23 research outputs found
Prevalence, Distribution and Functional Significance of the −237C to T Polymorphism in the IL-12Rβ2 Promoter in Indian Tuberculosis Patients
Cytokine/cytokine receptor gene polymorphisms related to structure/expression could impact immune response. Hence, the −237 polymorphic site in the 5′ promoter region of the IL-12Rβ2 (SNP ID: rs11810249) gene associated with the AP-4 transcription motif GAGCTG, was examined. Amplicons encompassing the polymorphism were generated from 46 pulmonary tuberculosis patients, 35 family contacts and 28 miscellaneous volunteers and sequenced. The C allele predominated among patients, (93.4%, 43/46), and in all volunteers and contacts screened, but the T allele was exclusively limited to patients, (6.5%, 3/46). The functional impact of this polymorphism on transcriptional activity was assessed by Luciferase-reporter and electrophoretic mobility shift assays (EMSA). Luciferase-reporter assays showed a significant reduction in transcriptional efficiency with T compared to C allele. The reduction in transcriptional efficiency with the T allele construct (pGIL-12Rb2-T), in U-87MG, THP-1 and Jurkat cell lines, were 53, 37.6, and 49.8% respectively, compared to the C allele construct (pGIL-12Rb2-C). Similarly, densitometric analysis of the EMSA assay showed reduced binding of the AP-4 transcription factor, to T compared to the C nucleotide probe. Reduced mRNA expression in all patients (3/3) harboring the T allele was seen, whereas individuals with the C allele exhibited high mRNA expression (17/25; 68%, p = 0.05). These observations were in agreement with the in vitro assessment of the promoter activity by Luciferase-reporter and EMSA assays. The reduced expression of IL-12Rβ2 transcripts in 8 patients despite having the C allele was attributed to the predominant over expression of the suppressors (IL-4 and GATA-3) and reduced expression of enhancers (IFN-α) of IL-12Rβ2 transcripts. The 17 high IL-12Rβ2 mRNA expressers had significantly elevated IFN-α mRNA levels compared to low expressers and volunteers. Notwithstanding the presence of high levels of IL-12Rβ2 mRNA in these patients elevated IFN-α expression could modulate their immune responses to Mycobacterium tuberculosis
GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture
Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment
Phospholipid metabolism and protein kinase C mediated protein phosphorylation in dietary protein deficiency in rat lung
606-613Nutritional deprivation of proteins
decreases the protein kinase C (PKC) activity in rat lung. The activity of
(PKC) is influenced by lipid metabolism. Changes in PKC activity may influence
phosphorylation of its substrate proteins in the tissues. Therefore, alterations
in phospholipid metabolism and PKC mediated protein phosphorylation in dietary
protein
deficiency in rat lung were envisaged.
The study was conducted on rats fed on three different types of diet viz .. casein
(20% protein), deficient (4% protein, rice flour as source of protein) and
supplemented (deficient diet supplemented with L-Iysine and DL-threoning). Feeding
of protein deficient diet caused reduction in incorporation of [3H] myo-inositol
in the total
phosphoinositides in lungs and an increase
in total inositol phosphate pool. There was a significant reduction in the
contents and turnover rate of phosphatidyl inositol and phosphatidyl inositol monophosphate.
Supplementation of diet with L-Iysine and DL-threonine had a reversing effect
on total pool of phosphoinositides and, the metabolism of phosphatidyl inositol
bisphosphate and phosphatidyl inositol. In phosphatidyl choline metabolism, the
dietary protein deficiency led to a decrease in incorporation of [14C-methyl]
choline-chloride in total phospholipids. In contrast, its incorporation
increased in
phosphatidyl choline pool. The contents
of phosphatidyl choline and residue, incorporation of [14C-methyl]
choline-chloride in them and their turnover rate also increased. Supplementation
of diet had a reversal effect on most of these parameters. Phosphorylation of
proteins of 84,47,35 and 16 kDa was identified to be mediated by PKC. In
dietary protein deficiency, phosphorylation of all these proteins, except that
of 47 kDa, increased. Supplementation of diet reversed the pattern except that of
84 kDa. The findings suggest that changes in phospholipid metabolism in dietary
protein deficiency may effect the activity of PKC thereby influencing the
phosphorylation of its substrate proteins and hence associated functions that
may lead to pathophysiology of lung
Effect of feeding protein deficient diet on phospholipid turnover and protein kinase C mediated protein phosphorylation in rat brain
323-331Feeding of protein deficient diet is known
to alter the transmembrane signalling in brain of rat by reducing total protein
kinase C (PKC) activity. Phospholipid metabolism regulates the activation of
PKC through generation of second messengers and the extent of PKC activation accordingly
influences the magnitude of phosphorylation of its endogenous substrate
proteins.Thus it was speculated that ingestion
of protein deficient diet may modify the turnover rate of membrane phospholipids
and magnitude of phosphorylation of endogenous substrate proteins of PKC. The
experiments were conducted on rats fed on three different types of laboratory prepared
diets viz. casein (20% casein), deficient (4% protein, rice flour as source of
protein ) and supplemented (deficient diet supplemented with L-lysine and DL-threonine)
for 28 days. The metabolism of phosphoinositides (PIs) and phosphatidyl choline
(PC) was studied by equilibrium labeling with [3H] myo inositol
and [14C methyl] choline chloride respectively. The phosphorylation
of endogenous substrate proteins of PKC was studied by using 32P-γ-ATP
followed by SDS-PAGE and autoradiography. The results suggest that in deficient
group, there is an increased incorporation of [3H] myo inositol
in PIs and inositol phosphate pool in comparison to the casein group. The phosphatidyl
inositol (PI) turnover reduced, although there was a marginal increase in the
phosphatidyl inositol monophosphate (PIP) and phosphatidyl inositol bis phosphate
(PIP2). Supplementation of diet showed a reversal of the pattern towards
control to a considerable extent. In the deficient group, PC metabolism showed
an increased incorporation of [14C methyl] choline in choline
phospholipids but decreased incorporation in phosphoryl choline in comaprison
with the casein group. The increase in total PC contents was significant but marginal
in residue contents. The turnover rate of PC increased only marginally and that
of residue declined. Supplementation of diet reduced the total contents of PC
and residue, but the turnover rate of PC and residue remained still higher.
Phosphorylation of endogenous proteins showed four different proteins of 78,
46, 33 and 16 kDa to be the substrates of PKC in casein group. In deficient group,
phosphorylation of these proteins increased markedly while supplementation of diet
had a reversing effect rendering the values to be intermediate between casein and
the supplemented group. The changes in phospholipid metabolism and in phosphorylation
of endogenous substrate proteins of PKC suggest that dietary protein deficiency
causes alterations in transmembrane signalling mechanism in rat brain. These effects
are partially reversed by improving the quality of proteins in the diet
Effect of feeding protein deficient diet on phospholipid turnover and protein kinase C mediated protein phosphorylation in rat brain
Feeding of protein deficient diet is known to alter the transmembrane signalling in brain of rat by reducing total protein kinase C (PKC) activity. Phospholipid metabolism regulates the activation of PKC through generation of second messengers and the extent of PKC activation accordingly influences the magnitude of phosphorylation of its endogenous substrate proteins. Thus it was speculated that ingestion of protein deficient diet may modify the turnover rate of membrane phospholipids and magnitude of phosphorylation of endogenous substrate proteins of PKC. The experiments were conducted on rats fed on three different types of laboratory prepared diets viz. casein (20% casein), deficient (4% protein, rice flour as source of protein) and supplemented (deficient diet supplemented with L-lysine and DL-threonine) for 28 days. The metabolism of phosphoinositides (PIs) and phosphatidyl choline (PC) was studied by equilibrium labeling with [3H] myo inositol and [14C methyl] choline chloride respectively. The phosphorylation of endogenous substrate proteins of PKC was studied by using 32P-γ-ATP followed by SDS-PAGE and autoradiography. The results suggest that in deficient group, there is an increased incorporation of [3H] myo inositol in PIs and inositol phosphate pool in comparison to the casein group. The phosphatidyl inositol (PI) turnover reduced, although there was a marginal increase in the phosphatidyl inositol monophosphate (PIP) and phosphatidyl inositol bis phosphate (PIP2). Supplementation of diet showed a reversal of the pattern towards control to a considerable extent. In the deficient group, PC metabolism showed an increased incorporation of [14C methyl] choline in choline phospholipids but decreased incorporation in phosphoryl choline in comparison with the casein group. The increase in total PC contents was significant but marginal in residue contents. The turnover rate of PC increased only marginally and that of residue declined. Supplementation of diet reduced the total contents of PC and residue, but the turnover rate of PC and residue remained still higher. Phosphorylation of endogenous proteins showed four different proteins of 78, 46, 33 and 16 kDa to be the substrates of PKC in casein group. In deficient group, phosphorylation of these proteins increased markedly while supplementation of diet had a reversing effect rendering the values to be intermediate between casein and the supplemented group. The changes in phospholipid metabolism and in phosphorylation of endogenous substrate proteins of PKC suggest that dietary protein deficiency causes alterations in transmembrane signalling mechanism in rat brain. These effects are partially reversed by improving the quality of proteins in the diet
Survival of Trial-Like and Non–Trial-Like Patients With Immunotherapy in Advanced Hepatocellular Carcinoma in Real World: A Collaborative Multicenter Indian Study (IMHEP)
PURPOSEImmune checkpoint inhibitors (ICIs) is the initial line of management in advanced hepatocellular carcinoma (HCC), but survivals in the real world are not known.MATERIALS AND METHODSA retrospective study of patients with advanced HCC receiving ICIs (as first-line therapy or as later lines of therapy) across 11 Indian institutions was conducted. Patients were divided into either cohort 1 (trial-like receiving ICI as first-line therapy), with a Child Pugh score (CTP) of ≤6, an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0/1, and no VP4 (main portal vein thrombosis [MPVT]) or cohort 2 (trial unlike) who did not satisfy at least one of the above criteria. The primary end point was 12-month overall survival (OS).RESULTSBetween January 2017 and January 2022, 133 patient data were analyzed. The presence of MPVT was seen in 33 patients (25%). The ICIs used were atezolizumab-bevacizumab, nivolumab, and pembrolizumab in 89 (66%), 44 (33%), and one (1%) patients, respectively. With a median follow-up of 13.8 months, the 12-month OS for the entire cohort was 33.4% (95% CI, 23.6 to 43.2). Patients in cohort 1 (n = 31) had a significantly improved OS compared with patients in cohort 2 (n = 102; 12-month OS, 57.9% [95% CI, 38.5 to 77.3] v 24% [95% CI, 13.4 to 34.6]; P = .005). Patients with CTP A as compared with CTP B (9.7 v 4.3 months; P < .001) and an ECOG PS of 0/1 as compared with a PS of ≥2 (8.7 v 7.2 months; P = .04) and without MPVT (9.4 v 4.0; P < .001) had superior survivals.CONCLUSIONPatients with advanced HCC in the real world, trial-like have survivals in consonance with trial data, whereas patients with features excluding them from trials, such as main portal vein thrombosis, poor ECOG PS, and child Pugh B status, have markedly inferior survivals, despite good tolerance to immunotherapy
Heat-induced SIRT1-mediated H4K16ac deacetylation impairs resection and SMARCAD1 recruitment to double strand breaks
Hyperthermia inhibits DNA double-strand break (DSB) repair that utilizes homologous recombination (HR) pathway by a poorly defined mechanism(s); however, the mechanisms for this inhibition remain unclear. Here we report that hyperthermia decreases H4K16 acetylation (H4K16ac), an epigenetic modification essential for genome stability and transcription. Heat-induced reduction in H4K16ac was detected in humans, Drosophila, and yeast, indicating that this is a highly conserved response. The examination of histone deacetylase recruitment to chromatin after heat-shock identified SIRT1 as the major deacetylase subsequently enriched at gene-rich regions. Heat-induced SIRT1 recruitment was antagonized by chromatin remodeler SMARCAD1 depletion and, like hyperthermia, the depletion of the SMARCAD1 or combination of the two impaired DNA end resection and increased replication stress. Altered repair protein recruitment was associated with heat-shock-induced γ-H2AX chromatin changes and DSB repair processing. These results support a novel mechanism whereby hyperthermia impacts chromatin organization owing to H4K16ac deacetylation, negatively affecting the HR-dependent DSB repair