STAT3 deficiency prevents hepatocarcinogenesis and promotes biliary proliferation in thioacetamide-induced liver injury

AIM To elucidate the role of STAT3 in hepatocarcinogenesis and biliary ductular proliferation following chronic liver injury. METHODS We investigated thioacetamide(TAA)-induced liver injury, compensatory hepatocyte proliferation, and hepatocellular carcinoma(HCC) development in hepatic STAT3-deficient mice. In addition, we evaluated TAAinduced biliary ductular proliferation and analyzed the activation of sex determining region Y-box9(SOX9) and Yes-associated protein(YAP), which regulate the transdifferentiation of hepatocytes to cholangiocytes.RESULTS Both compensatory hepatocyte proliferation and HCC formation were significantly decreased in hepatic STAT3-deficient mice as compared with control mice. STAT3 deficiency resulted in augmentation of hepatic necrosis and fibrosis. On the other hand, biliary ductular proliferation increased in hepatic STAT3-deficient livers as compared with control livers. SOX9 and YAP were upregulated in hepatic STAT3-deficient hepatocytes.CONCLUSION STAT3 may regulate hepatocyte proliferation as well as transdifferentiation into cholangiocytes and serve as a therapeutic target for HCC inhibition and biliary regeneration.

Predictive factors for interferon and ribavirin combination therapy in patients with chronic hepatitis C

AIM： To confirm the predictive factors for interferon （IFN）-α and ribavirin combination therapy for chronic hepatitis patients with hepatitis C virus （HCV） genotype lb. METHODS： HCV RNA from 50 patients infected with HCV genotype lb was studied by cloning and sequencing of interferon sensitivity determining region （ISDR）, PKR- eIF2α phosphorylation homology domain （PePHD）. Patients were treated with IFN-α and ribavirin for 6 mo and grouped by effectiveness of the therapy. A variety of factors were analyzed. RESULTS： Our data showed that age, HCV RNA titer, and ISDR type could be used as the predictive factors for combined IFN-α and ribavirin efficacy. Characteristically, mutations in PePHD appeared only when the combination therapy was effective. Other factors, such as sex and alanine aminotransferase （ALT） level, were not related to its efficacy. Adjusting for age and HCV RNA titer indicated that the ISDR type was the most potent predictive factor. CONCLUSION： HCV RNA ISDR type is an important factor for predicting efficacy of IFN-α and ribavirin combination therapy in Korean patients.

Molecular characterization of antimicrobial multi-drug resistance in non-typhoidal Salmonellae from chicken and clam in Mangalore, India

Salmonella enterica has been documented as one of the leading causes of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated food products. Thus, this research was aimed at studying the antimicrobial susceptibility pattern and detection of quinolone resistance in Salmonella spp isolated from food of animal origin. Thirty-six Salmonella isolates comprising 8 from poultry and 28 from seafood（clams） were identified, serotyped and characterized for their antimicrobial susceptibility against 10 different antibiotics. Plasmid DNA was isolated from all the isolates by alkaline lysis, quinolone resistant non-typhoidal S. Weltevreden were examined for mutation in the DNA gyrase coding gene. Among the 36 Salmonella isolates, 20 were S. weltevreden（8 from poultry and 12 from seafood） and 16 were S. Typhimurium（from seafood）. All the isolates showed multiple resistance to nalidixic acid, tetracycline, co-trimoxazole and nitrofurantoin, but, interestingly, the isolates were 100% susceptible to ampicillin, chloramphenicol and gentamicin. Resistant isolates from the study carried the genes responsible for resistance to respective antibiotics. The strain S130 isolated in the study showed single point mutation,Asp87Gly, at position 87 in quinolone resistance determining region. It revealed mutation in quinolone resistance determining region as a cause for quinolone resistance in non-typhoidal Salmonellae. The occurrence of genes accountable for plasmid mediated resistance to quinolones（viz., qnrA, qnrB and qnrS） in plasmid of non-typhoidal Salmonellae isolates provides evidence for plasmid mediated quinolone resistance.

Antibody-Like Phosphorylation Sites in Focus of Statistically Based Bilingual Approach

In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequently, we look here for the sequences 1) composing human and mouse proteins different from antigen receptors, 2) identical with or highly similar to nucleotide sequence representatives of conserved variable immunoglobulin segments and 3) identical with or closely related to phosphorylation sites. More precisely, we searched for the corresponding actual pairs of DNA and protein sequence segments using five-step bilingual approach employing among others a) different types of BLAST searches, b) two in-principle-different machine-learning methods predicting phosphorylated sites and c) two large databases recording existing phosphorylation sites. The approach identified seven existing phosphorylation sites and thirty-seven related human and mouse segments achieving limits for several predictions or phylogenic parameters. Mostly serines phosporylated with ataxia-telangiectasia-related kinase (involved in regulation of DNA-double-strand-break repair) were indicated or predicted in this study. Hypermutation motifs, located in effective positions of the selected sequence segments, occurred significantly less frequently in transcribed than non-transcribed DNA strands suggesting thus the incidence of mutation events. In addition, marked differences between the numbers and proportions of human and mouse cancer-related sequence items were found in different steps of selection process. The possible role of hypermutation changes within the selected segments and the observed structural relationships are discussed here with respect to DNA damage, carcinogenesis, cancer vaccination, ageing and evolution. Taken together, our data represent additional and sometimes perhaps complementary information to the existing databases of empirically proven phosphorylation sites or pathogenically important spots.

Prognostic significance of sex determining region Y-box 2,Ecadherin,and vimentin in esophageal squamous cell carcinoma

BACKGROUND Sex determining region Y-box 2(SOX2) can promote squamous cell carcinoma(SSC) because it regulates the migration and invasion of several different types of squamous carcinoma cells.However,few studies have examined the prognostic value of SOX2 and its effect on the epithelial-mesenchymal transition(EMT) in esophageal SSC(ESCC),a cancer characterized by high invasion and rapid metastasis.AIM To verify the relationship of SOX2 and the EMT in ESCC and determine the prognostic value and significance of SOX2 and protein markers of the EMT in ESCC.METHODS One hundred and eighty-five postsurgical ESCC patients were retrospectively examined.Immunohistochemistry was used to detect SOX2,E-cadherin,and vimentin in ESCC tissues.The chi-square test was used to determine the relationships of the expression of these proteins with clinical data.Kaplan-Meier survival curves were used to evaluate factors associated with overall survival(OS).RESULTS SOX2 and vimentin had high expression in ESCC tissues and correlated with the depth of local carcinoma invasion.SOX2 expression had positive correlations with tumor size,vimentin expression,and the EMT,and a negative correlation with Ecadherin expression.Expression of SOX2 and vimentin had negative correlations with OS.SOX2 expression was an independent prognostic risk factor for poor OS in patients with ESCC.CONCLUSION SOX2 expression was an independent risk factor for OS in patients with ESCC and its expression had a positive correlation with the expression of vimentin,a classic marker of the EMT.SOX2 promoted the migration and invasion of ESCC,and this may related to its effect on vimentin in promoting the EMT.

Antibody-Like Phosphorylation Sites. Theme for Studies of Cancer, Aging and Evolution

Sequence similarities were found between protein and DNA sequences encoding certain part of conserved variable immunoglobulin domains (i.e. conserved IgV) and phosphorylation sites. Hypermutation motifs were then indicated in the majority of the corresponding non-IgV nucleotide sequences. According to database confirmations or double prediction of phosphorylation sites, 80% of the selected human and mouse IgV-related phosphorylation sites or their highly probable candidates exhibited substrate relationship to ataxia-telangiectasia-mutated kinase known as ATM. In accordance with literature data, inactivation of ATM by mutations can participate in the mechanisms of carcinogenesis, neurodegeneration and possibly also in aging. In agreement with this relationship, some of the selected IgV-/ATM-related segments formed molecules specifically involved in carcinogenesis. The selected IgV-related sequence segments were also similar to certain segments of higher plants containing immunoglobulin-like repeats and related regions. Bioinformatic analysis of some selected plant sequences then indicated the presence of catalytic domains composing serine/threonine/tyrosine receptor/receptor-like kinases, which are considered important structures for evolution of very early and part of later Ig-domain-related immunity. The analyzed conserved domain similarities also suggested certain interesting structural and phylogenic relationships, which need to be further investigated. This review in fact briefly summarizes the findings on the subject from the last twenty years.

T-cell and B-cell repertoire diversity are selectively skewed in children with idiopathic nephrotic syndrome revealed by high-throughput sequencing

Background Clinical studies suggest that the dysfunction of T cells and B cells may play an essential role in the pathogenesis of idiopathic nephrotic syndrome(INS),but laboratory evidence is lacking.Therefore,this study explored T-cell receptor(TCR)and B-cell receptor(BCR)profiling in children with idiopathic nephrotic syndrome.Methods High-throughput sequencing technology was used to profile the TCR and BCR repertoires in children with INS.Peripheral blood was collected from ten INS patients,including five vinculin autoantibody-positive patients and five vin-culin autoantibody-negative patients,before and after treatment.TCR and BCR libraries were constructed by 5'-RACE and sequenced by a DNBSEQ-T7 sequencer,and sequence analyses were performed using ReSeqTools,FastP,MiXCR,and VDJtools.Results The TRA(T-cell receptorα),TRG(T-cell receptor y),and IGH(immunoglobulin heavy chain)repertoires of the INS group were occupied by highly abundant clonotypes,whereas small clonotypes occupied the healthy group,especially TRA.A significant increase in the Shannon-Weaver index was observed for the TRA and TRG repertoires after treatment in vinculin autoantibody-negative patients,but a significant increase in the IGH repertoire after treatment was observed in vinculin autoantibody-positive patients.The frequency of some V-J pairs was significantly enriched in steroid-sensitive nephrotic syndrome patients.The usage frequency of the V and J genes was skewed in patients,which seemed not related to immunosuppressive therapy.However,after effective treatment,dynamic changes in the size of the individual clonotype were observed.Conclusion T-cell and B-cell immunity contribute to the pathogenesis of different INSs.

Immunogenetic factors driving formation of ultralong VH CDR3 in Bos taurus antibodies

The antibody repertoire of Bos taurus is characterized by a subset of variable heavy(VH)chain regions with ultralong third complementarity determining regions(CDR3)which,compared to other species,can provide a potent response to challenging antigens like HIV env.These unusual CDR3 can range to over seventy highly diverse amino acids in length and form uniqueβ-ribbon‘stalk’and disulfide bonded‘knob’structures,far from the typical antigen binding site.The genetic components and processes for forming these unusual cattle antibody VH CDR3 are not well understood.Here we analyze sequences of Bos taurus antibody VH domains and find that the subset with ultralong CDR3 exclusively uses a single variable gene,IGHV1-7(VHBUL)rearranged to the longest diversity gene,IGHD8-2.An eight nucleotide duplication at the 3′end of IGHV1-7 encodes a longer V-region producing an extended Fβ-strand that contributes to the stalk in a rearranged CDR3.A low amino acid variability was observed in CDR1 and CDR2,suggesting that antigen binding for this subset most likely only depends on the CDR3.Importantly a novel,potentially AID mediated,deletional diversification mechanism of the B.taurus VH ultralong CDR3 knob was discovered,in which interior codons of the IGHD8-2 region are removed while maintaining integral structural components of the knob and descending strand of the stalk in place.These deletions serve to further diversify cysteine positions,and thus disulfide bonded loops.Hence,both germline and somatic genetic factors and processes appear to be involved in diversification of this structurally unusual cattle VH ultralong CDR3 repertoire.

Development of the expressed immunoglobulinμchain repertoire during maturation of mice B cells

In the bone marrow and spleen,the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire.To gain insight into the shift of the immunoglobulin heavy(IgH)chain repertoire during B cell development,we undertook large scale Igμchain repertoire analysis of pre-B,immature B and spleen B cell populations.We found that the majority of VH gene segments,VH families,JH and D gene segments,were observed to have significantly different usage frequencies when three B cell populations were compared,but the usage profile of the VH,D,and JH genes between different B cell populations showed high correlations.In both productive and nonproductive rearrangements,the length of CDRH3 shortened significantly on average when B cells entered the periphery.However,the CDRH3 length distribution of nonproductive rearrangements did not follow a Gaussian distribution,but decreased successively in the order 3n–2,3n–1 and 3n,suggesting a direct correlation between mRNA stability and CDRH3 length patterns of nonproductive rearrangements.Further analysis of the individual components comprising CDRH3 of productive rearrangements indicated that the decrease in CDRH3 length was largely due to the reduction of N addition at the 5′and 3′junctions.Moreover,with development,the amino acid content of CDRH3 progressed toward fewer positively charged and nonpolar residues but more polar residues.All these data indicated that the expressed Igμchain repertoire,especially the repertoire of CDRH3,was fine-tuned when B cells passed through several checkpoints of selection during the process of maturation.