The lung is the organ with the highest vascular density in the human body. It is therefore perceivable that the endothelium of the lung contributes significantly to the circulation of extracellular ...vesicles (EVs), which include exosomes, microvesicles, and apoptotic bodies. In addition to the endothelium, EVs may arise from alveolar macrophages, fibroblasts and epithelial cells. Because EVs harbor cargo molecules, such as miRNA, mRNA, and proteins, these intercellular communicators provide important insight into the health and disease condition of donor cells and may serve as useful biomarkers of lung disease processes. This comprehensive review focuses on what is currently known about the role of EVs as markers and mediators of lung pathologies including COPD, pulmonary hypertension, asthma, lung cancer and ALI/ARDS. We also explore the role EVs can potentially serve as therapeutics for these lung diseases when released from healthy progenitor cells, such as mesenchymal stem cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Human Fc receptor-like 3 (FCRL3) is an orphan receptor expressed by lymphocytes, including regulatory T cells. FCRL3 is implicated in several autoimmune diseases; however, its function on regulatory ...T cells is unknown. We discovered that FCRL3 stimulation of regulatory T cells inhibited their suppressive function. Moreover, FCRL3 stimulation induced IL-17, IL-26, and IFNγ production and promoted expression of the Th17-defining transcription factor RORγt without affecting FOXP3 expression. We suggest that FCRL3 engagement mediates a transition of regulatory T cells to a pro-inflammatory Th17-like phenotype. In addition, we identified secretory IgA as a specific FCRL3 ligand. Secretory IgA could serve as an environmental cue for mucosal breaches and locally drive regulatory T cell plasticity to help control infection. Our findings define a mechanism that explains the recognized association of FCRL3 with autoimmune diseases. Targeting FCRL3 to modulate regulatory T cell activity could be exploited to treat both malignancies and autoimmune diseases.
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•Secretory IgA binds FCRL3, whereas dimeric IgA and monomeric IgA do not bind•FCRL3 stimulation with an antibody or ligand inhibits regulatory T cell functionality•FCRL3-stimulated regulatory T cells express RORγt and produce IL-17, IL-26, and IFNγ
The key role of secretory IgA in neutralizing pathogens in mucosal surfaces is well established. Agarwal et al. propose that secretory IgA entering the body through breached mucosa engages FCRL3 on regulatory T cells and suppresses their inhibitory function. FCRL3 could be therapeutically targeted to modulate regulatory T cell activity.
The key sensor of energy status in mammalian cells, AMP-activated protein kinase (AMPK), can also be activated by the AMP analog aminoimidazolecarboxamide nucleoside monophosphate (ZMP) generated ...directly from aminoimidazolecarboxamide ribonucleoside (AICAR) or from inhibition of purine synthesis by the antifolate pemetrexed (PTX), a drug used extensively in the treatment of lung cancers. Despite this common mechanism, signaling downstream of AMPK activated by PTX or AICAR differed. AICAR-activated AMPK inhibited mTORC1 both directly by phosphorylation of the mTORC1 subunit Raptor and indirectly by phosphorylation of the regulator TSC2. In contrast, PTX-activated AMPK inhibited mTORC1 solely through Raptor phosphorylation. This dichotomy was due to p53 function. Transcription of p53 target genes, including TSC2, was activated by AICAR but not by PTX. Although both PTX and AICAR stabilized p53, only AICAR activated Chk2 phosphorylation, stimulating p53-dependent transcription. However, Raptor phosphorylation by AMPK was independent of p53 and was sufficient, after PTX treatment, to inhibit mTORC1. We concluded that PTX effects on mTORC1 were independent of TSC2 and p53 and that the activation of a p53 transcriptional response by AICAR was due to an activation of Chk2 that was not elicited by PTX.
The antifolate pemetrexed (PTX) and the nucleoside AICAR both activate AMPK via ZMP accumulation.
AICAR-activated AMPK signals to both TSC2 and Raptor arms of mTORC1 control, whereas PTX-activated AMPK uses only the Raptor arm because p53-mediated transcription is not activated.
Raptor phosphorylation by PTX-activated AMPK is necessary and sufficient to suppress mTORC1 in carcinomas.
PTX suppression of mTORC1 is p53- and TSC2-independent.
Purpose: To assess the cost of pediatric cataract surgery in a tertiary eye care hospital from a provider's perspective. Methods: Retrospective review of direct costs incurred for pediatric cataract ...surgery for the financial year April 1, 2018, to March 31, 2019. The cost analysis was done by standard costing methods. The fixed cost included the cost of land, buildings, construction, maintenance, personnel, operation theater (OT), and Out patient department (OPD) equipment. The variable cost included the cost of consumables used during surgery. The indirect costs were not considered. Results: The per-patient fixed facility cost was INR 1.52 ($0.02), maintenance cost was INR 39.06 ($0.55), OPD equipment and consultation were INR 19.64 ($0.28), OT equipment was INR 467.95 ($6.61), the cost for personnel was INR 5,300.33 ($74.92), and the cost of consumables varied between INR 16,418 ($314.44) and INR 22,313 ($397.76), with the choice of intraocular lenses (IOL) being the main determining factor. The net average cost for a pediatric cataract surgery varied between INR 22,246.50 ($ 314.44) and INR 28,141.50 ($ 397.76). Conclusion: Pediatric cataract surgeries are cost-intensive. High-volume surgeries and an increase in the number of patients in OPD reduce the fixed facility cost. But there is an overall increase in human resource (HR) and consumable cost owing to economic and technological reforms. However, the impact of operating a child, thereby, increasing his/her blindness-free years probably outweighs the cost and justifies it. High patient inflow, increased number of surgeries, and bulk purchase of consumables help in decreasing the cost.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chronic infection with HBV has been reported to be associated with the development of HCC. The inflammation mounted by cytokine-mediated immune system plays an important role in the pathogenesis of ...HBV-associated HCC. IL-18 is a pro-inflammatory cytokine whose role in the development of HBV-associated chronic to malignant disease state has not been much studied. The present study was conceived to determine the role of genetic polymorphisms in
IL-18,
serum levels of IL-18, and expression level of its signal transducers in the HBV disease progression. A total of 403 subjects were enrolled for this study including 102 healthy subjects and 301 patients with HBV infection in different diseased categories. Polymorphism was determined using PCR–RFLP. Genotypic distributions between the groups were compared using odd’s ratio and 95% CI were calculated to express the relative risk. Circulating IL-18 levels were determined by ELISA. Expression levels of pSTAT-1 and pNFƙB was determined by western blotting. In case of
IL-18(
−
607C
>
A),
the heterozygous genotype (CA) was found to be a protective factor while in case of
IL-18(
−
137G
>
C)
the heterozygous genotype (GC) acted as a risk factor for disease progression from HBV to HCC. Moreover, serum IL-18 levels were significantly increased during HBV disease progression to HCC as compared to controls. Also the levels of activated signal transducers (pSTAT-1 and pNF-κB) of IL-18 in stimulated PBMCs were significantly increased during HBV to HCC disease progression. These findings suggest that IL-18 has the potential to act as a biomarker of HBV-related disease progression to HCC.
The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its sublineages pose a new challenge to healthcare systems worldwide due to its ...ability to efficiently spread in immunized populations and its resistance to currently available therapies. COVID-19, although targeting primarily the respiratory system, is also now well established that later affects every organ in the body. Most importantly, despite the available therapy and vaccine-elicited protection, the long-term consequences of viral infection in breakthrough and asymptomatic individuals are areas of concern. In the past two years, investigators accumulated evidence on how the virus triggers our immune system and the molecular signals involved in the cross-talk between immune cells and structural cells in the pulmonary vasculature to drive pathological lung complications such as endothelial dysfunction and thrombosis. In the review, we emphasize recent updates on the pathophysiological inflammatory and immune responses associated with SARS-CoV-2 infection and their potential long-term consequences that may consequently lead to the development of pulmonary vascular diseases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The activity of mammalian target of rapamycin complex 1 (mTORC1) is frequently enhanced in carcinomas, an effect thought to contribute to the malignant phenotype. Here, it is demonstrated that either ...deletion or mutation of TP53 in colon or lung carcinoma cells substantially enhances mTORC1 kinase activity by an effect downstream of and independent of AMPK. Mechanistically, it was determined that loss or mutation of p53 decreased expression of TSC2 and Sestrin2 (SESN2). Complementation of p53 null cells with TSC2 or Sestrin2 reduced mTORC1 activity to levels found in p53 wild-type (wt) cells, whereas their genetic depletion enhanced mTORC1 activity in p53 wt cells. However, the primary causal event in enhanced mTORC1 activity upon loss of p53 appeared to be a diminished distribution of TSC2 to lysosomal membranes containing mTOR. Subsequently, there was increased Rheb in the lysosomal compartment, and a higher mTOR association with Raptor. Transfection of TSC2 into p53 null cells replaced TSC2 and diminished Rheb at the lysosome, recapitulating cells with wt p53. In contrast, transfection of Sestrin2 decreased mTOR in lysosomes, but the lower levels of Sestrin2 in p53 null cells did not change lysosomal mTOR. In summary, loss of the transcriptional activity of p53, either by deletion or by key mutations in the DNA-binding domain, diminishes expression of TSC2 and Sestrin2, thus, shifting membrane-bound TSC2 out of lysosomal membranes, increasing lysosomal Rheb and increasing the kinase activity of mTORC1.
This study establishes that loss of p53 function decreases lysosomal TSC2 and increases lysosomal Rheb resulting in hyperactive mTORC1, findings that are consistent with a more malignant phenotype.
Background
Earlier, we reported that the simultaneous exposure of pulmonary arterial smooth muscle cells to HIV proteins and cocaine results in the attenuation of antiproliferative bone morphogenetic ...protein receptor‐2 (BMPR2) protein expression without any decrease in its mRNA levels. Therefore, in this study, we aimed to investigate the micro RNA‐mediated posttranscriptional regulation of BMPR2 expression.
Methods and Results
We identified a network of BMPR2 targeting micro RNAs including miR‐216a to be upregulated in response to cocaine and Tat‐mediated augmentation of oxidative stress and transforming growth factor‐β signaling in human pulmonary arterial smooth muscle cells. By using a loss or gain of function studies, we observed that these upregulated micro RNAs are involved in the Tat‐ and cocaine‐mediated smooth muscle hyperplasia via regulation of BMPR2 protein expression. These in vitro findings were further corroborated using rat pulmonary arterial smooth muscle cells isolated from HIV transgenic rats exposed to cocaine. More importantly, luciferase reporter and in vitro translation assays demonstrated that direct binding of novel miR‐216a and miR‐301a to 3′UTR of BMPR2 results in the translational repression of BMPR2 without any degradation of its mRNA.
Conclusions
We identified for the first time miR‐216a as a negative modulator of BMPR2 translation and observed it to be involved in HIV protein(s) and cocaine‐mediated enhanced proliferation of pulmonary smooth muscle cells.
Pulmonary arterial hypertension (PAH) is a rare disease characterized by pulmonary vascular remodeling and right heart failure. Specific genetic variants increase the incidence of PAH in carriers ...with a family history of PAH, those who suffer from certain medical conditions, and even those with no apparent risk factors. Inflammation and immune dysregulation are related to vascular remodeling in PAH, but whether genetic susceptibility modifies the PAH immune response is unclear.
and
encode for immunomodulatory proteins that regulate NF-κB activation, a transcription factor complex associated with inflammation and vascular remodeling in PAH.
Two unrelated families with PAH cases underwent whole-exome sequencing (WES). A custom pipeline for variant prioritization was carried out to obtain candidate variants. To determine the impact of TNIP2 and TRAF2 in cell proliferation, we performed an MTS 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay on healthy lung pericytes transfected with siRNA specific for each gene. To measure the effect of loss of TNIP2 and TRAF2 on NF-kappa-beta (NF-κB) activity, we measured levels of Phospho-p65-NF-κB in siRNA-transfected pericytes using western immunoblotting.
We discovered a novel missense variant in the
gene in two affected individuals from the same family. The two patients had a complex form of PAH with interatrial communication and scleroderma. In the second family, WES of the proband with PAH and primary biliary cirrhosis revealed a
protein-truncating variant in the
. The knockdown of TNIP2 and TRAF2 increased NF-κB activity in healthy lung pericytes, which correlated with a significant increase in proliferation over 24 h.
We have identified two rare novel variants in
and
using WES. We speculate that loss of function in these genes promotes pulmonary vascular remodeling by allowing overactivation of the NF-κB signaling activity. Our findings support a role for WES in helping identify novel genetic variants associated with dysfunctional immune response in PAH.
We previously demonstrated that the combined exposure of human pulmonary microvascular endothelial cells (HPMECs) to morphine and viral protein(s) results in the oxidative stress-mediated induction ...of autophagy, leading to shift in the cells from early apoptotic to apoptosis-resistant proliferative status associated with the angioproliferative remodeling observed in pulmonary arterial hypertension (PAH). In this study, we tried to delineate the major source of HIV-1 protein Tat and morphine induced oxidative burst in HPMECs and its consequences on vascular remodeling and PAH in an in vivo model. We observed switch from the initial increased expression of NADPH oxidase (NOX) 2 in response to acute treatment of morphine and HIV-Tat to later increased expression of NOX4 on chronic treatment in the endoplasmic reticulum of HPMECs without any alterations in the mitochondria. Furthermore, NOX-dependent induction of autophagy was observed to play a pivotal role in regulating the endothelial cell survival. Our in vivo findings showed significant increase in pulmonary vascular remodeling, right ventricular systolic pressure, and Fulton index in HIV-transgenic rats on chronic administration of morphine. This was associated with increased oxidative stress in lung tissues and rat pulmonary microvascular endothelial cells. Additionally, endothelial cells from morphine-treated HIV-transgenic rats demonstrated increased expression of NOX2 and NOX4 proteins, inhibition of which ameliorated their increased survival upon serum starvation. In conclusion, this study describes NADPH oxidases as one of the main players in the oxidative stress-mediated endothelial dysfunction on the dual hit of HIV-viral protein(s) and opioids.
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