Successful Shortening of Tuberculosis Treatment Using Adjuvant Host-Directed Therapy with FDA-Approved Phosphodiesterase Inhibitors in the Mouse Model

Global control of tuberculosis (TB), an infectious disease that claims nearly 2 million lives annually, is hindered by the long duration of chemotherapy required for curative treatment. Lack of adherence to this intense treatment regimen leads to poor patient outcomes, development of new or additional drug resistance, and continued spread of M.tb. within communities. Hence, shortening the duration of TB therapy could increase drug adherence and cure in TB patients. Here, we report that addition of the United Stated Food and Drug Administration-approved phosphodiesterase inhibitors (PDE-Is) cilostazol and sildenafil to the standard TB treatment regimen reduces tissue pathology, leads to faster bacterial clearance and shortens the time to lung sterilization by one month, compared to standard treatment alone, in a murine model of TB. Our data suggest that these PDE-Is could be repurposed for use as adjunctive drugs to shorten TB treatment in humans

Myosin Sequestration Regulates Sarcomere Function, Cardiomyocyte Energetics, and Metabolism, Informing the Pathogenesis of Hypertrophic Cardiomyopathy

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is caused by pathogenic variants in sarcomere protein genes that evoke hypercontractility, poor relaxation, and increased energy consumption by the heart and increased patient risks for arrhythmias and heart failure. Recent studies show that pathogenic missense variants in myosin, the molecular motor of the sarcomere, are clustered in residues that participate in dynamic conformational states of sarcomere proteins. We hypothesized that these conformations are essential to adapt contractile output for energy conservation and that pathophysiology of HCM results from destabilization of these conformations. METHODS: We assayed myosin ATP binding to define the proportion of myosins in the super relaxed state (SRX) conformation or the disordered relaxed state (DRX) conformation in healthy rodent and human hearts, at baseline and in response to reduced hemodynamic demands of hibernation or pathogenic HCM variants. To determine the relationships between myosin conformations, sarcomere function, and cell biology, we assessed contractility, relaxation, and cardiomyocyte morphology and metabolism, with and without an allosteric modulator of myosin ATPase activity. We then tested whether the positions of myosin variants of unknown clinical significance that were identified in patients with HCM, predicted functional consequences and associations with heart failure and arrhythmias. RESULTS: Myosins undergo physiological shifts between the SRX conformation that maximizes energy conservation and the DRX conformation that enables cross-bridge formation with greater ATP consumption. Systemic hemodynamic requirements, pharmacological modulators of myosin, and pathogenic myosin missense mutations influenced the proportions of these conformations. Hibernation increased the proportion of myosins in the SRX conformation, whereas pathogenic variants destabilized these and increased the proportion of myosins in the DRX conformation, which enhanced cardiomyocyte contractility, but impaired relaxation and evoked hypertrophic remodeling with increased energetic stress. Using structural locations to stratify variants of unknown clinical significance, we showed that the variants that destabilized myosin conformations were associated with higher rates of heart failure and arrhythmias in patients with HCM. CONCLUSIONS: Myosin conformations establish work-energy equipoise that is essential for life-long cellular homeostasis and heart function. Destabilization of myosin energy-conserving states promotes contractile abnormalities, morphological and metabolic remodeling, and adverse clinical outcomes in patients with HCM. Therapeutic restabilization corrects cellular contractile and metabolic phenotypes and may limit these adverse clinical outcomes in patients with HCM

Risk factors for myocardial infarction among low socioeconomic status South Indian population

<p>Abstract</p> <p>Background</p> <p>As longevity increases, cases of myocardial infarction (MI) are likely to be more. Cardiovascular disease (CVD) is a major global health problem reaching epidemic proportions in the Indian subcontinent, also among low socio-economic status (SES) and thin individuals.</p> <p>Objectives</p> <p>The present study was undertaken to elicit risk factors for MI among low SES Southern Indians and to find out its association with body mass index (BMI).</p> <p>Materials and methods</p> <p>A case-control study of patients with MI matched against healthy control subjects was carried out in a tertiary care teaching hospital. Standard methods were followed to elicit risk factors and BMI. Chi-square and Fishers exact test for categorical versus categorical, to show relationship with risk factors were analyzed.</p> <p>Results</p> <p>A total of 949 patients (male (M) = 692 and post menopausal female (F) = 257) and 611 age and sex matched healthy controls were included. In our study, BMI was below 23 in 48.2% of patients and below 21 in 22.5%. The risk of developing MI was significantly more in males (odds ratio (OR) = 3.3, 95% confidence interval (C.I.) = 2.69-4.13), among females with post-menopausal duration (PMD) of more than or equal to 3 years (OR = 9.27, 95% C.I. = 6.36-13.50) and in those with BMI less than 23 with one or other risk factors (P = 0.002, OR = 1.38, 95% C.I. = 1.13-1.70).</p> <p>Conclusion</p> <p>BMI cannot be considered as a lone independent risk factor, as the study population had low BMI but had one or more modifiable risk factors. It would be advisable to keep BMI at least 21 kg/m²for screening program. Health education on life style modification and programs to diagnose and control diabetes and hypertension have to be initiated at community level in order to reduce the occurrence.</p

Expanding the clinical and genetic spectrum of ALPK3 variants: Phenotypes identified in pediatric cardiomyopathy patients and adults with heterozygous variants

Introduction: Biallelic damaging variants in ALPK3, encoding alpha-protein kinase 3, cause pediatric-onset cardiomyopathy with manifestations that are incompletely defined. Methods and Results: We analyzed clinical manifestations of damaging biallelic ALPK3 variants in 19 pediatric patients, including nine previously published cases. Among these, 11 loss-of-function (LoF) variants, seven compound LoF and deleterious missense variants, and one homozygous deleterious missense variant were identified. Among 18 live-born patients, 8 exhibited neonatal dilated cardiomyopathy (44.4%; 95% CI: 21.5%-69.2%) that subsequently transitioned into ventricular hypertrophy. The majority of patients had extracardiac phenotypes, including contractures, scoliosis, cleft palate, and facial dysmorphisms. We observed no association between variant type or location, disease severity, and/or extracardiac manifestations. Myocardial histopathology showed focal cardiomyocyte hypertrophy, subendocardial fibroelastosis in patients under 4 years of age, and myofibrillar disarray in adults. Rare heterozygous ALPK3 variants were also assessed in adult-onset cardiomyopathy patients. Among 1548 Dutch patients referred for initial genetic analyses, we identified 39 individuals with rare heterozygous ALPK3 variants (2.5%; 95% CI: 1.8%-3.4%), including 26 missense and 10 LoF variants. Among 149 U.S. patients without pathogenic variants in 83 cardiomyopathy-related genes, we identified six missense and nine LoF ALPK3 variants (10.1%; 95% CI: 5.7%-16.1%). LoF ALPK3 variants were increased in comparison to matched controls (Dutch cohort, P = 1.6×10−5; U.S. cohort, P = 2.2×10−13). Conclusion: Biallelic damaging ALPK3 variants cause pediatric cardiomyopathy manifested by DCM transitioning to hypertrophy, often with poor contractile function. Additional extracardiac features occur in most patients, including musculoskeletal abnormalities and cleft palate. Heterozygous LoF ALPK3 variants are enriched in adults with cardiomyopathy and may contribute to their cardiomyopathy. Adults with ALPK3 LoF variants therefore warrant evaluations for cardiomyopathy

A genome-scale integrated approach aids in genetic dissection of complex flowering time trait in chickpea

A combinatorial approach of candidate gene-based association analysis and genome-wide association study (GWAS) integrated with QTL mapping, differential gene expression profiling and molecular haplotyping was deployed in the present study for quantitative dissection of complex flowering time trait in chickpea. Candidate gene-based association mapping in a flowering time association panel (92 diverse desi and kabuli accessions) was performed by employing the genotyping information of 5724 SNPs discovered from 82 known flowering chickpea gene orthologs of Arabidopsis and legumes as well as 832 gene-encoding transcripts that are differentially expressed during flower development in chickpea. GWAS using both genome-wide GBS- and candidate gene-based genotyping data of 30,129 SNPs in a structured population of 92 sequenced accessions (with 200–250 kb LD decay) detected eight maximum effect genomic SNP loci (genes) associated (34 % combined PVE) with flowering time. Six flowering time-associated major genomic loci harbouring five robust QTLs mapped on a high-resolution intra-specific genetic linkage map were validated (11.6–27.3 % PVE at 5.4–11.7 LOD) further by traditional QTL mapping. The flower-specific expression, including differential up- and down-regulation (>three folds) of eight flowering time-associated genes (including six genes validated by QTL mapping) especially in early flowering than late flowering contrasting chickpea accessions/mapping individuals during flower development was evident. The gene haplotype-based LD mapping discovered diverse novel natural allelic variants and haplotypes in eight genes with high trait association potential (41 % combined PVE) for flowering time differentiation in cultivated and wild chickpea. Taken together, eight potential known/candidate flowering time-regulating genes [efl1 (early flowering 1), FLD (Flowering locus D), GI (GIGANTEA), Myb (Myeloblastosis), SFH3 (SEC14-like 3), bZIP (basic-leucine zipper), bHLH (basic helix-loop-helix) and SBP (SQUAMOSA promoter binding protein)], including novel markers, QTLs, alleles and haplotypes delineated by aforesaid genome-wide integrated approach have potential for marker-assisted genetic improvement and unravelling the domestication pattern of flowering time in chickpea

Intracellular cAMP levels increase within <i>M.tb.</i>-infected THP-1 human monocytic cells upon exposure to PDE-Is.

<p>The treated infected cells received 100 uM of PDE inhibitors (PDE-I 3, and 5 class) for 2 h followed by infection. UI: uninfected cells; the PDE5-I was 4-{[3′,4′-(Methylenedioxy)benzyl]amino}-6-methoxyquinazoline (MBM); and the PDE3-I was trequinsin. Results shown (mean and SD) represent two biological replicates, each with 2 technical replicates.</p

Interaction of PDE-Is with Rifampin.

<p>BALB/c mice were infected with 3.6 log₁₀CFU <i>M.tb.</i> and were treated daily by oral gavage (starting the day after infection) with 10 or 30 mg/kg cilostazol (C10 and C30, respectively), 10 mg/kg rifampin (R10), C10 plus R10, or C30 plus R10. Lung CFU counts were determined on days 14 and 28 post-infection.</p

Addition of PDE-Is to standard TB therapy.

<p>The addition of PDE-Is to standard TB therapy reduces bacterial load, lung pathology and time to lung sterilization, and does not negatively interact with rifampin in <i>M.tb.</i>-infected mice. BALB/c mice were infected with 3.97 log₁₀CFU <i>M.tb</i> and treatment was started 14 days post-infection. The mice were treated daily by oral gavage with standard therapy (SD, which is 2 months 10 mg/kg rifampin (R), 25 mg/kg isoniazid H), and 150 mg/kg pyrazinamide (Z), followed by 4 months of R and H), SD plus 10 mg/kg sildenafil (S10), cilostazol (C10) or both (CS10). (<b>A</b>) CFU counts in mouse lungs. (<b>B</b>) Histopathology analyses of mouse lungs (hematoxylin and eosin stained lung sections).</p