Impact of anesthesia on postoperative breast cancer prognosis: A narrative review.

The incidence of breast cancer has exhibited an annually increasing trend, and the disease has become the most common malignant tumour worldwide. Currently, the primary treatment for breast cancer is surgical resection. However, metastatic recurrence is the main cause of cancer-related death in this patient population. Various factors are associated with breast cancer prognosis, and anaesthesia-induced changes in the tumour microenvironment have attracted increasing attention. To date, however, it remains unclear whether anaesthetic drugs have a positive or negative impact on cancer outcomes after surgery. The present article reviews the effects of different anaesthetics on the postoperative prognosis of breast cancer surgery to guide the choice of anaesthetic technique(s) and agents for such patients.

N6-Methyladenosine methylase METTL3 contributes to neuropathic pain by epigenetic silencing of mu opioid receptor.

We aimed at exploring the role and mechanism of METTL3-mediated m6A modification in neuropathic pain. Male Sprague-Dawley rats were randomly divided into four groups: Sham operation group (Sham group), chronic constriction injury (CCI) of the sciatic nerve model group (NPP group), intrathecal injection of virus down-regulated METTL3 + CCI model group (M3 + NPP group) and intrathecal injection of negative control virus + CCI model group (Scr + NPP group). The M3 + NPP group and the Scr + NPP group were intrathecally injected with virus nineteen days before operation. The paw withdrawal mechanical thresholds and paw withdrawal latency were respectively recorded one day before operation, three days, five days and seven days after operation. The rats were sacrificed on the seventh day after operation, and their spinal cord tissues were taken. The frozen sections of rats were performed to observe the expression of green fluorescent protein of the virus. The methylation level of RNA, the protein expression of m6A-related enzyme (METTL3) and mu opioid receptor (MOR) in spinal cord tissues of the four groups were measured. Downregulation of METTL3 had no effect on the overall methylation level of the spinal cord, but it could regulate the methylation level of the OPRM1 gene RNA encoding MOR, partially restore the expression of MOR, and relieve pain in rats. In the process of NPP, METTL3 may inhibit the expression of MOR by regulating the methylation level of OPRM1 gene RNA encoding MOR, and ultimately promote the occurrence and development of NPP.

The glycoside hydrolase gene family profile and microbial function of Debaryomyces hansenii Y4 during South-road dark tea fermentation.

Microbes are crucial to the quality formation of Sichuan South-road Dark Tea (SSDT) during pile-fermentation, but their mechanism of action has not yet been elucidated. Here, the glycoside hydrolase (GH) gene family and microbial function of Debaryomyces hansenii Y4 during solid-state fermentation were analyzed, and the results showed that many GH genes being distributed in comparatively abundant GH17, GH18, GH76, GH31, GH47, and GH2 were discovered in D. hansenii. They encoded beta-galactosidase, alpha-D-galactoside galactohydrolase, alpha-xylosidase, mannosidase, etc., and most of the GHs were located in the exocellular space and participated in the degradation of polysaccharides and oligosaccharides. D. hansenii Y4 could develop the mellow mouthfeel and "reddish brown" factors of SSDT via increasing the levels of water extracts, soluble sugars and amino acids but decreasing the tea polyphenols and caffeine levels, combined with altering the levels of thearubiins and brown index. It may facilitate the isomerization between epicatechin gallate and catechin gallate. Moreover, the expression levels of DEHA2G24860g (Beta-galactosidase gene) and DEHA2G08602g (Mannan endo-1,6-alpha-mannosidase DFG5 gene) were sharply up-regulated in fermentative anaphase, and they were significantly and negatively correlated with epicatechin content, especially, the expression of DEHA2G08602g was significantly and negatively correlated with catechin gallate level. It was hypothesized that D. hansenii Y4 is likely to be an important functional microbe targeting carbohydrate destruction and catechin transformation during SSDT pile-fermentation, with DEHA2G08602g as a key thermotolerant functional gene.

Artificial intelligence diagnosis of intrauterine adhesion by 3D ultrasound imaging: a prospective study.

Background: There were a very large number of intrauterine adhesion (IUA) patients. As improving the classification of three-dimensional transvaginal ultrasound (3D-TVUS) of IUA or non-IUA images remains a clinical challenge and is needed to avoid inappropriate surgery. Our study aimed to evaluate deep learning as a method to classify 3D-TVUS of IUA or non-IUA images taken with panoramic technology. Methods: After meeting an inclusion/exclusion criteria, a total of 4,401 patients were selected for this study. This included 2,803 IUA patients and 1,598 non-IUA patients. IUA was confirmed by hysteroscopy, and each patient underwent one 3D-TVUS examination. Four well-known convolutional neural network (CNN) architectures were selected to classify the IUA images: Visual Geometry Group16 (VGG16), InceptionV3, ResNet50, and ResNet101. We used these pretrained CNNs on ImageNet by applying both TensorFlow and PyTorch. All 3D-TVUS images were normalized and mixed together. We split the data set into a training set, validation set, and test set. The performance of our classification model was evaluated according to sensitivity, precision, F1-score, and accuracy, which were determined by equations that used true-positive (TP), false-positive (FP), true-negative (TN), and false-negative (FN) numbers. Results: The overall performances of VGG16, InceptionV3, ResNet50, and ResNet101 were better in PyTorch as opposed to TensorFlow. Through PyTorch, the best CNN model was InceptionV3 with its performance measured as 94.2% sensitivity, 99.4% precision, 96.8% F1-score, and 97.3% accuracy. The area under the curve (AUC) results of VGG16, InceptionV3, ResNet50, and ResNet101 were 0.959, 0.999, 0.997, and 0.999, respectively. PyTorch also successfully transferred information from the source to the target domain where we were able to use another center's data as an external test data set. No overfitting that could have adversely affected the classification accuracy occurred. Finally, we successfully established a webpage to diagnose IUA based on the 3D-TVUS images. Conclusions: Deep learning can assist in the binary classification of 3D-TVUS images to diagnose IUA. This study lays the foundation for future research into the integration of deep learning and blockchain technology.

[Risk factors of early death after lung transplantation in patients with idiopathic pulmonary fibrosis complicated with pulmonary arterial hypertension].

OBJECTIVE: To investigate the risk factors of early death after lung transplantation in patients with idiopathic pulmonary fibrosis (IPF) complicated with pulmonary arterial hypertension (PAH). METHODS: A retrospective cohort study was conducted. The clinical data of 134 patients with IPF and PAH who underwent lung transplantation at Wuxi People's Hospital Affiliated to Nanjing Medical University from January 2017 to December 2020 were collected. The donor's gender, age, duration of mechanical ventilation, and cold ischemia time, the recipient's gender, age, body mass index (BMI), smoking, history of hypertension and diabetes, preoperative usage of hormones, mean pulmonary arterial pressure (mPAP), cardiac echocardiography and cardiac function, serum creatinine (SCr), N-terminal pro-brain natriuretic peptide (NT-proBNP) as well as surgical type, extracorporeal membrane oxygenation (ECMO) treatment, duration of operation, and plasma and red blood cell infusion ratio were collected. The cumulative survival rates of patients at 30, 60, and 180 days after lung transplantation were calculated by Kaplan-Meier method. The univariate and multivariate Cox proportional hazards regression models were used to analyze the effects of donor, recipient, and surgical factors on early survival in donors after lung transplantation. RESULTS: The majority of donors were male (80.6%). There was 63.4% of the donors older than 35 years old, 80.6% of the donors had mechanical ventilation duration less than 10 days, and the median cold ischemia time was 465.00 (369.25, 556.25) minutes. The recipients were mainly males (83.6%). Most of the patients were younger than 65 years old (70.9%). Most of them had no hypertension (75.4%) or diabetes (67.9%). The median mPAP of recipients was 36 (30, 43) mmHg (1 mmHg ≈ 0.133 kPa). There were 73 patients with single lung transplantation (54.5%), and 61 with double lung transplantation (45.5%). The survival rates of 134 IPF patients with PAH at 30, 60, 180 days after lung transplantation were 81.3%, 76.9%, and 67.4%, respectively. Univariate Cox proportional risk regression analysis showed that recipient preoperative use of hormone [hazard ratio (HR) = 2.079, 95% confidence interval (95%CI) was 1.048-4.128], mPAP ≥ 35 mmHg (HR = 2.136, 95%CI was 1.129-4.044), NT-proBNP ≥ 300 ng/L (HR = 2.411, 95%CI was 1.323-4.392), New York Heart Association (NYHA) cardiac function classification III-IV (HR = 3.021, 95%CI was 1.652-5.523) were the risk factors of early postoperative death in patients with IPF complicated with PAH (all P < 0.05). In the multivariable Cox proportional risk regression analysis, recipient preoperative hormone usage (model 1: HR = 2.072, 95%CI was 1.044-4.114, P = 0.037; model 2: HR = 2.098, 95%CI was 1.057-4.165, P = 0.034), NT-proBNP ≥ 300 ng/L (HR = 2.246, 95%CI was 1.225-4.116, P = 0.009) and NYHA cardiac function classification III-IV (HR = 2.771, 95%CI was 1.495-5.134, P = 0.001) were independent risk factors of early postoperative death in patients with IPF. CONCLUSIONS: Preoperative hormone usage, NT-proBNP ≥ 300 ng/L, NYHA cardiac function classification III-IV are independent risk factors for early death in patients with IPF and PAH after lung transplantation. For these patients, attention should be paid to optimize their functional status before operation. Preoperative reduction of receptor hormone usage and improvement of cardiac function can improve the early survival rate of such patients after lung transplantation.

Microbial Community Analysis in Sichuan South-road Dark Tea Piled Center at Pile-Fermentation Metaphase and Insight Into Organoleptic Quality Development Mediated by Aspergillus niger M10.

Microbes are critical in the Sichuan South-road Dark Tea (SSDT) organoleptic quality development during pile-fermentation. Piled tea center at fermenting metaphase is crucial for the conversion of its quality components. In this study, we investigated the microbial community of piled SSDT center below the stacked tea surface of 15 cm (SSDTB), 50 cm (SSDTX), and 85 cm (SSDTH) on the second turning time of pile-fermentation, respectively. Results showed that SSDTH and SSDTB had a higher similarity in the microbial community. Pantoea (36.8%), Klebsiella (67.7%), and Aspergillus (35.3%) were the most abundant in SSDTH, SSDTB, and SSDTX, respectively. We found 895 species were common among all samples, but 86, 293, and 36 species were unique to SSDTB, SSDTX, and SSDTH, respectively. Aspergillus niger showed high co-occurrence and was positively correlated with numerous microbes in SSDT samples, and Aspergillus niger M10 isolated from SSDTX was excellent at enhancing soluble sugar (SS), amino acids (AAs), theaflavin (TF), and thearubigins (TR) contents, while decreasing catechin (Cat), tea polyphenols (TPs)/AA, Caf/SS, Cat/SS, TPs/SS, and (TPs + Caf)/SS levels in AM10 post-fermentation, as compared with the control. Moreover, it also produced a noticeable difference in the CIELab parameters in dried, liquor, and infused tea colors between AM10 and control during fermentation. When it was further inoculated on differential mediums, we detected glycoside hydrolases, namely, ß-glucosidase, mannosidase, pectinase, cellulase, amylase, and α-galactosidase being secreted by Aspergillus niger M10. Taken together, SSDXT presented a more unique microbial community. Aspergillus niger M10 probably improved the sweet and mellow taste, and the yellow brightness and red color of SSDT during fermentation. It also provided new insights into the microbial profile and organoleptic quality development mechanism of SSDT during pile-fermentation.

Mycobacterium tuberculosis Rv1515c antigen enhances survival of M. smegmatis within macrophages by disrupting the host defence.

Mycobacterium tuberculosis (Mtb) infection is the major cause of tuberculosis. Mtb regions of difference (RD) genes are vital for survival of the pathogen within hosts and for the attenuation of the bacillus Calmette-Guérin vaccine. However, the function of most RD proteins largely remains unexplored. In the present study, we focused on Rv1515c, an RD6 member from M. tuberculosis, and characterised it as a cell surface-associated protein that functions in disrupting the cytokine profile and promoting endoplasmic reticulum stress-mediated apoptosis. Rv1515c expression in M. smegmatis, a nonpathogenic species, resulted in enhanced resistance of the bacterium to various in vitro stressors (such as low pH, sodium dodecyl sulfate, oxidative pressure, and nitrogen intermediate) and its cellular survival within macrophages. Our study is the first to identify the role of Rv1515c in the physiology and pathogenesis of mycobacterium.

Application via mechanical dropper alleviates sufentanil-induced cough: a prospective, randomized, single-blinded trial.

BACKGROUND: It was reported that prolonging the injection time or diluting administration can reduce the incidence of opioid-induced cough. However, the incidence of sufentanil-induced cough (SIC) via a standardized infusion rate is unclear. A mechanical dropper is an infusion filtering device commonly used for intravenous degassing; it can also be used to administer special drugs due to its temporary storage and dilution effect. This study assesses the effectiveness of administration via mechanical dropper on SIC. METHODS: Two hundred patients undergoing general anesthesia were enrolled. Patients received sufentanil at a strength of 0.3 µg·kg- 1 either via T-connector (group C) or by mechanical dropper (group M) at 1 ml·s- 1. Cough severity was graded as none (0), mild (1-2), moderate (3-5), or severe (> 5), and the incidence of SIC was evaluated for 5 min after the start of sufentanil injection. Other adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, hypoxemia, vomiting, and aspiration during the induction period of general anesthesia were also observed. The primary outcome was the incidence of SIC. The secondary outcomes were the severity of SIC and other adverse reactions. RESULTS: The incidence of SIC in group M was significantly lower than that in group C (2% versus 21%, P = 0.000), and the prevalence of moderately severe coughing was also statistically different (none in group M versus 11% in group C, P = 0.001). However, there were no statistical differences in the incidence of other adverse reactions between two groups (P > 0.05). CONCLUSION: Sufentanil application via mechanical dropper can significantly alleviate the occurrence of SIC during the induction phase of total intravenous general anesthesia. This method is simple, safe, and reliable, and has wide prospective application for clinical use. TRIAL REGISTRATION: Chinese Clinical Trial Register, ChiCTR-IOR-17011561 . Registered on 3 June 2017.

DJ-1 promotes survival of human colon cancer cells under hypoxia by modulating HIF-1α expression through the PI3K-AKT pathway.

BACKGROUND: Protein/nucleic acid deglycase (DJ-1) and hypoxia-inducible factor-1α (HIF-1α) play significant roles in the progression of various types of cancer and are associated with the phosphatidylinositol 3-kinase (PI3K) pathway. However, their functions in colorectal cancer (CRC) have not been identified. The aim of this study was to analyze the putative signaling pathway encompassing DJ-1, PI3K, and HIF-1α in a series of CRC tissues and cell lines. PURPOSE: This study aimed at exploring the expression status of DJ-1 in colon cancer and its role in survival of cancer cell lines. METHODS: The expression and localization of DJ-1, PI3K-p110α, phosphorylated Akt (p-AKT), and HIF-1α were determined by immunohistochemistry in 73 resected CRC tissues. The effect of DJ-1 on cell activity was explored by in vitro knockdown and overexpression experiments in SW480 and HT-29 cells. The cells were treated with a PI3K inhibitor (LY294002 or wortmannin), and p-AKT and HIF-1α protein expression were then analyzed. Apoptosis was analyzed by flow cytometry. The expression levels of several HIF-1 target genes were assessed under hypoxic conditions by reverse transcription-PCR and Western blot. Xenograft tumor growth studies were conducted in DJ-1 knockdown or overexpression cells. RESULTS: High DJ-1 expression was found in 68.49% (50/73) of CRC tissues and associated with larger tumor size and advanced clinical stages. DJ-1 expression was positively associated with PI3K-p110α, p-AKT, and HIF-1α expression in CRC. HIF-1α and p-AKT protein levels were lower in SW480 and HT-29 cells with stable DJ-1 knockdown than in those with DJ-1 overexpression. PI3K inhibitors almost completely blocked DJ-1-induced AKT phosphorylation. However, the expression of HIF-1α was partially preserved after treatment with PI3K inhibitors. We also show that DJ-1 is necessary for the transcriptional ability of HIF-1α and CRC cell survival after hypoxic stress. Moreover, DJ-1 promoted the growth of established tumor xenografts in nude mice. CONCLUSION: Our findings are the first to show that DJ-1 is overexpressed in CRC. We suggest a model in which DJ-1 mediates CRC cell survival by regulating the PI3K-AKT-HIF-1α pathway.

Effects of small-dose remifentanil combined with index of consciousness monitoring on gastroscopic polypectomy: a prospective, randomized, single-blinded trial.

BACKGROUND: With the development of painless diagnosis and treatment, remifentanil, a synthetic opioid agonist, is increasingly used in gastroscopy for its rapid, short-term, and potent analgesic effect. However, the dosage of remifentanil used in endoscopy is unclear. Index of consciousness (IOC) is a new anesthesia depth-monitoring indicator that can be divided into index of consciousness 1 (IOC1) and index of consciousness 2 (IOC2); IOC1 is used for estimating a patient's sedation state, whereas IOC2 reflects analgesic depth. We hypothesized that combining with IOC1 and IOC2 monitoring may be helpful to identify an optimal remifentanil dosage in gastroscopic polypectomy. METHODS: One hundred twenty patients scheduled for gastroscopic polypectomy were enrolled and were randomly assigned to remifentanil 2 ng/mL (group R2), 4 ng/mL (group R4), or 6 ng/mL (group R6), and 40 cases were in each group. During the anesthesia period, remifentanil was kept at the initial given concentration but propofol was adjusted according to IOC1. The primary outcomes were the dosage of propofol and remifentanil. The secondary outcomes were the variety of IOC1 and IOC2, patients' awakening time, and peri-operative adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, body movements, hypoxemia, therapy interruption, nausea, vomiting, aspiration, and intra-operative awareness. RESULTS: With the increasing dosage of remifentanil, the propofol dosage and patients' awakening time decreased significantly, the morbidity of hypertension and body movements also declined, but the incidence of hypotension, bradycardia, and hypoxemia rose. In group R2, the value of IOC2 remained above 50 during the treatment. However, IOC2 dropped to below 30 at the beginning of the gastroscopy in group R6, and there was statistical difference in hypoxemia between groups R2 and R6 (P <0.05). CONCLUSIONS: With the help of IOC monitoring, we found that a target concentration of remifentanil 4 ng/mL is comparatively ideal in patients under gastroscopic polypectomy. TRIAL REGISTRATION: Chinese Clinical Trial Register: ChiCTR-OOD-16009489 , on October 19, 2016.

Administration of fentanyl via a slow intravenous fluid line compared with rapid bolus alleviates fentanyl-induced cough during general anesthesia induction.

OBJECTIVE: Fentanyl-induced cough (FIC) is a common complication with a reported incidence from 18.0% to 74.4% during general anesthesia induction. FIC increases the intrathoracic pressure and risks of postoperative nausea and vomiting, yet available treatments are limited. This study was designed to investigate whether administering fentanyl via a slow intravenous fluid line can effectively alleviate FIC during induction of total intravenous general anesthesia. METHODS: A total number of 1200 patients, aged 18-64 years, were enrolled, all of whom were American Society of Anesthesiologists (ASA) grade I or II undergoing scheduled surgeries. All patients received total intravenous general anesthesia, which was induced sequentially by midazolam, fentanyl, propofol, and cisatracurium injection. Patients were randomly assigned to receive fentanyl 3.5 µg/kg via direct injection (control group) or via a slow intravenous fluid line. FIC incidence and the severity grades were analyzed with the Mann-Whitney test. Other adverse reactions, such as hypotension, hypertension, bradycardia, tachycardia, hypoxemia, vomiting, and aspiration, during induction were also observed. The online clinical registration number of this study was ChiCTR-IOR-16009025. RESULTS: Compared with the control group, the incidence of FIC was significantly lower in the slow intravenous fluid line group during induction (9.1%, 95% confidence interval (CI): 6.7%-11.4% vs. 55.9%, 95% CI: 51.8%-60.0%, P=0.000), as were the severity grades (P=0.000). There were no statistical differences between the two groups with regard to other adverse reactions (P>0.05). CONCLUSIONS: The administration of fentanyl via a slow intravenous fluid line can alleviate FIC and its severity during induction for total intravenous general anesthesia. This method is simple, safe, and reliable, and deserves clinical expansion.

TLR2-Dependent Signaling for IL-15 Production Is Essential for the Homeostasis of Intestinal Intraepithelial Lymphocytes.

TLR2 signaling is related to colitis and involved in regulation of innate immunity in the intestinal tract, but the mechanisms remain unclear. The aim of this study is to investigate how TLR2 affects differentiation of intraepithelial lymphocytes (IELs) and regulates the susceptibility of colitis. IELs were isolated from the small intestine and colon of mice, respectively. The IEL phenotype, activation, and apoptosis were examined using flow cytometry and RT-PCR. IL-15 expression and IEL location were detected through immunohistochemistry. The experimental colitis was induced by administration of dextran sulfate sodium (DSS). We found that the numbers of CD8αα (+), CD8αß (+), and TCRγδ (+) IELs were significantly decreased in TLR2-deficient mice and the residual IELs displayed reduced activation and proliferation and increased apoptosis, accompanied with impaired IL-15 expression by intestinal epithelial cells (IECs). Further study showed that TLR2 signaling maintained the expression of IL-15 in IEC via NF-κB activation. Moreover, TLR2-deficient mice were found to be more susceptible to DSS-induced colitis as shown by the increased severity of colitis. Our results demonstrate that IECs contribute to the maintenance of IELs at least partly via TLR2-dependent IL-15 production, which provides a clue that may link IECs to innate immune protection of the host via IELs.

CD8αα TCRαß Intraepithelial Lymphocytes in the Mouse Gut.

The epithelium of the mouse small intestine harbors an abundant CD8αα(+)TCRαß(+) intraepithelial lymphocyte (IEL) population. This unique IEL subset is a self-reactive population that requires exposure to self-agonists for selection in the thymus, similarly to other regulatory T cell populations. After leaving the thymus, these cells directly seed the intestinal epithelium, which provides a unique combination of cellular interactions together with cytokines, nutrients, and antigens that guide the lineage-specific differentiation and function of these IELs. For instance, epithelial cells and nearby immune cells secrete a number of cytokines, including interleukin-15 (IL-15), IL-7, and transforming growth factor-ß, resulting in an assortment of cellular responses, including activation of master transcription factors, cell proliferation, and cytokine secretion. Recent advances have also highlighted the importance of diet-derived substances and commensal metabolites, such as the aryl hydrocarbon receptor ligands and vitamin D, in controlling the survival and gene expression of CD8αα(+)TCRαß(+) IELs. Furthermore, these cells function in the epithelium and require constant communication between cells in the form of cell-to-cell contacts. These interactions tune the antigen sensitivity of the TCR and maintain the quiescence of the CD8αα(+)TCRαß(+) IELs. Finally, we discuss how these cells might contribute to tolerance and immunopathological responses in the gut. Therefore, an increased understanding of CD8αα(+)TCRαß(+) IELs in the gut will help us understand how these cells participate in immune regulation and protection.

The effect of Mycobacterium tuberculosis CRISPR-associated Cas2 (Rv2816c) on stress response genes expression, morphology and macrophage survival of Mycobacterium smegmatis.

Clustered regularly interspaced short palindromic repeats (CRISPR) are present in the genome of 40% bacteria and 90% archaea. CRISPR and accompanying Cas proteins constitute an adaptive immune system against disruptive mobile genetic elements. Two CRISPRs and 9 genes encoding CRISPR-associated proteins have been found in the genome of Mycobacterium tuberculosis. The CRISPR-associated Cas2 is an endoribonuclease required for the acquisition of new spacers. In this study, Cas2 encoded by Rv2816c was expressed in Mycobacterium smegmatis lacking CRISPR-Cas system and its role in stress responses of M. smegmatis in vitro and within macrophages was studied. We found that Cas2 mediated M. smegmatis stress response changes were associated with the altered expression of sigma factors which involved in mycobacterial stress response and virulence. We also found that Cas2 decreased the survival of M. smegmatis within macrophages. This study provides new insights on the role of Cas2.

Rv3369 Induces Cytokine Interleukin-1ß Production and Enhances Mycobacterium smegmatis Intracellular Survival.

The pathogenesis of tuberculosis, caused by Mycobacterium tuberculosis, is largely because of the pathogen's successful entry and survival within macrophages. We predicted that rv3369, a gene encoding a conserved protein, might play a role in the interactions with host cells. To test this, rv3369 gene was heterologously expressed in a nonpathogenic fast-growing Mycobacterium smegmatis strain. The recombinant strain survives better than the control within macrophages, accompanied by more host cell death and a marked higher secretion of interleukin-1ß (IL-1ß). Furthermore, pharmacological inhibition experiments showed that the NF-κB and ERK pathways were involved in the Rv3369-triggered IL-1ß changes. These results provided evidence for the engagement of Rv3369 in the interaction between mycobacteria and host.

Mycobacterium tuberculosis Rv1265 promotes mycobacterial intracellular survival and alters cytokine profile of the infected macrophage.

Mycobacterium tuberculosis cAMP and underlying regulatory network are crucial for its survival and thrive in the presence of numerous stresses mounted by the host. Our studies mainly focus on the cAMP-induced M. tuberculosis gene Rv1265, which was shown to be up-regulated under hypoxia and during macrophage infection by addition of exogenous cAMP. To explore the role of Rv1265 in host-pathogen interactions, Rv1265 was expressed in a non-pathogenic Mycobacterium smegmatis. We found that Rv1265 was associated with cell envelope and can up-regulate some cell wall fatty acid components, especially the C26:0. The survival of the recombinant Ms_Rv1265 was enhanced within macrophages and under stress conditions such as low pH and SDS. Macrophages infected with Ms_Rv1265 increased transcription of pro-inflammatory cytokines IL-1ß, IL-6, and IL-12 P40 and anti-inflammatory cytokine IL-10 possibly through activation of NF-κB and ERK1/2 pathway. Our findings indicate that Rv1265 can enhance mycobacterial survival within macrophages, and perturb the cytokine profile of macrophage.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Mycobacterium biofilms: factors involved in development, dispersal, and therapeutic strategies against biofilm-relevant pathogens.

Many bacteria can develop biofilm (BF), a multicellular structure largely combining bacteria and their extracellular polymeric substances (EPS). The formation of biofilm results in an alternative existence in which microbes ensure their survival in adverse environments. Biofilm-relevant infections are more persistent, resistant to most antibiotics, and more recalcitrant to host immunity. Mycobacterium tuberculosis, the causative agent of tuberculosis, can develop biofilm, though whether M. tuberculosis can form biofilm within tuberculosis patients has yet to be determined. Here, we summarize the factors involved in the development and dispersal of mycobacterial biofilms, as well as underlying regulatory factors and inhibitors against biofilm to deepen our understanding of their development and to elucidate potential novel modes of action for future antibiotics. Key factors in biofilm formation identified as drug targets represent a novel and promising avenue for developing better antibiotics.

Mycobacterium tuberculosis Rv3402c enhances mycobacterial survival within macrophages and modulates the host pro-inflammatory cytokines production via NF-kappa B/ERK/p38 signaling.

Intracellular survival plays a central role in the pathogenesis of Mycobacterium tuberculosis, a process which depends on an array of virulence factors to colonize and replicate within the host. The M. tuberculosis iron regulated open reading frame (ORF) rv3402c, encoding a conserved hypothetical protein, was shown to be up-regulated upon infection in both human and mice macrophages. To explore the function of this ORF, we heterologously expressed the rv3402c gene in the non-pathogenic fast-growing Mycobacterium smegmatis strain, and demonstrated that Rv3402c, a cell envelope-associated protein, was able to enhance the intracellular survival of recombinant M. smegmatis. Enhanced growth was not found to be the result of an increased resistance to intracellular stresses, as growth of the Rv3402c expressing strain was unaffected by iron depletion, H2O2 exposure, or acidic conditions. Colonization of macrophages by M. smegmatis expressing Rv3402c was associated with substantial cell death and significantly greater amount of TNF-α and IL-1ß compared with controls. Rv3402c-induced TNF-α and IL-1ß production was found to be mediated by NF-κB, ERK and p38 pathway in macrophages. In summary, our study suggests that Rv3402c delivered in a live M. smegmatis vehicle can modify the cytokines profile of macrophage, promote host cell death and enhance the persistence of mycobacterium within host cells.