Preliminary nomogram model for predicting irreversible organ damage of patients with systemic sclerosis.

OBJECTIVE: To investigate predictive factors for irreversible organ damage in systemic sclerosis (SSc) and establish a nomogram model. METHODS: This retrospective study included patients with SSc who were treated at our hospital between March 2013 and March 2023. Irreversible organ damage included heart failure, respiratory failure, renal failure, and gangrene of the hands and feet. Cox and LASSO regression analyses were performed to determine the predictive factors. Based on the results, a nomogram model was developed. The model was evaluated using the C-indices, calibration plots, and DCA. RESULTS: A total of 361 patients with systemic sclerosis were randomly divided into the development (n = 181) and validation (n = 180) groups. Multivariate Cox regression analysis showed that age ≥65 years, weight loss, digital ulcers, mRSS ≥16, elevated creatinine, elevated myoglobin, elevated C-reactive protein, renal involvement, and cardiac involvement were independent risk factors. Based on the LASSO analysis, a nomogram model of irreversible organ damage was established. The C-indices of the development group at 24, 60, and 96 m were 96.7, 84.5, and 85.7, whereas those of the validation group at 24, 60, and 96 m were 86.6, 79.1, and 78.5, respectively. The results of the DCA showed that the nomogram can be used as a valuable tool to predict irreversible organ damage in patients with SSc. CONCLUSION: We included commonly used clinical indicators. According to the nomogram, the probability of irreversible organ damage can be calculated and high-risk patients can be identified.

Impact of Sjögren's syndrome on maternal and fetal outcomes following pregnancy: a systematic review and meta-analysis of studies published between years 2007-2022.

OBJECTIVE: To show the impact of Sjögren's syndrome (SS) on maternal and fetal outcomes following pregnancy. METHODS: We performed a literature search based on PubMed, Web of science, Wan fang, China National Knowledge Infrastructure and ProQuest databases from 1 January 2007 to 6 November 2022. Grading of Recommendations, Assessment, Development, and Evaluations approach was used to assess the certainty of the evidence. Systematic reviews and meta-analyses were performed using RevMan 5.3 software. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird. Trial sequential analyses were performed by TSA 0.9. RESULTS: Nine studies with 2341 patients and 2472 pregnancies with SS were included in our analysis. This current analysis showed pregnancy hypertension and preeclampsia/eclampsia to be significantly higher in pregnant women with SS compared to pregnant women without SS (OR: 1.65, 95% CI: 1.04-2.63; P = 0.03), (OR: 2.06, 95% CI: 1.16-3.65; P = 0.01) respectively. Cesarean section, thromboembolic disease, premature rupture of membranes, and spontaneous abortion were also significantly higher in the SS women with OR: 2.07, 95% CI: 1.48-2.88; P < 0.0001, OR: 9.45, 95% CI: 1.99-44.87; P = 0.005, OR: 1.36, 95% CI: 1.13-1.64; P = 0.001, OR: 9.30, 95% CI: 4.13-20.93; P < 0.00001, respectively. Significantly higher premature births were observed with infants who were born from SS mothers (OR: 2.19, 95% CI: 1.54-3.12; P < 0.0001). Infants defined as 'small for gestational age/intrauterine growth restriction' and 'weighing < 2500 g' were also significantly higher in patients suffering from SS (OR: 2.26, 95% CI: 1.38-3.70; P = 0.001), (OR: 3.84, 95% CI: 1.39-10.61; P = 0.009) respectively. In addition, live birth significantly favored infants who were born from mothers without SS (OR: 21.53, 95% CI: 8.36-55.44; P < 0.00001). Subgroup analysis by sample size revealed that pregnancy hypertension risk has significantly increased in small cohort (OR: 2.74, 95%CI: 1.45-5.18), and a slight increase was found in population-based studies (OR: 1.14, 95%CI: 0.91-1.43). In both small cohorts and population-based researches, cesarean section was significantly higher in SS (OR: 2.13, 95% CI: 1.29, 3.52; OR: 1.85, 95% CI: 1.29-2.64, respectively). The number of infants with intrauterine growth restriction did not grow in the population-based researches (OR: 2.07, 95%CI: 0.92-4.66) although there has been an increase in small reports (OR: 2.53, 95%CI: 1.16-5.51). Subgroup analysis was conducted on the basis of study location (not Asian vs. Asian countries) indicated that cesarean section was significantly higher in SS in both countries (OR: 1.69, 95% CI: 1.31-2.18; OR: 3.37, 95% CI: 2.39-4.77, respectively). CONCLUSION: This meta-analysis has shown SS to have a high impact on maternal and fetal outcomes following pregnancy.

Propionate reduces the viability of Salmonella enterica Serovar Typhi in macrophages by propionylation of PhoP K102.

Propionate, a major constituent of short chain fatty acids, has recently been reported to be involved in both prokaryotic and eukaryotic lysine propionylation (Kpr). However, the propionylation characteristics of the enteric pathogen Salmonella enterica serovar Typhi (S. Typhi) following invasion of the human gut under the influence of propionate, whether virulence is affected, and the underlying mechanisms are not yet known. In the present study, we report that propionate significantly reduces the viability of S. Typhi in macrophages through intra-macrophage survival assays. We also demonstrate that the concentration of propionate and the propionate metabolic intermediate propionyl coenzyme A can affect the level of modification of PhoP by propionylation, which is tightly linked to intracellular survival. By expressing and purifying PhoP protein in vitro and performing EMSA and protein phosphorylation analyses, We provide evidence that K102 of PhoP is modified by Kpr propionate, which regulates S. Typhi viability in macrophages by decreasing the phosphorylation and DNA-binding ability of PhoP. In conclusion, our study reveals a potential molecular mechanism by which propionate reduces the viability of S. Typhi in macrophages via Kpr.

Faecal microbial biomarkers in early diagnosis of colorectal cancer.

Colorectal cancer (CRC) is ranked as the second most common cause of cancer deaths and the third most common cancer globally. It has been described as a 'silent disease' which is often easily treatable if detected early-before progression to carcinoma. Colonoscopy, which is the gold standard for diagnosis is not only expensive but is also an invasive diagnostic procedure, thus, effective and non-invasive diagnostic methods are urgently needed. Unfortunately, the current methods are not sensitive and specific enough in detecting adenomas and early colorectal neoplasia, hampering treatment and consequently, survival rates. Studies have shown that imbalances in such a relationship which renders the gut microbiota in a dysbiotic state are implicated in the development of adenomas ultimately resulting in CRC. The differences found in the makeup and diversity of the gut microbiota of healthy individuals relative to CRC patients have in recent times gained attention as potential biomarkers in early non-invasive diagnosis of CRC, with promising sensitivity, specificity and even cost-effectiveness. This review summarizes recent studies in the application of these microbiota biomarkers in early CRC diagnosis, limitations encountered in the area of the faecal microbiota studies as biomarkers for CRC, and future research exploits that address these limitations.

Interactions between Salmonella and host macrophages - Dissecting NF-κB signaling pathway responses.

Salmonella not only invades host cells, but also replicates intracellularly to cause a range of diseases, including gastroenteritis and systemic infections such as typhoid fever. The body's first line of defense against pathogens is the innate immune response system that can protect against Salmonella invasion and replication. Nuclear factor κB (NF-κB) is an important transcriptional regulator that plays an important role in host inflammatory responses to pathogens. Both the canonical and non-canonical NF-κB signaling pathways are activated by Salmonella in many different ways through its virulence factors, leading to the release of inflammatory factors and the activation of inflammatory responses in mammalian hosts. Equally, Salmonella, as an enteropathogen, has accordingly evolved strategies to disturb NF-κB activation, such as secreting some effector proteins by type III secretion systems as well as inducing host cells to express NF-κB pathway inhibitors, allowing it to colonize and persistently infect the hosts. This review focuses on how Salmonella activates NF-κB signaling pathway and the strategies used by Salmonella to interfere with the NF-κB pathway activation.

Disruption of Fis reduces bacterial persister formation by regulating glutamate metabolism in Salmonella.

The presence of persisters causes recalcitrance to antibiotic treatment, and can be attributed to a fairly large number of clinically refractory infections in several species of bacteria. Many studies have explored this phenomenon, but the mechanisms remain poorly understood. In this study, we found that the deletion of fis, which encodes a key DNA-binding protein mediating various biological processes, significantly reduced persister formation in S. Typhi. Persister assays and glutamate determination analysis showed that Fis mediated Salmonella persistence through regulating glutamate metabolism. Additionally, glutamate incubation altered the expression of the stringent response regulatory genes, demonstrating that the stringent response was related to glutamate regulation by Fis. The findings revealed that glutamate metabolism regulated by Fis serves as a mechanism for persister formation in S. Typhi.

A novel cis antisense RNA AsfD promotes Salmonella enterica serovar Typhi motility and biofilm formation.

Bacterial non-coding RNAs (ncRNAs) can participate in multiple biological processes, including motility, biofilm formation, and virulence. Using high-throughput sequencing and transcriptome analysis of Salmonella enterica serovar Typhi (S. Typhi), we identified a novel antisense RNA located at the opposite strand of the flhDC operon. In this study, a northern blot and qRT-PCR were used to confirm the expression of this newfound antisense RNA in S. Typhi. Moreover, 5' RACE and 3' RT-PCR were performed to reveal the molecular characteristics of the antisense RNA, which was 2079 nt - 2179 nt in length, covered the entire flhDC operon sequence, and termed AsfD. The level of AsfD expression was higher during the stationary phase of S. Typhi and activated by the regulators, OmpR and Fis. When AsfD was overexpressed, the level of flagellar gene flhDC transcription increased; moreover, the level of fliA and fljB expression, as well as the motility and biofilm formation of S. Typhi were also enhanced. The results of this study suggest that AsfD is likely to enhance the motility and biofilm formation of S. Typhi by up-regulating flhDC expression.

QsvR integrates into quorum sensing circuit to control Vibrio parahaemolyticus virulence.

Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis worldwide, requires the two type-III secretion systems (T3SS1 and T3SS2) and a thermostable direct hemolysin (encoded by tdh1 and tdh2) for full virulence. The tdh genes and the T3SS2 gene cluster constitute an 80 kb pathogenicity island known as Vp-PAI located on the chromosome II. Expression of T3SS1 and Vp-PAI is regulated in a quorum sensing (QS)-dependent manner but its detailed mechanisms remain unknown. Herein, we show that three factors (QS regulators AphA and OpaR and an AraC-type transcriptional regulator QsvR) form a complex regulatory network to control the expression of T3SS1 and Vp-PAI genes. At low cell density (LCD), whereas Vp-PAI expression is repressed, T3SS1 genes are induced by AphA, which directly binds (an operator region of) the exsBAD-vscBCD operon. At high cell density (HCD), the bacterium turns off T3SS1 expression by replacing AphA with OpaR, triggering the induction of Vp-PAI. Furthermore, QsvR binds to the regulatory regions of all the tested T3SS1 and Vp-PAI genes to activate their transcription at HCD. Taken together, our data highlight how multiple QS regulators contribute to the pathogenicity of V. parahaemolyticus by precisely controlling the expression of major virulence determinants during different stages of growth.

Mig-14 may contribute to Salmonella enterica serovar Typhi resistance to polymyxin B by decreasing the permeability of the outer-membrane and promoting the formation of biofilm.

Mig-14 is essential for Salmonella enterica serovar Typhimurium (S. Typhimurium) resistance to antimicrobial peptides, including polymyxin B (PB). However, the molecular mechanism is as yet unknown. In this study, we demonstrated that mig-14 also played a crucial role in Salmonella enterica serovar Typhi (S. Typhi) resistance to PB. A series of genes associated with drug-resistance controlled by Mig-14 were identified in the presence of PB. Among which, ompF and ompC were up-regulated 8 and 6 folds in mig-14 mutant (Δmig-14) strains, respectively. Further, the deletion of ompF or/and ompC in Δmig-14 strains decreased their sensitivity to PB. Besides, the biofilm formation ability was reduced in Δmig-14 strains. Our results indicate that Mig-14 may contribute to PB resistance in S. Typhi by decreasing the permeability of the outer membrane and promoting biofilm formation.

The Periplasmic Chaperone SurA Affects Motility and Biofilm Formation via the RcsCDB Pathway in Salmonella enterica Serovar Typhi.

SurA, a periplasmic chaperone, is a key factor in the biogenesis of ß-barrel outer membrane proteins (OMPs). It is also associated with virulence, invasion and biofilm formation in Escherichia and Salmonella species. To investigate whether SurA affects bacterial motility and biofilm formation in Salmonella enterica serovar Typhi, we prepared a surA deleted mutant. Motility assay and quantitative real-time PCR (qRT-PCR) indicated that surA deletion reduced swimming motility and decreased flagellar gene expression, respectively. ß-galactosidase assay and qRT-PCR further showed that surA deletion also activated the RcsCDB pathway, which we verified affected motility. We also examined the effects of the surA deletion on biofilm formation and established that the surA mutant exhibited significantly reduced ability to form biofilms compared with the wild-type. From our findings, we proposed that the periplasmic chaperone, SurA, affects flagella expression via the RcsCDB pathway thereby influencing biofilm formation in Salmonella enterica serovar Typhi. Collectively, these studies confirmed a new physiological role for SurA in Salmonella enterica serovar Typhi.

Pathogenicity-island-encoded regulatory RNAs regulate bacterial virulence and pathogenesis.

Bacterial regulatory RNAs (regRNAs) have been widely studied for decades and shown to be involved in various aspects of bacterial survival, including their virulence and pathogenesis. Recently, many regRNAs have been found to be encoded within bacterial pathogenicity islands (PAIs). These PAI-encoded regRNAs also play important regulatory roles in bacterial virulence and pathogenesis. In this review, we introduce the reported PAI-encoded regRNAs individually, focusing on their types, target genes, regulatory roles, regulatory mechanisms and significance. We also summarize the virulence and pathogenesis of the pathogens concerned.

OxyR positively and directly regulates Vi polysaccharide capsular antigen in Salmonella enterica serovar Typhi.

Salmonella enterica serovar Typhi (S. Typhi) is a human enteropathogen that can overcome oxidative stress and survive in macrophages. OxyR is an important part of the antioxidant defense system. S. Typhi expresses a virulence (Vi) polysaccharide capsular antigen, which provides the bacterium with the ability to avoid host defenses and suppress detection by the innate immune system. This study investigated the effect of OxyR on Vi antigen in S. Typhi. In the oxyR mutant strain, microarray analysis, quantitative real time PCR and ß-galactosidase assay confirmed that the viaB operon was positively regulated by OxyR. The Vi enzyme-linked immunosorbent assay and flow cytometry results showed that Vi capsule level was decreased in the oxyR mutant strain. Also, the EMSA revealed that OxyR directly binds to the promoter region of tviA. Thus, we propose that S. Typhi OxyR positively regulates expression of Vi capsule antigen in a direct manner.

The malS-5'UTR weakens the ability of Salmonella enterica serovar Typhi to survive in macrophages by increasing intracellular ATP levels.

Bacterial non-coding RNAs (ncRNAs), as important regulatory factors, are involved in many cellular processes, including virulence and protection against environmental stress. The 5' untranslated region (UTR) of malS (named malS-5'UTR), a regulatory ncRNA, increases the invasive capacity and influences histidine biosynthesis in Salmonella enterica serovar Typhi (S. Typhi). In this study, we found that overexpression of the malS-5'UTR decreased S. Typhi survival within macrophages. A microarray analysis of a strain overexpressing the malS-5'UTR revealed a significant increase in the mRNA levels of the atp operon. The intracellular ATP levels were elevated in the malS-5'UTR overexpression strain. Quantitative real-time polymerase chain reaction results showed that the malS-5'UTR downregulated the mRNA levels of phoP, phoQ, and mgtC. MgtC, its expression is regulated by PhoP/PhoQ two-component regulatory system, inhibits the F1F0 ATP synthase, thereby preventing the accumulation of ATP to non-physiological levels and the acidification of the cytoplasm within macrophages. Thus, we propose that the malS-5'UTR weakens the ability of S. Typhi to survive in macrophages, probably because of the accumulation of ATP within macrophages, by regulating the mRNA levels of mgtC and the atp operon in a phoP-dependent manner.

Reciprocal Regulation of OmpR and Hfq and Their Regulatory Actions on the Vi Polysaccharide Capsular Antigen in Salmonella enterica Serovar Typhi.

Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of human typhoid fever. S. Typhi expresses a major virulence determinant called Vi polysaccharide capsular antigen, which is encoded by the viaB locus containing 10 consecutive genes including tviA and tviB. Expression of Vi antigen is regulated by the two-component regulatory system EnvZ/OmpR and the global RNA-binding factor Hfq. In this study, we show that OmpR coordinates with Hfq to regulate the transcription of Vi antigen genes under osmotic stress conditions. OmpR binds to the promoters of tviA and its own genes to activate their transcription; however, it positively regulates tviB and negatively regulates hfq in an indirect manner. Moreover, Hfq reversely inhibits ompR, tviA and tviB, and positively regulates its own gene expression. Thus, we report of a complex gene regulatory network involving the reciprocal regulation and autoregulation of OmpR and Hfq, and their regulatory actions on Vi polysaccharide capsular antigen genes in S. Typhi.

The extracellular proteases produced by Vibrio parahaemolyticus.

Vibrio parahaemolyticus, a Gram-negative bacterium, inhabits marine and estuarine environments and it is a major pathogen responsible globally for most cases of seafood-associated gastroenteritis in humans and acute hepatopancreatic necrosis syndrome in shrimps. There has been a dramatic worldwide increase in V. parahaemolyticus infections over the last two decades. The pathogenicity of V. parahaemolyticus has been linked to the expression of different kinds of virulence factors including extracellular proteases, such as metalloproteases and serine proteases. V. parahaemolyticus expresses the metalloproteases; PrtV, VppC, VPM and the serine proteases; VPP1/Protease A, VpSP37, PrtA. Extracellular proteases have been identified as potential virulence factors which directly digest many kinds of host proteins or indirectly are involved in the processing of other toxic protein factors. This review summarizes findings on the metalloproteases and serine proteases produced by V. parahaemolyticus and their roles in infections. Identifying the role of V. parahaemolyticus virulence-associated extracellular proteases deepens our understanding of diseases caused by this bacterium.

QseB mediates biofilm formation and invasion in Salmonella enterica serovar Typhi.

QseB is a response regulator of the QseBC two-component system (TCS) which is associated with quorum sensing and functions as a global regulator of flagella, biofilm formation, and virulence. The function of QseB and its interaction with QseC has been the subject of study in some organisms, however, little work was done in Salmonella enterica serovar Typhi (S. Typhi). The objective of this study was to investigate the effect of QseB on biofilm formation and virulence in S. Typhi. It showed that the biofilm formation ability of qseC mutant was limited as compared to the wild type strain. We also show overexpression of qseB was in a qseC mutant. Interestingly, deletion of qseB in a qseC mutant restored a wild type phenotype. These results suggested that QseB may account for the impaired biofilm formation in the absence of QseC. Furthermore, deletion of qseB in wild type cells decreased biofilm formation, whereas overexpression of qseB in wild type cells increased biofilm formation. Quantitative real-time PCR also revealed the up-regulation of some fimbria-associated genes in a qseB overexpression strain. These results indicate that QseB may enhance biofilm formation in the presence of QseC. Taken together, we hypothesize that QseB has dual regulatory functions which are dependent upon its cognate sensor. Additionally, invasion of HeLa cells was enhanced in qseB mutant but attenuated in a qseC mutant compared with wild-type. The ß-galactosidase activity of invF::lacZ was increased in qseB mutant but decreased in qseC mutant which was consistent with invasion results. In conclusion, QseB may have dual regulatory functions concerning biofilm formation and plays a negative role in virulence of S. Typhi.

CalR is required for the expression of T6SS2 and the adhesion of Vibrio parahaemolyticus to HeLa cells.

Vibrio parahaemolyticus expresses one major virulence determinant T6SS2, which is constituted into three putative operons, i.e., VPA1027-1024, VPA1043-1028, and VPA1044-1046. CalR, a LysR-type transcriptional regulator, was originally identified as a repressor of the swarming motility and T3SS1 gene expression. As shown in this study, CalR binds to the promoter-proximal region of each of the three operons to activate their transcription, and moreover, CalR activates the adhesion of V. parahaemolyticus to HeLa cells. In addition, competitive EMSAs demonstrated that CalR acts as an antagonist of H-NS in V. parahaemolyticus. Collectively, these studies confirmed a new physiological role for CalR in V. parahaemolyticus.

The malS-5'UTR regulates hisG, a key gene in the histidine biosynthetic pathway in Salmonella enterica serovar Typhi.

Bacterial noncoding RNAs (ncRNA) regulate diverse cellular processes, including virulence and environmental fitness. The malS 5' untranslated region (named malS-5'UTR) was identified as a regulatory ncRNA that increases the invasive capacity of Salmonella enterica serovar Typhi. An IntaRNA search suggested base pairing between malS-5'UTR and hisG mRNA, a key gene in the histidine biosynthetic pathway. Overexpression of malS-5'UTR markedly reduced bacterial growth in minimal medium without histidine. Overexpression of malS-5'UTR increased mRNA from his operon genes, independently of the bax gene, and decreased HisG protein in Salmonella Typhi. RNA structure analysis showed base pairing of the malS-5'UTR RNA with the hisG mRNA across the ribosome binding site. Thus, we propose that malS-5'UTR inhibited hisG translation, probably by base pairing to the Shine-Dalgarno sequence.

Transcription of exsD is repressed directly by H-NS in Vibrio parahaemolyticus.

Vibrio parahaemolyticus is a leading cause of seafood-associated diarrhea and gastroenteritis. This bacteria expresses a major virulence determinant called T3SS1. Expression of T3SS1 is tightly regulated by the ExsA-ExsC-ExsD regulatory system. The transcription of exsA and probably exsC is repressed directly by the H-NS protein. In this study, the regulation of exsD by H-NS was investigated using quantitative RT-PCR, primer extension, LacZ fusion, electrophoretic mobility shift, and DNase I footprinting assays. The results showed that His-H-NS protected a single region from 61 bp to 174 bp upstream of exsD against DNase I digestion, and a transcription start site located at 105 bp upstream of exsD was detected and its activity was repressed by H-NS. Therefore, a single H-NS-dependent promoter was transcribed for exsD in V. parahaemolyticus. Thus, all three genes in the ExsA-ExsC-ExsD regulatory system of T3SS1 are directly repressed by H-NS in V. parahaemolyticus.

The Master Quorum-Sensing Regulator OpaR is Activated Indirectly by H-NS in Vibrio parahaemolyticus.

AphA and OpaR are the master regulators of quorum sensing in Vibrio parahaemolyticus and there is reciprocal negative regulation between AphA and OpaR. The histone-like nucleoid structure (H-NS) protein is a global transcriptional repressor of horizontally transferred genes, but a few prokaryotic genes, for example flagella genes, are stimulated by H-NS. The regulation of opaR by H-NS was investigated using the following methods: primer extension, LacZ fusion, quantitative RT-PCR, and electrophoretic mobility shift assay. One transcription start site located at 74 bp upstream of opaR was detected and its activity was induced by H-NS. Therefore, a single H-NS-dependent promoter was transcribed for opaR in V. parahaemolyticus. Because the H-NS protein could not bind to the upstream region of opaR and H-NS does not regulate aphA, indirect activation of the transcription of opaR by H-NS cannot be mediated by the AphA repressor.