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1.
QJM ; 115(4): 222-227, 2022 Apr 20.
Article in English | MEDLINE | ID: mdl-35199176

ABSTRACT

BACKGROUND: Herpes simplex virus encephalitis (HSVE) is one of the most common infectious causes of sporadic encephalitis. Coronavirus disease (COVID-19) has been associated with immune dysregulation of the host that might increase the risk of infections like HSVE following SARS-CoV-2 infection. There is paucity of literature on post COVID-19 HSVE. This study was conducted with the aim of analyzing the clinical presentation, brain imaging, and outcome of patients presenting with HSVE within 6 weeks of COVID-19 and providing a comprehensive review on the possible mechanisms of post-COVID-19 HSVE. METHODS: This observational study included patients who had laboratory-confirmed HSVE (type 1 or type 2) and a history of COVID-19 within the previous 6 weeks. Patients were followed up for 3 months. RESULTS: Eight patients were included and all of them had type 1 HSVE. The mean latency of onset of neurological symptoms from being diagnosed with COVID-19 is 23.87 days and a majority of the patients have received injectable steroids with a mean duration of 6.5 days. Behavioral abnormality was the commonest neurological presentation and typical brain imaging involved T2 FLAIR hyperintensities of the medial temporal lobes. All patients received intravenous acyclovir 10 mg/kg every eight hourly for atleast 14 days. One patient with concomitant rhinocerebral mucormycosis succumbed while the majority had a complete recovery. CONCLUSION: Possible immune dysregulation in COVID-19 may increase the susceptibility of HSVE in patients with a history of recent SARS-CoV-2 infection. The clinical manifestations and laboratory findings of HSVE in such patients are similar to typical HSVE.


Subject(s)
COVID-19 , Encephalitis, Herpes Simplex , Herpes Simplex , Acyclovir/therapeutic use , COVID-19/complications , Encephalitis, Herpes Simplex/complications , Encephalitis, Herpes Simplex/diagnosis , Encephalitis, Herpes Simplex/drug therapy , Humans , Observational Studies as Topic , SARS-CoV-2
2.
Eur. j. psychiatry ; 35(1): 56-61, enero-marzo 2021.
Article in English | IBECS | ID: ibc-217542

ABSTRACT

Cognitive impairment and varied psychiatric manifestations are common in thyroid disorders. But autoimmune thyroid disorders masquerading as dementia or psychotic disorders without other overt systemic features of dysthyroidism are rare. Here we are presenting a detailed analysis of four heterogeneous cases of thyroid related cognitive impairments mimicking and fulfilling criteria of known psychiatric diagnosis for a brief period of time, requiring multiple psychotropic medications without any significant improvement. Cognitive impairment and behavioral abnormalities with a known psychiatric diagnosis, with unknown temporal profiling of anti-thyroid peroxidase (TPO) positivity, without encephalopathy and subsequent complete or partial responsiveness with levothyroxin, point towards a possible new entity not well explored so far.(AU)


Subject(s)
Humans , Cognitive Dysfunction , Dementia , Mental Disorders , Diagnosis
3.
Acta Neurol Scand ; 132(3): 203-11, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25689886

ABSTRACT

BACKGROUND: Disability-adjusted life year (DALY) is a time-based measure of disease burden incorporating both disability and mortality. Our study aimed to determine the DALY lost from epilepsy in an Indian metropolis. METHODS: A population-based prospective study on epilepsy was conducted over 5 years (2003-8) in Kolkata, India, on randomly selected 100,802 subjects (males 53,209, females 47,593) to assess prevalence as well as to capture incident cases of epilepsy and those incident cases that died. Standard case definitions were used. The data were used to estimate years of life lost (YLL) due to premature mortality, years of life lived with disability (YLD), and DALY, utilizing the prevalence-based Global Burden of Disease (GBD) 2010 approach. Age- and gender-specific figures were computed. RESULTS: During 2003-2004, a total of 476 subjects with active epilepsy were detected and the age-adjusted prevalence rate was 4.71 per 1000. Over 5 years, there were 197 incident cases of epilepsy of whom 26 died. The age-adjusted annual incidence rate of epilepsy was 38.3 per 100,000. The all-cause standardized mortality rate (SMR) of epilepsy was 2.4. The burden of epilepsy in the year 2007-8 revealed the overall YLL was 755 per 100,000, and the overall YLD ranged from 14.45 to 31.0 per 100,000 persons depending on the clinical severity of the epilepsy. Both YLL and YLD values were higher in males than in females. The overall DALY lost due to epilepsy in 2007-8 was found to be 846.96 (males 1183.04, females 463.81) per 100,000. CONCLUSIONS: This is the first study in India to determine the DALY of epilepsy using GBD 2010. The results reveal a substantial burden of epilepsy in our setting. Similar such studies are needed in other parts of India in both urban and rural settings.


Subject(s)
Cost of Illness , Epilepsy/epidemiology , Adult , Aged , Asian People , Female , Humans , India/epidemiology , Male , Middle Aged , Prevalence , Prospective Studies , Quality-Adjusted Life Years , Rural Population
4.
Neurology ; 75(15): 1362-9, 2010 Oct 12.
Article in English | MEDLINE | ID: mdl-20938028

ABSTRACT

OBJECTIVE: No well-designed longitudinal study on Parkinson disease (PD) has been conducted in India. Therefore, we planned to determine the prevalence, incidence, and mortality rates of PD in the city of Kolkata, India, on a stratified random sample through a door-to-door survey. METHOD: This study was undertaken between 2003 to 2007 with a validated questionnaire by a team consisting of 4 trained field workers in 3 stages. Field workers screened the cases, later confirmed by a specialist doctor. In the third stage, a movement disorders specialist undertook home visits and reviewed all surviving cases after 1 year from last screening. Information on death was collected through verbal autopsy. A nested case-control study (1:3) was also undertaken to determine putative risk factors. The rates were age adjusted to the World Standard Population. RESULT: A total population of 100,802 was screened. The age-adjusted prevalence rate (PR) and average annual incidence rate were 52.85/100,000 and 5.71/100,000 per year, respectively. The slum population showed significantly decreased PR with age compared with the nonslum population. The adjusted average annual mortality rate was 2.89/100,000 per year. The relative risk of death was 8.98. The case-control study showed that tobacco chewing protected and hypertension increased PD occurrence. CONCLUSION: This study documented lower prevalence and incidence of PD as compared with Caucasian and a few Oriental populations. The mortality rates were comparable. The decreased age-specific PR among slum populations and higher relative risk of death need further probing.


Subject(s)
Parkinson Disease/epidemiology , Residence Characteristics , Adult , Age Factors , Aged , Aged, 80 and over , Case-Control Studies , Cross-Sectional Studies , Female , Health Surveys , Humans , Incidence , India/epidemiology , Longitudinal Studies , Male , Middle Aged , Mortality , Parkinson Disease/diagnosis , Parkinson Disease/mortality , Residence Characteristics/statistics & numerical data , Retrospective Studies , Risk Factors , Sex Factors
5.
J Assoc Physicians India ; 53: 141-3, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15847036

ABSTRACT

A 55 years old, hypertensive, diabetic lady presented with sudden onset jerky movement of lower trunk and legs. It was present both in awake and sleep and got aggravated by mental stress as well as sensory stimulation. Examination revealed rhythmic jerks affecting muscles of lower abdomen and legs. The lower limbs had normal muscle bulk and power, increased tone, exaggerated deep tendon reflexes, bilateral flexor plantar response with normal sensory autonomic and cerebellar function. Investigations including CSF study, MRI of dorsal spine and NCV were normal. A combination therapy with tizanidine, baclofen and clonazepam induced gradual improvement within 6 weeks.


Subject(s)
Clonidine/analogs & derivatives , Lower Extremity/physiopathology , Myoclonus/diagnosis , Spinal Cord Diseases/diagnosis , Spinal Cord/physiopathology , Baclofen/therapeutic use , Clonazepam/therapeutic use , Clonidine/therapeutic use , Diagnosis, Differential , Humans , Middle Aged , Myoclonus/drug therapy , Spinal Cord Diseases/drug therapy
7.
J Immunol ; 167(4): 2343-8, 2001 Aug 15.
Article in English | MEDLINE | ID: mdl-11490023

ABSTRACT

Serum amyloid A-activating factor-1 (SAF-1) is a zinc finger transcription factor that is activated by many mediators of inflammation including IL-1, IL-6, and bacterial LPS. However, the mechanism of activation is not fully understood. To identify possible activation partners for SAF-1, we used a yeast two-hybrid system that detected interaction between the catalytic subunit of cyclic AMP-dependent protein kinase (PKA-Calpha) and SAF-1. Immunofluorescence and combined immunoprecipitation-Western blot analyses revealed colocalization and interaction between SAF-1 and PKA-Calpha. In vivo evidence of SAF-1 and PKA-Calpha interaction was further revealed by coimmunoprecipitation of these two proteins in cAMP-activated liver cells. We further show that SAF-1 is phosphorylated in vitro by PKA-Calpha and that addition of cAMP markedly induces in vivo phosphorylation of SAF-1 and transcription of SAF-regulated reporter genes. These results showed that SAF1-PKA-Calpha interaction is involved in functional activation of SAF-1.


Subject(s)
Catalytic Domain , Cyclic AMP-Dependent Protein Kinases/metabolism , DNA-Binding Proteins/metabolism , Serum Amyloid A Protein/metabolism , Transcription Factors/metabolism , Animals , Catalytic Domain/genetics , Cell Line , Cyclic AMP/pharmacology , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Cyclic AMP-Dependent Protein Kinases/biosynthesis , Cyclic AMP-Dependent Protein Kinases/genetics , DNA-Binding Proteins/genetics , Enzyme Inhibitors/pharmacology , Gene Expression Regulation/drug effects , Genes, Reporter/drug effects , Inflammation/enzymology , Inflammation/metabolism , Mice , Mice, Inbred BALB C , Phosphorylation/drug effects , Saccharomyces cerevisiae/genetics , Transcription Factors/genetics , Two-Hybrid System Techniques , Up-Regulation
8.
J Biol Chem ; 275(50): 39727-33, 2000 Dec 15.
Article in English | MEDLINE | ID: mdl-10995778

ABSTRACT

The transcription factor serum amyloid A (SAA)-activating factor (SAF), a family of zinc finger proteins, plays a significant role in the induced expression of the SAA gene. Activity of SAF is regulated by a phosphorylation event involving serine/threonine protein kinase (Ray, A., Schatten, H., and Ray, B. K. (1999) J. Biol. Chem. 274, 4300-4308; Ray, A., and Ray, B. K. (1998) Mol. Cell. Biol. 18, 7327-7335). However, the identity of the protein kinase has so far remained unknown. Induction of SAA by phorbol 12-myristate 13-acetate, a known agonist of protein kinase C (PKC), suggested a potential role of the PKC signaling pathway in the activation process. The DNA binding activity of endogenous SAF was increased by agonists of PKC. In vitro phosphorylation of SAF-1 by PKC-beta markedly increased its DNA binding ability. Consistent with these findings, treatment of cells with activators of PKC or overexpression of PKC-betaII in transfected cells increased expression of an SAF-regulated promoter. Further analysis with a GAL4 reporter system indicated that PKC-mediated phosphorylation mostly increases the DNA binding activity of SAF-1. Together these data indicated that the PKC signaling pathway plays a major role in controlling expression of SAF-regulated genes by increasing the interaction between promoter DNA and phosphorylated SAF.


Subject(s)
DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Protein Kinase C/metabolism , Animals , Cell Line , Cell Nucleus/metabolism , Chloramphenicol O-Acetyltransferase/metabolism , DNA-Binding Proteins/genetics , Genes, Reporter , Isoenzymes/metabolism , Phosphorylation , Plasmids/metabolism , Promoter Regions, Genetic , Protein Binding , Protein Kinase C beta , Rabbits , Signal Transduction , Tetradecanoylphorbol Acetate/pharmacology , Transcription Factors , Transfection , Zinc Fingers
9.
J Immunol ; 163(4): 2143-50, 1999 Aug 15.
Article in English | MEDLINE | ID: mdl-10438955

ABSTRACT

The serum amyloid A (SAA) protein has been implicated in the pathogenesis of several chronic inflammatory diseases. Its induction mechanism in response to a chronic inflammatory condition was investigated in rabbits following multiple s.c. injections of AgNO3 over a period of 35 days. During unremitting exposure to inflammatory stimulus, a persistently higher than normal level of SAA2 expression was seen in multiple tissues. Induction of SAA was correlated with higher levels of several transcription factor activities. Increased SAA-activating factor (SAF) activity was detected in the liver, lung, and brain tissues under both acute and chronic inflammatory conditions. In the heart, kidney, and skeletal muscle tissues, this activity remained virtually constant. In contrast, CCAAT enhancer binding protein (C/EBP) DNA-binding activity was transiently induced in selective tissues. Higher than normal NF-kappa B DNA-binding activity was detected in the lung and to a lesser extent in the liver and kidney tissues under both acute and chronic conditions. This result suggested that C/EBP, SAF, and NF-kappa B are required for transient acute phase induction of SAA whereas SAF and NF-kappa B activities are necessary for persistent SAA expression during chronic inflammatory conditions.


Subject(s)
DNA-Binding Proteins/metabolism , Inflammation/metabolism , NF-kappa B/metabolism , Nuclear Proteins/metabolism , Serum Amyloid A Protein/biosynthesis , Acute Disease , Animals , CCAAT-Enhancer-Binding Proteins , Chronic Disease , DNA-Binding Proteins/physiology , Enhancer Elements, Genetic/immunology , Inflammation/chemically induced , Inflammation/immunology , Injections, Subcutaneous , Nuclear Proteins/physiology , Organ Specificity/immunology , Rabbits , Silver Nitrate/administration & dosage , Transcription Factors/physiology
10.
J Leukoc Biol ; 66(1): 83-9, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10410993

ABSTRACT

The beta2 integrin CD11b plays a central role in inflammation and the systemic inflammatory response syndrome (SIRS). The CD11b molecule activates in two ways: the density of membrane-bound CD11b up-regulates and the molecule undergoes a conformational change that confers adhesiveness to counter-receptors. We studied the kinetics of CD11b activation in patients with SIRS. We found a significantly diminished CD11b activation in response to tumor necrosis factor alpha (TNF-alpha). This affected all circulating polymorphonuclear neutrophils (PMN) and was an intrinsic property of the cells and not due to antagonism by soluble TNF-alpha receptors or loss of cellular receptors for TNF-alpha. Diminished responsiveness correlated with the severity of organ failure and lasted for months in some patients but had no impact on mortality. We speculate that reduced CD11b responsiveness in SIRS contributes to the high risk of recurrent infection, but that it may also be protective against excessive PMN activation within the vascular space.


Subject(s)
Macrophage-1 Antigen/immunology , Neutrophils/immunology , Systemic Inflammatory Response Syndrome/immunology , Tumor Necrosis Factor-alpha/immunology , Adult , Aged , Aged, 80 and over , CD18 Antigens/blood , CD18 Antigens/immunology , Cell Adhesion Molecules/blood , Cytokines/blood , Cytokines/immunology , Humans , Macrophage-1 Antigen/blood , Middle Aged , Systemic Inflammatory Response Syndrome/blood
11.
DNA Cell Biol ; 18(1): 65-73, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10025510

ABSTRACT

Minimally modified low-density lipoprotein (MM-LDL) is regarded as a major risk factor for the development of atherosclerosis. In this report, we show that this lipoprotein complex can induce expression of an inflammatory protein, serum amyloid A (SAA), in monocyte/macrophage cells, a key cell type implicated in the pathogenesis of atherosclerosis. By promoter function analysis and site-directed mutagenesis, we have located promoter regions responsive to MM-LDL action. Using electrophoretic mobility shift, antibody ablation/supershift, and Western blot assays, we showed that induction of SAA by MM-LDL is mediated via activation of SAS binding factor (SAF) and C/EBP transcription factors. We further show that tamoxifen, a downregulator of CD36, one of the major scavenger receptors which binds MM-LDL, can inhibit MM-LDL-mediated SAA induction in THP-1 cells. This finding suggests that CD36 participates in the manifestation of the inflammatory effects of MM-LDL. Our experiments provide the first evidence for transcription factor activation by MM-LDL.


Subject(s)
Lipoproteins, LDL/pharmacology , Macrophages/metabolism , Monocytes/metabolism , Serum Amyloid A Protein/genetics , Transcriptional Activation/drug effects , Blotting, Northern , Blotting, Western , CCAAT-Enhancer-Binding Proteins , CD36 Antigens/metabolism , Cell Line , DNA-Binding Proteins/metabolism , Down-Regulation/drug effects , Humans , Macrophages/drug effects , Monocytes/drug effects , Mutation , Nuclear Proteins/metabolism , Promoter Regions, Genetic/genetics , Response Elements/genetics , Serum Amyloid A Protein/biosynthesis , Tamoxifen/pharmacology , Transcription Factors , Transfection
12.
J Biol Chem ; 274(7): 4300-8, 1999 Feb 12.
Article in English | MEDLINE | ID: mdl-9933631

ABSTRACT

The serum amyloid A (SAA) protein has been implicated in the progression and pathogenesis of rheumatoid arthritis through induction of collagenase activity in synovial fibroblast cells that line the joint tissues. We demonstrate that SAA is synergistically induced in synovial cells by interleukin (IL)-1 and IL-6 that are present at significantly high level in the synovial fluid of arthritis patients. These cytokines induced phenotypic changes in synovial cells, promoting protrusion and increased cellular contact. Induction of SAA under this condition is mediated by promoter elements located between -254 and -226, which contains binding sites for transcription factors Sp1 and SAA activating sequence binding factor (SAF). Mutation of these sequences abolishes SAA promoter response to IL-1 and IL-6. The role of Sp1 in SAA induction was demonstrated by increased DNA binding activity, phosphorylation, and increased protein content of Sp1 during cytokine treatment. Sp1 interacts with the SAA promoter in association with SAF as an SAF. Sp1 heteromeric complex. Furthermore, using a phosphatase inhibitor, we demonstrated increased transactivation potential of both Sp1 and SAF as a consequence of a phosphorylation event. These results provide first evidence for cytokine-mediated activation of Sp1 in synovial fibroblast cells and its participation in regulating SAA expression by acting in conjunction with SAF.


Subject(s)
Apolipoproteins/genetics , Apolipoproteins/metabolism , Gene Expression Regulation/drug effects , Interleukin-1/pharmacology , Interleukin-6/pharmacology , Serum Amyloid A Protein/genetics , Serum Amyloid A Protein/metabolism , Sp1 Transcription Factor/metabolism , Synovial Membrane/metabolism , Animals , Blotting, Northern , Cell Line , DNA/metabolism , Drug Synergism , Electrophoresis, Polyacrylamide Gel , Microscopy, Electron, Scanning , Promoter Regions, Genetic , RNA, Messenger/metabolism , Rabbits , Synovial Membrane/drug effects , Synovial Membrane/ultrastructure , Transcriptional Activation , Transfection
13.
J Diarrhoeal Dis Res ; 17(1): 43-5, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10892497

ABSTRACT

Immunoproliferative small intestinal disease (IPSID) is commonly reported from developing countries with poor socioeconomic conditions, hygiene, and high frequency of gastrointestinal infections and infestations. The disease requires anti-malignant chemotherapy in lymphomatous stage. Reported here is a 20-year old man with IPSID lymphoma who responded to anti-malignant chemotherapy initially, but later deteriorated due to Strongyloides stercoralis infestation, which was treated successfully with mebendazole. Importance of an early recognition and adequate treatment for gastrointestinal infections and infestations before anti-malignant chemotherapy for this disease is highlighted considering the occurrence of this disease in the developing world. The patient developed alternate brown black and white lines in the finger nails after combination chemotherapy, which has not been reported earlier in this disease; the nail changes disappeared 6 months after the withdrawal of doxorubicin suggesting this drug as the cause for such nail changes during anti-malignant combination chemotherapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Immunoproliferative Small Intestinal Disease/complications , Intestinal Neoplasms/complications , Nails/drug effects , Strongyloides stercoralis , Strongyloidiasis/complications , Adult , Animals , Antinematodal Agents/therapeutic use , Humans , Immunoproliferative Small Intestinal Disease/drug therapy , Intestinal Neoplasms/drug therapy , Male , Mebendazole/therapeutic use , Nails/pathology , Strongyloidiasis/drug therapy , Strongyloidiasis/parasitology
14.
Mol Cell Biol ; 18(12): 7327-35, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9819419

ABSTRACT

Serum amyloid A (SAA), a plasma protein inducible in response to many inflammatory conditions, is associated with the pathogenesis of several diseases including reactive amyloidosis, rheumatoid arthritis, and atherosclerosis. We have previously reported an element of the SAA promoter, designated SAA-activating sequence (SAS), that is involved in the inflammation-induced SAA expression, and a nuclear factor, SAS-binding factor (SAF), that interacts with the SAS element has been identified previously (A. Ray and B. K. Ray, Mol. Cell. Biol. 16:1584-1594, 1996). To evaluate how SAF is involved in SAA promoter activation, we have investigated structural features and functional characteristics of this transcription factor. Our studies indicate that SAF belongs to a family of transcription factors characterized by the presence of multiple zinc finger motifs of the Cys2-His2 type at the carboxyl end. Of the three cloned SAF cDNAs (SAF-1, SAF-5, and SAF-8), SAF-1 isoform showed a high degree of homology to MAZ/ZF87/Pur-1 protein while SAF-5 and SAF-8 isoforms are unique and are related to SAF-1/MAZ/ZF87/Pur-1 at the zinc finger domains but different elsewhere. Although structurally distinct, all members are capable of activating SAS element-mediated expression and display virtually identical sequence specificities. However, varying levels of expression of members of this gene family were observed in different tissues. Functional activity of SAF is regulated by a posttranslational event as SAF DNA-binding and transactivation abilities are increased by a protein phosphatase inhibitor, okadaic acid, and inhibited by a protein kinase inhibitor, H7. Consistent with this observation, increased DNA binding of the cloned SAF and its hyperphosphorylation, in response to okadaic acid treatment of the transfected cells, were observed. Taken together, our results suggest that, in addition to tissue-specific expression, SAFs, a family of zinc finger transcription factors, undergo a modification by a posttranslational event that confers their SAA promoter-binding activity and transactivation potential.


Subject(s)
DNA-Binding Proteins/genetics , Promoter Regions, Genetic/genetics , Serum Amyloid A Protein/genetics , Transcription Factors/genetics , Amino Acid Sequence , Base Sequence , Cell Line , Cloning, Molecular , Molecular Sequence Data , Nuclear Proteins/analysis , Phosphorylation , RNA, Messenger/genetics , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Transcriptional Activation/genetics , Zinc Fingers/genetics
15.
J Biol Chem ; 272(46): 28948-53, 1997 Nov 14.
Article in English | MEDLINE | ID: mdl-9360966

ABSTRACT

Serum amyloid A (SAA) is a plasma protein that is associated with many inflammatory diseases including amyloidosis, arthritis, and atherosclerosis. SAA level is significantly increased during inflammatory condition, and such abnormal expression of this protein is linked to the pathogenesis of the above-mentioned diseases. A promoter element, designated as SAA-activating sequence (SAS), located between -280 and -226 has been implicated in the induction mechanism and a nuclear factor, SAS-binding factor (SAF), has been shown to bind to this region. In this report, using a cloned SAF gene in transient transfection assay, we provide evidence that SAF potentiates SAA gene expression through SAS element. Furthermore, we show that during lipopolysaccharide-mediated induction of SAF, heteromeric complex with transcription factor Sp1 is formed. Transfection assays using both transcription factor genes have demonstrated that SAF-Sp1 heteromer is a highly potent transactivator of SAA expression.


Subject(s)
Amyloid/metabolism , Apolipoproteins/genetics , Macrophages/metabolism , Monocytes/metabolism , Serum Amyloid A Protein/genetics , Sp1 Transcription Factor/metabolism , Cell Line , DNA-Binding Proteins/metabolism , Gene Expression Regulation/drug effects , Kinetics , Lipopolysaccharides/pharmacology , Promoter Regions, Genetic , Transcriptional Activation
16.
Biochemistry ; 36(15): 4662-8, 1997 Apr 15.
Article in English | MEDLINE | ID: mdl-9109677

ABSTRACT

Serum amyloid A (SAA) has been linked to atherosclerosis because of its ability to remodel high-density lipoprotein by the depletion of apolipoprotein A1, its ability to bind cholesterol, and its presence in the atherosclerotic plaques of coronary and carotid arteries. In the present study, we investigated the induction mechanism of SAA gene in THP-1 monocyte/macrophage cells which play a critical role in the development of atherosclerotic fatty streak and plaque formation. We and others have shown that SAA gene is induced in monocyte/macrophage cells by lipopolysaccharide (LPS). By promoter function analysis, we show that the SAA promoter sequence between -280 and -226 can confer LPS responsiveness. Gel electrophoretic mobility shift assay detected an induced DNA-binding activity in these cells in response to LPS. Characterization of the DNA-binding protein by UV cross-linking, Southwestern blot, and antibody ablation/supershift assays revealed that it is similar to a recently reported nuclear factor designated SAF. These results demonstrated that LPS-mediated SAA gene induction in monocyte/macrophage cells is primarily due to the induction of SAF activity.


Subject(s)
Amyloid/chemistry , Apolipoproteins/genetics , Gene Expression Regulation , Macrophages/metabolism , Monocytes/metabolism , Serum Amyloid A Protein/genetics , Transcription Factors/genetics , Animals , Base Sequence , Cell Extracts/chemistry , Cell Line , Humans , Lipopolysaccharides/pharmacology , Macrophages/radiation effects , Molecular Sequence Data , Monocytes/radiation effects , Nuclear Proteins/biosynthesis , Nuclear Proteins/chemistry , Promoter Regions, Genetic , RNA, Messenger/biosynthesis , Rabbits , Transcription Factors/chemistry , Transcription Factors/radiation effects , Transcriptional Activation , Ultraviolet Rays
17.
DNA Cell Biol ; 16(1): 1-7, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9022039

ABSTRACT

Serum amyloid A (SAA) is highly induced during many inflammatory episodes. The induction mechanism in response to turpentine and lipopolysaccharide (LPS), two major inducers of this gene, was investigated. Here we present evidence that although both agents triggered expression, SAA mRNA synthesized in the turpentine-injected rabbit liver is many-fold higher compared to that found in LPS-injected rabbit liver. We demonstrate that differential level of activation of C/EBP and NF-kappaB that interact with the proximal promoter of SAA gene is responsible for the differential expression. A very high level of C/EBP induction with little or no activation of NF-kappaB factors was noted when turpentine was used as the inducer. LPS, on the other hand, activated NF-kappaB and C/EBP, which were detected only at the early phase of induction process. These results indicate that different pathways might be activated for the regulation of hepatic expression of SAA by different inflammatory agents. One of the pathways, triggered by LPS, requires participation of both NF-kappaB and C/EBP. A second pathway, triggered by turpentine, involves only C/EBP family of transcription factors.


Subject(s)
Apolipoproteins/genetics , Gene Expression Regulation , Inflammation/metabolism , Liver/metabolism , Serum Amyloid A Protein/genetics , Transcription Factors/metabolism , Animals , CCAAT-Enhancer-Binding Proteins , Cell Nucleus/metabolism , DNA-Binding Proteins/metabolism , Gene Expression Regulation/drug effects , Inflammation/chemically induced , Lipopolysaccharides/pharmacology , Male , NF-kappa B/metabolism , Nuclear Proteins/metabolism , Protein Binding , RNA, Messenger/metabolism , Rabbits , Turpentine/pharmacology
19.
Indian J Exp Biol ; 34(8): 802-5, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8979489

ABSTRACT

Embryos (80 days old) developed after selfing P. tankervilliae were cultured on Nitsch medium for protocorm development. Protocorms (70 days old) thus developed were encapsulated with alginate matrix. Ninety six per cent of freshly prepared encapsulated protocorms differentiated into shoots and roots when cultured on Nitsch medium. Storage of encapsulated protocorms in sealed petri plates or by embedding in liquid paraffin at 4 degrees C showed no reduction in their regeneration frequency up to 120 days when cultured on Nitsch medium. However, 90% of encapsulated protocorms stored at room temperature in empty petri plates differentiated within 35-40 days. Regeneration frequency of encapsulated protocorms was drastically reduced when stored in liquid paraffin at room temperature.


Subject(s)
Cryopreservation , Plant Physiological Phenomena , Regeneration/physiology , Seeds , Alginates , Glucuronic Acid , Hexuronic Acids , Plants/embryology
20.
Mol Cell Biol ; 16(4): 1584-94, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8657133

ABSTRACT

Serum amyloid A (SAA) is a plasma protein which has been associated with several diseases, including amyloidosis, arthritis, and atherosclerosis, and its abnormal expression, particularly in nonhepatic cells, is implicated in the pathogenesis of these diseases. Transfection and DNA-binding studies were performed to investigate the mechanism controlling cytokine-induced, nonhepatic expression of the SAA gene. We have identified a novel promoter, located between positions -280 and 224, that confers interleukin-6 (IL-6) inducibility to an SAA-chloramphenicol acetyltransferase reporter gene in both nonhepatic and hepatic cells. DNase I protection assays revealed, within this region, three homologous highly pyrimidine rich octanucleotide sequence motifs, termed SAA-activating sequences (SAS). Specific mutations within these three SAS motifs severely reduced IL-6-mediated induction of the reporter gene in transfected nonhepatic cells but not in liver cells. A nuclear factor activated by IL-6 in both hepatic and nonhepatic cells efficiently interacts with the SAS. The induction kinetics and cycloheximide sensitivity of this SAS-binding factor (SAF) suggested that de novo synthesis of this factor itself or an activator protein is essential. Loss of DNA-binding ability as a result of in vitro dephosphorylation, induction of SAA-chloramphenicol acetyltransferase reporter gene activity in the presence of genistein, a protein kinase inhibitor, further indicate that a phosphorylation step is necessary for the activation of SAF. Our results suggest that SAF is a key regulator of cytokine-mediated SAA gene expression in some nonhepatic cells.


Subject(s)
Interleukin-6/genetics , Serum Amyloid A Protein/biosynthesis , Trans-Activators/genetics , Transcription, Genetic , Animals , Base Sequence , Cell Line , Enhancer Elements, Genetic/genetics , Female , Liver/metabolism , Mice , Molecular Sequence Data , Rabbits , Rats , Serum Amyloid A Protein/genetics
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