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1.
J Assoc Physicians India ; 70(4): 11-12, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35443330

ABSTRACT

Adrenal insufficiency (AI) is well entrenched in medical constraints like septic shock, critically ill and multi-morbid hemodynamically unstable patients but its exact prevalence or differences in the cases of chronic liver disease (CLD) at variable grades of severity has recently gained momentum. The eventuality of AI propounding in stable compensated and decompensated cirrhosis without sepsis or in early and late stages of liver desecration are the existing lacunae in popular literature that this study aims to address. MATERIAL: A prospective, analytical study was conducted from March 2021 to December 2021 encompassing 100 hemodynamically stable patients with cirrhosis without infection, admitted at SMS Medical College, Jaipur, who were assessed clinically, biochemically and for adrenal functions. Adrenal insufficiency was defined on multivariable approach including basal 8am cortisol levels, followed by giving 250mcg synthetic adrenocorticotrophic hormone IM injection and retaking serum cortisol levels post-hourly interval to delineate peak and delta cortisol variables. All samples were processed by chemoluminiscence based method on fully automatic immunoassay analyser. OBSERVATION: The study comprised 81 males and 19 females with the mean age being 45.4±12.92 years, with CLD etiology concentrating substantially around alcohol consumption (71%). Viral comorbidities viz. HBV, HCV, both viral and alcohol related and miscellaneous causes were documented in 23, 10, 14 and 12 patients respectively. AI surfaced in 38% patients with CLD being statistically significant with p< 0.001. Inclusively, 10.5% patients with Child-Turcotte-Pugh (CTP) class A, 57.89% with CTP class B and 31.57% cases with CTP class C developed adrenal insufficiency. No statistical differences were found in age, sex; mean arterial pressure, heart rate, HDL, cirrhosis etiology, degree of alcohol consumption and manifestations of portal hypertension between patients with or without AI. For prudence, serum albumin levels were lower (p<0.5) with INR raised (p<0.33) in patients with AI than their counterparts. However, multivariate analysis revealed no direct independent adrenal insufficiency predictor. ROC curve showed that the CTP score may be a good predictor for AI in liver cirrhosis patients as supplemented by significant negative correlations found between CTP score and peak cortisol levels (p=0.001). CONCLUSION: Adrenal insufficiency found frequent even in stable cirrhotic patients form an integral division of the CLD spectra and worsening glucocorticoid levels should be periodically assessed in such patients for preventing parallel comorbidities.


Subject(s)
Adrenal Insufficiency , Hydrocortisone , Adult , Female , Humans , Male , Middle Aged , Adrenal Insufficiency/diagnosis , Adrenal Insufficiency/epidemiology , Adrenal Insufficiency/etiology , Liver Cirrhosis/complications , Liver Cirrhosis/epidemiology , Prospective Studies
3.
Oncogene ; 32(7): 920-9, 2013 Feb 14.
Article in English | MEDLINE | ID: mdl-22430213

ABSTRACT

p53 is essential for the cellular responses to DNA damage that help to maintain genomic stability. However, the great majority of human cancers undergo disruption of the p53-network. Identification and characterization of molecular components important in both p53-dependent and -independent apoptosis might be useful in developing novel therapies for cancers. In the complete absence of p53, cells treated with N-(phosphonacetyl)-L-aspartate (PALA) continue to synthesize DNA slowly and eventually progress through S-phase, suffering severe DNA damage that in turn triggers apoptosis, whereas cells with functional p53 undergo growth arrest. In this study, we investigated apoptotic signaling in response to PALA and the role of p53 expression in this pathway. We found that treatment of cells lacking p53 with PALA induced TAp73, Noxa and Bim and inactivation of these proteins with dominant-negative plasmids or small interfering RNAs significantly inhibited apoptosis, suggesting that PALA-induced apoptosis was mediated via TAp73-dependent expression of Noxa and Bim. However, PALA treatment inhibited the expression of ΔNp73 only in cells lacking p53 but not in cells expressing p53. In addition, PALA treatment inhibited Bcl-2, and overexpression of Bcl-2 significantly inhibited PALA-induced apoptosis. Moreover, expression of p53 in these cells protected them from PALA-induced apoptosis by activating p21, sustaining the expression of ΔNp73 and inhibiting the induction of Noxa and Bim. Taken together, our study identifies novel but opposing roles for the p53 and TAp73 in the induction of Noxa and Bim and regulation of apoptosis. Our data will help to develop strategies to eliminate cancer cells lacking p53 while protecting normal cells with wild-type p53.


Subject(s)
Apoptosis/drug effects , Aspartic Acid/analogs & derivatives , DNA-Binding Proteins/physiology , Neoplasms/drug therapy , Nuclear Proteins/physiology , Phosphonoacetic Acid/analogs & derivatives , Proto-Oncogene Proteins c-bcl-2/genetics , Tumor Suppressor Proteins/physiology , Antimetabolites, Antineoplastic/pharmacology , Antimetabolites, Antineoplastic/therapeutic use , Apoptosis/genetics , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Aspartic Acid/pharmacology , Aspartic Acid/therapeutic use , Bcl-2-Like Protein 11 , Cells, Cultured , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Drug Evaluation, Preclinical , Gene Expression Regulation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Membrane Proteins/genetics , Membrane Proteins/metabolism , Neoplasms/genetics , Neoplasms/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Phosphonoacetic Acid/pharmacology , Phosphonoacetic Acid/therapeutic use , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Tumor Protein p73 , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/physiology , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism , Up-Regulation/drug effects
4.
Leukemia ; 26(6): 1277-85, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22222598

ABSTRACT

Acute myeloid leukemia (AML) is the most common form of leukemia in adults. Unfortunately, the standard therapeutic agents used for this disease have high toxicities and poor efficacy. The one exception to these poor outcomes is the use of the retinoid, all-trans retinoic acid (ATRA), for a rare subtype of AML (APL). The use of the differentiation agent, ATRA, in combination with low-dose chemotherapy leads to the long-term survival and presumed cure of 75-85% of patients. Unfortunately ATRA has not been clinically useful for other subtypes of AML. Though many non-APL leukemic cells respond to ATRA, they require significantly higher concentrations of ATRA for effective differentiation. Here we show that the combination of ATRA with glycogen synthase kinase 3 (GSK3) inhibition significantly enhances ATRA-mediated AML differentiation and growth inhibition. These studies have revealed that ATRA's receptor, the retinoic acid receptor (RAR), is a novel target of GSK3 phosphorylation and that GSK3 can impact the expression and transcriptional activity of the RAR. Overall, our studies suggest the clinical potential of ATRA and GSK3 inhibition for AML and provide a mechanistic framework to explain the promising activity of this combination regimen.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Differentiation/drug effects , Glycogen Synthase Kinase 3/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/pathology , Receptors, Retinoic Acid/genetics , Tretinoin/pharmacology , Animals , Blotting, Western , Cells, Cultured , Drug Synergism , Enzyme Inhibitors/pharmacology , Female , Glycogen Synthase Kinase 3/metabolism , Humans , Immunoprecipitation , Leukemia, Myeloid, Acute/metabolism , Luciferases/metabolism , Mice , Mice, Nude , Phosphorylation , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Receptors, Retinoic Acid/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Transcriptional Activation/drug effects
5.
Vascul Pharmacol ; 40(6): 269-77, 2004 Jan.
Article in English | MEDLINE | ID: mdl-15063830

ABSTRACT

We investigated the regulation of the epithelial sodium channel (ENaC) in human bone marrow endothelial cells (HBMEC) responding to mineralocorticoid hormones and other accessory effectors. The message for both the mineralocorticoid receptor (MCR) and the alpha subunit of ENaC was expressed in HBMEC as predicted bands of 838 and 521 bp, respectively. In Western blots, the MCR of about 107 kDa was localized primarily in the cytoplasmic compartment but migrated to the nucleus when cell cultures were exposed to exogenous aldosterone. On the other hand, the alphaENaC was revealed as a membrane-bound protein of approximately 82 kDa, whose abundance increased after aldosterone treatment. Confocal microscopy confirmed the presence of both the MCR and ENaC as nucleocytoplasmic and membrane-bound proteins, respectively, and both colocalized with tubulin in situ. On Matrigel, the mineralocorticoid aldosterone, by itself, did not influence capillary formation by HBMEC, but the diuretic amiloride reduced the organization of HBMEC into capillary-like networks; curiously, aldosterone further exacerbated this inhibitory effect of amiloride. On the fibrin matrix, aldosterone had no influence at all on the length of the newly formed capillaries, but the capillary diameter was highly increased over the control. Aldosterone-mediated capillary swelling was totally reversed by amiloride, which, by itself, also inhibited capillary elongation by HBMEC. Thus, cell signaling by mineralocorticoid hormones in HBMEC appears to proceed in a manner very similar to that in the epithelial cell, thereby leading to an increase in the endothelial cell volume, which may underline the hypertensive state and which may also modify angiogenesis.


Subject(s)
Aldosterone/pharmacology , Bone Marrow Cells/drug effects , Capillaries/drug effects , Endothelium, Vascular/drug effects , Neovascularization, Physiologic/drug effects , Signal Transduction/drug effects , Aldosterone/physiology , Amiloride/pharmacology , Blotting, Western , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Capillaries/physiology , Cell Line , Diuretics/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Humans , Immunohistochemistry , Microscopy, Confocal , Polymerase Chain Reaction , Protein Subunits/biosynthesis , Protein Subunits/drug effects , Protein Subunits/genetics , Receptors, Mineralocorticoid/biosynthesis , Receptors, Mineralocorticoid/drug effects , Receptors, Mineralocorticoid/genetics , Sodium Channels/biosynthesis , Sodium Channels/drug effects , Sodium Channels/genetics , Tubulin/metabolism
6.
Int J Toxicol ; 22(4): 297-304, 2003.
Article in English | MEDLINE | ID: mdl-12933324

ABSTRACT

The authors studied mineralocorticoid receptor (MCR)-mediated effects of steroids on CD34(+) progenitor cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed the presence of mRNA for both the MCR and the alpha subunit of the epithelial sodium channel, a member of the amiloride-sensitive sodium channel (ASSC) superfamily, in human CD41(+) megacaryoblastic cells derived from cultured bone marrow CD34(+) isolates, as well as in the human erythromegakaryoblastic leukemia (HEL) cell line. Immunofluorescence also revealed the presence of both the MCR and ASSC in circulating CD34(+) and medullar CD41(+) megacaryoblastic cells, the former as a nucleocytoplasmic protein and the latter as a membrane-bound protein, as expected from earlier studies using MCR-specific targets. In a selective medium, the formation of erythrocyte burst-forming units, and of the granulocyte-macrophage colony-forming units, by circulating CD34(+) cells was influenced by the agonists deoxycorticosterone and aldosterone, as well as by the antagonists RU 26752 and ZK 91587, targeted for the MCR. The multiplication of the leukemic HEL progeny, derived from CD41(+) cells, was similarly altered by these steroids targeted for the MCR. In contrast, in the optimal growth medium, the multiplication, and colony formation by bone marrow CD34(+) progenitor cells were not altered by either aldosterone or ZK 91587. These and other studies reveal that the receptor-mediated action of mineralocorticoids may influence the functional maturation of the hematopoietic progenitor lineage, contrary to the classical notion where the mineralotropic effect would be a unique feature of the epithelial cell.


Subject(s)
Mineralocorticoids/metabolism , Pluripotent Stem Cells/metabolism , Antigens, CD34/metabolism , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Cells, Cultured , Flow Cytometry , Humans , Immunohistochemistry , Immunomagnetic Separation , Megakaryocytes/cytology , Megakaryocytes/metabolism , Platelet Membrane Glycoprotein IIb/metabolism , Pluripotent Stem Cells/cytology , Receptors, Mineralocorticoid/genetics , Receptors, Mineralocorticoid/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sodium Channels/genetics , Sodium Channels/metabolism
7.
Int J Toxicol ; 21(3): 191-9, 2002.
Article in English | MEDLINE | ID: mdl-12055020

ABSTRACT

Although the administration of adrenocortical hormones to pregnant rats provokes only limited effect on the growth and development of the fetus, the direct influence of these steroids on cultured embryos has never been studied. The disruption of cell signaling by ZK 91587, which specifically occupies the mineralocorticoid receptor, resulted within 2 days in significant and pronounced adverse effects on the total length, the somite number, the embryo curvature, the communication between vitelline and umbilical blood vessels in the allantoid, and the vascularization of the vitelline sac, in 244-hour Wistar rat embryos in culture. The average score of 16 organs declined in a dose-dependent manner, following exposure to ZK 91587, and this was totally reversed by 10 microM aldosterone which, by itself, did not at all influence the embryonic development. The organogenesis was inhibited in the order: hind limb > fore limb > optic stalk > brain > olfactory pit > otic vesicle. ZK 91587 was completely ineffective in embryos that had attained the age of 260 hours. Similar, but less dramatic, results were obtained with the mineralocorticoid antagonist RU 26752, and with the antiglucocorticoid RU 38486. Sprague-Dawley rat embryos responded in a manner similar to the Wistar conceptuses. Thus, steroid receptor-mediated cell signaling is of critical importance to the growth and development of cultured rat embryos, which form a new model system to unravel adrenocortical hormone action.


Subject(s)
Embryo, Mammalian/drug effects , Mineralocorticoids/antagonists & inhibitors , Receptors, Mineralocorticoid/biosynthesis , Signal Transduction/drug effects , Sodium Channels/biosynthesis , Spironolactone/analogs & derivatives , Teratogens/toxicity , Animals , Dose-Response Relationship, Drug , Epithelial Sodium Channels , Female , Immunohistochemistry , Male , Mifepristone/toxicity , Mineralocorticoid Receptor Antagonists , Organ Culture Techniques , Polymerase Chain Reaction , Pregnancy , RNA, Messenger/analysis , Rats , Spironolactone/toxicity
8.
Oncogene ; 20(20): 2527-36, 2001 May 03.
Article in English | MEDLINE | ID: mdl-11420662

ABSTRACT

Activation of MAP kinase leads to the activation of p53-dependent pathways, and vice-versa. Although the amount of p53 protein increases in response to MAP kinase-dependent signaling, the basis of this increase is not yet fully understood. We have isolated the mutant cell line AP14, defective in p53 expression, from human HT1080 fibrosarcoma cells, which have an activated ras allele. The expression of p53 mRNA and protein is approximately 10-fold lower in AP14 cells than in the parental cells. The high constitutive phosphorylation and activities of the MAP kinases ERK1 and ERK2 in HT1080 cells are greatly reduced in AP14 cells, although the levels of these proteins are unchanged, suggesting that the defect in the mutant cells affects the steady-state phosphorylation of ERK1 and ERK2. Overexpression of ERK2 in AP14 cells restored both MAP kinase activity and p53 expression, and incubation of the mutant cells with the phosphatase inhibitor orthovanadate resulted in strong coordinate elevation of MAP kinase activity and p53 expression. The levels of expression of the p53-regulated gene p21 parallel those of p53 throughout, showing that basal p21 expression depends on p53. The levels of p53 mRNA increased by 5-8-fold when activated ras was introduced into wild-type cells, and the levels of the p53 and p21 proteins decreased substantially in wild-type cells treated with the MEK inhibitor U0216. We conclude that MAP kinase-dependent pathways help to regulate p53 levels by regulating the expression of p53 mRNA.


Subject(s)
Gene Expression Regulation, Neoplastic/physiology , MAP Kinase Kinase Kinase 1 , MAP Kinase Signaling System/physiology , Tumor Suppressor Protein p53/biosynthesis , ras Proteins/physiology , 3T3 Cells , Animals , Fibrosarcoma/enzymology , Fibrosarcoma/genetics , Fibrosarcoma/metabolism , Humans , Mice , Mitogen-Activated Protein Kinases/metabolism , Mutagenesis , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/physiology , Proto-Oncogene Proteins c-raf/metabolism , Proto-Oncogene Proteins c-raf/physiology , Proto-Oncogene Proteins p21(ras)/biosynthesis , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics
9.
Biochem Biophys Res Commun ; 280(5): 1300-6, 2001 Feb 09.
Article in English | MEDLINE | ID: mdl-11162670

ABSTRACT

The PCR analysis followed by sequence alignment showed that both the mineralocorticoid receptor (MCR) and the epithelial sodium channel (ENaC) genes were expressed in the human vascular endothelial cell line (ECV). The growth and multiplication of the ECV in culture were influenced by both aldosterone and the MCR-specific antagonist ZK 91587. Following double labelled immunofluorescence recorded by confocal microscopy, both the MCR and the ENaC were found to colocalize with the tubulin filaments in ECV cells in situ; no association was observed with cellular actin. ZK 91587 not only eliminated the basal expression, but it also impaired the transactivation of the ENaC gene by aldosterone. The disruption of actin and tubulin by cytochalasin D and colchicine, respectively, resulted in the total elimination of ENaC induction by aldosterone. These studies suggest that (i) the transcriptional regulation of the ENaC gene by the MCR-mediated signalling is not restricted to epithelial cells and requires cytoskeleton integrity in ECV cells in situ, (ii) tubulin may form a new and novel mediator in cell regulation, and (iii) the vascular tone may actually be regulated via transactivation of the ion gated sodium channel in the endothelial cell of the blood vessels under direct, receptor-mediated action of aldosterone.


Subject(s)
Cytoskeleton/metabolism , Endothelium, Vascular/metabolism , Receptors, Mineralocorticoid/physiology , Sodium Channels/metabolism , Spironolactone/analogs & derivatives , Actins/analysis , Aldosterone/pharmacology , Cell Line , Cytochalasin D/pharmacology , Cytoskeleton/drug effects , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Epithelial Sodium Channels , Ethanol/pharmacology , Humans , Immunohistochemistry , Microscopy, Confocal , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Mineralocorticoid/analysis , Receptors, Mineralocorticoid/genetics , Signal Transduction/drug effects , Sodium Channels/genetics , Spironolactone/pharmacology , Tubulin/analysis
10.
Ophthalmic Res ; 33(1): 7-19, 2001.
Article in English | MEDLINE | ID: mdl-11114599

ABSTRACT

We investigated the regulation of sodium absorption by steroid hormones in embryologically diverse cells from the human eye. A cell extract from human corneal fibroblasts was positive for both the epithelial sodium channel (ENaC) and the mineralocorticoid receptor (MCR) as 82- to 85-kD and 102-kD bands, respectively, by the Western blot technique. In fluorescent, confocal and electron microscopy, the MCR was revealed as a nucleocytoplasmic protein, whereas the ENaC was almost exclusively membrane bound; both appeared aligned along actin filaments of corneal keratocytes, and both were widely colocalized in various cell types of human cornea in situ. Following reverse transcription and amplification of total RNA isolated from corneal fibroblasts, the ENaC and MCR genes in the PCR product were evident as predicted bands of 520 and 843 bp, respectively, whose sequence exhibited 100% identity with those from known human sources. The multiplication of corneal fibroblasts was influenced by both the MCR-specific antagonist RU 26752 and the natural hormone aldosterone, and these steroids also stimulated protein phosphorylation. In quantitative PCR, both the basal and aldosterone-induced levels of ENaC were diminished by the MCR-specific antagonist ZK 91587. Consequently, the ocular sodium channel appears to be regulated by steroid signalling in cells of diverse embryological origins, contrary to the existing notions where (a) this process would be limited exclusively to the epithelial cells and (b) ocular sodium transport would be regulated via the Na(+)-K(+)-ATPase in the basolateral membrane.


Subject(s)
Aldosterone/pharmacology , Epithelium, Corneal/metabolism , Fibroblasts/metabolism , Sodium Channels/metabolism , Base Sequence , DNA Primers/chemistry , Epithelium, Corneal/drug effects , Epithelium, Corneal/ultrastructure , Fibroblasts/drug effects , Fibroblasts/ultrastructure , Humans , Ion Transport/drug effects , Ion Transport/physiology , Microscopy, Confocal , Molecular Sequence Data , RNA/analysis , Receptors, Mineralocorticoid/drug effects , Receptors, Mineralocorticoid/genetics , Receptors, Mineralocorticoid/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Signal Transduction/drug effects , Sodium Channels/drug effects
11.
Leukemia ; 14(6): 1097-104, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10865975

ABSTRACT

We studied the expression of the mineralocorticoid receptor (MCR), and of the amiloride-sensitive sodium channel (ASSC) regulated by the MCR, in human leukemic cell lines. Cell extracts from TF1 (proerythroblastic), HEL (human erythroblastic leukemia) and U937 (myeloblastic) cell line were positive for the ASSC, as a 82 kDa band in Western blots developed with the aid of a polyclonal antibody raised against the peptide QGLGKGDKREEQGL, corresponding to the region 44-58 of the alpha subunit of the epithelial sodium channel (ENaC) cloned from rat colon, linked to KLH. The polyclonal antibody against the MCR revealed a single band of about 102 kDa in extracts from HEL and TF1 cells. The immunofluorescent labelling of the MCR in all cell lines showed a nucleocytoplasmic localization of the receptor but the ASSC was exclusively membrane-bound and these results were confirmed by confocal microscopy. The expression of the MCR in the HEL cells was evident as a predicted band of 843 bp (234 amino acids) in electrophoresis of the PCR product obtained after total RNA had been reverse transcribed and then amplified using the primers 5'-AGGCTACCACAGTCTCCCTG-3' and 5'-GCAGTGTAAAATCTCCAGTC-3' (sense and antisense, respectively). The ENaC was similarly evident with the aid of the primers 5'-CTGCCmATG GATGATGGT-3' (sense) and 5'-GTTCAGCTCGAAGAAGA-3' (antisense) as a predicted band of 520 bp. In both cases, 100% identity was observed between the sequences of the PCR products compared to those from known human sources. The multiplication of the HEL cells was influenced by antagonists (RU 26752, ZK 91587) targeted for specificity to the MCR and this was selectively reversed by the natural hormone aldosterone. These steroids also provoked chromatin condensation in the HEL population. These permit new and novel possibilities to understand the pathobiology of human leukemia and to delineate sodium-water homeostasis in nonepithelial cells.


Subject(s)
Leukemia/metabolism , Receptors, Mineralocorticoid/metabolism , Amino Acid Sequence , Animals , Base Sequence , Blotting, Western , DNA Primers , Humans , Immunohistochemistry , Leukemia/pathology , Microscopy, Confocal , Polymerase Chain Reaction , Rats , Tumor Cells, Cultured
12.
Biochem Biophys Res Commun ; 270(3): 811-5, 2000 Apr 21.
Article in English | MEDLINE | ID: mdl-10772907

ABSTRACT

PCR analysis and Western blotting revealed the expression of the mineralocorticoid receptor (MCR) and the epithelial sodium channel (ENaC) genes at the level of RNA, DNA, and protein in several leukemic cell lines, fibroblasts from human cornea, and epithelial cells from ocular tissues. Following immunofluorescence, the MCR appeared to be primarily nuclear whereas the ENaC was almost exclusively membrane-bound. Paradoxically, the MCR-specific antagonist ZK 91587 actually stimulated the multiplication of human erythroblastic leukemia cells, contrary to the inhibitory effect of the antagonist RU 26752 on the multiplication of corneal fibroblasts; both effects were opposed by aldosterone. In quantitative PCR, both basal and aldosterone-induced levels of ENaC were diminished by ZK 91587 in the corneal fibroblast, in contrast to the stimulation observed in the retinal pigmentary epithelium. Thus, contrary to the existing notions, (a) antimineralocorticoids can act both as agonists and antagonists, and (b) the receptor-mediated action of mineralocorticoids on the sodium channel is not restricted to the epithelial cell.


Subject(s)
Aldosterone/pharmacology , Cornea/physiology , Mineralocorticoids/pharmacology , Receptors, Mineralocorticoid/physiology , Sodium Channels/physiology , Animals , Cattle , Cell Division/drug effects , Cells, Cultured , Cornea/cytology , Cornea/drug effects , Embryo, Mammalian , Epithelial Sodium Channels , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/physiology , Humans , Ion Channel Gating/drug effects , Leukemia, Erythroblastic, Acute , Mineralocorticoid Receptor Antagonists , Mineralocorticoids/antagonists & inhibitors , Pigment Epithelium of Eye/cytology , Pigment Epithelium of Eye/drug effects , Pigment Epithelium of Eye/physiology , Receptors, Mineralocorticoid/genetics , Sodium Channels/drug effects , Sodium Channels/genetics , Spironolactone/analogs & derivatives , Spironolactone/pharmacology , Tumor Cells, Cultured
13.
Indian J Chest Dis Allied Sci ; 42(4): 249-58, 2000.
Article in English | MEDLINE | ID: mdl-15597671

ABSTRACT

In the present study, allergenic significance of thirteen species of Aspergillus and their allergenic and antigenic relationship was studied. Of the 3025 ID tests performed with the 13 species of Aspergillus on 289 patients suffering with allergic respiratory diseases, 627 (20.7%) were positive (1+ to 4+), 386 (12.8%) being significantly positive (2+ to 4+) . Of the 64 patients eliciting a positive cutaneous response to at least one species, 42(65.6%) were positive to 5 or less number of species while others showed a broad spectrum of positive skin reactivity to different Aspergillus extracts. In RAST inhibition assays using pooled sera ofpatients sensitive to A. tamarii dose related inhibition was produced by homologous as well as 5 of the 12 heterologous species. Similarly, in A. terreus RAST inhibition was observed with homologous and A. tamarii extracts only. Our results suggested the presence of both species specific as well as shared allergenic components among different Aspergillus species. In TDIEP experiments using rabbit antisera to A. tamarii and A. terreus extracts multiple precipitin bands were observed with the homologous extracts. However, only 1-2 bands were produced by 6 heterologous Aspergillus species in each system. Collectively, these results gave evidence that there is heterogeneity of immune response in the patients with allergic respiratory diseases to different species of Aspergillus and also in rabbits immunized with Aspergillus extracts.


Subject(s)
Antigens, Fungal/immunology , Aspergillus/immunology , Aspergillus/pathogenicity , Hypersensitivity/immunology , Lung Diseases, Fungal/immunology , Case-Control Studies , Humans , Immunoglobulin E/blood , Radioallergosorbent Test , Skin Tests
14.
Indian J Otolaryngol Head Neck Surg ; 52(4): 360-3, 2000 Oct.
Article in English | MEDLINE | ID: mdl-23119724

ABSTRACT

This study was conducted on 40 biopsy proved patients of head and neck cancers,85% of patients presented with squamous cell carcinoma in various grades of differentiation. When seruma denosine deaminase activity was compared between controls and cases, significant increase was found in the activities (control 51.54 ±12.09 IU/L and cases 106.87 ±29.75 IU/ L). The duration of illness didn't reflect any statistical significance with the adenosine deminase activity. It was 97.59 ±62.93 IU/L in case where duration of illness was 98 ±30.98 IU/L in patient with more than one year of disease. The lymph node showed stronger correlation with adenosine deaminase activity, its level was 83.41±1.41 IU/L in patients with N(3) The rise in serum adenosine deaminase activity was found to be directly related to the stage I disease. It was 57.80 ±4.60 IU/ L in patient with stage I disease while in patients with stage IV had 135.87 ±18.39 IU/L of activity. According to histological grading, highest level was found in patients having squamous cell carcinoma( 113.41 ±32 IU/L). The activity of adenosine deaminase decreases with radiotherapy and after surgery. This may help in assessing the decrease in tumour mass and improvement in patient’s clinical condition.

15.
Exp Eye Res ; 69(1): 21-32, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10375446

ABSTRACT

The presence of the amiloride-sensitive sodium channel (ASSC) in ocular tissues was studied with the aid of a polyclonal antiserum raised against the 14 amino acid peptide QGLGKGDKREEQGL. This sequence corresponds to the region 44-58 of the alpha subunit of the channel, termed ENaC, cloned from rat colon. The antibody titers, measured by the ELISA technique, rose to 1∶2560 4 weeks after immunization, and this bleed was used in all subsequent experiments. Immunoblotting with the polyclonal anti-alphaENaC serum, revealed a major band of 82-86 kDa in extracts prepared from whole bovine or rat retina; a minor component of 92 kDa in the extract from bovine ciliary body may represent a glycosylated species. Immunohistochemistry, using the alphaENaC-specific antiserum, revealed strong fluorescence in specific areas of the rat and human eye. Pronounced labelling was observed in the epithelial cell layer of the retina, the lens, as well as both the pigmented and the nonpigmented epithelium of the ciliary body and the iris. All of the cell layers (epithelium, endothelium and fibroblasts) in the cornea, the blood vessels in the iris, and iris epithelium, were also strongly immunopositive. The somatic body of the photoreceptor cells (cones and rods) in the inner and outer segments could be traced to forming a synapse in both the internal and external portions of the internal nuclear layer. The bipolar cells and ganglia in the neuronal compartment also exhibited occasional immunofluorescence. The method of fixation and the source of the tissue were important parameters for the immunochemical localization of the ENaC. The resolution was very poor when rat eye was fixed in Bouin's solution but this method was satisfactory for human tissues. For rat eye, optimum resolution was obtained with AMeX fixation. This widespread distribution of the ENaC generally colocalizes with the previously observed immunopositivity for the mineralocorticoid receptor such that steroid hormone-mediated ion regulation would appear to add a new parameter to the functional expression of ocular tissues.


Subject(s)
Eye/metabolism , Rats/metabolism , Sodium Channels/metabolism , Amiloride/pharmacology , Animals , Blotting, Western , Cattle/metabolism , Fluorescent Antibody Technique , Humans , Immune Sera/immunology , Peptide Fragments/immunology , Sodium Channels/drug effects , Sodium Channels/immunology , Tissue Fixation/methods
16.
Cancer Lett ; 135(1): 53-60, 1999 Jan 08.
Article in English | MEDLINE | ID: mdl-10077221

ABSTRACT

Recently, we have shown that sustained ROS generation by prolonged porphyrin-mediated photosensitization in murine skin acts as a stage I and weak complete tumor promoter. Further to this, in the present study, we show that porphyrin photosensitization of DMBA-initiated murine skin results in the augmentation of TPA-mediated tumor promoting response. The photosensitization increased tumor yield to 15 tumors per mouse as compared to 7.5 tumors per mouse in the group treated with TPA alone. Further, 100% tumor incidence in the TPA-treated photosensitized group occurred at week 11 whereas it occurred at week 19 in the TPA alone treated group. Porphyrin photosensitization slightly decreased the latency period of TPA-mediated tumor formation by 1 week. The TPA-mediated ODC induction (1300% of saline-treated control) has been augmented in the photosensitized group (1950%). However, the amount of [3H]thymidine incorporation was not significantly different in the photosensitized TPA-treated and TPA alone-treated groups. Similarly, TPA treatment in photosensitized animals augmented the depletion of cutaneous glutathione and enhancement of lipid peroxidation. These changes were attenuated in butylated hydroxytoluene-pretreated animals. Our results suggest that cutaneous porphyrin photosensitization augments TPA-mediated tumor promotion in murine skin.


Subject(s)
9,10-Dimethyl-1,2-benzanthracene/pharmacology , Carcinogens/pharmacology , Photosensitizing Agents/pharmacology , Porphyrins/pharmacology , Reactive Oxygen Species/metabolism , Skin Neoplasms/chemically induced , Tetradecanoylphorbol Acetate/pharmacology , Animals , Female , Mice , Papilloma/chemically induced , Papilloma/metabolism , Photosensitivity Disorders/chemically induced , Photosensitivity Disorders/metabolism , Skin Neoplasms/metabolism
17.
Pharmacol Ther ; 84(3): 273-326, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10665831

ABSTRACT

The adrenal cortex elaborates two major groups of steroids that have been arbitrarily classified as glucocorticoids and mineralocorticoids, despite the fact that carbohydrate metabolism is intimately linked to mineral balance in mammals. In fact, glucocorticoids assured both of these functions in all living cells, animal and photosynthetic, prior to the appearance of aldosterone in teleosts at the dawn of terrestrial colonization. The evolutionary drive for a hormone specifically designed for hydromineral regulation led to zonation for the conversion of 18-hydroxycorticosterone into aldosterone through the catalytic action of a synthase in the secluded compartment of the adrenal zona glomerulosa. Corticoid hormones exert their physiological action by binding to receptors that belong to a transcription factor superfamily, which also includes some of the proteins regulating steroid synthesis. Steroids stimulate sodium absorption by the activation and/or de novo synthesis of the ion-gated, amiloride-sensitive sodium channel in the apical membrane and that of the Na+/K+-ATPase in the basolateral membrane. Receptors, channels, and pumps apparently are linked to the cytoskeleton and are further regulated variously by methylation, phosphorylation, ubiquination, and glycosylation, suggesting a complex system of control at multiple checkpoints. Mutations in genes for many of these different proteins have been described and are known to cause clinical disease.


Subject(s)
Mineralocorticoids/physiology , Amiloride/pharmacology , Animals , Humans , Immunohistochemistry , Mineralocorticoid Receptor Antagonists , Mineralocorticoids/antagonists & inhibitors , Receptors, Mineralocorticoid/analysis , Receptors, Mineralocorticoid/genetics , Receptors, Mineralocorticoid/physiology , Sodium Channels/physiology , Sodium-Potassium-Exchanging ATPase/chemistry , Sodium-Potassium-Exchanging ATPase/metabolism , Structure-Activity Relationship
18.
Biochem Biophys Res Commun ; 244(1): 120-5, 1998 Mar 06.
Article in English | MEDLINE | ID: mdl-9514896

ABSTRACT

The relative abundance and availability of the mineralocorticoid receptor (MCR) appeared to be similar in the heart, kidney and ocular tissues of the genetically hypertensive SHR and normotensive WKY rats by a number of criteria including Western blotting, immunoprecipitation, dot blot analysis, and immunohistochemistry. On the other hand, the activation of the MCR, as judged by binding to DNA cellulose, was significantly enhanced in the hearts and kidneys of 14 week-old, hypertensive, SHR rats compared to the normotensive WKY animals. The activation of the renal MCR was elevated in the SHR strain even at the age of six weeks when the tail arterial pressure was statistically identical to that of the WKY strain. Thus, precocious receptor activation may represent a primary lesion leading to hypertension in the SHR strain, thereby providing a new model to elucidate the hypertensive state.


Subject(s)
Hypertension/genetics , Hypertension/metabolism , Receptors, Mineralocorticoid/metabolism , Animals , Binding Sites/genetics , Blotting, Western , Hypertension/physiopathology , Immunohistochemistry , Kidney/metabolism , Male , Molecular Weight , Myocardium/metabolism , Radioligand Assay , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Receptors, Mineralocorticoid/isolation & purification
19.
Endocr Res ; 24(3-4): 455-9, 1998.
Article in English | MEDLINE | ID: mdl-9888525

ABSTRACT

A Cell extract from the HEL (human erythroblastic leukemia) cell line was positive for both the epithelial sodium channel (ENaC) and the mineralocorticoid receptor (MCR) as glycosylated 82-84 kDa bands, and a single 102 kDa band, respectively, in Western blots using polyclonal antibodies raised against these proteins. The immunofluorescent labeling of the MCR in all cell lines showed a nucleocytoplasmic localization of the receptor whereas the ENaC was exclusively membrane-bound. These results were confirmed by confocal microscopy. The expression of the MCR in HEL cells was evident as a predicted band of 843 bp (234 amino acids) after total RNA from HEL cells had been reverse transcribed and then amplified by PCR; the ENaC was similarly evident as a predicted band of 520 bp. In both cases, near 100% identity was observed between the deduced amino acid sequences of the PCR products and those from known human sources. The multiplication of HEL cells was influenced by antagonists (RU 26752, ZK 91587) targeted for specificity to the MCR and this was reversed by the natural hormone aldosterone. These steroids also provoked chromatin condensation in the HEL population.


Subject(s)
Leukemia, Erythroblastic, Acute/metabolism , Receptors, Mineralocorticoid/metabolism , Sodium Channels/metabolism , Amino Acid Sequence/genetics , Cell Division/drug effects , Chromatin/metabolism , Dose-Response Relationship, Drug , Epithelial Sodium Channels , Humans , Leukemia, Erythroblastic, Acute/pathology , Mineralocorticoid Receptor Antagonists , Molecular Sequence Data , Osmolar Concentration , RNA, Messenger/metabolism , Receptors, Mineralocorticoid/genetics , Sequence Homology, Amino Acid , Sodium Channels/genetics , Spironolactone/analogs & derivatives , Spironolactone/pharmacology , Tumor Cells, Cultured/pathology
20.
Indian J Otolaryngol Head Neck Surg ; 50(1): 43-5, 1998 Jan.
Article in English | MEDLINE | ID: mdl-23119377

ABSTRACT

A rare cse of aspergillosis of the maxillary sinus is reported. Surgical excision including the lining of the infected sinus is the preferred method of treatment. Antifungal therapy does not seem to affect the prognosis of this disease.

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