The role of desmoglein-2 in kidney disease

Desmosomes are multi-protein cell-cell adhesion structures supporting cell stability and mechanical stress resilience of tissues, best described in skin and heart. The kidney is exposed to various mechanical stimuli and stress, yet little is known about kidney desmosomes. In healthy kidneys, we found desmosomal proteins located at the apical-junctional complex in tubular epithelial cells. In four different animal models and patient biopsies with various kidney diseases, desmosomal components were significantly upregulated and partly miss-localized outside of the apical-junctional complexes along the whole lateral tubular epithelial cell membrane. The most upregulated component was desmoglein-2 (Dsg2). Mice with constitutive tubular epithelial cell-specific deletion of Dsg2 developed normally, and other desmosomal components were not altered in these mice. When challenged with different types of tubular epithelial cell injury (unilateral ureteral obstruction, ischemia-reperfusion, and 2,8-dihydroxyadenine crystal nephropathy), we found increased tubular epithelial cell apoptosis, proliferation, tubular atrophy, and inflammation compared to wild-type mice in all models and time points. In vitro, silencing DSG2 via siRNA weakened cell-cell adhesion in HK-2 cells and increased cell death. Thus, our data show a prominent upregulation of desmosomal components in tubular cells across species and diseases and suggest a protective role of Dsg2 against various injurious stimuli.

Endurance Training Provokes Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Heterozygous Desmoglein-2 Mutants: Alleviation by Preload Reduction

Desmoglein-2 mutations are detected in 5-10% of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Endurance training accelerates the development of the ARVC phenotype, leading to earlier arrhythmic events. Homozygous Dsg2 mutant mice develop a severe ARVC-like phenotype. The phenotype of heterozygous mutant (Dsg2mt/wt) or haploinsufficient (Dsg20/wt) mice is still not well understood. To assess the effects of age and endurance swim training, we studied cardiac morphology and function in sedentary one-year-old Dsg2mt/wt and Dsg20/wt mice and in young Dsg2mt/wt mice exposed to endurance swim training. Cardiac structure was only occasionally affected in aged Dsg20/wt and Dsg2mt/wt mice manifesting as small fibrotic foci and displacement of Connexin 43. Endurance swim training increased the right ventricular (RV) diameter and decreased RV function in Dsg2mt/wt mice but not in wild types. Dsg2mt/wt hearts showed increased ventricular activation times and pacing-induced ventricular arrhythmia without obvious fibrosis or inflammation. Preload-reducing therapy during training prevented RV enlargement and alleviated the electrophysiological phenotype. Taken together, endurance swim training induced features of ARVC in young adult Dsg2mt/wt mice. Prolonged ventricular activation times in the hearts of trained Dsg2mt/wt mice are therefore a potential mechanism for increased arrhythmia risk. Preload-reducing therapy prevented training-induced ARVC phenotype pointing to beneficial treatment options in human patients.

Exploiting Enhanced Lipid Metabolism in Glioblastoma through Diet Modification

PURPOSE/OBJECTIVE(S)

Enhanced lipid metabolism has emerged as a central metabolic node in glioblastoma, serving as a 'gain of function' that allows these cells to efficiently adapt to their dynamic tumor microenvironment. Seemingly contradictory to this, pre-clinical studies have demonstrated anti-tumor activity in mice fed a high-fat/low-carbohydrate ketogenic diet (KD), both alone and in combination with radiation therapy (RT). In this study, we sought to identify mechanisms underlying the antitumor activity of a KD in glioblastoma from a metabolic perspective to better understand factors contributing to this apparent disconnect.

MATERIALS/METHODS

Immunocompromised and immunocompetent mice were injected orthotopically with human and mouse-derived glioblastoma cell lines and randomized to four treatment arms. Mice were fed ad libitum a standard diet (SD), KD (Bio-Serve), or a modified unsaturated fatty acid (uFA) rich diet (MD; 60/30/10: fat/protein/carb) alone or in combination with hypofractionated RT (6 Gy x 3). Global metabolomic profiling of tumors and serum were carried out using LC/GC-MS. Lipid droplets were analyzed by flow cytometer and confocal microscopy using BODIPY staining and free fatty acids were measured using a commercially available kit.

RESULTS

A KD demonstrated independent anti-tumor activity and potent synergy with RT in two aggressive glioblastoma models. Metabolomic profiling of tumors revealed significant changes in tumor metabolism in KD-fed mice when compared to SD, with an accumulation of uFAs being a key finding. We therefore sought to determine if this accumulation of fatty acids in KD mice contributed towards the observed anti-tumor activity. Consistent with in vivo results, in vitro studies using the uFA linoleic acid demonstrated anti-proliferative activity, reduced clonogenic capacity, and potent synergy when combined with RT in glioblastoma cells. Through a series of investigations, we went on to determine that this anti-tumor activity was attributed to the ability of uFA to override lipid storage homeostasis in glioblastoma cells, resulting in lipotoxicity. Based on these findings, we hypothesized high fat concentrations, rather than carbohydrate restriction, contributed to the anti-tumor activity of a KD. To test this, we generated a MD rich in uFA that did not require carbohydrate restriction. Similar to a KD, mice fed a MD demonstrated both independent anti-tumor activity and potent synergy when combined with RT.

CONCLUSION

High concentrations of uFA represents a key factor underlying the anti-tumor activity of a KD in glioblastoma by targeting lipid homeostasis. A MD consisting of high concentrations of uFA without carbohydrate restriction demonstrates promising anti-tumor activity in glioblastoma models. As a major limitation of a KD is tolerability, particularly in glioblastoma patients, a MD represents a promising form of dietary modification that may be translated clinically.

Nrf2 induces malignant transformation of hepatic progenitor cells by inducing β-catenin expression

The Nrf2 signaling pathway prevents cancer initiation, but genetic mutations that activate this pathway are found in various types of cancer. The molecular mechanisms underlying this Janus-headed character are still not understood. Here, we show that sustained Nrf2 activation induces proliferation and dedifferentiation of a Wnt-responsive perivenular hepatic progenitor cell population, transforming them into metastatic cancer cells. The neoplastic lesions display many histological features known from human hepatoblastoma. We describe an Nrf2-induced upregulation of β-catenin expression and its activation as the underlying mechanism for the observed malignant transformation. Thus, we have identified the Nrf2–β-catenin axis promoting proliferation of hepatic stem cells and triggering tumorigenesis. These findings support the concept that different functional levels of Nrf2 control both the protection against various toxins as well as liver regeneration by activating hepatic stem cells. Activation of the hepatic stem cell compartment confers the observation that unbridled Nrf2 activation may trigger tumorigenesis.

Lipocalin 2 attenuates oligodendrocyte loss and immune cell infiltration in mouse models for multiple sclerosis

Multiple sclerosis (MS) is a central nervous system disease characterized by both degenerative and inflammatory processes. Various mediators are involved in the interplay of degeneration and innate immunity on one hand and peripheral adaptive immunity on the other hand. The secreted protein lipocalin 2 (LCN2) is an inflammatory modulator in a variety of pathologies. Although elevated intrathecal levels of LCN2 have been reported in MS patients, it's functional role is widely unknown. Here, we identified a subpopulation of astrocytes as a source of LCN2 in MS lesions and respective animal models. We investigated the functional role of LCN2 for both autoimmune and degenerative aspects in three MS mouse models including both wild type (WT) and Lcn2^-/- mouse strains. While the experimental autoimmune encephalomyelitis (EAE) model reflects primary autoimmunity, the cuprizone model reflects selective oligodendrocyte loss and demyelination. In addition, we included a combinatory Cup/EAE model in which primary cytodegeneration is followed by inflammatory lesions within the forebrain. While in the EAE model, the disease outcome was comparable in between the two mouse strains, cuprizone intoxicated Lcn2^-/- animals showed an increased loss of oligodendrocytes. In the Cup/EAE model, Lcn2^-/- animals showed increased inflammation when compared to WT mice. Together, our results highlight LCN2 as a potentially protective molecule in MS lesion formation, which might be able to limit loss of oligodendrocytes immune-cell invasion. Despite these findings, it is not yet clear which glial cell phenotype (and to which extent) contributes to the observed neuroprotective effects, that is, microglia and/or astroglia or even endothelial cells in the brain.

Analyzing occupational heat stress using sensor-based monitoring: a wearable approach with environmental ergonomics perspective

Occupational heat stress could impose a greater risk of heat-related morbidities among the exposed users, declining their work productivity and contributing to a financial burden. This necessitate the implementation of adequate preventive measures and control policies to improve the users' well-being and productive capacity. The emergence of modernistic sensors gives rise to workplace heat stress monitoring at a substantially lower cost than expensive conventional equipment. Present work unveils the productive role of sensor-based safety helmet, which could monitor the environmental variables, heat stress indices, and users' physiological variables as an indicator of heat strain. The proposed safety helmet was tested under three different work environments with users' engaged in specific work activities. Notable variations were perceived among the measured data under respective work conditions and physical activity performed. Higher heat risk exposures were attributable to the outdoor condition compared to indoor work conditions. For wet bulb globe temperature index, strong association (p-value < 0.01) was observed with fighter index of thermal stress (R ²-value = 0.959) followed by discomfort index (R ²-value = 0.899) and heat index (R ²-value = 0.867). Results revealed a rise in measured physiological parameters under the heavy workload activity (shoveling task; outdoor location) followed by hacksaw cutting task (indoor location), while least values were associated with light workload activity (drilling task; indoor location). The proposed design intervention could be considered an effective site-specific solution for monitoring heat stress exposures and keeping exposed users well aware of the prevalent thermal work conditions at the individual level.

Autophagy and Endoplasmic Reticulum Stress during Onset and Progression of Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is a heritable, potentially lethal disease without a causal therapy. AC is characterized by focal cardiomyocyte death followed by inflammation and progressive formation of connective tissue. The pathomechanisms leading to structural disease onset and progression, however, are not fully elucidated. Recent studies revealed that dysregulation of autophagy and endoplasmic/sarcoplasmic reticulum (ER/SR) stress plays an important role in cardiac pathophysiology. We therefore examined the temporal and spatial expression patterns of autophagy and ER/SR stress indicators in murine AC models by qRT-PCR, immunohistochemistry, in situ hybridization and electron microscopy. Cardiomyocytes overexpressing the autophagy markers LC3 and SQSTM1/p62 and containing prominent autophagic vacuoles were detected next to regions of inflammation and fibrosis during onset and chronic disease progression. mRNAs of the ER stress markers Chop and sXbp1 were elevated in both ventricles at disease onset. During chronic disease progression Chop mRNA was upregulated in right ventricles. In addition, reduced Ryr2 mRNA expression together with often drastically enlarged ER/SR cisternae further indicated SR dysfunction during this disease phase. Our observations support the hypothesis that locally altered autophagy and enhanced ER/SR stress play a role in AC pathogenesis both at the onset and during chronic progression.

Desmoglein 2 regulates cardiogenesis by restricting hematopoiesis in the developing murine heart

Cardiac morphogenesis relies on intricate intercellular signaling. Altered signaling impacts cardiac function and is detrimental to embryonic survival. Here we report an unexpected regulatory role of the desmosomal cell adhesion molecule desmoglein 2 (Dsg2) on murine heart development. A large percentage of Dsg2-mutant embryos develop pericardial hemorrhage. Lethal myocardial rupture is occasionally observed, which is not associated with loss of cardiomyocyte contact but with expansion of abnormal, non-myocyte cell clusters within the myocardial wall. Two types of abnormal cell clusters can be distinguished: Type A clusters involve endocard-associated, round-shaped CD31⁺ cells, which proliferate and invade the myocardium. They acquire Runx1- and CD44-positivity indicating a shift towards a hematopoietic phenotype. Type B clusters expand subepicardially and next to type A clusters. They consist primarily of Ter119⁺ erythroid cells with interspersed Runx1⁺/CD44⁺ cells suggesting that they originate from type A cell clusters. The observed pericardial hemorrhage is caused by migration of erythrocytes from type B clusters through the epicardium and rupture of the altered cardiac wall. Finally, evidence is presented that structural defects of Dsg2-depleted cardiomyocytes are primary to the observed pathogenesis. We propose that cardiomyocyte-driven paracrine signaling, which likely involves Notch1, directs subsequent trans-differentiation of endo- and epicardial cells. Together, our observations uncover a hitherto unknown regulatory role of Dsg2 in cardiogenesis.

Signatures for chronic obstructive pulmonary disease (COPD) and asthma: a comparative genetic analysis

Background: Chronic obstructive pulmonary disease (COPD) and asthma are obstructive lung diseases which progress in severity with time. Environmental causes and genetic makeup of individuals play important roles in disease manifestation. The aim of present study was to search for diagnostic/prognostic biomarkers to differentiate COPD and asthma.Materials and methods: Seven ADAM33 and two AQP5 single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. The association of genotypes, haplotypes and allelic combination of variants in different genes was analyzed in 194 COPD, 150 asthma patients and 220 controls.Results: The genotype frequencies of SNPs V4(C/G), T1(T/C), S2(G/C) of ADAM33 and AQP5 A/G (rs3736309) were associated with COPD and asthma (P=0.038 to P<0.001), while S1(A/G) and F+1(C/T) were associated with asthma (both P<0.001) and V1(G/T) with 20 COPD (P<0.001). The allele frequencies of V4(C/G) (both P<0.001), V1(G/T) (both P<0.05), S2(G/C) (both P<0.01) and S1(A/G) (both P<0.05) were associated with COPD and asthma, while F+1(C/T) was associated only with asthma (P=0.005). Haplotypes of ADAM33 'GGTGGGT' (P=0.027), 'CGTCGGC' (P<0.001) and AQP5 'GA' and 'AG' (both P<0.001) were significant only in COPD.Conclusion: ADAM33 F+1(C/T) variant and allele combination 'GGTGGGTGA' may be specific markers for asthma, while AQP5 'AG' appeared as a haplotype associated only with COPD. These specific genetic biomarkers may be exploited to predict individual predisposition to COPD and asthma.

COPD exacerbation rates are higher in non-smoker patients in India

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is common among non-smokers exposed to solid fuel combustion at home. Different clinical characteristics in these patients may have significant therapeutic and prognostic implications.METHODS: We used medical record review and a questionnaire among COPD patients at 15 centres across India to capture data on demographic details, different types of exposures and clinical characteristics. Chest radiography and pulmonary function testing were performed in all 1984 cases; C-reactive protein and exhaled breath nitric oxide were measured wherever available.RESULTS: There were 1388 current or ex-smokers and 596 (30.0%) non-smokers who included 259 (43.5%) male and 337 (56.5%) female patients. Sputum production was significantly more common in smokers with COPD (P < 0.05). The frequency of acute symptomatic worsening, emergency visits and hospitalisation were significantly higher (P < 0.05) in non-smokers with COPD; however, intensive care unit admissions were similar in the two groups. There was no significant difference with respect to the use of bronchodilators, inhalational steroids or home nebulisation among smoker and non-smoker patients. The mean predicted forced expiratory volume in 1 sec in smokers (43.1%) was significantly lower than in non-smokers (46.5%).CONCLUSION: Non-smoker COPD, more commonly observed in women exposed to biomass fuels, was characterised by higher rate of exacerbations and higher healthcare resource utilisation.

Inflammation shapes pathogenesis of murine arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is an incurable genetic disease, whose pathogenesis is poorly understood. AC is characterized by arrhythmia, fibrosis, and cardiodilation that may lead to sudden cardiac death or heart failure. To elucidate AC pathogenesis and to design possible treatment strategies of AC, multiple murine models have been established. Among them, mice carrying desmoglein 2 mutations are particularly valuable given the identification of desmoglein 2 mutations in human AC and the detection of desmoglein 2 auto-antibodies in AC patients. Using two mouse strains producing either a mutant desmoglein 2 or lacking desmoglein 2 in cardiomyocytes, we test the hypothesis that inflammation is a major component of disease pathogenesis. We show that multifocal cardiomyocyte necrosis initiates a neutrophil-dominated inflammatory response, which also involves macrophages and T cells. Increased expression of Ccl2/Ccr2, Ccl3/Ccr5, and Cxcl5/Cxcr2 mRNA reflects the observed immune cell recruitment. During the ensuing acute disease phase, Mmp12⁺ and Spp1⁺ macrophages and T cells accumulate in scars, which mature from cell- to collagen-rich. The expression of Cx3cl1/Cx3cr1, Ccl2/Ccr2, and Cxcl10/Cxcr3 dominates this disease phase. We furthermore find that during chronic disease progression macrophages and T cells persist within mature scars and are present in expanding interstitial fibrosis. Ccl12 and Cx3cl1 are predominant chemokines in this disease phase. Together, our observations provide strong evidence that specific immune cell populations and chemokine expression profiles modulate inflammatory and repair processes throughout AC progression.

Stabilization of desmoglein-2 binding rescues arrhythmia in arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is a genetic disease causing arrhythmia and sudden cardiac death with only symptomatic therapy available at present. Mutations of desmosomal proteins, including desmoglein-2 (Dsg2) and plakoglobin (Pg), are the major cause of AC and have been shown to lead to impaired gap junction function. Recent data indicated the involvement of anti-Dsg2 autoantibodies in AC pathogenesis. We applied a peptide to stabilize Dsg2 binding similar to a translational approach to pemphigus, which is caused by anti-desmoglein autoantibodies. We provide evidence that stabilization of Dsg2 binding by a linking peptide (Dsg2-LP) is efficient to rescue arrhythmia in an AC mouse model immediately upon perfusion. Dsg2-LP, designed to cross-link Dsg2 molecules in proximity to the known binding pocket, stabilized Dsg2-mediated interactions on the surface of living cardiomyocytes as revealed by atomic force microscopy and induced Dsg2 oligomerization. Moreover, Dsg2-LP rescued disrupted cohesion induced by siRNA-mediated Pg or Dsg2 depletion or l-tryptophan, which was applied to impair overall cadherin binding. Dsg2-LP rescued connexin-43 mislocalization and conduction irregularities in response to impaired cardiomyocyte cohesion. These results demonstrate that stabilization of Dsg2 binding by Dsg2-LP can serve as a novel approach to treat arrhythmia in patients with AC.

Enhanced osteogenic differentiation of human mesenchymal stromal cells as response to periodical microstructured Ti6Al4V surfaces

Titanium-based alloys, for example, Ti6Al4V, are frequently employed for load-bearing orthopedic and dental implants. Growth of new bone tissue and therefore osseointegration can be promoted by the implant's microtopography, which can lead to improved long-term stability of the implant. This study investigates the effect that an organized, periodical microstructure produced by an electron beam (EB) technique has on the viability, morphology, and osteogenic differentiation capacity of human mesenchymal stromal cells (hMSC) in vitro. The technique generates topographical features of 20 μm in height with varying distances of 80-240 μm. Applied alterations of the surface roughness and local alloy composition do not impair hMSC viability (>94%) or proliferation. A favorable growth of hMSC onto the structure peaks and well-defined focal adhesions of the analyzed cells to the electron beam microstructured surfaces is verified. The morphological adaptation of hMSC to the underlying topography is detected using a three-dimensional (3D) visualization. In addition to the morphological changes, an increase in the expression of osteogenic markers such as osteocalcin (up to 17-fold) and osteoprotegerin (up to sixfold) is observed. Taken together, these results imply that the proposed periodical microstucturing method could potentially accelerate and enhance osseointegration of titanium-based bone implants.

Relationship between body mass index and percentage of body fat, estimated by bio-electrical impedance among adult females in a rural community of North India: A cross-sectional study

Introduction:

Body adiposity measured by percentage of body fat (BF%) is found to be better predictor of cardiovascular morbidity and mortality than body mass index (BMI). Limited information exists showing relationship between BMI and BF% in North Indian population.

Objectives:

To study the relationship between BMI and BF% among North Indian adult females across various age strata and level of BMI.

Materials and Methods:

This was a cross-sectional study conducted at Ballabgarh Health and Demographic Surveillance Site (HDSS) among randomly selected females. BMI using standard techniques and BF% using bioelectrical impedance analysis was estimated. Linear regression was performed using general linear model with BF% as dependent variable and BMI as main independent variable.

Results:

Mean (±2 SD) age of participants was 41.3 ± 15.7 years. Mean BMI (±SD) was 23.3 (±4.6) kg/m², whereas mean fat mass (±2 SD) and BF% (±95% CI) was 19.2 (±7.9) kg and 33.6 (±6.9) %. BMI and BF% were highly correlated among obese (r = 0.77), whereas least correlated (r = 0.32) in underweight females. Across age strata, correlation between BMI and BF% was maximum in 18–35 years age group (r = 0.95), whereas least in females ≥56 years (r = 0.67). Age and BMI together predicted 73% of variability in BF% in hierarchical linear regression model.

Conclusions:

In this population, we have found strong correlation between BMI and BF% particularly at higher level of BMI and in younger females. There is need to conduct more robust prospective longitudinal studies to assess BF%, which is a better predictor of cardiovascular morbidity and mortality.

Desmoglein 2 mutation provokes skeletal muscle actin expression and accumulation at intercalated discs in murine hearts

Arrhythmogenic cardiomyopathy (AC) is an incurable progressive disease that is linked to mutations in genes coding for components of desmosomal adhesions that are localized to the intercalated disc region, which electromechanically couples adjacent cardiomyocytes. To date, the underlying molecular dysfunctions are not well characterized. In two murine AC models, we find an upregulation of the skeletal muscle actin gene (Acta1), which is known to be a compensatory reaction to compromised heart function. Expression of this gene is elevated prior to visible morphological alterations and clinical symptoms, and persists throughout pathogenesis with an additional major rise during the chronic disease stage. We provide evidence that the increased Acta1 transcription is initiated through nuclear activation of the serum response transcription factor (SRF) by its transcriptional co-activator megakaryoblastic leukemia 1 protein (MKL1, also known as MRTFA). Our data further suggest that perturbed desmosomal adhesion causes Acta1 overexpression during the early stages of the disease, which is amplified by transforming growth factor β (TGFβ) release from fibrotic lesions and surrounding cardiomyocytes during later disease stages. These observations highlight a hitherto unknown molecular AC pathomechanism.

A rare presentation of angioedema with isolated retropharyngeal and supraglottic involvement

Angiotensin converting-enzyme (ACE) inhibitors are commonly prescribed drugs with multiple indications including congestive heart failure, hypertension, and diabetic nephropathy. ACE inhibitor induced angioedema is commonly seen across emergency departments and clinics, with transient swelling of lips, tongue, and other facial structures being the common presentation. Isolated airway obstruction as a result of pharyngeal and laryngeal swelling without facial swelling is a rare presentation. We present a case of a patient on lisinopril therapy for one year who experienced severe airway compromise without the classic symptoms of ACE inhibitor induced angioedema. He required emergent cricothyroidotomy to secure his airway, as fiberoptic laryngoscopy showed 90% obstruction and inability to visualize true vocal cords. His ACE inhibitor therapy was discontinued, and he was discharged home within a few days with no residual symptoms.

Desmoglein 2, but not desmocollin 2, protects intestinal epithelia from injury

Desmosomes are the least understood intercellular junctions in the intestinal epithelia and provide cell-cell adhesion via the cadherins desmoglein (Dsg)2 and desmocollin (Dsc)2. We studied these cadherins in Crohn's disease (CD) patients and in newly generated conditional villin-Cre DSG2 and DSC2 knockout mice (DSG2^ΔIEC; DSC2^ΔIEC). CD patients exhibited altered desmosomes and reduced Dsg2/Dsc2 levels. The intestines of both transgenic animal lines were histopathologically inconspicuous. However, DSG2^ΔIEC, but not DSC2^ΔIEC mice displayed an increased intestinal permeability, a wider desmosomal space as well as alterations in desmosomal and tight junction components. After dextran sodium sulfate (DSS) treatment and Citrobacter rodentium exposure, DSG2^ΔIEC mice developed a more-pronounced colitis, an enhanced intestinal epithelial barrier disruption, leading to a stronger inflammation and activation of epithelial pSTAT3 signaling. No susceptibility to DSS-induced intestinal injury was noted in DSC2^ΔIEC animals. Dsg2 interacted with the cytoprotective chaperone Hsp70. Accordingly, DSG2^ΔIEC mice had lower Hsp70 levels in the plasma membrane compartment, whereas DSC2^ΔIEC mice displayed a compensatory recruitment of galectin 3, a junction-tightening protein. Our results demonstrate that Dsg2, but not Dsc2 is required for the integrity of the intestinal epithelial barrier in vivo.

Periodic microstructures on bioactive glass surfaces enhance osteogenic differentiation of human mesenchymal stromal cells and promote osteoclastogenesis in vitro

Bioactive glasses (BG) are known for their ability to bond to hard and soft tissues. We hypothesized that the stimulation of bone remodeling, including cellular bone forming and bone resorbing processes, can be increased by applying periodic microstructures on the glass surfaces in vitro. To test our hypothesis, two different BG (45S5 and 13-93) were microstructured in a groove-and-ridge pattern of different sizes by a novel casting process and tested in cell culture experiments using human mesenchymal stromal cells (hMSCs) and RAW 264.7 cells. The microstructures induced contact guidance of hMSCs and increased osteogenic marker gene expression of the stem cells, compared to non-structured glass surfaces as verified by ELISA and quantitative real-time PCR (qPCR) analyses. Furthermore, the structures stimulated the differentiation of RAW cells to osteoclast-like cells confirmed by TRAP gene expression and their resorption activity causing visible resorption lacunae. Our results demonstrate that periodically microstructured BG (especially 45S5) might improve the osteogenic differentiation of hMSCs and influence the activity of material resorbing cells in vitro. Hence, microstructuring of BG could enhance the remodeling process of bone substitutes critical for the formation of new bone tissue in vivo and thus be used to trigger bone remodeling kinetics in vivo. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1965-1978, 2018.

Renal transplantation in anti-neutrophil cytoplasmic antibody vasculitis

INTRODUCTION

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) has the propensity to acquire a devastating disease course. Despite the advances in therapeutics, a significant proportion of patients progress to end-stage renal disease (ESRD). Renal transplantation is being increasingly employed in this population, with gradual improvement in outcomes over the years, however, recurrence of disease requires constant surveillance and is associated with graft failure. Areas covered: A structured literature search in PubMed and Medline and abstracts of international conferences was performed to identify cases and cohorts of AAV patients who had undergone renal transplantation for ESRD. The primary objective was to describe the long-term allograft and patient survival and to reflect on current trends in transplantation in AAV and provide recommendations for the phases of pre- and post-transplantation. Expert commentary: Renal transplantation is the treatment of choice for AAV patients with ESRD. The risk of relapse is low with modern immunosuppressive regimes employing mycophenolate mofetil and tacrolimus. It is recommended that the vasculitis be in clinical remission for 12 months prior to transplantation. Although ANCA positivity is not a contraindication for renal transplantation, these patients should be monitored closely for vasculitis relapse post-transplant.

Accelerating wheat breeding for end-use quality with multi-trait genomic predictions incorporating near infrared and nuclear magnetic resonance-derived phenotypes

Using NIR and NMR predictions of quality traits overcomes a major barrier for the application of genomic selection to accelerate improvement in grain end-use quality traits of wheat. Grain end-use quality traits are among the most important in wheat breeding. These traits are difficult to breed for, as their assays require flour quantities only obtainable late in the breeding cycle, and are expensive. These traits are therefore an ideal target for genomic selection. However, large reference populations are required for accurate genomic predictions, which are challenging to assemble for these traits for the same reasons they are challenging to breed for. Here, we use predictions of end-use quality derived from near infrared (NIR) or nuclear magnetic resonance (NMR), that require very small amounts of flour, as well as end-use quality measured by industry standard assay in a subset of accessions, in a multi-trait approach for genomic prediction. The NIR and NMR predictions were derived for 19 end-use quality traits in 398 accessions, and were then assayed in 2420 diverse wheat accessions. The accessions were grown out in multiple locations and multiple years, and were genotyped for 51208 SNP. Incorporating NIR and NMR phenotypes in the multi-trait approach increased the accuracy of genomic prediction for most quality traits. The accuracy ranged from 0 to 0.47 before the addition of the NIR/NMR data, while after these data were added, it ranged from 0 to 0.69. Genomic predictions were reasonably robust across locations and years for most traits. Using NIR and NMR predictions of quality traits overcomes a major barrier for the application of genomic selection for grain end-use quality traits in wheat breeding.

Response of umbilical cord mesenchymal stromal cells to varying titanium topographical signals

A wide variety of titanium implant modifications have been developed to improve tissue- or cell-material interactions including bone bonding, implant failure, and contact osteogenesis. Osteogenesis can be stimulated by mechanobiological signals such as topography though translation of in vivo reactions to in vitro bioactivity and stem cell culture data, and vice versa, is challenging. We hypothesized that a systematic in vitro approach comparing clinically well-accepted implant surface topographical modifications could shed light on potential cell biological mechanisms provoked by submicron-, micron- or macrostructured surfaces. In this study, we investigated the response of umbilical cord derived mesenchymal stromal cells (UC-MSCs) to anodized, particle blasted, and plasma sprayed highly porous Plasmapore surfaces, which is known to promote bony ingrowth in vivo. After 21 days, UC-MSCs undergo a morphological shift from a 2D to 3D behavior on micro- or macrostructures visualized by actin-vinculin fluorescence and are able to fill the porous surfaces completely. Cell viability after 7 days was significantly decreased on the micro- and macrostructured surfaces particle blasted and Plasmapore, compared to polished controls. The analysis of osteogenic differentiation under noninduced conditions revealed a significantly elevated ALP activity on Plasmapore, indicating a beneficial effect of this macrostructured surface toward osteogenic differentiation supported by late elevated gene expression of osteopontin evaluated by qPCR. Mineralization as well as in vitro bioactivity was pronounced on anodized surfaces. Our findings point to synergistic implant modification strategies allowing early contact osteogenesis and bone ingrowth for future implant designs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 180-191, 2018.

Cardiomyocyte Hypertrophy in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is a hereditary disease leading to sudden cardiac death or heart failure. AC pathology is characterized by cardiomyocyte loss and replacement fibrosis. Our goal was to determine whether cardiomyocytes respond to AC progression by pathological hypertrophy. To this end, we examined tissue samples from AC patients with end-stage heart failure and tissue samples that were collected at different disease stages from desmoglein 2-mutant mice, a well characterized AC model. We find that cardiomyocyte diameters are significantly increased in right ventricles of AC patients. Increased mRNA expression of the cardiac stress marker natriuretic peptide B is also observed in the right ventricle of AC patients. Elevated myosin heavy chain 7 mRNA expression is detected in left ventricles. In desmoglein 2-mutant mice, cardiomyocyte diameters are normal during the concealed disease phase but increase significantly after acute disease onset on cardiomyocyte death and fibrotic myocardial remodeling. Hypertrophy progresses further during the chronic disease stage. In parallel, mRNA expression of myosin heavy chain 7 and natriuretic peptide B is up-regulated in both ventricles with right ventricular preference. Calcineurin/nuclear factor of activated T cells (Nfat) signaling, which is linked to pathological hypertrophy, is observed during AC progression, as evidenced by Nfatc2 and Nfatc3 mRNA in cardiomyocytes and increased mRNA of the Nfat target regulator of calcineurin 1. Taken together, we demonstrate that pathological hypertrophy occurs in AC and is secondary to cardiomyocyte loss and cardiac remodeling.

Inkjet printed periodical micropatterns made of inert alumina ceramics induce contact guidance and stimulate osteogenic differentiation of mesenchymal stromal cells

Bioinert high performance ceramics exhibit detrimental features for implant components with direct bone contact because of their low osseointegrating capability. We hypothesized that periodical microstructures made of inert alumina ceramics can influence the osteogenic differentiation of human mesenchymal stromal cells (hMSC). In this study, we manufactured pillared arrays made of alumina ceramics with periodicities as low as 100μm and pillar heights of 40μm employing direct inkjet printing (DIP) technique. The response of hMSC to the microstructured surfaces was monitored by measuring cell morphology, viability and formation of focal adhesion complexes. Osteogenic differentiation of hMSCs was investigated by alkaline phosphatase activity, mineralization assays and expression analysis of respective markers. We demonstrated that MSCs react to the pillars with contact guidance. Subsequently, cells grow onto and form connections between the microstructures, and at the same time are directly attached to the pillars as shown by focal adhesion stainings. Cells build up tissue-like constructs with heights up to the micropillars resulting in increased cell viability and osteogenic differentiating properties. We conclude that periodical micropatterns on the micrometer scale made of inert alumina ceramics can mediate focal adhesion dependent cell adhesion and stimulate osteogenic differentiation of hMSCs.

High correlation of clinical criteria in the diagnosis of drug-resistant TB and prevalence of ofloxacin resistance

OBJECTIVE

To study the drug resistance profile of patients with suspected multidrug-resistant tuberculosis (MDR-TB).

MATERIAL AND METHODS

This was a prospective study conducted among patients with suspected MDR-TB attending the Department of Respiratory Medicine, King George's Medical University, Lucknow, India, from August 2014 to April 2015. Sputum samples obtained from 50 such patients were subjected to drug susceptibility testing against first- and second-line drugs. Data on baseline characteristics were obtained from the patients and their previous medical records.

RESULTS

Mycobacterium tuberculosis was detected in 47/50 (94%) and non-tuberculous mycobacteria (NTM) in 3/50 (6%). Of the 47 patients with M. tuberculosis, 36 (76.6%) had MDR-TB: 24 (66.7%) of these had pre-extensively drug-resistant TB (pre-XDR-TB) and 4 (11.1%) had XDR-TB.

CONCLUSIONS

Among proven MDR-TB cases, approximately two thirds were pre-XDR-TB cases and more than 10% were XDR-TB cases. These form a sizeable proportion and may result in the failure of second-line treatment.

Influence of alcohol on condom use pattern during non-spousal sexual encounter in male migrant workers in north India

CONTEXT

Migrant workers constitute an important risk group for Human Immunodeficiency Virus/Acquired Immuno-Deficiency Syndrome transmission in India. Alcohol consumption before sexual intercourse has been postulated to influence condom use practices. This study aimed to assess this association with regard to non-spousal sexual encounters among male migrant workers in northern India.

MATERIALS AND METHODS

A cross-sectional facility-based survey was conducted in 2011. Male migrant workers aged ≥18 years, who were born outside Haryana, who had moved to the current location after 15 years of age,had worked in the current factory for at least 1 year, who were willing to participate and were able to give written, informed consent were included in the study. A consecutive sampling was performed. Descriptive, bivariate and multiple logistic regression analyses were carried out.

RESULTS

A total of 162 participants reported having experienced non-spousal sexual encounters in the last 1 year. The proportion of men who reported not having used a condom at their last non-spousal sexual encounter was 59.3%, and 78.4% of the men reported having consumed alcohol in the last 1 year. About 48.1% of men reported having consumed alcohol before their last non-spousal sexual encounter. Men who consumed alcohol were three times more likely to not use a condom at their last non-spousal sexual encounter (OR = 3.1, 95% CI: 1.5-6.4). This association persisted even after adjusting for relevant confounders.

CONCLUSION

Alcohol consumption had a negative influence on condom use during non-spousal sexual encounter among male migrant workers. An integrated approach to promote condom use and reduce alcohol consumption among migrant men needs to be undertaken through targeted intervention strategies.

Loss of plakoglobin immunoreactivity in intercalated discs in arrhythmogenic right ventricular cardiomyopathy: protein mislocalization versus epitope masking

AIMS

To examine the relevance and cause of reduced plakoglobin IF in intercalated discs for arrhythmogenic right ventricular cardiomyopathy (ARVC) and ARVC-like disease in mouse and human.

METHODS AND RESULTS

Normalized semi-quantitative IF measurements were performed in a standardized format in desmoglein 2-mutant mice with an ARVC-like phenotype (n = 6) and in cardiac biopsies from humans with ARVC and non-ARVC heart disease (n = 10). Reduced plakoglobin staining was detectable in ARVC only with one antibody directed against a defined epitope but not with three other antibodies reacting with different epitopes of plakoglobin.

CONCLUSIONS

Reduced plakoglobin staining in intercalated discs of heart tissue from human ARVC patients and in a murine ARVC model is caused by alterations in epitope accessibility and not by protein relocalization.

Desmoglein 2-Dependent Arrhythmogenic Cardiomyopathy Is Caused by a Loss of Adhesive Function

BACKGROUND

The desmosomal cadherin desmoglein 2 (Dsg2) localizes to the intercalated disc coupling adjacent cardiomyocytes. Desmoglein 2 gene (DSG2) mutations cause arrhythmogenic cardiomyopathy (AC) in human and transgenic mice. AC is characterized by arrhythmia, cardiodilation, cardiomyocyte necrosis with replacement fibrosis, interstitial fibrosis, and intercalated disc dissociation. The genetic DSG2 constellations encountered are compatible with loss of adhesion and altered signaling. To further elucidate pathomechanisms, we examined whether heart-specific Dsg2 depletion triggers cardiomyopathy.

METHODS AND RESULTS

Because DSG2 knockouts die during early embryogenesis, mice were prepared with cardiomyocyte-specific DSG2 ablation. Healthy transgenic animals were born with a functional heart presenting intercalated discs with incorporated desmosomal proteins. Dsg2 protein expression was reduced below 3% in the heart. All animals developed AC during postnatal growth with pronounced chamber dilation, calcifying cardiomyocyte necrosis, aseptic inflammation, interstitial and focal replacement fibrosis, and conduction defects with altered connexin 43 distribution. Electron microscopy revealed absence of desmosome-like structures and regional loss of intercalated disc adhesion. Mice carrying 2 mutant DSG2 alleles coding for Dsg2 lacking part of the adhesive EC1-EC2 domains present an indistinguishable phenotype, which is similar to that observed in human AC patients.

CONCLUSIONS

The observations show that the presence of Dsg2 is not essential for late heart morphogenesis and for cardiac contractility to support postnatal life. On increasing mechanical demands, heart function is severely compromised as evidenced by the onset of cardiomyopathy with pronounced morphological alterations. We propose that loss of Dsg2 compromises adhesion, and that this is a major pathogenic mechanism in DSG2-related and probably other desmosome-related ACs.

Associations of CYP1A1, GSTM1 and GSTT1 polymorphisms with lung cancer susceptibility in a Northern Indian population

BACKGROUND

Susceptibility to lung cancer has been shown to be modulated by inheritance of polymorphic genes encoding cytochrome P450 1A1 (CYP1A1) and glutathione S transferases (GSTM1 and GSTT1), which are involved in the bioactivation and detoxification of environmental toxins. This might be a factor in the variation in lung cancer incidence with ethnicity.

MATERIALS AND METHODS

We conducted a case-control study of 218 northern Indian lung cancer patients along with 238 healthy controls, to assess any association between CYP1A1, GSTM1 and GSTT1 polymorphisms, either separately or in combination, with the likelihood of development of Lung cancer in our population.

RESULTS

We observed a significant difference in the GSTT1 null deletion frequency in this population when compared with other populations (OR=1.87, 95%CI: 1.25-2.80-0.73, P=0.002). However, GSTM1 null genotype was found associated with lung cancer in the non-smoking subgroup. (P=0.170).

CONCLUSIONS

Our study showed the GSTT1 null polymorphism to be associated with smoking-induced lung cancer and the GSTM1 null polymorphism to have a link with non-smoking related lung cancer.

Use of GenoType® MTBDRplus assay to assess drug resistance and mutation patterns of multidrug-resistant tuberculosis isolates in northern India

PURPOSE

The emergence and spread of multidrug-resistant tuberculosis (MDR-TB) is a major public health problem. The diagnosis of MDR-TB is of paramount importance in establishing appropriate clinical management and infection control measures. The aim of this study was to evaluate drug resistance and mutational patterns in clinical isolates MDR-TB by GenoType® MTBDRplus assay.

MATERIAL AND METHODS

A total of 350 non-repeated sputum specimens were collected from highly suspected drug-resistant pulmonary tuberculosis (PTB) cases; which were processed by microscopy, culture, differentiation and first line drug susceptibility testing (DST) using BacT/ALERT 3D system.

RESULTS

Among a total of 125 mycobacterium tuberculosis complex (MTBC) strains, readable results were obtained from 120 (96%) strains by GenoType® MTBDRplus assay. Only 45 MDR-TB isolates were analysed for the performance, frequency and mutational patterns by GenoType® MTBDRplus assay. The sensitivity of the GenoType® MDRTBplus assay for detecting individual resistance to rifampicin (RIF), isoniazid (INH) and multidrug resistance was found to be 95.8%, 96.3% and 97.7%, respectively. Mutation in codon S531L of the rpoB gene and codon S315T1 of katG genes were dominated in MDR-TB strains, respectively (P < 0.05).

CONCLUSIONS

The GenoType® MTBDRplus assay is highly sensitive with short turnaround times and a rapid test for the detection of the most common mutations conferring resistance in MDR-TB strains that can readily be included in a routine laboratory workflow.

Cephalometric evaluation of mandibular advancement at different horizontal jaw positions in obstructive sleep apnoea patients: a pilot study

BACKGROUND

The aim of this study was to comparatively evaluate the efficacy of the mandibular advancement device (MAD) at 50% (P2) and 75% (P3) of maximum mandibular advancement, relative to maximum intercuspation (P1) subjectively and objectively.

METHODS

Eighteen subjects previously diagnosed with obstructive sleep apnoea (OSA) were selected for the study. ESS score, VAS score, soft palate angle, MP-H distance, S-H distance, a C4 -H distance, a Pu -p Pu distance and total pharyngeal area were calculated at P1, P2 and P3 positions with the help of an adjustable MAD. The results were statistically analysed.

RESULTS

ESS score, VAS score, soft palate angle, MP-H distance, S-H distance and radius of curvature of airway at P2 and P3 were significantly lower compared to P1, but there was no significant difference between P2 and P3.

CONCLUSIONS

The MAD produced significant improvement in objective signs and subjective symptoms at both 50% and 75% of the maximum mandibular protrusion positions at comparable comfort levels. Therefore, MAD may be given at 50% of maximum advancement in order to reduce dental or temporomandibular joint disturbances.

Detection of 123 bp fragment of insertion element IS6110 Mycobacterium tuberculosis for diagnosis of extrapulmonary tuberculosis

PURPOSE

Extrapulmonary tuberculosis (EPTB) is emerging problem in developing and developed countries. The diagnosis of EPTB in its different clinical presentations remains a true challenge. IS6110-based polymerase chain reaction (PCR) is used for rapid identification and positivity rate of the Mycobacterium tuberculosis complex in clinical isolates of different sites of EPTB. The present study was carried out to study the prevalence of M. tuberculosis complex in clinical isolates of EPTB at tertiary care centres in Lucknow.

MATERIALS AND METHODS

Seven hundred fifty-six specimens were collected from the suspected cases of EPTB which were processed for Mycobacteria by Ziehl Neelson (ZN) staining and BACTEC culture. All the specimens were also processed for IS6110-based PCR amplification with primers targeting 123 bp fragment of insertion element IS6110 of the M. tuberculosis complex.

RESULTS

Of these 756 specimens, 71(9.3%) were positive for acid fast bacilli (AFB) by ZN staining, 227(30.1%) were positive for mycobacteria by BACTEC culture and IS6110 PCR were positive for M. tuberculosis complex in 165 (20.7%) isolates. We found a significant difference in sensitivities of different tests (P<0.05).

CONCLUSIONS

This study reveals the positivity of M. tuberculosis complex in clinical isolates of EPTB case in tertiary care hospitals in Northern India. 72.7% of M. tuberculosis complex was confirmed by IS6110-PCR in culture isolates from different sites of EPTB. The high prevalence of the M. tuberculosis complex was seen in lymph node aspirate and synovial fluid. However, utility of PCR may play a potentially significant role in strengthening the diagnosis of EPTB especially targeting IS6110.

Drug susceptibility pattern of Mycobacterium tuberculosis isolates from patients of category-II failure of pulmonary tuberculosis under directly observed treatment short-course from north India

The major contributing factors for the causation of treatment failure in cases of pulmonary tuberculosis under Category-II directly observed treatment short-course treatment (DOTS) are treatment after default, poor treatment compliance, and development of multi-drug resistant (MDR) tuberculosis. The objective of the present study is to find out the demographic profile and drug susceptibility pattern in Category-II failure patients of pulmonary tuberculosis under Revised National Tuberculosis Control Programme (RNTCP) of India. Two hundred and twenty four patients with Category-II treatment failure of pulmonary tuberculosis were enrolled from Department of Pulmonary Medicine, at Chatrapati Sahuji Maharaj Medical University, UP, Lucknow, India, from August 2003 to July 2008. Their complete bacteriological assessment in terms of sputum smear for acid-fast bacilli, culture for Mycobacterium tuberculosis and drug sensitivity pattern were done in the Department of Microbiology. Among 224 patients, 16 (7.1%) patients were lost to follow-up and the final analysis was done among 208 (92.8%) cases. The reasons for inclusion of these 224 cases in the Category II regimen were treatment failure in the previous regimen (n = 75, 33%), default in 57% (n = 129 cases), and relapse in 8.9% (n = 20 cases). Among 208 patients, culture was positive in 170 (81.7%) cases, negative in 17 (8.1%) cases and contaminated in 21 (10%) cases. The drug sensitivity pattern of culture positive cases of Category-II failure patients revealed that, 58.2% (n = 99) had MDR tuberculosis and 40.5% (n = 69) were resistant but were non-MDR tuberculosis and 1.1 % (n = 2) cases were sensitive to all first line antituberculosis drugs.