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1.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33836587

RESUMO

The brain requires continuously high energy production to maintain ion gradients and normal function. Mitochondria critically undergird brain energetics, and mitochondrial abnormalities feature prominently in neuropsychiatric disease. However, many unique aspects of brain mitochondria composition and function are poorly understood. Developing improved neuroprotective therapeutics thus requires more comprehensively understanding brain mitochondria, including accurately delineating protein composition and channel-transporter functional networks. However, obtaining pure mitochondria from the brain is especially challenging due to its distinctive lipid and cell structure properties. As a result, conflicting reports on protein localization to brain mitochondria abound. Here we illustrate this problem with the neuropsychiatric disease-associated L-type calcium channel Cav1.2α1 subunit previously observed in crude mitochondria. We applied a dual-process approach to obtain functionally intact versus compositionally pure brain mitochondria. One branch utilizes discontinuous density gradient centrifugation to isolate semipure mitochondria suitable for functional assays but unsuitable for protein localization because of endoplasmic reticulum (ER) contamination. The other branch utilizes self-forming density gradient ultracentrifugation to remove ER and yield ultrapure mitochondria that are suitable for investigating protein localization but functionally compromised. Through this process, we evaluated brain mitochondria protein content and observed the absence of Cav1.2α1 and other previously reported mitochondrial proteins, including the NMDA receptor, ryanodine receptor 1, monocarboxylate transporter 1, excitatory amino acid transporter 1, and glyceraldehyde 3-phosphate dehydrogenase. Conversely, we confirmed mitochondrial localization of several plasma membrane proteins previously reported to also localize to mitochondria. We expect this dual-process isolation procedure will enhance understanding of brain mitochondria in both health and disease.


Assuntos
Encéfalo/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Retículo Endoplasmático/metabolismo , Feminino , Homeostase , Humanos , Transporte de Íons , Masculino , Proteínas de Membrana/isolamento & purificação , Camundongos , Camundongos Knockout
2.
Cytokine ; 166: 156183, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37011542

RESUMO

BACKGROUND: Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are the most eminent forms of pulmonary involvement in Scleroderma. In this study we investigate the interaction between cytokines and apoptotic proteins in treatment naive Scleroderma (SSc) patients with and without pulmonary involvement. METHODS: Newly diagnosed treatment naïve Scleroderma (SSc) patients (n = 100) and healthy controls (n = 100) were enrolled. Patients were classified as ILD-SSc, PAH-SSc and non-pulmonary SSc (np-SSc). Study variables like mRSS score, autoantibody profile, serum cytokines, serum TGF-ß (1,2,3) and apoptotic proteins were assessed for these patients. RESULTS: Scleroderma patients showed elevated levels of serum cytokines, but significantly lower IL-22 and TGF- ß1 when compared to healthy controls (p < 0.05). Apoptotic proteins were significantly elevated among Scleroderma patients, but the patient groups also showed significant lower caspase 1/3/9 levels when compared to healthy controls (p < 0.05). ILD-SSc patients reported higher mRSS score (p = 0.0436) when compared with PAH-SSc and np-SSc. In ILD-SSc patients, finger tightening (p = 0.0481) and calcinosis/lesions (p = 0.0481) were significant clinical presentations whereas, digital ulcers were significantly prominent in np-SSc patients (p = 0.0132). Elevated TGF-ß3 levels (p = 0.02) in SSC-ILD and reduced IL-4 levels (p = 0.02) in SSC-PAH were significant cytokines as compared to np-SSc. Significant correlations were obtained among serum cytokines and apoptotic proteins in Scleroderma patients with and without pulmonary involvement. (p < 0.05) CONCLUSION: Our study highlights the correlation between mRSS score, cytokines and apoptotic proteins in SSc patients with pulmonary involvement. A longitudinal follow up in these patients with assessment of these immunological parameters may be helpful in monitoring the disease.


Assuntos
Doenças Pulmonares Intersticiais , Escleroderma Sistêmico , Humanos , Citocinas/uso terapêutico , Pulmão , Escleroderma Sistêmico/complicações
3.
Blood ; 136(7): 857-870, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32403132

RESUMO

Immunomodulatory drugs, such as thalidomide and related compounds, potentiate T-cell effector functions. Cereblon (CRBN), a substrate receptor of the DDB1-cullin-RING E3 ubiquitin ligase complex, is the only molecular target for this drug class, where drug-induced, ubiquitin-dependent degradation of known "neosubstrates," such as IKAROS, AIOLOS, and CK1α, accounts for their biological activity. Far less clear is whether these CRBN E3 ligase-modulating compounds disrupt the endogenous functions of CRBN. We report that CRBN functions in a feedback loop that harnesses antigen-specific CD8+ T-cell effector responses. Specifically, Crbn deficiency in murine CD8+ T cells augments their central metabolism manifested as elevated bioenergetics, with supraphysiological levels of polyamines, secondary to enhanced glucose and amino acid transport, and with increased expression of metabolic enzymes, including the polyamine biosynthetic enzyme ornithine decarboxylase. Treatment with CRBN-modulating compounds similarly augments central metabolism of human CD8+ T cells. Notably, the metabolic control of CD8+ T cells by modulating compounds or Crbn deficiency is linked to increased and sustained expression of the master metabolic regulator MYC. Finally, Crbn-deficient T cells have augmented antigen-specific cytolytic activity vs melanoma tumor cells, ex vivo and in vivo, and drive accelerated and highly aggressive graft-versus-host disease. Therefore, CRBN functions to harness the activation of CD8+ T cells, and this phenotype can be exploited by treatment with drugs.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Metabolismo Energético/genética , Ativação Linfocitária/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos T CD8-Positivos/metabolismo , Células Cultivadas , Imunomodulação/genética , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
4.
Mol Psychiatry ; 26(3): 927-940, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-31988435

RESUMO

Social memory processing requires functional CA2 neurons, however the specific mechanisms that regulate their activity are poorly understood. Here, we document that SorCS2, a member of the family of the Vps10 family of sorting receptors, is highly expressed in pyramidal neurons of CA2, as well as ventral CA1, a circuit implicated in social memory. SorCS2 specifically localizes to the postsynaptic density and endosomes within dendritic spines of CA2 neurons. We have discovered that SorCS2 is a selective regulator of NMDA receptor surface trafficking in hippocampal neurons, without altering AMPA receptor trafficking. In addition, SorCS2 regulates dendritic spine density in CA2 neurons where SorCS2 expression is enriched, but not in dorsal CA1 neurons, which normally express very low levels of this protein. To specifically test the role of SorCS2 in behavior, we generated a novel SorCS2-deficient mouse, and identify a significant social memory deficit, with no change in sociability, olfaction, anxiety, or several hippocampal-dependent behaviors. Mutations in sorCS2 have been associated with bipolar disease, schizophrenia, and attention deficient-hyperactivity disorder, and abnormalities in social memory are core components of these neuropsychiatric conditions. Thus, our findings provide a new mechanism for social memory formation, through regulating synaptic receptor trafficking in pyramidal neurons by SorCS2.


Assuntos
Memória , Proteínas do Tecido Nervoso , Células Piramidais , Receptores de Superfície Celular , Receptores de N-Metil-D-Aspartato , Animais , Espinhas Dendríticas/metabolismo , Hipocampo/metabolismo , Camundongos , Neurônios/metabolismo , Células Piramidais/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo
5.
Mol Psychiatry ; 26(6): 2286-2298, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32332995

RESUMO

Post-traumatic stress disorder (PTSD) is characterized by persistent fear memory of remote traumatic events, mental re-experiencing of the trauma, long-term cognitive deficits, and PTSD-associated hippocampal dysfunction. Extinction-based therapeutic approaches acutely reduce fear. However, many patients eventually relapse to the original conditioned fear response. Thus, understanding the underlying molecular mechanisms of this condition is critical to developing new treatments for patients. Mutations in the neuropsychiatric risk gene CACNA1C, which encodes the Cav1.2 isoform of the L-type calcium channel, have been implicated in both PTSD and highly comorbid neuropsychiatric conditions, such as anxiety and depression. Here, we report that male mice with global heterozygous loss of cacna1c exhibit exacerbated contextual fear that persists at remote time points (up to 180 days after shock), despite successful acute extinction training, reminiscent of PTSD patients. Because dopamine has been implicated in contextual fear memory, and Cav1.2 is a downstream target of dopamine D1-receptor (D1R) signaling, we next generated mice with specific deletion of cacna1c from D1R-expressing neurons (D1-cacna1cKO mice). Notably, D1-cacna1cKO mice also show the same exaggerated remote contextual fear, as well as persistently elevated anxiety-like behavior and impaired spatial memory at remote time points, reminiscent of chronic anxiety in treatment-resistant PTSD. We also show that D1-cacna1cKO mice exhibit elevated death of young hippocampal neurons, and that treatment with the neuroprotective agent P7C3-A20 eradicates persistent remote fear. Augmenting survival of young hippocampal neurons may thus provide an effective therapeutic approach for promoting durable remission of PTSD, particularly in patients with CACNA1C mutations or other genetic aberrations that impair calcium signaling or disrupt the survival of young hippocampal neurons.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Animais , Canais de Cálcio Tipo L/genética , Condicionamento Clássico , Dopamina , Extinção Psicológica , Medo , Humanos , Masculino , Camundongos , Neurônios , Transtornos de Estresse Pós-Traumáticos/genética
6.
J Assoc Physicians India ; 70(5): 11-12, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35598135

RESUMO

INTRODUCTION: Metabolic syndrome is a constellation of interrelated risk factors that increase the risk of cardiovascular diseases (CVD) and diabetes mellitus. The increase in prevalence of hyperuricemia was considered to be directly related to increasing incidence of obesity and Metabolic Syndrome in developing and developed countries. Hyperuricemia is defined as serum uric acid of 6.0mg/dl and 7.0mg/dl for females and males respectively. AIMS AND OBJECTIVES: To study correlation of hyperuricemia with metabolic syndrome or its components. MATERIALS AND METHODS: An observational, cross sectional single centre study with 316 patients fulfilling inclusion and exclusion criteria was carried out. RESULTS: Out of 316 patients, 202 (63.9%) were males and 114 (36.1%) were females. 138(43.7%) were from rural areas and 178 (56.3%) were from urban areas. 126 (39.9%) patients had an active lifestyle and 190 (60.1%) had a sedentary lifestyle. Mean waist circumference among114 females was 82.10 cm and among men was 87.07cm. 113 patients fulfilled the criteria for central obesity with the mean uric acid level of 8.14 mg/dl (p=0.001); Mean uric acid level of patients without central obesity was 7.36 mg/dl. 99 (31.33%) fulfilled the criteria for hypertriglyceridemia with mean s.uric acid level 8.24mg/dl (p=0.0440). 124 had elevated blood pressure with mean s.uric acid 8.28 mg/dl (p=0.004). Patients with normal blood pressure had a mean value of s. uric acid 7.86 mg/dl. 33.44% fulfilled the criteria for metabolic syndrome (41.23%of total females and 32.10% of total males). Odds ratio was 1.28 and 0.864 for females and males respectively. CONCLUSION: Prevalence of metabolic syndrome in patients with hyperuricemia was 35.4%. More common in females than males. Hyperuricemia is more prevalent in patients with a sedentary lifestyle. Hyperuricemia positively correlates with central obesity, blood pressure, hypertriglyceridemia and hyperglycemia. Hence, it is of utmost importance to screen patients of hyperuricemia for metabolic syndrome or its components to prevent mortality and morbidity associated with CVDs.


Assuntos
Doenças Cardiovasculares , Hipertrigliceridemia , Hiperuricemia , Síndrome Metabólica , Doenças Cardiovasculares/complicações , Estudos Transversais , Feminino , Humanos , Hiperuricemia/complicações , Hiperuricemia/epidemiologia , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Obesidade/complicações , Obesidade Abdominal , Prevalência , Fatores de Risco , Centros de Atenção Terciária , Ácido Úrico
7.
J Assoc Physicians India ; 70(5): 11-12, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35598129

RESUMO

BACKGROUND: Dysregulated serum levels of Mannan binding lectin (MBL) has a probable role in Systemic Lupus Erythematosus (SLE) pathogenesis. OBJECTIVE: To evaluate the association between serum MBL levels in SLE patients from western India with the severity of disease Methods: SLE patients (n=70) from Western India were included. Based on MBL levels, patients were classified into four categories, viz. low (<100 ng/ml), mild (100-500 ng/ml), moderate (500-1000 ng/ml) and high (>1000 ng/ml). Correlation of serum MBL levels with disease severity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). MBL levels and circulating immune complex levels were detected by ELISA. C3, C4 and CRP levels were detected by nephelometer. RESULTS: Serum MBL levels of SLE patients (1954 ± 202.4 ng/ml) was lower than that of healthy controls (2388 ± 205.0 ng/ ml). There was no significant correlation between MBL levels with severity of SLE on the basis of ACR criteria and SLEDAI scores (p> 0.05). No significant difference was observed among MBL levels and SLE patients with (1847 ± 246.7) or without (1900 ± 246.8) Lupus Nephritis. SLE patients without infections (n= 33) had low MBL levels (1700 ± 301.0 ng/ ml) as compared with SLE patients with infection (n= 37) (2189 ± 284.6 ng/ ml) (p=0.30) Conclusion: Present study indicated that low MBL levels were not associated with disease severity, haematological manifestations and infections among SLE patients from Western India.


Assuntos
Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Lectina de Ligação a Manose , Ensaio de Imunoadsorção Enzimática , Humanos , Lúpus Eritematoso Sistêmico/complicações , Lectina de Ligação a Manose/sangue , Índice de Gravidade de Doença
8.
Mol Psychiatry ; 25(10): 2373-2391, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31501511

RESUMO

Cocaine-associated memories are critical drivers of relapse in cocaine-dependent individuals that can be evoked by exposure to cocaine or stress. Whether these environmental stimuli recruit similar molecular and circuit-level mechanisms to promote relapse remains largely unknown. Here, using cocaine- and stress-primed reinstatement of cocaine conditioned place preference to model drug-associated memories, we find that cocaine drives reinstatement by increasing the duration that mice spend in the previously cocaine-paired context whereas stress increases the number of entries into this context. Importantly, both forms of reinstatement require Cav1.2 L-type Ca2+ channels (LTCCs) in cells of the prelimbic cortex that project to the nucleus accumbens core (PrL→NAcC). Utilizing fiber photometry to measure circuit activity in vivo in conjunction with the LTCC blocker, isradipine, we find that LTCCs drive differential recruitment of the PrL→ NAcC pathway during cocaine- and stress-primed reinstatement. While cocaine selectively activates PrL→NAcC cells prior to entry into the cocaine-paired chamber, a measure that is predictive of duration in that chamber, stress increases persistent activity of this projection, which correlates with entries into the cocaine-paired chamber. Using projection-specific chemogenetic manipulations, we show that PrL→NAcC activity is required for both cocaine- and stress-primed reinstatement, and that activation of this projection in Cav1.2-deficient mice restores reinstatement. These data indicate that LTCCs are a common mediator of cocaine- and stress-primed reinstatement. However, they engage different patterns of behavior and PrL→NAcC projection activity depending on the environmental stimuli. These findings establish a framework to further study how different environmental experiences can drive relapse, and supports further exploration of isradipine, an FDA-approved LTCC blocker, as a potential therapeutic for the prevention of relapse in cocaine-dependent individuals.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Cocaína/farmacologia , Corpo Estriado/efeitos dos fármacos , Lobo Frontal/efeitos dos fármacos , Memória/efeitos dos fármacos , Vias Neurais/efeitos dos fármacos , Estresse Psicológico/psicologia , Animais , Transtornos Relacionados ao Uso de Cocaína/prevenção & controle , Corpo Estriado/citologia , Lobo Frontal/citologia , Isradipino/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/citologia , Núcleo Accumbens/efeitos dos fármacos
10.
J Assoc Physicians India ; 69(4): 11-12, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34470188

RESUMO

INTRODUCTION: Systemic Lupus Erythematosus (SLE) is a chronic multi-system autoimmune disease with varied clinical presentations. Complement components are the major players in disease pathogenesis. This retrospective cross-sectional study was aimed at assessing the role of autoantibodies to these complement components and their association disease activity in newly diagnosed SLE patients from India. METHOD: Clinically diagnosed SLE patients (n=57) classified as per 2015 ACR/SLICC revised criteria were enrolled between November 2016 to April 2017. Patients' sera were tested for C3 and C4 by nephelometry, while serum levels of factor H, factor P (properdin) as well as autoantibodies to C3, C4, factor H and factor P were detected by ELISA. GraphPad Prism Version 6.01 was used for statistical analysis. Mean, SD, SEM were calculated. Mann Whittney U-test, ANOVA, Chi-square test, Odd's Ratio were calculated. Pearson's correlation was used to study relativeness of the study parameters. RESULTS: Among the 57 SLE patients, low C3 were seen in 51% patients, low C4 in 49%, low factor H in 19% and low factor P in 49% patients. Positivity for autoantibodies against complement components, anti-C3 were seen in 42% patients, anti-C4 in 7%, anti-factor H in 19% and anti-factor P in 28% patients. Serum levels of C3 (p=0.0009), C4 (p=0.0031) and anti-C3 autoantibodies (p=0.0029) were significantly associated with ACR/SLICC 2015 scores. CONCLUSION: Hypocomplementemia was found to be associated with higher disease damage score in newly diagnosed SLE patients. This study adds novel arguments for the importance of the anti-C3 autoantibodies as a marker of SLE.


Assuntos
Autoanticorpos , Lúpus Eritematoso Sistêmico , Complemento C4 , Estudos Transversais , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Estudos Retrospectivos
11.
Cytokine ; 135: 155240, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32795905

RESUMO

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with unclear etiology. Several loci associated with genetic susceptibility for lupus have been described. However, it lacks reports on cytokine gene-gene interactions among SLE patients from Asian population. Epistasis interaction among single nucleotide polymorphisms (SNPs) of cytokine genes in Indian SLE patients was tested using multifactor-dimensionality reduction (MDR) analysis. A total of fourteen SNPs lacking linkage disequilibrium among different cytokines genes were genotyped in a cohort of 200 SLE patients and 201 healthy individuals as controls of Indian origin. A high degree of synergism among Lymphotoxin-α (LT-α), Interleukin-1ß (IL-1ß) and Interleukin-10 (IL-10) gene polymorphisms was detected in our SLE patients. Furthermore, by virtue of biological inter-relations among different cytokines, a high strength of interactions was observed among pro-inflammatory (IL-1ß, IL-6) and anti-inflammatory (IL-10) cytokine gene SNPs. Also, among studied pro-inflammatory cytokines and chemokines, a strong synergistic effect among Tumor Necrosis Factor-α (TNF-α), LT-α and Monocyte Chemo-attractant Protein-1 (MCP-1) SNPs was occurred. A nature of strong interaction among the candidate cytokine genes may speculate a proactive role in causing genetic susceptibility to the disease in SLE patients with Indian origin.


Assuntos
Povo Asiático/genética , Citocinas/genética , Predisposição Genética para Doença/genética , Lúpus Eritematoso Sistêmico/genética , Alelos , Epistasia Genética/genética , Feminino , Genótipo , Humanos , Desequilíbrio de Ligação/genética , Linfotoxina-alfa/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
12.
J Assoc Physicians India ; 68(5): 18-21, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32610860

RESUMO

OBJECTIVES: Infections are a major cause of morbidity and mortality in patients of Systemic Lupus erythematosus (SLE). We therefore aimed to determine the spectrum of infections in patients of SLE, find a correlation between various disease parameters and the severity and outcome of infections and to compare the outcome between different modalities of immunosuppressive therapy. METHODS: A cross-sectional study was carried out by including all the diagnosed patients of Systemic lupus erythematosus (based on SLICC criteria[1]) aged 12 years and above who developed infections during the study period of 18 months. Immunocompromised patients because of coexisting diseases like diabetes, retroviral disease and cancer patients on immunosuppression were excluded. 139 cases of infections were identified in 104 patients of SLE during the study period. RESULTS: 92 patients had one episode of infection, 19 patients had two episodes and 3 patients contracted infections thrice during the study period. The mean age of the sample population was 29.45 ± 7.9 years. 21-30 years age group constituted 51.75% (59/114) of the patients. 61/139 infections (44%) were bacterial, 22/139 (16%) fungal, 20/139 (14%) viral and 4/139 (3%) parasitic. Tuberculosis was the most common infection (40/139, 28.78%). Lower respiratory tract was the most common site of infections found in the study (37/139, 26.62%). 75/139 (54%) were major infections. 50% tuberculous infections were extrapulmonary. The mean duration of SLE until the time of infection was 35.84 ± 53.80 months. SLE Disease Activity Index (SLEDAI) was ≥ 5 in 92.09% of cases. End organ damage was found in 82.7% (115 cases) and amongst them, renal lupus was found in 110/115 cases. No association was found between end organ damage and severity or outcome of infections. In 89 cases patients were on prednisolone alone, in 29 cases patients were additionally on Cyclophosphamide or had received it in the past, and in 15 cases Mycophenolate mofetil (MMF) with prednisolone while in 6 cases all the three drugs had been given at some point of time. Tuberculosis was the most common infection amongst all the groups. The mean daily dose of prednisolone was 19.62 ± 16.04 mg/day. The mean cumulative steroid dose in patients of our study was 9165.76 ± 7833.72 mg. Central nervous system infections occurred more in patients who had received Cyclophosphamide (p = 0.01). Five deaths occurred due to life threatening infections and all of them were either on high dose prednisolone or on cytotoxic drugs (Cyclophosphamide/Mycophenolate mofetil [MMF]). There was no association between treatment modality and severity and outcome of infection. CONCLUSION: SLE patients are predisposed to various minor as well as lifethreatening infections. It is essential to prevent infections by screening, reducing exposure to sources or contacts of infection and minimizing the exposure to immunosuppressive agents while controlling disease activity.


Assuntos
Lúpus Eritematoso Sistêmico , Adulto , Criança , Estudos Transversais , Ciclofosfamida , Humanos , Imunossupressores , Ácido Micofenólico , Índice de Gravidade de Doença , Adulto Jovem
13.
J Assoc Physicians India ; 68(9): 72-73, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32798350

RESUMO

Hypervitaminosis D is rare but potentially serious condition. It occurs most commonly due to excess doses of vitamin D supplementation, most commonly intramuscular. Here we report a case of iatrogenic hypervitaminosis D who presented with altered sensorium, cortical venous thrombosis and acute renal failure.


Assuntos
Trombose Venosa , Injúria Renal Aguda , Humanos , Doenças Metabólicas , Vitamina D
14.
J Neurosci ; 38(11): 2780-2795, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29459374

RESUMO

A homozygous nonsense mutation in the cereblon (CRBN) gene results in autosomal recessive, nonsyndromic intellectual disability that is devoid of other phenotypic features, suggesting a critical role of CRBN in mediating learning and memory. In this study, we demonstrate that adult male Crbn knock-out (CrbnKO) mice exhibit deficits in hippocampal-dependent learning and memory tasks that are recapitulated by focal knock-out of Crbn in the adult dorsal hippocampus, with no changes in social or repetitive behavior. Cellular studies identify deficits in long-term potentiation at Schaffer collateral CA1 synapses. We further show that Crbn is robustly expressed in the mouse hippocampus and CrbnKO mice exhibit hyperphosphorylated levels of AMPKα (Thr172). Examination of processes downstream of AMP-activated protein kinase (AMPK) finds that CrbnKO mice have a selective impairment in mediators of the mTORC1 translation initiation pathway in parallel with lower protein levels of postsynaptic density glutamatergic proteins and higher levels of excitatory presynaptic markers in the hippocampus with no change in markers of the unfolded protein response or autophagy pathways. Acute pharmacological inhibition of AMPK activity in adult CrbnKO mice rescues learning and memory deficits and normalizes hippocampal mTORC1 activity and postsynaptic glutamatergic proteins without altering excitatory presynaptic markers. Thus, this study identifies that loss of Crbn results in learning, memory, and synaptic defects as a consequence of exaggerated AMPK activity, inhibition of mTORC1 signaling, and decreased glutamatergic synaptic proteins. Thus, CrbnKO mice serve as an ideal model of intellectual disability to further explore molecular mechanisms of learning and memory.SIGNIFICANCE STATEMENT Intellectual disability (ID) is one of the most common neurodevelopmental disorders. The cereblon (CRBN) gene has been linked to autosomal recessive, nonsyndromic ID, characterized by an intelligence quotient between 50 and 70 but devoid of other phenotypic features, making cereblon an ideal protein for the study of the fundamental aspects of learning and memory. Here, using the cereblon knock-out mouse model, we show that cereblon deficiency disrupts learning, memory, and synaptic function via AMP-activated protein kinase hyperactivity, downregulation of mTORC1, and dysregulation of excitatory synapses, with no changes in social or repetitive behaviors, consistent with findings in the human population. This establishes the cereblon knock-out mouse as a model of pure ID without the confounding behavioral phenotypes associated with other current models of ID.


Assuntos
Deficiência Intelectual/genética , Deficiência Intelectual/fisiopatologia , Deficiências da Aprendizagem/genética , Deficiências da Aprendizagem/fisiopatologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Transtornos da Memória/genética , Transtornos da Memória/fisiopatologia , Proteínas do Tecido Nervoso/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Região CA1 Hipocampal/fisiopatologia , Potenciais Pós-Sinápticos Excitadores/genética , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Deficiência Intelectual/tratamento farmacológico , Deficiências da Aprendizagem/tratamento farmacológico , Potenciação de Longa Duração/genética , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/biossíntese , Transtornos da Memória/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Inibidores de Proteínas Quinases/uso terapêutico , Comportamento Social
15.
J Biol Chem ; 293(16): 6187-6200, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29449372

RESUMO

Upon binding to thalidomide and other immunomodulatory drugs, the E3 ligase substrate receptor cereblon (CRBN) promotes proteosomal destruction by engaging the DDB1-CUL4A-Roc1-RBX1 E3 ubiquitin ligase in human cells but not in mouse cells, suggesting that sequence variations in CRBN may cause its inactivation. Therapeutically, CRBN engagers have the potential for broad applications in cancer and immune therapy by specifically reducing protein expression through targeted ubiquitin-mediated degradation. To examine the effects of defined sequence changes on CRBN's activity, we performed a comprehensive study using complementary theoretical, biophysical, and biological assays aimed at understanding CRBN's nonprimate sequence variations. With a series of recombinant thalidomide-binding domain (TBD) proteins, we show that CRBN sequence variants retain their drug-binding properties to both classical immunomodulatory drugs and dBET1, a chemical compound and targeting ligand designed to degrade bromodomain-containing 4 (BRD4) via a CRBN-dependent mechanism. We further show that dBET1 stimulates CRBN's E3 ubiquitin-conjugating function and degrades BRD4 in both mouse and human cells. This insight paves the way for studies of CRBN-dependent proteasome-targeting molecules in nonprimate models and provides a new understanding of CRBN's substrate-recruiting function.


Assuntos
Proteínas Culina/metabolismo , Peptídeo Hidrolases/química , Peptídeo Hidrolases/metabolismo , Proteólise , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Azepinas/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Sequência Conservada , Humanos , Fatores Imunológicos/metabolismo , Fatores Imunológicos/farmacologia , Lenalidomida/farmacologia , Ligantes , Camundongos , Sondas Moleculares , Proteínas Nucleares/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Linfócitos T/metabolismo , Talidomida/análogos & derivados , Talidomida/metabolismo , Talidomida/farmacologia , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Triazóis/farmacologia , Ubiquitina/metabolismo
16.
J Assoc Physicians India ; 67(8): 26-30, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31562712

RESUMO

BACKGROUND: : Systemic sclerosis (SSc) is a demyelinating disease of skin, subcutaneous tissue, muscles and internal organs, with fibrosis as an important pathological event. AIM: : To understand cytokine interplay of IL-1ß, IL-4 and IL-6 and their association with disease activity in treatment naïve active cases of systemic sclerosis from Western India. METHODS: Twenty-five SSc patients as per ACR-EULAR 2013 criteria (classified based on pulmonary fibrosis and generalized fibrosis) and 25 age-sex matched controls were enrolled. Serum cytokine levels of IL-1ß, IL-4 and IL-6 were assessed by multiplex bead based immunoassay. RESULTS: Ten patients had Interstitial lung disease (ILD), whereas, 16 patients had generalized fibrosis. Anti-nuclear antibodies were seen in 22 patients (88%); antiScl70 in 15 patients (60%) and anti-Centromere antibodies in 5 patients (20%). Serum levels of IL-1ß in patients were significantly higher than healthy controls (p=0.0006). IL-4 levels in all SSc patients were marginally raised (p=0.0102), while IL-6 levels were significantly raised (p<0.0001). IL-4 was found to be significantly raised in SSc patients with ILD (p=0.021) as compared to patients without ILD. IL-1ß (p=0.0293) and IL-4 (p<0.0001) were significantly higher in SSc patients with fibrosis. On the contrary, IL-6 levels in patients with fibrosis were found to be lower than in patients without fibrosis. CONCLUSION: Significantly raised cytokine levels among treatment naïve systemic sclerosis patients were found to be associated with higher disease severity in our study. Higher levels of IL-1ß and IL-6 indicated an active inflammatory status, whereas significantly raised IL-4 levels indicated at higher fibrotic activity.


Assuntos
Citocinas/metabolismo , Fibrose , Doenças Pulmonares Intersticiais , Escleroderma Sistêmico , Humanos , Índia
17.
J Neurosci ; 37(49): 11894-11911, 2017 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-29089442

RESUMO

Exposure to cocaine-associated contextual cues contributes significantly to relapse. Extinction of these contextual associations, which involves a new form of learning, reduces cocaine-seeking behavior; however, the molecular mechanisms underlying this process remain largely unknown. We report that extinction, but not acquisition, of cocaine conditioned place preference (CPP) in male mice increased Cav1.2 L-type Ca2+ channel mRNA and protein in postsynaptic density (PSD) fractions of the hippocampus, a brain region involved in drug-context associations. Moreover, viral-mediated deletion of Cav1.2 in the dorsal hippocampus attenuated extinction of cocaine CPP. Molecular studies examining downstream Cav1.2 targets revealed that extinction recruited calcium/calmodulin (Ca2+/CaMK)-dependent protein kinase II (CaMKII) to the hippocampal PSD. This occurred in parallel with an increase in phosphorylation of the AMPA GluA1 receptor subunit at serine 831 (S831), a CaMKII site, along with an increase in total PSD GluA1. The necessity of S831 GluA1 was further demonstrated by the lack of extinction in S831A GluA1 phosphomutant mice. Of note hippocampal GluA1 levels remained unaltered at the PSD, but were reduced near the PSD and at perisynaptic sites of dendritic spines in extinction-resistant S831A mutant mice. Finally, conditional knock-out of Cav1.2 in dopamine D1 receptor (D1R)-expressing cells resulted in attenuation of cocaine CPP extinction and lack of extinction-dependent changes in hippocampal PSD CaMKII expression and S831 GluA1 phosphorylation. In summary, we demonstrate an essential role for the hippocampal Cav1.2/CaMKII/S831 GluA1 pathway in cocaine CPP extinction, with data supporting contribution of hippocampal D1R-expressing cells in this process. These findings demonstrate a novel role for Cav1.2 channels in extinction of contextual cocaine-associated memories.SIGNIFICANCE STATEMENT Continued drug-seeking behavior, a defining characteristic of cocaine addiction, can be precipitated by contextual cues, yet the molecular mechanisms required for extinction of these context-specific memories remain poorly understood. Here, we have uncovered a novel and selective role of the Cav1.2 L-type Ca2+ channel and its downstream signaling pathway in the hippocampus that mediate extinction of cocaine conditioned place preference (CPP). We additionally provide evidence that supports a role of Cav1.2 within dopamine D1 receptor-expressing cells of the hippocampus for extinction of cocaine CPP. Therefore, these findings reveal a previously unknown role of Cav1.2 channels within the hippocampus and in D1 receptor-expressing cells in extinction of cocaine-associated memories, providing a framework for further exploration of mechanisms underlying extinction of cocaine-seeking behavior.


Assuntos
Canais de Cálcio Tipo L/fisiologia , Cocaína/administração & dosagem , Extinção Psicológica/fisiologia , Hipocampo/metabolismo , Memória/fisiologia , Receptores de Dopamina D1/biossíntese , Animais , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Extinção Psicológica/efeitos dos fármacos , Expressão Gênica , Hipocampo/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Dopamina D1/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Método Simples-Cego
18.
J Med Virol ; 90(3): 559-563, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28734074

RESUMO

Epstein-Barr viral infection is one of the known environmental factors involved in development of Systemic Lupus Erythematous (SLE). Though not much is known about the exact role of Epstein-Barr virus (EBV) in SLE pathogenesis, the theory of switching of lytic and lysogenic cycles of EBV in memory B cells fits well with the periods of waning disease activity and intermittent flares in SLE patients. In this study, we investigate the association of EBV antibody profile with clinical and serological parameters in SLE. Eighty-seven clinically diagnosed SLE patients fulfilling the American College of Rheumatology (ACR) classification criteria and fifty healthy individuals were enrolled in this case control study. Anti-VCA IgM, anti-VCA IgG, and anti-EBNA IgG were detected by ELISA technique. Antibodies concentrations between two groups were compared using Mann-Whitney whereas the difference in categorical data was compared using Chi-square considering statistical significance at P < 0.05. This study demonstrated a significant increase in EBV VCA-IgG, VCA-IgM, and EBNA-IgG antibodies levels of SLE patients when compared to healthy controls (P < 0.05). High seroprevalence was seen in both the study groups for EBV VCA-IgG and EBNA-IgG antibodies when compared to VCA-IgM antibodies. A significant increase was noted in the anti-VCA-IgG levels with dsDNA autoantibody positivity (P < 0.05). Though there was no significant association between EBV antibody profile and clinical manifestations, 100% seropositivity for anti-VCA-IgG was seen in SLE patients with renal manifestations. Association of anti-VCA IgG levels with presence of anti-dsDNA antibodies suggests a possible role of EBV as an environmental trigger in pathogenesis of SLE.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Vírus Epstein-Barr/imunologia , Imunoglobulina G/sangue , Lúpus Eritematoso Sistêmico/imunologia , Adolescente , Adulto , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Infecções por Vírus Epstein-Barr/sangue , Feminino , Herpesvirus Humano 4 , Humanos , Imunoglobulina M/sangue , Lúpus Eritematoso Sistêmico/virologia , Masculino , Mimetismo Molecular , Estudos Soroepidemiológicos , Adulto Jovem
19.
Cytokine ; 111: 20-27, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30098476

RESUMO

BACKGROUND: Adipokines are chemical mediators released from adipose tissue involved in regulation of appetite, insulin sensitivity, immune system and inflammatory responses. Adipokines contributes to low grade inflammatory response in autoimmune disease like Systemic Lupus Erythematosus (SLE) but the pathophysiology is yet not clear. The aim of this study is to understand role of adipokine interactions in SLE disease pathogenesis. METHODS: Sixty newly diagnosed treatment naïve SLE patients fulfilling the ACR criteria and forty age-sex matched healthy subjects were enrolled in thiscase-control study. Disease activity in SLE patients was evaluated using SELENA-SLEDAI. Array of adipokines, C1q circulating immune complexes (C1q-CIC), anti-C1q, anti-ribososmal P0 (anti-RibP0) and anti-mitochondrial antibodies (AMA) levels were detected by ELISA. Antinuclear antibodies (ANA) and anti-dsDNA autoantibodieswere detected by Indirect Immunofluorescence (IIF), while antigen specificities were detected by Immunoassay blot. Serum levels of C3 and C4 complement factors were assessed by nephlometer. RESULTS: Statistically significant elevation in progranulin, adipsin and resistin levels was seen among SLE patients when compared to healthy controls (p < 0.0001). Leptin and omentin levels were significantly reduced in SLE patients (p < 0.0001). There was no statistically significant difference in serum adiponectin, chemerin and visfatin levels when these two groups were compared (p > 0.05). Adiponectin, adipsin and resistin levels were elevated in SLE patients with renal manifestations (p < 0.05). Reduced leptin levels were significantly associated with presence of renal manifestations (p < 0.05). Adiponectin levels positively correlated with disease activity (r = 0.294, p = 0.027) whereas negatively correlated with C3 levels (r = -0.439, p = 0.0007). A positive correlation was observed between hypocomplementemia and leptin levels (p < 0.05). Leptin levels were negatively correlated with disease activity, anti-dsDNA, C1q-CIC and anti-C1q levels (p < 0.05). A significant positive correlation was observed between progranulin levels and anti-ribosomal P0 antibodies (r = 0.499, p < 0.0001). CONCLUSION: Adipokines levels and associated clinical manifestations suggest involvement of adipokines in disease pathogenesis of SLE. SLE disease activity and complement components may suggest regulatory effect of adipokines (adiponectin and leptin) on disease pathogenesis. Further studies on adipokines in SLE patients with renal manifestations may propose them as prognostic markers in renal damage. TRIAL REGISTRATION: NA.


Assuntos
Adipocinas/sangue , Lúpus Eritematoso Sistêmico/sangue , Adolescente , Adulto , Humanos , Lúpus Eritematoso Sistêmico/patologia , Masculino
20.
J Biol Chem ; 291(33): 17209-27, 2016 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-27325702

RESUMO

The amyloid precursor protein (APP), whose mutations cause Alzheimer disease, plays an important in vivo role and facilitates transmitter release. Because the APP cytosolic region (ACR) is essential for these functions, we have characterized its brain interactome. We found that the ACR interacts with proteins that regulate the ubiquitin-proteasome system, predominantly with the E3 ubiquitin-protein ligases Stub1, which binds the NH2 terminus of the ACR, and CRL4(CRBN), which is formed by Cul4a/b, Ddb1, and Crbn, and interacts with the COOH terminus of the ACR via Crbn. APP shares essential functions with APP-like protein-2 (APLP2) but not APP-like protein-1 (APLP1). Noteworthy, APLP2, but not APLP1, interacts with Stub1 and CRL4(CRBN), pointing to a functional pathway shared only by APP and APLP2. In vitro ubiquitination/ubiquitome analysis indicates that these E3 ligases are enzymatically active and ubiquitinate the ACR residues Lys(649/650/651/676/688) Deletion of Crbn reduces ubiquitination of Lys(676) suggesting that Lys(676) is physiologically ubiquitinated by CRL4(CRBN) The ACR facilitated in vitro ubiquitination of presynaptic proteins that regulate exocytosis, suggesting a mechanism by which APP tunes transmitter release. Other dementia-related proteins, namely Tau and apoE, interact with and are ubiquitinated via the ACR in vitro This, and the evidence that CRBN and CUL4B are linked to intellectual disability, prompts us to hypothesize a pathogenic mechanism, in which APP acts as a modulator of E3 ubiquitin-protein ligase(s), shared by distinct neuronal disorders. The well described accumulation of ubiquitinated protein inclusions in neurodegenerative diseases and the link between the ubiquitin-proteasome system and neurodegeneration make this concept plausible.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Complexos Multienzimáticos/metabolismo , Transmissão Sináptica , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Proteínas Adaptadoras de Transdução de Sinal , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Proteínas Culina/genética , Proteínas Culina/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Camundongos , Complexos Multienzimáticos/genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas tau/genética , Proteínas tau/metabolismo
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