scholarly journals Prophage Gene Rv2650c Enhances Intracellular Survival of Mycobacterium smegmatis

2022 ◽  
Vol 12 ◽  
Author(s):  
Xiangyu Fan ◽  
Zichen Liu ◽  
Zhibin Wan ◽  
Hanlu Zou ◽  
Mengzhi Ji ◽  
...  

BackgroundInduced by the pathogen Mycobacterium tuberculosis, tuberculosis remains one of the most dangerous infectious diseases in the world. As a special virus, prophage is domesticated by its host and are major contributors to virulence factors for bacterial pathogenicity. The function of prophages and their genes in M. tuberculosis is still unknown.MethodsRv2650c is a prophage gene in M. tuberculosis genome. We constructed recombinant Mycobacterium smegmatis (M. smegmatis) to observe bacteria morphology and analyze the resistance to various adverse environments. Recombinant and control strains were used to infect macrophages, respectively. Furthermore, we performed ELISA experiments of infected macrophages.ResultsRv2650c affected the spread of colonies of M. smegmatis and enhanced the resistance of M. smegmatis to macrophages and various stress agents such as acid, oxidative stress, and surfactant. ELISA experiments revealed that the Rv2650c can inhibit the expression of inflammatory factors TNF-α, IL-10, IL-1β, and IL-6.ConclusionThis study demonstrates that the prophage gene Rv2650c can inhibit the spread of colonies and the expression of inflammatory factors and promote intracellular survival of M. smegmatis. These results build the foundation for the discovery of virulence factors of M. tuberculosis, and provide novel insights into the function of the prophage in Mycobacterium.

2021 ◽  
Vol 9 (2) ◽  
pp. 414
Author(s):  
Oksana Bychenko ◽  
Yulia Skvortsova ◽  
Rustam Ziganshin ◽  
Artem Grigorov ◽  
Leonid Aseev ◽  
...  

Small non-coding RNAs play a key role in bacterial adaptation to various stresses. Mycobacterium tuberculosis small RNA MTS1338 is upregulated during mycobacteria infection of macrophages, suggesting its involvement in the interaction of the pathogen with the host. In this study, we explored the functional effects of MTS1338 by expressing it in non-pathogenic Mycobacterium smegmatis that lacks the MTS1338 gene. The results indicated that MTS1338 slowed the growth of the recombinant mycobacteria in culture and increased their survival in RAW 264.7 macrophages, where the MTS1338-expressing strain significantly (p < 0.05) reduced the number of mature phagolysosomes and changed the production of cytokines IL-1β, IL-6, IL-10, IL-12, TGF-β, and TNF-α compared to those of the control strain. Proteomic and secretomic profiling of recombinant and control strains revealed differential expression of proteins involved in the synthesis of main cell wall components and in the regulation of iron metabolism (ESX-3 secretion system) and response to hypoxia (furA, whiB4, phoP). These effects of MTS1338 expression are characteristic for M. tuberculosis during infection, suggesting that in pathogenic mycobacteria MTS1338 plays the role of a virulence factor supporting the residence of M. tuberculosis in the host.


2020 ◽  
Author(s):  
Xiaoling Wu ◽  
Xinyu Zou ◽  
Mi Zhang ◽  
Haiqiang Hu ◽  
Xueliang Wei ◽  
...  

Abstract Background: Osteocalcin (OCN), as an energy-regulating hormone, involves in preventing nonalcoholic steatohepatitis. Laying hens have been used as an animal model for investigating liver function and related metabolic disordersas that the synthesis of fat in laying hens is much faster than in mammals with limited adipose tissue. The aim of this study was to investigate the effects of OCN on fatty liver hemorrhagic syndrome (FLHS) in aged laying hens. Methods: Thirty 68-week-old White Plymouth laying hens were randomly assigned into conventional single-bird cages, and the cages were randomly allocated into one of three treatments: normal diet (ND + vehicle , ND+V), high-fat diet (HFD + vehicle, HFD+V), and HFD + OCN (3 μg/bird, 1 time/2 days, i.m.) for 40 days. At experimental day 30, oral glucose tolerance tests (OGTT) and insulin tolerance tests (ITT) were performed. At the end of experiment, the hens were euthanized followed blood collection. The plasma aspartate transaminase (AST), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured using an automatic biochemistry analyzer. Pathological changes in the liver were examined under both light and transmission electron microscopes. The plasma inflammatory factors including interleukin-1 (IL-1), IL-6, and tumor Necrosis Factor-alpha (TNF-α) were analyzed by ELISA, and the gene expressions of these inflammatory factors in the liver were analyzed by Real-time PCR. And oxidative stress was evaluated using Malondialdehyde (MDA) and Glutathione peroxidase (GSH-Px) assay kits. Results: The results showed HFD hens had more severe liver haemorrhage and fibrosis than ND hens. The ultra-microstructural examination showed that hepatocytes of HFD hens appeared necrotic pyknosis associated with great intracellular electron, mitochondrial swelling, shrunk nucleus and absence of autolysosomes. OCN mitigated these pathological changes by improved HFD hens’ insulin resistance via alleviating the glucose intolerence and improving insulin sensitivity; inhibited HFD-induced oxidative stress as evidenced by decreased liver concentrations of MDA but increased GSH-Px; and reduced the inflammatory reaction with reducing blood IL-6 and TNF-α concentrations and mRNA expressions. Conclusion: These results suggest a high-fat diet promotes the FLHS development in aged hens, while OCN prevents the FLHS process through inhibiting insulin resistance, inflammatory reaction, oxidative stress and fibrosis, and acting autophagy.


2019 ◽  
Vol 35 (1) ◽  
Author(s):  
Ju-Bin Kang ◽  
Dong-Ju Park ◽  
Murad-Ali Shah ◽  
Myeong-Ok Kim ◽  
Phil-Ok Koh

Abstract Lipopolysaccharide (LPS) acts as an endotoxin, releases inflammatory cytokines, and promotes an inflammatory response in various tissues. This study investigated whether LPS modulates neuroglia activation and nuclear factor kappa B (NF-κB)-mediated inflammatory factors in the cerebral cortex. Adult male mice were divided into control animals and LPS-treated animals. The mice received LPS (250 μg/kg) or vehicle via an intraperitoneal injection for 5 days. We confirmed a reduction of body weight in LPS-treated animals and observed severe histopathological changes in the cerebral cortex. Moreover, we elucidated increases of reactive oxygen species and oxidative stress levels in LPS-treated animals. LPS administration led to increases of ionized calcium-binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP) expression. Iba-1 and GFAP are well accepted as markers of activated microglia and astrocytes, respectively. Moreover, LPS exposure induced increases of NF-κB and pro-inflammatory factors, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Increases of these inflammatory mediators by LPS exposure indicate that LPS leads to inflammatory responses and tissue damage. These results demonstrated that LPS activates neuroglial cells and increases NF-κB-mediated inflammatory factors in the cerebral cortex. Thus, these findings suggest that LPS induces neurotoxicity by increasing oxidative stress and activating neuroglia and inflammatory factors in the cerebral cortex.


2019 ◽  
Vol 14 (16) ◽  
pp. 1397-1415
Author(s):  
Pratibha Maan ◽  
Jagdeep Kaur

Aim: To elucidate the role of Rv2223c in Mycobacterium tuberculosis. Methods: Purified recombinant Rv2223c protein was characterized. Expression of rv2223c in the presence of different stress environment and subcellular localization were performed in M. tuberculosis H37Ra and Mycobacterium smegmatis ( MS_2223c). Effect of its overexpression on growth rate, infection and intracellular survival in THP-1/PBMC cells were studied. Results: rRv2223c demonstrated esterase activity with preference for pNP-octanoate and hydrolyzed trioctanoate to di- and mono-octanoate. Expression of rv2223c was upregulated in acidic and nutritive stress conditions. rRv2223c was identified in extracellular and cell wall fractions. MS_2223c exhibited enhanced growth, survival during in vitro stress, infection and intracellular survival. Conclusions: Rv2223c is a secretary, carboxyl-esterase, with enhanced expression under acidic and nutritive stress condition and might help in intracellular survival of bacteria.


2021 ◽  
Vol 20 (9) ◽  
pp. 1961-1968
Author(s):  
Wei Wei ◽  
Liefeng Ji ◽  
Wanli Duan ◽  
Jiang Zhu

Purpose: To investigate the effect of Klotho and FOXO1/3 on the CH viability in OA.Methods: The survival rate of CHs, Klotho and FOXO1/3 protein expression, and ROS production were measured in the OA cartilages of different degenerative phases. H2O2 was also used to injure CHs, and the cell viability, Klotho and FOXO1/3 expressions, as well as ROS levels were investigated to clarify the effect of exogenic Klotho on the injured CHs. Additionally, in order to verify the role of FOXO1/3 in Klotho-treated CHs, SOD2, GPX1, inflammatory factors, collagen I/II, SOX9, and Runx-2 levels were analyzed by silencing FOXO1 and FOXO3 expression via siRNA transfection.Results: Klotho and FOXO1/3 expressions significantly decreased, and ROS production increased in severely human OA cartilage (p <0.05). Besides, H2O2 affected CHs viability with the suppression of Klotho and FOXO1/3 expression but ROS production was elevated. Exogenic Klotho application partly reversed the injury caused by H2O2. Furthermore, Klotho treatment of the injured CHs contributed to SOD2 and GPX1 expressions, and suppressed IL-1β, IL-6, TNF-α and MMP-13 production, resulting in  the upregulation of collagen II and SOX9 as well as downregulation of collagen I and Runx-2. However, the protective effect of Klotho was weakened by FOXO1 and FOXO3 gene silencing.Conclusion: Klotho protects CHs viability by suppressing oxidative stress and inflammation, which is associated with the mediation of FOXO1 and FOXO3. These findings provide new insights into the treatment of OA.


2021 ◽  
Author(s):  
Yuehong Liu ◽  
Zhongyu Kong ◽  
Song Shi

Abstract Background: The main purpose of this study was to determine sVAP-1 levels in patients with moderate and severe obstructive sleep apnea (OSA) compared with healthy controls, and further determine the relationship between sVAP-1 concentration and biomarkers of vascular endothelial dysfunction (ED), including adropin and inflammatory factors.Methods: In this study, we included 50 male patients with OSA (25 moderate and 25 severe) and 20 age- and sex-matched control subjects. The OSA patients underwent polysomnography and all subjects underwent fasting sampling of peripheral blood for laboratory analyses.Results: Serum sVAP-1 levels and inflammatory biomarkers (IL-6, TNF-α, hsCRP) were significantly higher in patients with severe OSA in comparison with the moderate OSA and control groups, whereas plasma adropin levels presented a completely reverse trend. Moreover, sVAP-1 levels were in significant positive correlation with levels of AHI, ODI, TNF-α, IL-6 and hsCRP. However, it was significantly negative correlated with adropin levels. Receiver Operating Characteristic (ROC) analysis showed that AUC for sVAP-1levels in predicting OSA was 0.876 (P <.001,95% CI 0.784−0.968). Serum sVAP-1 cutoff value more than 445.5ng/mL provided 88% sensitivity and 80% specificity for the detection of OSA status. A multivariate regression analysis showed that sVAP-1 remained as a significant positive predictor of severe OSA status.Conclusions: Serum sVAP-1 concentration significantly correlates with indices of OSA severity and biomarkers of ED, suggesting that sVAP-1 plays a vital role in the pathophysiology of ED-related diseases.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Yu Chen ◽  
Chenglin Jia ◽  
Minqi Xiong ◽  
Jingang Cui ◽  
Qinbo Yang ◽  
...  

Atherosclerosis is a chronic pathological condition featured by accumulation of lipids and fibrous elements in the artery. Atherosclerosis remains as the primary cause of cardiovascular diseases and agents that effectively intervenes the development of atherosclerosis are still needed. Panax notoginseng has been extensively used as therapeutic agent in Asia to treat cardiovascular disorders. Panax notoginseng saponins (PNS) is the major class of active components of Panax notoginseng. PNS has been reported to possess anti-atherosclerotic effect. However, which component of PNS is responsible for this effect remains unknown. The current study evaluated the effects of a component unique to PNS, PNS-R1, on atherosclerosis in ApoE-/- mouse model. Histological examination revealed that the extent of atherosclerotic lesion was significantly alleviated in PNS-R1-treated ApoE-/- mice compared to that from the ApoE-/- controls. Meanwhile, PNS-R1 treatment significantly reduced the level of oxidative stress in the atherosclerotic lesion, which was prominently enhanced in ApoE-/- controls. This effect on oxidative stress was corroborated by increased serum level of GSH and SOD and decreased level of MDH in PNS-treated mice. Furthermore, PNS-R1 treatment significantly decreased the levels of total cholesterol, triglycerides and increased the level of HDL without affecting the level of LDL, suggesting an effect of PNS-R1 on lipid metabolism, which could in part contribute to its action in attenuating atherosclerosis. Additionally, the levels of inflammatory factors including IL-2, IL-6, TNF-α, γ-IFN and ox-LDL were markedly reduced in PNS-R1-treated mice compared to that from the ApoE-/- controls, demonstrating a significant anti-inflammatory effect of PNS-R1 in the development of atherosclerosis. Expression of microRNAs known to be involved in the pathogenesis of atherosclerosis was further evaluated and showed that PNS-R1 treatment led to a significant reduction in the expression of miR-122, miR-132 and miR-155. Collectively, our results provided for the first time the experimental evidence supporting the anti-atherosclerotic effects of PNS-R1, which could be a promising therapeutic agent treating atherosclerosis.


2021 ◽  
pp. 1-10
Author(s):  
Ke Sun ◽  
Xiaojing Tang ◽  
Shuwei Song ◽  
Yuan Gao ◽  
Hongjing Yu ◽  
...  

<b><i>Introduction:</i></b> Cardiovascular disease is the most common cause of morbidity and mortality in patients with ESRD. In addition to phosphate overload, oxalate, a common uremic toxin, is also involved in vascular calcification in patients with ESRD. The present study investigated the role and mechanism of hyperoxalemia in vascular calcification in mice with uremia. <b><i>Methods:</i></b> A uremic atherosclerosis (UA) model was established by left renal excision and right renal electrocoagulation in apoE<sup>−/−</sup> mice to investigate the relationship between oxalate loading and vascular calcification. After 12 weeks, serum and vascular levels of oxalate, vascular calcification, inflammatory factors (TNF-α and IL-6), oxidative stress markers (malondialdehyde [MDA], and advanced oxidation protein products [AOPP]) were assessed in UA mice. The oral oxalate-degrading microbe <i>Oxalobacter formigenes</i> (<i>O. formigenes</i>) was used to evaluate the effect of a reduction in oxalate levels on vascular calcification. The mechanism underlying the effect of oxalate loading on vascular calcification was assessed in cultured human aortic endothelial cells (HAECs) and human aortic smooth muscle cells (HASMCs). <b><i>Results:</i></b> Serum oxalate levels were significantly increased in UA mice. Compared to the control mice, UA mice developed more areas of aortic calcification and showed significant increases in aortic oxalate levels and serum levels of oxidative stress markers and inflammatory factors. The correlation analysis showed that serum oxalate levels were positively correlated with the vascular oxalate levels and serum MDA, AOPP, and TNF-α levels, and negatively correlated with superoxide dismutase activity. The <i>O. formigenes</i> intervention decreased serum and vascular oxalate levels, while did not improve vascular calcification significantly. In addition, systemic inflammation and oxidative stress were also improved in the <i>O. formigenes</i> group. In vitro, high concentrations of oxalate dose-dependently increased oxidative stress and inflammatory factor expression in HAECs, but not in HASMCs. <b><i>Conclusions:</i></b> Our results indicated that hyperoxalemia led to the systemic inflammation and the activation of oxidative stress. The reduction in oxalate levels by <i>O. formigenes</i> might be a promising treatment for the prevention of oxalate deposition in calcified areas of patients with ESRD.


Author(s):  
Bijan Helli ◽  
Hadis Gerami ◽  
Maria Kavianpour ◽  
Habib Heybar ◽  
Seyed Kianoosh Hosseini ◽  
...  

Background: Curcumin demonstrated many pharmacological effects including antioxidants, anti-inflammation, eliminating free radicals, anti-tumor, lipid regulation, and anti-coagulation. Objective: This study aimed to assess and compare curcumin and nano-curcumin effects on lipid profile, oxidative stress, and inflammatory factors related to patients ‘heart. Method: This randomized, double-blind, placebo-controlled clinical trial was conducted on 90 patients undergoing coronary elective angioplasty which were randomly divided into 3 groups. The doses administered for 8 weeks were a 500 mg capsule of curcumin daily for the first group and an 80 mg capsule of nano-curcumin for the second group. However, the placebo group received capsules like curcumin. Lipid profile, oxidative stress factors, and inflammatory markers were measured at the baseline and end of the experiment. Results: Statistically significant changes were observed in the total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C) in the intervention groups to the control group (p<0.05). Curcumin and nano-curcumin supplementation also improved significant changes in plasma levels of total antioxidant capacity (TAC), malondialdehyde (MDA), Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), high-sensitivity C-reactive protein (hs-CRP), Interleukin 1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in comparison to the placebo (p<0.05). Furthermore, the nano-curcumin group compared to the curcumin group demonstrated significant changes (p<0.05) in TC, TG, SOD, MDA and TNF-α levels. Conclusion: The effects of curcumin on nano formula may be better for cardiac patients due to its high bioavailability.


Author(s):  
Hamed Fanaei ◽  
Akram Pourbakht ◽  
Sadegh Jafarzadeh

Background and Aim: Ischemic injury is a major cause of hearing loss and oxidative stress is an important part of ischemic injury. The goal of this study was to evaluate the cochlear oxidative stress effect on auditory responses in male rats. Methods: Cochlear oxidative stress was induced by bilateral carotid artery occlusion for 20 minutes. The rats were evaluated by biochemical inflammatory factors tumor necrosis factor-α [TNF-α] and C-reactive protein (CRP) in the day before and 1st, 4th, and 7th days following surgery. The auditory brainstem response (ABR) and electrocochleography (ECochG) were evaluated on the day before surgery and 14th, 21th and 28th days after surgery. Results: TNF-α and CRP levels concentrations increased one day after ischemia and subsequently decreased on the 7th day. The click and tone burst evoked ABR showed increased thresholds on day14th, 21th, and 28th. The highest threshold was recorded on day14th. The ECochG results also were abnormal for 55%, 70%, and 45% of cases on day 14th, 21th, and 28th, respectively. Conclusion: Cochlear oxidative stress affects hearing sensitivity. The ABR shows elevated thresholds and abnormal ECochG was found in many cases.


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