222 research outputs found
Deregulation of the cyclin-dependent kinase inhibitor p27 as a putative candidate for transformation in Chlamydia trachomatis infected mesenchymal stem cells
Corrigendum to: Loss in Pluripotency Markers in Mesenchymal Stem Cells upon Infection with Chlamydia trachomatis
A Chlamydia effector recruits CEP170 to reprogram host microtubule organization
The obligate intracellular bacterial pathogen Chlamydia trachomatis deploys virulence effectors to subvert host cell functions enabling its replication within a specialized membrane-bound compartment termed an inclusion. The control of the host cytoskeleton is critical for Chlamydia uptake, inclusion biogenesis and cell exit. Here we demonstrate how a Chlamydia effector rearranges the microtubule network by initiating organization of the microtubules at the inclusion surface. We identified an inclusion-localized effector sufficient to interfere with microtubule assembly that we term inclusion protein acting on microtubules (IPAM). We established that IPAM recruits and stimulates the centrosomal protein 170kDa (CEP170) to hijack the microtubule organizing functions of the host cell. We show that CEP170 is essential for chlamydial control of host microtubule assembly, and is required for inclusion morphogenesis and bacterial infectivity. Together, we demonstrate how a pathogen effector reprograms the host microtubule network to support its intracellular development
Loss in Pluripotency Markers in Mesenchymal Stem Cells upon Infection with Chlamydia trachomatis
The intracellular pathogen Chlamydia trachomatis can inflict substantial damage on the host. Notably, Chlamydia infection is acknowledged for its precise modulation of diverse host signaling pathways to ensure cell survival, a phenomenon intricately connected to genetic regulatory changes in host cells. To monitor shifts in gene regulation within Chlamydia-infected cells, we employed mesenchymal stem cells (MSCs) as a naïve, primary cell model. Utilizing biochemical methods and imaging, our study discloses that acute Chlamydia infection in human MSCs leads to the downregulation of transcription factors Oct4, Sox2, and Nanog, suggesting a loss of pluripotency markers. Conversely, pluripotency markers in MSCs were sustained through treatment with conditioned medium from infected MSCs. Additionally, there is an augmentation in alkaline phosphatase activity, along with elevated Sox9 and CD44 mRNA expression levels observed during acute infection. A comprehensive screening for specific cell markers using touchdown PCR indicates an upregulation of mRNA for the early chondrogenesis gene Sox9 and a decrease in mRNA for the MSC marker vimentin. Real-time PCR quantification further corroborates alterations in gene expression, encompassing increased Sox9 and CD44 mRNA levels, alongside heightened alkaline phosphatase activity. In summary, the infection of MSCs with C. trachomatis induces numerous genetic deregulations, implying a potential trend towards differentiation into chondrocytes. These findings collectively underscore a targeted impact of Chlamydia on the gene regulations of host cells, carrying significant implications for the final fate and differentiation of these cells
Cytokine changes in patients with heatstroke during pilgrimage to Makkah
Circulating levels and role of IL-6, IL-1ra, TNFsr-II and CRP in patients with heatstroke is not fully known. This study correlated levels of these mediators with outcome in 26 patients. In survivors (n=20), IL-6 concentration declined on cooling, whereas in non-survivors levels continued to increase at 6 h following admission before declining. Admission TNFsr-II concentrations in survivors were significantly lower than non-survivors and levels continued to rise in both groups. IL-1ra levels were markedly elevated in both groups. Changes in cytokine levels were not influenced by renal function. Elevated C-reactive protein levels were observed for both groups and remained so despite cooling, furthermore, there was no correlation with alanine aminotransferase levels. The study demonstrated the elevation of the above mediators and suggested a role in the pathogenesis of heatstroke. Markedly elevated levels or those that remained elevated despite cooling were associated with mortality
Tribalism Manifestations in Tribal Conflicts in Southern West Bank
The study aimed at answering the following main question: What are the manifestations of tribalism that appear in tribal conflicts in southern West Bank? This question is divided into three sub-questions that embodies the reasons for the emergence of tribalism: what are the most important forms of tribalism? And to what extent can these forms be overcome? The researchers used the qualitative method. To collect the data of the study, 20 semi-structured interviews were conducted in-depth with well- experienced tribesmen from Bethlehem and Hebron Governorates. Results of the study showed that there are many reasons that stand behind tribalism and loyalty to the tribe. These reasons were represented in the nature of the epistemological, social, moral, economic, and political structure. This has been contributed to the reproduction of the concept of tribalism leading to the formation of symbolic human capital. The forms of tribalism practices were embodied by killing, revenge, clan domination, tribe recruitment (Faizah), extreme anger (Forat Addam), and the deportation of the murderer\u27s family and his first-degree relatives (Jalwa). These practices can be attributed to a state of cultural heritage that shows tribesmen how to deal with problems in a way that reserve their mental images as the center of power by location and loyalty. These mental images were associated with false tribal understanding of the whole issue. The results of the study also showed that the Palestinian society in its cognitive, social, ideological, and economic structure is identical with the pastoral and agricultural community structure below the advanced industrial level; and that the desired change will not be in the short term. Therefore, there is an urgent need for deep thinking to create a society that is more developed and urbanized within a future vision in favor of the supreme symbol of affair and prestige, which is the homeland and the citizen as a substitute for loyalty of the tribalism concept
Loss of p53 Expression in Gastric Epithelial Cells of Helicobacter pylori-Infected Jordanian Patients
BACKGROUND: Around half of the global population is chronically infected with the stomach bacterium Helicobacter pylori, making it one of the most common chronic infections worldwide. H. pylori induces the production of reactive oxygen species, DNA damage, and accelerates the degradation of the tumor suppressor protein p53, which may lead to cancer development. In this study, we investigated the relationship between H. pylori infection and the expression of p53 in gastric mucosa in a group of patients from Jordan. METHODS: In this retrospective case-control study, the epithelium of gastric glands in subjects chronically infected with H. pylori was examined for the expression of p53. Paraffin-embedded gastric biopsy samples from the archives for 50 Jordanian patients diagnosed with chronic H. pylori infection and 25 samples free of H. pylori infection and any other gastric abnormalities were selected. Samples were analyzed for the presence of H. pylori as well as p53 expression levels in the mucosa and submucosa by immunohistochemical analyses and Western blotting. RESULTS: H. pylori was detected in the gastric tissues of infected individuals (n = 50); whereas, no H. pylori infection was detected in uninfected healthy individuals (n = 25) using immunohistochemistry. In contrast to the noninfected samples of gastric mucosa, no nuclear p53 expression was detected in the infected samples using immunohistochemistry. In addition, the levels of p53 in H. pylori-positive samples detected by Western blotting were significantly lower than those in the negative individuals. CONCLUSION: Our data reveal that p53 protein expression decreased in gastric mucosa of patients infected with H. pylori. The loss of this tumor suppressor may play a role in the increased risk for tumor initiation associated with H. pylori carriage
Chlamydia trachomatis prevents apoptosis via activation of PDPK1-MYC and enhanced mitochondrial binding of hexokinase II
The intracellular human bacterial pathogen Chlamydia trachomatis pursues effective strategies to protect infected cells against death-inducing stimuli. Here, we show that Chlamydia trachomatis infection evokes 3-phosphoinositide-dependent protein kinase-1 (PDPK1) signaling to ensure the completion of its developmental cycle, further leading to the phosphorylation and stabilization of MYC. Using biochemical approaches and imaging we demonstrate that Chlamydia-induced PDPK1-MYC signaling induces host hexokinase II (HKII), which becomes enriched and translocated to the mitochondria. Strikingly, preventing the HKII interaction with mitochondria using exogenous peptides triggers apoptosis of infected cells as does inhibiting either PDPK1 or MYC, which also disrupts intracellular development of Chlamydia trachomatis. These findings identify a previously unknown pathway activated by Chlamydia infection, which exhibits pro-carcinogenic features. Targeting the PDPK1-MYC-HKII-axis may provide a strategy to overcome therapeutic resistance of infection
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