP activity, F-actin formation and osteoclastogenesis-related genes expression in RAW264.7 cells. Moreover, pretreatment with T63 markedly decreased the activation of mitogen-activated protein kinases and Akt, both of which are positively involved in the regulation of osteoclastogenesis. Collectively, our findings suggest T63 has a protective effect against bone loss by inhibiting bone resorption. Its regulatory effect on bone metabolism makes the compound a more promising candidate for the potential application in the treatment of osteoporosis.

Therapeutic effect of intensive glycemic control therapy in patients with traumatic brain injury: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Hyperglycemia is associated with dismal outcomes in patients with traumatic brain injury (TBI), which is frequently treated with insulin therapy. In this study, a systematic review and meta-analysis of the published randomized controlled trials (RCTs) was performed to assess the safety and efficacy of intensive glycemic control (IGC) versus conventional glycemic control (CGC) for patients following TBI. METHODS: Databases, including PubMed, Embase, and the Cochran database, were retrieved up to January 2018. The outcomes evaluated in this study included mortality, neurological outcome, infection rate, hypoglycemia episode, and length of stay (LOS) in intensive care unit (ICU). The enrolled trials were analyzed using the Review Manager 5.3 software. RESULTS: A total of 7 randomized controlled trials (RCTs) involving 1013 cases were enrolled in this study, and the results indicated no significant difference in 6-month mortality (risk ratio [RR], 0.92; 95% confidence interval [CI] 0.76-1.10; P = .34). Subsequently, IGC was associated with a better neurological outcome (RR, 1.22; 95% CI 1.05-1.43; P = .01), lower infection rate (RR, 0.65; 95% CI 0.51-0.82; P = .0003) and shorter LOS in ICU (mean difference [MD] = -1.37; 95%CI = -2.11, -0.63; P = .0003). In addition, IGC would also increase the risk of hypoglycemia episode (RR, 4.53; 95% CI 2.18-9.42; P < .001). CONCLUSIONS: IGC plays a protective role in improving neurological outcome, decreasing infection rate and reducing the LOS in ICU. However, IGC therapy can also remarkably increase the risk of hypoglycemia, but it will not affect the mortality in TBI patients.

Molecular cloning and expression study on Toll-like receptor 5M in turbot, Scophthalmus maximus.

Toll-like receptor 5 (TLR5) is responsible for the recognition of bacterial flagellin in mammals and play an important role in innate immunity. In the present study, a TLR5M gene was cloned from turbot, Scophthalmus maximus, and its immune responsive expression was subsequently studied in vivo. The Scophthalmus maximus (Sm)TLR5M gene is 4268 bp in length, consists of four exons and three introns and encodes a peptide of 892 amino acids (aa). The deduced protein possesses a signal peptide sequence, a leucine-rich repeat (LRR) domain composed of 23 LRR motifs, a transmembrane (TM) domain and a Toll/interleukin-1 receptor (TIR) domain. Phylogenetic analysis grouped SmTLR5M with other teleost TLR5Ms. A number of binding sites for transcription factors involved in immune response regulation were predicted in the 5'-flanking region of SmTLR5M. Quantitative real-time PCR (qPCR) analysis demonstrated that SmTLR5M mRNA was expressed ubiquitously with higher levels in head kidney and spleen. Its expression following stimulation with flagellin and lipopolysaccharide (LPS) was further tested in gills, spleen, head kidney and muscle. The maximum increases of SmTLR5M transcript levels ranged from 1.3 to 6.8-fold and appeared at 3 h to 5 day post-injection depending on different organs and stimuli. These findings suggest that SmTLR5M may play an important role in immune responses to infections with bacterial pathogens.

BRD4 regulates cellular senescence in gastric cancer cells via E2F/miR-106b/p21 axis.

Small molecules targeting bromodomains of BET proteins possess strong anti-tumor activities and have emerged as potential therapeutics for cancer. However, the underlying mechanisms for the anti-proliferative activity of these inhibitors are still not fully characterized. In this study, we demonstrated that BET inhibitor JQ1 suppressed the proliferation and invasiveness of gastric cancer cells by inducing cellular senescence. Depletion of BRD4, which was overexpressed in gastric cancer tissues, but not other BET proteins recapitulated JQ1-induced cellular senescence with increased cellular SA-ß-Gal activity and elevated p21 levels. In addition, we showed that the levels of p21 were regulated at the post-transcriptional level by BRD4-dependent expression of miR-106b-5p, which targets the 3'-UTR of p21 mRNA. Overexpression of miR-106b-5p prevented JQ1-induced p21 expression and BRD4 inhibition-associated cellular senescence, whereas miR-106b-5p inhibitor up-regulated p21 and induced cellular senescence. Finally, we demonstrated that inhibition of E2F suppressed the binding of BRD4 to the promoter of miR-106b-5p and inhibited its transcription, leading to the increased p21 levels and cellular senescence in gastric cancer cells. Our results reveal a novel mechanism by which BRD4 regulates cancer cell proliferation by modulating the cellular senescence through E2F/miR-106b-5p/p21 axis and provide new insights into using BET inhibitors as potential anticancer drugs.

Selective killing of Helicobacter pylori with pH-responsive helix-coil conformation transitionable antimicrobial polypeptides.

Current clinical treatment of Helicobacter pylori infection, the main etiological factor in the development of gastritis, gastric ulcers, and gastric carcinoma, requires a combination of at least two antibiotics and one proton pump inhibitor. However, such triple therapy suffers from progressively decreased therapeutic efficacy due to the drug resistance and undesired killing of the commensal bacteria due to poor selectivity. Here, we report the development of antimicrobial polypeptide-based monotherapy, which can specifically kill H. pylori under acidic pH in the stomach while inducing minimal toxicity to commensal bacteria under physiological pH. Specifically, we designed a class of pH-sensitive, helix-coil conformation transitionable antimicrobial polypeptides (HCT-AMPs) (PGA)m-r-(PHLG-MHH)n, bearing randomly distributed negatively charged glutamic acid and positively charged poly(γ-6-N-(methyldihexylammonium)hexyl-l-glutamate) (PHLG-MHH) residues. The HCT-AMPs showed unappreciable toxicity at physiological pH when they adopted random coiled conformation. Under acidic condition in the stomach, they transformed to the helical structure and exhibited potent antibacterial activity against H. pylori, including clinically isolated drug-resistant strains. After oral gavage, the HCT-AMPs afforded comparable H. pylori killing efficacy to the triple-therapy approach while inducing minimal toxicity against normal tissues and commensal bacteria, in comparison with the remarkable killing of commensal bacteria by 65% and 86% in the ileal contents and feces, respectively, following triple therapy. This strategy renders an effective approach to specifically target and kill H. pylori in the stomach while not harming the commensal bacteria/normal tissues.

Small molecule T63 suppresses osteoporosis by modulating osteoblast differentiation via BMP and WNT signaling pathways.

Osteoporosis results from the imbalance between bone resorption and bone formation, and restoring the normal balance of bone remodeling is highly desirable for identification of better treatment. In this study, using a cell-based high-throughput screening model representing Runt-related transcription factor 2 (RUNX2) transcriptional activity, we identified a novel small-molecular-weight compound, T63, as an efficient up-regulator of osteogenesis. T63 increased the alkaline phosphatase (ALPL) activity and mineralization as well as gene expression of Alpl and other osteogenic marker genes in mouse osteoblasts and mesenchymal stem cell-like cells. Upon induction of osteoblast differentiation, T63 inhibited adipogenic differentiation in the pluripotent mesenchymal cells. Consistently, T63 up-regulated RUNX2 mRNA and protein levels, and knockdown of RUNX2 reduced the osteogenic role of T63. Mechanistically, T63 activated both BMPs and WNT/ß-catenin signaling pathways. Inhibition of either signaling pathway with specific inhibitor suppressed T63-induced RUNX2 expression and the osteogenic phenotypes. Moreover, T63 markedly protected against bone mass loss in the ovariectomized and dexamethasone treated rat osteoporosis model. Collectively, our data demonstrate that T63 could be a promising drug candidate and deserves further development for potential therapeutics in osteoporosis.

Brd4 modulates the innate immune response through Mnk2-eIF4E pathway-dependent translational control of IκBα.

Bromodomain-containing factor Brd4 has emerged as an important transcriptional regulator of NF-κB-dependent inflammatory gene expression. However, the in vivo physiological function of Brd4 in the inflammatory response remains poorly defined. We now demonstrate that mice deficient for Brd4 in myeloid-lineage cells are resistant to LPS-induced sepsis but are more susceptible to bacterial infection. Gene-expression microarray analysis of bone marrow-derived macrophages (BMDMs) reveals that deletion of Brd4 decreases the expression of a significant amount of LPS-induced inflammatory genes while reversing the expression of a small subset of LPS-suppressed genes, including MAP kinase-interacting serine/threonine-protein kinase 2 (Mknk2). Brd4-deficient BMDMs display enhanced Mnk2 expression and the corresponding eukaryotic translation initiation factor 4E (eIF4E) activation after LPS stimulation, leading to an increased translation of IκBα mRNA in polysomes. The enhanced newly synthesized IκBα reduced the binding of NF-κB to the promoters of inflammatory genes, resulting in reduced inflammatory gene expression and cytokine production. By modulating the translation of IκBα via the Mnk2-eIF4E pathway, Brd4 provides an additional layer of control for NF-κB-dependent inflammatory gene expression and inflammatory response.

Worldwide revision of the genus Fraseroscyphus Boero and Bouillon, 1993 (Cnidaria: Hydrozoa): an integrative approach to establish new generic diagnoses.

The morphological character of the hydrocladium and gonotheca origin from within the hydrothecal cavity has rarely been applied for generic diagnoses in hydrozoans. Its taxonomic value has been controversial for more than a century. The genus Fraseroscyphus Boero and Bouillon, 1993 (Hydrozoa: Sertulariidae) is a relatively recently debated case and it has been distinguished from Symplectoscyphus Marktanner-Turneretscher, 1890 based on this character. A review of this character in all published nominal species of the family Sertulariidae reveals that its occurrence is inconsistent at the genus level. However, phylogenetic analyses based on mitochondrial (16S) and nuclear (18S, 28S) genes support the position of Fraseroscyphus as a genus within the family Symplectoscyphidae Maronna et al., 2016. Comparisons of 16 morphological characters of 10 related species support the distinction of Fraseroscyphus from Antarctoscyphus and Symplectoscyphus by other characters in addition to the hydrocladial and gonothecal origin character. These new characters include the rarely-branched hydrocaulus, the absence of an apophysis, and the absence of an axillary hydrotheca. Furthermore, a revision based on the morphological character complex mentioned above using type and topotypic material, demonstrated that Sertularella sinuosa Fraser, 1948 (type species of Fraseroscyphus) and Symplectoscyphus huanghaiensis Tang & Huang, 1986 are junior synonyms of F. hozawai (Stechow, 1931) comb. nov. The assignment of Sertularella irregularis Trebilcock, 1928 and Sertularella macrogona Trebilcock, 1928 to Fraseroscyphus is also supported. In addition, sequence polymorphism of mitochondrial genes even within a single hydroid fragment was detected by the molecular cloning method, and is probably in part attributable to errors introduced by PCR, mitochondrial heteroplasmy and/or nuclear mitochondrial DNA (NUMTs). The adoption of the cloning method may be crucial to improve the sequence accuracy for some colonial hydrozoans.