192 research outputs found
TRAIL treatment prevents renal morphological changes and TGF-\u3b2-induced mesenchymal transition associated with diabetic nephropathy
BACKGROUND: TNF-related apoptosis-inducing ligand (TRAIL) has attracted attention not only as an anti-cancer agent, but also as a potential treatment for diabetes. Animal studies have shown that TRAIL delivery ameliorated glucose control in type 1 and type 2 diabetes. It is currently unknown whether TRAIL positive effects are maintained in more severe forms of type 2 diabetes, and whether they include renoprotection. Our study aimed at evaluating TRAIL effects in a severe form of type 2 diabetes with nephropathy. MATERIALS AND METHODS: A total of 20 db/db mice were treated with saline or TRAIL twice per week for 12 weeks. In parallel, renal tubular epithelial cells were cultured with TGF-\u3b21 in the presence and absence of TRAIL, with and without silencing TRAIL-specific receptor (DR5) and leptin receptor. RESULTS: TRAIL did not improve glucose control, but it significantly reduced circulating interleukin (IL)-6 and resistin. In the kidney, TRAIL treatment significantly ameliorated glomerular and tubular morphology with an improvement in kidney function, but no effect on proteinuria. Our in vitro studies on TGF-\u3b21-treated cells, showed that by binding to DR5, TRAIL rescued normal tubular cell morphology, increasing E-cadherin and reducing \u3b1-smooth muscle actin (SMA) expression, with no effects on cell viability. Interestingly, both in vivo and in vitro, TRAIL reduced the accumulation of the autophagy substrate p62. CONCLUSIONS: Our data confirm TRAIL protective effects against organ damage and shed light on to promising anti-fibrotic actions, which are independent of glucose control. TRAIL anti-fibrotic actions might be due to the rescue of autophagy in diabetes
COVID-19 and individual genetic susceptibility/receptivity: Role of ACE1/ACE2 genes, immunity, inflammation and coagulation. might the double x-chromosome in females be protective against SARS-COV-2 compared to the single x-chromosome in males?
In December 2019, a novel severe acute respiratory syndrome (SARS) from a new coronavirus (SARS-CoV-2) was recognized in the city of Wuhan, China. Rapidly, it became an epidemic in China and has now spread throughout the world reaching pandemic proportions. High mortality rates characterize SARS-CoV-2 disease (COVID-19), which mainly affects the elderly, causing unrestrained cytokines-storm and subsequent pulmonary shutdown, also suspected micro thromboembolism events. At the present time, no specific and dedicated treatments, nor approved vaccines, are available, though very promising data come from the use of anti-inflammatory, anti-malaria, and anti-coagulant drugs. In addition, it seems that males are more susceptible to SARS-CoV-2 than females, with males 65% more likely to die from the infection than females. Data from the World Health Organization (WHO) and Chinese scientists show that of all cases about 1.7% of women who contract the virus will die compared with 2.8% of men, and data from Hong Kong hospitals state that 32% of male and 15% of female COVID-19 patients required intensive care or died. On the other hand, the long-term fallout of coronavirus may be worse for women than for men due to social and psychosocial reasons. Regardless of sex-or gender-biased data obtained from WHO and those gathered from sometimes controversial scientific journals, some central points should be considered. Firstly, SARS-CoV-2 has a strong interaction with the human ACE2 receptor, which plays an essential role in cell entry together with transmembrane serine protease 2 (TMPRSS2); it is interesting to note that the ACE2 gene lays on the X-chromosome, thus allowing females to be potentially heterozygous and differently assorted compared to men who are definitely hemizygous. Secondly, the higher ACE2 expression rate in females, though controversial, might ascribe them the worst prognosis, in contrast with worldwide epidemiological data. Finally, several genes involved in inflammation are located on the X-chromosome, which also contains high number of immune-related genes responsible for innate and adaptive immune responses to infection. Other genes, out from the RAS-pathway, might directly or indirectly impact on the ACE1/ACE2 balance by influencing its main actors (e.g., ABO locus, SRY, SOX3, ADAM17). Unexpectedly, the higher levels of ACE2 or ACE1/ACE2 rebalancing might improve the outcome of COVID-19 in both sexes by reducing inflammation, thrombosis, and death. Moreover, X-heterozygous females might also activate a mosaic advantage and show more pronounced sex-related differences resulting in a sex dimorphism, further favoring them in counteracting the progression of the SARS-CoV-2 infection
Treatment With Recombinant Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand Alleviates the Severity of Streptozotocin-Induced Diabetes
OBJECTIVE: To evaluate the potential therapeutic effect of recombinant human tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) treatment in a model of type 1 diabetes. RESEARCH DESIGN AND METHODS: Recombinant TRAIL was added in vitro to primary human and mouse peripheral blood mononuclear cells (PBMCs) and isolated human islets to evaluate the expression of the immunoregulatory gene SOCS1. Diabetes was induced by five consecutive daily injections of low-concentration (50 mg/kg) streptozotocin (STZ) in C57 black mice (n = 24). A group of these mice (n = 12) was co-injected with recombinant TRAIL (20 microg/day) for 5 days, and the diabetic status (glycemia and body weight) was followed over time. After 6 weeks, circulating levels of insulin, TNF-alpha, and osteoprotegerin (OPG) were measured, and animals were killed to perform the histological analysis of the pancreas. RESULTS: The in vitro exposure of both PBMCs and human islets to recombinant TRAIL significantly upregulated the expression of SOCS1. With respect to STZ-treated animals, mice co-injected with STZ+TRAIL were characterized by 1) lower levels of hyperglycemia, 2) higher levels of body weight and insulinemia, 3) a partial preservation of pancreatic islets with normal morphology, and 4) a lower expression of both systemic (TNF-alpha and OPG) and pancreatic (vascular cell adhesion molecule [VCAM]-1) inflammatory markers. CONCLUSIONS: Overall, these data demonstrate that the administration of recombinant TRAIL ameliorates the severity of STZ-induced type 1 diabetes, and this effect was accompanied by the upregulation of SOCS1 expressio
Herpesvirus telomeric repeats facilitate genomic integration into host telomeres and mobilization of viral DNA during reactivation
Some herpesviruses, particularly lymphotropic viruses such as Marek's disease
virus (MDV) and human herpesvirus 6 (HHV-6), integrate their DNA into host
chromosomes. MDV and HHV-6, among other herpesviruses, harbor telomeric
repeats (TMRs) identical to host telomeres at either end of their linear
genomes. Using MDV as a natural virus-host model, we show that herpesvirus
TMRs facilitate viral genome integration into host telomeres and that
integration is important for establishment of latency and lymphoma formation.
Integration into host telomeres also aids in reactivation from the quiescent
state of infection. Our results and the presence of TMRs in many herpesviruses
suggest that integration mediated by viral TMRs is a conserved mechanism,
which ensures faithful virus genome maintenance in host cells during cell
division and allows efficient mobilization of dormant viral genomes. This
finding is of particular importance as reactivation is critical for virus
spread between susceptible individuals and is necessary for continued
herpesvirus evolution and survival
MDM2 antagonist Nutlin-3a potentiates antitumour activity of cytotoxic drugs in sarcoma cell lines
<p>Abstract</p> <p>Background</p> <p>Frequent failure and severe side effects of current sarcoma therapy warrants new therapeutic approaches. The small-molecule MDM2 antagonist Nutlin-3a activates the p53 pathway and efficiently induces apoptosis in tumours with amplified <it>MDM2 </it>gene and overexpression of MDM2 protein. However, the majority of human sarcomas have normal level of MDM2 and the therapeutic potential of MDM2 antagonists in this group is still unclear. We have investigated if Nutlin-3a could be employed to augment the response to traditional therapy and/or reduce the genotoxic burden of chemotherapy.</p> <p>Methods</p> <p>A panel of sarcoma cell lines with different <it>TP53 </it>and <it>MDM2 </it>status were treated with Nutlin-3a combined with Doxorubicin, Methotrexate or Cisplatin, and their combination index determined.</p> <p>Results</p> <p>Clear synergism was observed when Doxorubicin and Nutlin-3a were combined in cell lines with wild-type <it>TP53 </it>and amplified <it>MDM2</it>, or with Methotrexate in both <it>MDM2 </it>normal and amplified sarcoma cell lines, allowing for up to tenfold reduction of cytotoxic drug dose. Interestingly, Nutlin-3a seemed to potentiate the effect of classical drugs as Doxorubicin and Cisplatin in cell lines with mutated <it>TP53</it>, but inhibited the effect of Methotrexate.</p> <p>Conclusion</p> <p>The use of Nutlin in combination with classical sarcoma chemotherapy shows promising preclinical potential, but since clear biomarkers are still lacking, clinical trials should be followed up with detailed tumour profiling.</p
Helicobacter pylori Infection of Gastrointestinal Epithelial Cells in vitro Induces Mesenchymal Stem Cell Migration through an NF-κB-Dependent Pathway
The role of bone marrow-derived mesenchymal stem cells (MSC) in the physiology of the gastrointestinal tract epithelium is currently not well established. These cells can be recruited in response to inflammation due to epithelial damage, home, and participate in tissue repair. In addition, in the case of tissue repair failure, these cells could transform and be at the origin of carcinomas. However, the chemoattractant molecules responsible for MSC recruitment and migration in response to epithelial damage, and particularly to Helicobacter pylori infection, remain unknown although the role of some chemokines has been suggested. This work aimed to get insight into the mechanisms of mouse MSC migration during in vitro infection of mouse gastrointestinal epithelial cells by H. pylori. Using a cell culture insert system, we showed that infection of gastrointestinal epithelial cells by different H. pylori strains is able to stimulate the migration of MSC. This mechanism involves the secretion by infected epithelial cells of multiple cytokines, with a major role of TNFα, mainly via a Nuclear Factor-kappa B-dependent pathway. This study provides the first evidence of the role of H. pylori infection in MSC migration and paves the way to a better understanding of the role of bone marrow-derived stem cells in gastric pathophysiology and carcinogenesis
Activation of the p53 pathway by the MDM2 inhibitor nutlin-3a overcomes BCL2 overexpression in a preclinical model of diffuse large B-cell lymphoma associated with t(14;18)(q32;q21)
p53 is frequently wild type (wt) in diffuse large B-cell lymphoma (DLBCL) associated with t(14;18)(q32;q21) that overexpresses BCL2. Nutlin-3a is a small molecule that activates the p53 pathway by disrupting p53–MDM2 interaction. We show that nutlin-3a activates p53 in DLBCL cells associated with t(14;18)(q32;q21), BCL2 overexpression and wt p53, resulting in cell cycle arrest and apoptosis. Nutlin-3a treatment had similar effects on DLBCL cells of activated B-cell phenotype with wt p53. Cell cycle arrest was associated with upregulation of p21. Nutlin-3a-induced apoptosis was accompanied by BAX and PUMA upregulation, BCL-XL downregulation, serine-70 dephosphorylation of BCL2, direct binding of BCL2 by p53, caspase-9 upregulation and caspase-3 cleavage. Cell death was reduced when p53-dependent transactivation activity was inhibited by pifithrin-α (PFT-α), or PFT-μ inhibited direct p53 targeting of mitochondria. Nutlin-3a sensitized activation of the intrinsic apoptotic pathway by BCL2 inhibitors in t(14;18)-positive DLBCL cells with wt p53, and enhanced doxorubicin cytotoxicity against t(14;18)-positive DLBCL cells with wt or mutant p53, the latter in part via p73 upregulation. Nutlin-3a treatment in a xenograft animal lymphoma model inhibited growth of t(14;18)-positive DLBCL tumors, associated with increased apoptosis and decreased proliferation. These data suggest that disruption of the p53–MDM2 interaction by nutlin-3a offers a novel therapeutic approach for DLBCL associated with t(14;18)(q32;q21)
Structural and ultrastructural alterations in human olfactory pathways and possible associations with herpesvirus 6 infection
Publisher Copyright: © 2017 Skuja et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Structural and ultrastructural alterations in human olfactory pathways and putative associations with human herpesvirus 6 (HHV-6) infection were studied. The olfactory bulb/tract samples from 20 subjects with an unspecified encephalopathy determined by pathomorphological examination of the brain autopsy, 17 healthy age-matched and 16 younger controls were used. HHV-6 DNA was detected in 60, 29, and 19% of cases in these groups, respectively. In the whole encephalopathy group, significantly more HHV-6 positive neurons and oligodendrocytes were found in the gray matter, whereas, significantly more HHV-6 positive astrocytes, oligodendrocytes, microglia/macrophages and endothelial cells were found in the white matter. Additionally, significantly more HHV-6 positive astrocytes and, in particular, oligodendrocytes were found in the white matter when compared to the gray matter. Furthermore, when only HHV-6 PCR+ encephalopathy cases were studied, we observed similar but stronger associations between HHV-6 positive oligodendrocytes and CD68 positive cells in the white matter. Cellular alterations were additionally evidenced by anti-S100 immunostaining, demonstrating a significantly higher number of S100 positive cells in the gray matter of the whole encephalopathy group when compared to the young controls, and in the white matter when compared to both control groups. In spite the decreased S100 expression in the PCR+ encephalopathy group when compared to PCR- cases and controls, groups demonstrated significantly higher number of S100 positive cells in the white compared to the gray matter. Ultrastructural changes confirming the damage of myelin included irregularity of membranes and ballooning of paranodal loops. This study shows that among the cellular targets of the nervous system, HHV-6 most severely affects oligodendrocytes and the myelin made by them.publishersversionPeer reviewe
TRAIL promotes caspase-dependent pro-inflammatory responses via PKCδ activation by vascular smooth muscle cells
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is best known for its selective cytotoxicity against transformed tumor cells. Most non-transformed primary cells and several cancer cell lines are not only resistant to death receptor-induced apoptosis, but also subject to inflammatory responses in a nuclear factor-κB (NF-κB)-dependent manner. Although the involvement of TRAIL in a variety of vascular disorders has been proposed, the exact molecular mechanisms are unclear. Here, we aimed to delineate the role of TRAIL in inflammatory vascular response. We also sought possible molecular mechanisms to identify potential targets for the prevention and treatment of post-angioplastic restenosis and atherosclerosis. Treatment with TRAIL increased the expression of intercellular adhesion molecule-1 by primary human vascular smooth muscle cells via protein kinase C (PKC)δ and NF-κB activation. Following detailed analysis using various PKCδ mutants, we determined that PKCδ activation was mediated by caspase-dependent proteolysis. The protective role of PKCδ was further confirmed in post-traumatic vascular remodeling in vivo. We propose that the TRAIL/TRAIL receptor system has a critical role in the pathogenesis of inflammatory vascular disorders by transducing pro-inflammatory signals via caspase-mediated PKCδ cleavage and subsequent NF-κB activation
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