Inhibition of TAF1B impairs ribosome biosynthesis and suppresses cell proliferation in stomach adenocarcinoma through promoting c-MYC mRNA degradation.

Hyperactivation of ribosome biosynthesis (RiBi) is a hallmark of cancer, and targeting ribosome biogenesis has emerged as a potential therapeutic strategy. The depletion of TAF1B, a major component of selectivity factor 1 (SL1), disrupts the pre-initiation complex, preventing RNA polymerase I from binding ribosomal DNA and inhibiting the hyperactivation of RiBi. Here, we investigate the role of TAF1B, in regulating RiBi and proliferation in stomach adenocarcinoma (STAD). We disclosed that the overexpression of TAF1B correlates with poor prognosis in STAD, and found that knocking down TAF1B effectively inhibits STAD cell proliferation and survival in vitro and in vivo. TAF1B knockdown may also induce nucleolar stress, and promote c-MYC degradation in STAD cells. Furthermore, we demonstrate that TAF1B depletion impairs rRNA gene transcription and processing, leading to reduced ribosome biogenesis. Collectively, our findings suggest that TAF1B may serve as a potential therapeutic target for STAD and highlight the importance of RiBi in cancer progression.

Complete genetic characterization of carbapenem-resistant Acinetobacter johnsonii, co-producing NDM-1, OXA-58, and PER-1 in a patient source.

The emergence of carbapenemase-producing Acinetobacter spp. has been widely reported and become a global threat. However, carbapenem-resistant A. johnsonii strains are relatively rare and without comprehensive genetic structure analysis, especially for isolates collected from human specimen. Here, one A. johnsonii AYTCM strain, co-producing NDM-1, OXA-58, and PER-1 enzymes, was isolated from sputum in China in 2018. Antimicrobial susceptibility testing showed that it was resistant to meropenem, imipenem, ceftazidime, ciprofloxacin, and cefoperazone/sulbactam. Whole-genome sequencing and bioinformatic analysis revealed that it possessed 11 plasmids. bla OXA-58 and bla PER-1 genes were located in the pAYTCM-1 plasmid. Especially, a complex class 1 integron consisted of a 5' conserved segment (5' CS) and 3' CS, which was found to carry sul1, arr-3, qnrVC6, and bla PER-1 cassettes. Moreover, the bla NDM-1 gene was located in 41,087 conjugative plasmids and was quite stable even after 70 passages under antibiotics-free conditions. In addition, six prophage regions were identified. Tracking of closely related plasmids in the public database showed that pAYTCM-1 was similar to pXBB1-9, pOXA23_010062, pOXA58_010030, and pAcsw19-2 plasmids, which were collected from the strains of sewage in China. Concerning the pAYTCM-3 plasmids, results showed that strains were collected from different sources and their hosts were isolated from various countries, such as China, USA, Japan, Brazil, and Mexico, suggesting that a wide spread occurred all over the world. In conclusion, early surveillance is warranted to avoid the extensive spread of this high-risk clone in the healthcare setting.

Genome sequence of a tigecycline-resistant Acinetobacter seifertii recovered in human bloodstream infection in China.

OBJECTIVES: The phylogenetic characteristics of Acinetobacter seifertii clinical strain are not well-studied. Here, we reported one tigecycline-resistant ST1612Pasteur A. seifertii isolated from bloodstream infections (BSI) in China. METHODS: Antimicrobial susceptibility tests were conducted via broth microdilution. Whole-genome sequencing (WGS) was performed and annotation was conducted using rapid annotations subsystems technology (RAST) server. Multilocus sequence typing (MLST), capsular polysaccharide (KL), and lipoolygosaccharide (OCL) were analysed using PubMLST and Kaptive. Resistance genes, virulence factors, and comparative genomics analysis were performed. Cloning, mutations of efflux pump-related genes, and expression level were further investigated. RESULTS: The draft genome sequence of A. seifertii ASTCM strain is made up of 109 contigs with a total length of 4,074,640 bp. Based on the RAST results, 3923 genes that belonged to 310 subsystems were annotated. Acinetobacter seifertii ASTCM was ST1612Pasteur with KL26 and OCL4, respectively. It was resistant to gentamicin and tigecycline. ASTCM harboured tet(39), sul2, and msr(E)-mph(E), and one amino acid mutation in Tet(39) (T175A) was further identified. Nevertheless, the signal mutation failed to contribute to susceptibility change of tigecycline. Of note, several amino acid substitutions were identified in AdeRS, AdeN, AdeL, and Trm, which could lead to overexpression of adeB, adeG, and adeJ efflux pump genes and further possibly lead to tigecycline resistance. Phylogenetic analysis showed that a huge diversity was observed among A. seifertii strains based on 27-52,193 SNPs difference. CONCLUSION: In summary, we reported a tigecycline-resistant ST1612Pasteur A. seifertii in China. Early detection is recommended to prevent their further spread in clinical settings.

Emergence of IS26-mediated pLVPK-like virulence and NDM-1 conjugative fusion plasmid in hypervirulent carbapenem-resistant Klebsiella pneumoniae.

Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) has been widely reported and poses a global threat. However, the comprehensive genetic structure of ST11-KL64 hv-CRKP and the possible evolutionary mechanisms from a genetic structure perspective of this high-risk clone remain unclear. Here, a blaKPC-2-blaNDM-1-positive ST11-KL64 hv-CRKP isolate was obtained from a human bloodstream infection (BSI). Whole-genome sequencing and bioinformatics analyses revealed that it contained a fusion plasmid, pKPTCM2-1. pKPTCM2-1 is a conjugative plasmid composed of an oriT-positive pLVPK-like virulence plasmid and a type IV secretion system-produced blaNDM-1-bearing IncX3 plasmid mediated by IS26-based co-integration. This progress generated 8-bp target site duplications (TGAAAACC) on both sides. The fusion plasmid possessed self-transferability and could be transferred to blaKPC-2-harboring ST11-KL64 CRKP to form the ST11-KL64 hv-CRKP clone. The pLVPK-like-positive ST11-KL64 strain exhibited virulence levels similar to those of the typical hypervirulent K. pneumoniae NTUH-2044. The mutation, Tet(A) (A276S), which was believed to lead to tigecycline resistance was observed. Overall, this high-risk clone has emerged as a tremendous threat in fatal BSIs and thus, targeted surveillance is an urgent need to contain the hv-CRKP clones.

Whole genome sequencing of OXA-232-producing wzi93-KL112-O1 carbapenem-resistant Klebsiella pneumoniae in human bloodstream infection co-harboring chromosomal ISEcp1-based bla CTX-M-15 and one rmpA2-associated virulence plasmid.

Objectives: To characterize one OXA-232-producing wzi93-KL112-O1 carbapenem-resistant Klebsiella pneumoniae (CRKP) co-harboring chromosomal bla CTX-M-15 and one rmpA2-associated virulence plasmid. Methods: Minimum inhibitory concentrations (MICs) were measured via broth microdilution method. Conjugation, chemical transformation, string test and Galleria mellonella infection model experiments were also conducted. Whole-genome sequencing (WGS) was performed on the Illumina and Nanopore platforms. Antimicrobial resistance determinants were identified using ABRicate program with ResFinder database. Insertion sequences (ISs) were identified using ISfinder. Bacterial virulence factors were identified using virulence factor database (VFDB). Wzi, capsular polysaccharide (KL) and lipoolygosaccharide (OCL) were analyzed using Kleborate with Kaptive. Phylogenetic analysis of 109 ST15 K. pneumoniae strains was performed using core genome multilocus sequence typing (cgMLST) on the Ridom SeqSphere+ server. MLST, replicons type, SNP strategies and another cgMLST analysis for 45 OXA-232-producing K. pneumoniae strains were further conducted using BacWGSTdb server. Results: K. pneumoniae KPTCM strain belongs to ST15 with wzi93, KL112 and O1. It possessed a multidrug-resistant (MDR) profile and was resistant to carbapenems (meropenem and ertapenem), ciprofloxacin and amikacin. Virulence assays demonstrated KPTCM strain possesses a low virulence phenotype. WGS revealed it contained one circular chromosome and nine plasmids. The carbapenemase-encoding gene bla OXA-232 was located in a 6141-bp ColKP3-type non-conjugative plasmid and flanked by ΔISEcp1 and ΔlysR-ΔereA. Interestingly, bla CTX-M-15 was located in the chromosome mediated by ISEcp1-based transposon Tn2012. Importantly, it harbored a rmpA2-associated pLVPK-like virulence plasmid with iutA-iucABCD gene cluster and one IS26-mediated MDR fusion plasmid according to 8-bp (AGCTGCAC or GGCCTTTG) target site duplications (TSD). Based on the cgMLST and SNP analysis, data showed OXA-232-producing ST15 K. pneumoniae isolates were mainly isolated from China and have evolved in recent years. Conclusions: Early detection of CRKP strains carrying chromosomal bla CTX-M-15, OXA-232 carbapenemase and pLVPK-like virulence plasmid is recommended to avoid the extensive spread of this high-risk clone.

Inhibition of histone acetyltransferase by naringenin and hesperetin suppresses Txnip expression and protects pancreatic ß cells in diabetic mice.

BACKGROUND: The damage of pancreatic ß cells is a major pathogenesis of the development and progression of type 2 diabetes and there is still no effective therapy to protect pancreatic ß cells clinically. In our previous study, we found that Quzhou Fructus Aurantii (QFA), which is rich in flavanones, had the protective effect of pancreatic ß cells in diabetic mice. However, the underlying mechanism is still unclear. PURPOSE: In the current study, we administered naringenin and hesperetin, two major active components of QFA, to protect pancreatic ß cells and to investigate the underlying molecular mechanism focusing on the epigenetic modifications. METHODS: We used diabetic db/db mouse and INS-1 pancreatic ß cell line as in vivo and in vitro models to investigate the protective effect of naringenin and hesperetin on pancreatic ß cells under high glucose environment and the related mechanism. The phenotypic changes were evaluatedby immunostaining and the measurement of biochemical indexes. The molecular mechanism was explored by biological techniques such as western blotting, qPCR, ChIP-seq and ChIP-qPCR, flow cytometry and lentivirus infection. RESULTS: We found that naringenin and hesperetin had an inhibitory effect on histone acetylation. We showed that naringenin and hesperetin protected pancreatic ß cells in vivo and in vitro, and this effect was independent of their direct antioxidant capacity. The further study found that the inhibition of thioredoxin-interacting protein (Txnip) expression regulated by histone acetylation was critical for the protective role of naringenin and hesperetin. Mechanistically, the histone acetylation inhibition by naringenin and hesperetin was achieved through regulating AMPK-mediated p300 inactivation. CONCLUSION: These findings highlight flavanones and the phytomedicine rich in flavanones as important dietary supplements in protecting pancreatic ß cells in advanced diabetes. In addition, targeting histone acetylation by phytomedicine is a potential strategy to delay the development and progression of diabetes.

Hesperetin, a SIRT1 activator, inhibits hepatic inflammation via AMPK/CREB pathway.

Silent mating type information regulation 2 homolog 1 (SIRT1) is an important inflammatory regulator, which epigenetically reprograms inflammation by altering the acetylation of NF-κB. Hesperetin, as a common flavonoid, has been proven to have a significant effect on acute inflammatory diseases. However, the detailed molecular mechanism by which hesperetin alleviates inflammatory response and accompanied tissue injury is poorly understood. Our results show that SIRT1 is required for the inhibitory effect of hesperetin on inflammation. Hesperetin suppresses the acetylation of RelA/p65 to reduce NF-κB activity by inducing SIRT1 expression. Mechanistically, hesperetin increases SIRT1 expression through AMPK/CREB pathway. Additionally, the protective effect of hesperetin against LPS/D-GalN-induced hepatitis in mice is also dependent on SIRT1. Our study suggests that hesperetin is an SIRT1 activator and could be potential candidates for the treatments of inflammatory conditions.

Neohesperidin enhances PGC-1α-mediated mitochondrial biogenesis and alleviates hepatic steatosis in high fat diet fed mice.

BACKGROUNDS: Mitochondria plays a critical role in the development and pathogenesis of nonalcoholic fatty liver disease (NAFLD). Neohesperidin (NHP) could lower blood glucose and prevent obesity in mice. However, the direct effect of NHP on hepatic steatosis has not been reported. METHODS: Mice were fed with either a chow diet or HFD with or without oral gavage of NHP for 12 weeks. A variety of biochemical and histological indicators were examined. In vitro cell culture model was utilized to demonstrate underlying molecular mechanism of the effect induced by NHP treatment. RESULTS: NHP increases mitochondrial biogenesis, improves hepatic steatosis and systematic insulin resistance in high fat diet (HFD) fed mice. NHP elevates hepatic mitochondrial biogenesis and fatty acid oxidation by increasing PGC-1α expression. Mechanistically, the activation of AMP-activated protein kinase (AMPK) is involved in NHP induced PGC-1α expression. CONCLUSIONS: PGC-1α-mediated mitochondrial biogenesis plays a vital role in the mitigation of hepatic steatosis treated by NHP. Our result suggests that NHP is a good candidate to be dietary supplement for the auxiliary treatment of NAFLD.

Cinobufacini ameliorates experimental colitis via modulating the composition of gut microbiota.

BACKGROUND: Cinobufacini, the sterilized hot water extraction of dried toad skin, has been widely used in the treatment of inflammation and cancers. Recently we found cinobufacini could ameliorate dextran sulfate sodium (DSS)-induced colitis in mice, but the underlying mechanism was not fully understood. In current study, we explored the effect of cinobufacini on gut microbiota in DSS-induced acute colitic mouse model by pyrosequencing of colonic contents. METHODS: C57BL/6 mice were supplied with normal or 3.0% DSS containing drinking water. DSS-treat mice were gavaged daily either with vehicle (water) or cinobufacini (10.0 or 30.0 mg/kg) for 7 days. The composition of the gut microbiota was assessed by analyzing 16S rRNA gene sequences. RESULTS: Our data indicated that cinobufacini reversed DSS-induced gut dysbiosis and enhanced intestinal barrier integrity. Moreover, changing of some specific microbial groups such as Proteobacteria and Bacteroides was closely correlated with the re-establishment of intestinal equilibrium and the recovery of intestinal function. CONCLUSION: Cinobufacini prevents colitis in mice by modifying the composition and function of gut microbiota. The current study provides additional mechanistic insight in the therapeutic effect of cinobufacini treatment and may pave the way for clinical application of cinobufacini in colitis therapy.

The flavonoid-rich Quzhou Fructus Aurantii extract modulates gut microbiota and prevents obesity in high-fat diet-fed mice.

BACKGROUND: Flavonoids are reported to modulate the composition of gut microbiota, which play an important role in preventing obesity and associated metabolic diseases. In this study, we investigated the effect of Total Flavonoids of Quzhou Fructus Aurantii Extract (TFQ) on gut microbial community in mice fed with a high-fat diet (HFD). METHODS: C57BL/6J mice were fed with either a chow diet or HFD with or without oral gavage of TFQ (300 mg/kg/day) for 12 weeks. RESULTS: Our data indicate TFQ significantly reduced obesity, inflammatio,n and liver steatosis. TFQ elevates the expression of tight junction proteins and reduces metabolic endotoxemia. In addition, TFQ treatment reverses HFD-induced gut dysbiosis, as indicated by the reduction of Firmicutes to Bacteroidetes ratio, the increase of genera Akkermansia and Alistipes, and the decrease of genera Dubosiella, Faecalibaculum, and Lactobacillus. CONCLUSION: These findings support a prebiotic role of TFQ as a dietary supplement for the intervention of gut dysbiosis and obesity-related metabolic disorders.

Yes-associated protein at the intersection of liver cell fate determination.

A recent publication highlights the importance of high yes-associated protein (YAP) expressing cells in liver regeneration following partial hepatectomy. Although the names of the cell populations described in these articles [hybrid periportal hepatocytes (HybHP) or epithelial-mesenchymal transition (EMT)-reprogrammed hepatocytes] are not identical, they all express high levels of YAP. We hypothesize that the HybHP and EMT-reprogrammed hepatocytes might be a similar cell population. Hippo signaling is the primary pathway that regulates YAP activity. According to the contribution of these two types of cells to liver regeneration and the high YAP expression, Hippo-YAP signaling activation may be a common regulatory pathway experienced by cells undergoing dedifferentiation and reactivating proliferative activity during liver regeneration. Although no evidence has shown that HybHP cells contribute to hepatocellular carcinoma in mouse models, we can not rule out the possibility that these highly regenerative cells can further develop into tumor cells when they acquire mutations caused by viral infection or other risk factors like alcohol. The detailed mechanistic insight of the regulation of YAP expression and activity in HybHP (or other types of cells contributing to liver regeneration) is unknown. We hypothesize that liver regeneration under various conditions will eventually lead to divergent consequences, likely due to the duration of YAP activation regulated by Hippo-large tumor suppressor 1 and 2 pathway in a context- and cell type-dependent manner.

Cinobufacini Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice through Inhibiting M1 Macrophage Polarization.

Cinobufacini is a traditional Chinese medicine used clinically that has antitumor and anti-inflammatory effects. It improves colitis outcomes in the clinical setting, but the mechanism underlying its function yet to be uncovered. We investigated the protective effects and mechanisms of cinobufacini on colitis using a dextran sulfate sodium (DSS)-induced colitis mouse model, mainly focusing on the impact of macrophage polarization. Our results showed that cinobufacini dramatically ameliorated DSS-induced colitis in mice. Cinobufacini treatment reduced the infiltration of activated F4/80+ and/or CD68+ macrophages into the colon in DSS-induced colitis mice. More importantly, cinobufacini significantly decreased the quantity of M1 macrophages and the expression of proinflammatory cytokines such as interleukin-6, tumor necrosis factor α, and inducible nitric oxide synthase. Cinobufacini also increased the population of M2 macrophages and the expression of anti-inflammatory factors such as interleukin-10 and arginase-1 in DSS-induced colitis mice. Furthermore, our study demonstrated that cinobufacini inhibited M1 macrophage polarization in lipopolysaccharide-induced RAW 264.7 cells. Mechanistically, our in vivo and in vitro results showed that cinobufacini inhibition of M1 macrophage polarization may be associated with the suppression of nuclear factor κB activation. Our study suggests that cinobufacini could ameliorate DSS-induced colitis in mice by inhibiting M1 macrophage polarization.

NF-кB increases LPS-mediated procalcitonin production in human hepatocytes.

For years, procalcitonin (PCT) has been employed as a diagnostic biomarker for the severity of sepsis and septic shock, as well as for guiding the application of antibiotics. However, the molecular/cellular basis for the regulation of PCT production is not fully understood. In this study, we identified the signalling pathway by which the expression of PCT was induced by lipopolysaccharide in human hepatocytes at the mRNA and protein levels. This expression was dependent on nuclear transcription factor κB (NF-κB), as indicated by a NF-κB binding site (nt -53 to -44) found in the PCT promoter region. We also showed that microRNA-513b (miR-513b) was also able to bind to the 3'-untranslated region (UTR) of the PCT promoter sequence. Meanwhile, the activation of NF-κB down-regulated the expression of miR-513b. In conclusion, we suggest that NF-κB is capable of enhancing the expression of PCT by either directly activating the transcription of the PCT gene or indirectly modulating the expression of its regulatory component, miR-513b. Our results indicate a molecular mechanism responsible for the regulation of PCT production.

Lipin-1 determines lung cancer cell survival and chemotherapy sensitivity by regulation of endoplasmic reticulum homeostasis and autophagy.

Cancer cells undergo comprehensive metabolic reprogramming to meet the increased requirements of energy and building blocks for proliferation. Lipin-1, a phosphatidic acid phosphatase converting phosphatidic acid (PA) to diacylglycerol (DAG), is upregulated in lung adenocarcinoma (LUAD) cell lines and tumor tissues. In this study, we reveal high lipin-1 expression is correlated with poor prognosis of patients with LUAD. Knockdown of lipin-1 decreases cell viability and proliferation in LUAD cells, whereas it has less effect on nontumorigenic lung cells. Autophagy and ER stress play important roles in tumor initiation and progression. Lipin-1 knockdown induces the initiation of autophagy while disrupts formation of autolysosome. Lipin-1 silencing induces the activation of ER stress through the IRE1α pathway. Furthermore, we demonstrate disrupted ER homeostasis contributes to the cell phenotype, and the elevated autophagy initiation is due to the ER stress in part. For the first time, we show lack of lipin-1 enhances the sensitivity of LUAD cells to cisplatin treatment. Our results suggest that lipin-1 is a potential target, alone or combined with other treatment, for lung cancer therapy.

SLC2A5 promotes lung adenocarcinoma cell growth and metastasis by enhancing fructose utilization.

The metabolism of cancer cells is highly plastic. Cancer cells can change their preference for nutrient uptake under nutrient stress. Fructose is one of the most common carbohydrates in diet and its metabolism is also involved in the development and progression of tumors. GLUT5, encoded by SLC2A5, is the specific fructose transporter in mammalian cells. In this study, we found that SLC2A5 is significantly upregulated in lung adenocarcinoma (LUAD) patients and overexpression of SLC2A5 is highly correlated with poor prognosis of LUAD patients. The expression of SLC2A5 determined fructose uptake and utilization efficacy in LUAD cells. GLUT5 is critical for the survival of LUAD cells in fructose-containing culture medium. Depletion of SLC2A5 undermined cell proliferation and invasion meanwhile increased cell apoptosis. Overexpression of SLC2A5 enhances cell proliferation, migration, invasion, and tumorigenic. Compared to glucose, fructose is prone to strengthen intracellular-free fatty acid accumulation and ATP production. Moreover, inhibition of GLUT5 by specific small chemical inhibitor sensitizes LUAD cells to paclitaxel treatment. Taken together, our results suggest that GLUT5 could be a potential target alone or combination with other treatment for lung cancer therapy.

Astilbin ameliorates cisplatin-induced nephrotoxicity through reducing oxidative stress and inflammation.

Oxidative stress and inflammation are considered to be the main pathogenesis of cisplatin nephrotoxicity. Astilbin, a flavonoid with anti-oxidation and anti-inflammation function, has been used to treat heavy metal induced kidney injury. In this study, we investigated the protective effects of astilbin on cisplatin-induced nephrotoxicity and its underlying mechanisms. Our results showed that astilbin markedly inhibited cisplatin-induced cell apoptosis and recovered cell growth. Astilbin significantly decreased reactive oxygen species (ROS) accumulation and alleviated ROS-induced activation of p53, MAPKs and AKT signaling cascades, which in turn attenuated cisplatin-induced HEK-293 cell apoptosis. Astilbin effectively enhanced NRF2 activation and transcription of its targeting antioxidant genes to reduce ROS accumulation in cisplatin-induced HEK-293 cells. Furthermore, we found that astilbin obviously suppressed tumor necrosis factor alpha (TNF-α) expression and NF-κB activation, and also inhibited the expression of induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Finally, we confirmed that the effect of astilbin to improve renal oxidative stress and inflammation in cisplatin induced acute nephrotoxic mice. In conclusion, our study suggests that astilbin could ameliorate the cisplatin-induced nephrotoxicity by reducing oxidative stress and inflammation.

miR-125b regulates procalcitonin production in monocytes by targeting Stat3.

Sepsis is a leading cause of mortality in clinical infection, early identification and intervention is critical to improve its outcomes. Nonetheless, it is difficult to determine whether the cause of inflammation in patients is of bacterial origin at early stage. Procalcitonin (PCT) is considered as a promising marker in clinical laboratory test of bacterial infection. But the details for the regulation of PCT expression are not fully understood. miR-125b is important to immune system development and immunological host defense, while its role in the regulation of PCT production remains unexplored. In this study, we demonstrate that the expression of PCT is regulated by miR-125b in human monocytes. miR-125b modulates PCT expression by manipulating the amount and transcriptional activity of Stat3.