The sites of near-contact between the mitochondrion and the endoplasmic reticulum (ER) have earned a lot of attention due to their key role in the maintenance of lipid and calcium (Ca(2+)) ...homeostasis, in the initiation of autophagy and mitochondrial division, and in sensing metabolic shifts. At these sites, typically called MAMs (mitochondria-associated ER membranes) or MERCs (mitochondria-ER contacts), the organelles juxtapose at a distance that can range from ~10 to ~50 nm. The multifunctional role of this subcellular compartment is puzzling; further, recent studies have shown that mitochondria-ER contacts are highly plastic structures that remodel upon metabolic transitions and that their activity in controlling lipid homeostasis could be involved in Alzheimer's disease pathogenesis. This review aims at integrating the functions of this subcellular compartment to its most characterizing and unexplored structural parameter, their 'thickness': that is, the width of the cleft that separates the cytosolic face of the outer mitochondrial membrane from that of the ER. We describe and discuss the reasons why the thickness of a MERC should be considered a regulated structural parameter of the cell that defines and controls its function. Further, we propose a MERC classification that will help organize the expanding field of MERCs biology and of their role in cell physiology and human disease.
The newly emerged human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic of respiratory illness. Current evidence suggests that severe cases of ...SARS-CoV-2 are associated with a dysregulated immune response. However, little is known about how the innate immune system responds to SARS-CoV-2. In this study, we modeled SARS-CoV-2 infection using primary human airway epithelial (pHAE) cultures, which are maintained in an air-liquid interface. We found that SARS-CoV-2 infects and replicates in pHAE cultures and is directionally released on the apical, but not basolateral, surface. Transcriptional profiling studies found that infected pHAE cultures had a molecular signature dominated by proinflammatory cytokines and chemokine induction, including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and CXCL8, and identified NF-κB and ATF-4 as key drivers of this proinflammatory cytokine response. Surprisingly, we observed a complete lack of a type I or III interferon (IFN) response to SARS-CoV-2 infection. However, pretreatment and posttreatment with type I and III IFNs significantly reduced virus replication in pHAE cultures that correlated with upregulation of antiviral effector genes. Combined, our findings demonstrate that SARS-CoV-2 does not trigger an IFN response but is sensitive to the effects of type I and III IFNs. Our studies demonstrate the utility of pHAE cultures to model SARS-CoV-2 infection and that both type I and III IFNs can serve as therapeutic options to treat COVID-19 patients.
The current pandemic of respiratory illness, COVID-19, is caused by a recently emerged coronavirus named SARS-CoV-2. This virus infects airway and lung cells causing fever, dry cough, and shortness of breath. Severe cases of COVID-19 can result in lung damage, low blood oxygen levels, and even death. As there are currently no vaccines approved for use in humans, studies of the mechanisms of SARS-CoV-2 infection are urgently needed. Our research identifies an excellent system to model SARS-CoV-2 infection of the human airways that can be used to test various treatments. Analysis of infection in this model system found that human airway epithelial cell cultures induce a strong proinflammatory cytokine response yet block the production of type I and III IFNs to SARS-CoV-2. However, treatment of airway cultures with the immune molecules type I or type III interferon (IFN) was able to inhibit SARS-CoV-2 infection. Thus, our model system identified type I or type III IFN as potential antiviral treatments for COVID-19 patients.
The COVID-19 pandemic has led to extensive morbidity and mortality throughout the world. Clinical features that drive SARS-CoV-2 pathogenesis in humans include inflammation and thrombosis, but the ...mechanistic details underlying these processes remain to be determined. In this study, we demonstrate endothelial disruption and vascular thrombosis in histopathologic sections of lungs from both humans and rhesus macaques infected with SARS-CoV-2. To define key molecular pathways associated with SARS-CoV-2 pathogenesis in macaques, we performed transcriptomic analyses of bronchoalveolar lavage and peripheral blood and proteomic analyses of serum. We observed macrophage infiltrates in lung and upregulation of macrophage, complement, platelet activation, thrombosis, and proinflammatory markers, including C-reactive protein, MX1, IL-6, IL-1, IL-8, TNFα, and NF-κB. These results suggest a model in which critical interactions between inflammatory and thrombosis pathways lead to SARS-CoV-2-induced vascular disease. Our findings suggest potential therapeutic targets for COVID-19.
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•SARS-CoV-2 infection leads to macrophage infiltrates in the lung of infected macaques•SARS-CoV-2 upregulates proinflammatory cytokines and ISGs in macaques•SARS-CoV-2 upregulates complement and coagulation cascade in macaques•SARS-CoV-2 infection leads to endothelial damage and thrombosis in macaques
Aid et al. show that SARS-CoV-2 causes endothelial disruption and vascular thrombosis in both human and rhesus macaques lungs by inducing an upregulation of proinflammatory cytokines. Using an approach that combines histopathology and multiomics in macaques, they show the progression to vascular disease over time, which involves complement, macrophage, cytokine, and thrombosis cascades.
In response to the emerging crisis and growing calls from patients and clinicians for guidance 5, a working group of clinical experts from the International College of Obsessive Compulsive Spectrum ...Disorders (ICOCS) and the Obsessive-Compulsive and Related Disorders Research Network of the European College of Neuropsychopharmacology (OCRN) have produced this consensus statement with the aim of delivering pragmatic guidance at the earliest opportunity to clinicians for managing this complex challenge. Based on the risks associated with exposure and response prevention (ERP) in the pandemic (see below), and uncertainty as to which of the two evidence-based treatments, pharmacotherapy or cognitive behaviour therapy (CBT), represents the most efficacious first line treatment modality 11, pharmacotherapy should be the first option for adults and children with OCD with contamination, washing or cleaning symptoms during the COVID-19 pandemic. Consider A) type of medication; most patients should receive an SSRI, or if not responsive, another SSRI and as a third choice clomipramine (for which an ECG may be required in certain patient groups); Note US Food and Drug Administration "black box" warnings or advice from equivalent national regulatory authorities regarding increased risk in young people and other vulnerable patient groups. Check for adverse effects and be available for any concerns related to "activation" or newly emergent or increased suicidal ideation, which in the young can be mitigated by starting treatment at a low dose and titrating more gradually; B) dosage; if the patient is on a suboptimal dose, consider increasing it, paying attention to any contraindications; C) SSRI-resistance; consider a low dose of adjunctive antipsychotic (aripiprazole, risperidone, quetiapine, olanzapine), especially if a tic is present; D) adherence; ensure the patient is able to obtain an adequate supply and is taking the treatment regularly.
•C. beijerinckii DSM 791 is a robust organism for 1,3-PDO production from glycerol.•Replacing yeast extract with corn steep liquor increased cell growth and productivity.•Stable, long-term 1,3-PDO ...production was obtained in repeated batch fermentations.•Cell was engineered to overexpress GDH and DHAK.•1,3-PDO productivity increased 26.8–37.5% with a greatly increased growth rate.
1,3-Propanediol (1,3-PDO) production from crude glycerol, a byproduct from biodiesel manufacturing, by Clostridium beijerinckii DSM 791 was studied with corn steep liquor as an inexpensive nitrogen source replacing yeast extract in the fermentation medium. A stable, long-term 1,3-PDO production from glycerol was demonstrated with cells immobilized in a fibrous bed bioreactor operated in a repeated batch mode, which partially circumvented the 1,3-PDO inhibition problem. The strain was then engineered to overexpress Escherichia coli gldA encoding glycerol dehydrogenase (GDH) and dhaKLM encoding dihydroxyacetone kinase (DHAK), which increased 1,3-PDO productivity by 26.8–37.5% compared to the wild type, because of greatly increased specific growth rate (0.25–0.40h−1 vs. 0.13–0.20h−1 for the wild type). The engineered strain gave a high 1,3-PDO titer (26.1g/L), yield (0.55g/g) and productivity (0.99g/L·h) in fed-batch fermentation. Overexpressing GDH and DHAK was thus effective in increasing 1,3-PDO production from glycerol.
The hormonal milieu influences immune tolerance and the immune response against viruses and cancer, but the direct effect of androgens on cellular immunity remains largely uncharacterized. We ...therefore sought to evaluate the effect of androgens on murine and human T cells in vivo and in vitro. We found that murine androgen deprivation in vivo elicited RNA expression patterns conducive to IFN signaling and T-cell differentiation. Interrogation of mechanism showed that testosterone regulates T-helper 1 (Th1) differentiation by inhibiting IL-12–induced Stat4 phosphorylation: in murine models, we determined that androgen receptor binds a conserved region within the phosphatase, Ptpn1, and consequent up-regulation of Ptpn1 then inhibits IL-12 signaling in CD4 T cells. The clinical relevance of this mechanism, whereby the androgen milieu modulates CD4 T-cell differentiation, was ascertained as we found that androgen deprivation reduced expression of Ptpn1 in CD4 cells from patients undergoing androgen deprivation therapy for prostate cancer. Our findings, which demonstrate a clinically relevant mechanism by which androgens inhibit Th1 differentiation of CD4 T cells, provide rationale for targeting androgens to enhance CD4-mediated immune responses in cancer or, conversely, for modulating androgens to mitigate CD4 responses in disorders of autoimmunity.
Mitochondria are crucial amplifiers of death signals. They release cytochrome c and other pro-apoptotic factors required to fully activate effector caspases. This release is accompanied by ...fragmentation of the mitochondrial reticulum and by remodelling of the internal structure of the organelle. Here we review data supporting the existence of a regulatory network in the inner mitochondrial membrane that includes optic atrophy 1 (Opa1), a dynamin-related protein, and presenilin-associated rhomboid-like (Parl), a rhomboid protease. Opa1 regulates remodelling of the cristae independent of its effect on fusion. Cristae remodelling conversely requires Parl, which participates in the production of a soluble form of Opa1 retrieved together with the integral membrane one in oligomers that are disrupted early during apoptosis. Parl itself is regulated by proteolysis to generate a cleaved form, which in turn modulates the shape of the mitochondrial reticulum. Cleavage of Parl depends on its phosphorylation state around the cleavage site, implicating mitochondrial kinases and phosphatases in the regulation of mitochondrial shape.
The high incidence of acute and chronic kidney injury due to various environmental factors such as heavy metals or chemicals has been a major problem in developing countries. However, the diagnosis ...of kidney injury in these areas can be more challenging due to the lack of highly sensitive and specific techniques that can be applied in point-of-care settings. To address this, we have developed a technique called 'micro-urine nanoparticle detection (μUNPD)', that allows the detection of trace amounts of molecular markers in urine. Specifically, this technique utilizes an automated on-chip assay followed by detection with a hand-held device for the read-out. Using the μUNPD technology, the kidney injury markers KIM-1 and Cystatin C were detected down to concentrations of 0.1 ng/ml and 20 ng/ml respectively, which meets the cut-off range required to identify patients with acute or chronic kidney injury. Thus, we show that the μUNPD technology enables point of care and non-invasive detection of kidney injury, and has potential for applications in diagnosing kidney injury with high sensitivity in resource-limited settings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pepsin is one of the major enzymes with significant importance in the food industry, biomedicines, and pharmaceutical formulations. In this work, the main objective was to biochemically characterize ...a pepsin-like enzymatic extract obtained from Pygocentrus nattereri, a predatory freshwater fish, focusing on their potential industrial application. The obtained extract exhibited optimal activity at 45 °C and pH 1.0–2.0. These proteases remained stable after 2 h of incubation at temperatures ranging from 0° to 45 °C and within pH range of 1.0 to 7.0. Their activity was significantly affected in presence of pepstatin A and SDS, 10 μM and 3.46 mM respectively, while EDTA and PMSF showed partial inhibitory effects. Divalent cations (Ca2+ and Mg2+) did not inhibit the proteolytic activity of the extract; in fact, it improved at a 5 mM CaCl2 concentration. As the NaCl concentration increased, the enzyme activity decreased. However, after desalination, 90 % of the activity was recovered within the tested exposure time. Besides, this extract demonstrated exceptional versatility across diverse industrial applications, including collagen extraction augmentation, IgG hydrolysis facilitation, and silver and polyester recovery from X-ray films. Our results suggest that the obtained enzymatic extract has a wide range of potential applications.
•Pygocentrus nattereri offers fishing by-products containing high value proteins•Simple extractive method like as acid precipitation yields an acidic protease-rich extract.•The proteolytic activity exhibit by the acid extract demonstrated a remarkable pH stability range (1.0-7.0).•The extract demonstrates versatility in industrial applications, including collagen extraction, IgG hydrolysis, and recovery of silver and polyester from X-ray films.
In this commentary we critically discuss the suitability of payments for ecosystem services and the most important challenges they face. While such instruments can play a role in improving ...environmental governance, we argue that over‐reliance on payments as win‐win solutions might lead to ineffective outcomes, similar to earlier experience with integrated conservation and development projects. Our objective is to raise awareness, particularly among policy makers and practitioners, about the limitations of such instruments and to encourage a dialogue about the policy contexts in which they might be appropriate.
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