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1.
Cell Mol Life Sci ; 81(1): 33, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214819

RESUMO

P38γ (MAPK12) is predominantly expressed in triple negative breast cancer cells (TNBC) and induces stem cell (CSC) expansion resulting in decreased survival of the patients due to metastasis. Abundance of G-rich sequences at MAPK12 promoter implied the functional probability to reverse tumorigenesis, though the formation of G-Quadruplex (G4) structures at MAPK12 promoter is elusive. Here, we identified two evolutionary consensus adjacent G4 motifs upstream of the MAPK12 promoter, forming parallel G4 structures. They exist in an equilibria between G4 and duplex, regulated by the binding turnover of Sp1 and Nucleolin that bind to these G4 motifs and regulate MAPK12 transcriptional homeostasis. To underscore the gene-regulatory functions of G4 motifs, we employed CRISPR-Cas9 system to eliminate G4s from TNBC cells and synthesized a naphthalene diimide (NDI) derivative (TGS24) which shows high-affinity binding to MAPK12-G4 and inhibits MAPK12 transcription. Deletion of G4 motifs and NDI compound interfere with the recruitment of the transcription factors, inhibiting MAPK12 expression in cancer cells. The molecular basis of NDI-induced G4 transcriptional regulation was analysed by RNA-seq analyses, which revealed that MAPK12-G4 inhibits oncogenic RAS transformation and trans-activation of NANOG. MAPK12-G4 also reduces CD44High/CD24Low population in TNBC cells and downregulates internal stem cell markers, arresting the stemness properties of cancer cells.


Assuntos
Quadruplex G , Proteína Quinase 12 Ativada por Mitógeno , Neoplasias de Mama Triplo Negativas , Humanos , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Neoplasias de Mama Triplo Negativas/genética , Proteína Quinase 12 Ativada por Mitógeno/genética
2.
Chem Soc Rev ; 51(24): 9882-9916, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36420611

RESUMO

Following an overview of the approaches and techniques used to acheive super-resolution microscopy, this review presents the advantages supplied by nanoparticle based probes for these applications. The various clases of nanoparticles that have been developed toward these goals are then critically described and these discussions are illustrated with a variety of examples from the recent literature.


Assuntos
Terapia de Alvo Molecular , Nanopartículas , Microscopia de Fluorescência/métodos
3.
iScience ; 25(4): 104062, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35359805

RESUMO

The gastrointestinal (GI) tract is one of the major sites for reactive oxygen species generation (ROS). Physiological ROS, lower than the threshold concentration, is beneficial for human physiology to preserve gut functional integrity. However, ROS generated in large quantities in presence of external stimuli overwhelms the cellular antioxidant defense mechanism and results in oxidative damage and associated physiological disorder. Graphene quantum dots (GQDs) are a class of carbon-based nanomaterials that have attracted tremendous attention not only for their tunable optical properties but also for their broad-spectrum antioxidant properties. In this report we have shown that GQDs are highly efficient in scavenging ROS and suppressing stress-induced gastric ulcers by targeting the MMP-9 pathway and reducing the inflammatory burden by suppressing excessive oxidative stress by inducing high caspase activity, overproduction of Bax, and downregulation of BCL2.

4.
Toxicol Appl Pharmacol ; 437: 115887, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35063459

RESUMO

Chemoresistance is an imminent therapeutic challenge for breast cancer. Previous evidence suggests that breast cancer stem cells (BCSC) develop resistance through upregulation of stemness and chemo-evasion markers viz. SOX2, OCT4, NANOG, MDR1 and CD44, following anticancer chemotherapeutic treatments. Early studies suggest an inhibitory role of Kaempferol in BCSC propagation through downregulation of epithelial to mesenchymal transition. We hypothesized that the pathway involved in chemoresistance could be effectively addressed through Kaempferol (K), alone or in combination with Verapamil (V), which is an inhibitor of MDR1. We used K in combination with V, in multiple assays to determine if there was an inhibitory effect on BCSC. Both K and KV attenuated pH-dependent mammosphere formation in primary BCSC and MDA-MB-231 cells. RNA and protein (immunocytochemistry, western blot) expression of candidate markers viz. SOX2, OCT4, NANOG, MDR1 and CD44 were carried out in the presence or absence of candidate drugs in ex-vivo grown primary BCSC and MDA-MB-231 cell line. Immunoprecipitation assay, cell cycle analysis was carried out in MDA-MB-231. Our candidate drugs were not only anti-proliferative, but also downregulated candidate genes expression at RNA and protein level in both settings, with more robust efficacy in KV treatment than K; induced G2/M dependent cell cycle arrest, and interrupted physical association of CD44 with NANOG as well as MDR1 in MDA-MB-231. In primary tumor explant but not in adjacent normal tissue, our candidate drugs K and KV induced robust γH2AX expression. Thus, our candidate drugs are effective in attenuating BCSC survival.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Receptores de Hialuronatos/metabolismo , Quempferóis/farmacologia , Proteína Homeobox Nanog/metabolismo , Verapamil/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Receptores de Hialuronatos/genética , Quempferóis/administração & dosagem , Proteína Homeobox Nanog/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Verapamil/administração & dosagem , Gencitabina
5.
ACS Bio Med Chem Au ; 2(2): 125-139, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37101746

RESUMO

G-Quadruplex (GQ) nucleic acids are promising therapeutic targets in anticancer research due to their structural robustness, polymorphism, and gene-regulatory functions. Here, we presented the structure-activity relationship of carbazole-based monocyanine ligands using region-specific functionalization with benzothiazole (TCA and TCZ), lepidine (LCA and LCZ), and quinaldine (QCA and QCZ) acceptor moieties and evaluated their binding profiles with different oncogenic GQs. Their differential turn-on fluorescence emission upon GQ binding confirmed the GQ-to-duplex selectivity of all carbazole ligands, while the isothermal titration calorimetry results showed selective interactions of TCZ and TCA to c-MYC and BCL-2 GQs, respectively. The aldehyde group in TCA favors stacking interactions with the tetrad of BCL-2 GQ, whereas TCZ provides selective groove interactions with c-MYC GQ. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) showed that these molecules interfere with the recruitment of specific transcription factors at c-MYC and BCL-2 promoters and stabilize the promoter GQ structures to inhibit their constitutive transcription in cancer cells. Their intrinsic turn-on fluorescence response with longer lifetimes upon GQ binding allowed real-time visualization of GQ structures at subcellular compartments. Confocal microscopy revealed the uptake of these ligands in the nucleoli, resulting in nucleolar stress. ChIP studies further confirmed the inhibition of Nucleolin occupancy at multiple GQ-enriched regions of ribosomal DNA (rDNA) promoters, which arrested rRNA biogenesis. Therefore, carbazole ligands act as the "double-edged swords" to arrest c-MYC and BCL-2 overexpression as well as rRNA biogenesis, triggering synergistic inhibition of multiple oncogenic pathways and apoptosis in cancer cells.

6.
Mol Oncol ; 16(7): 1523-1540, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34689394

RESUMO

TOP1-binding arginine/serine-rich protein (TOPORS), a really interesting new gene finger protein, has the ability to bind to a palindromic consensus DNA sequence that enables it to function as a potential transcriptional regulator. However, its role in regulating the transcription of cancer-associated genes is yet to be explored. As Toll-like receptor 4 (TLR4) agonists are known to regress solid tumors, we observed that lipopolysaccharide (LPS) induces TOPORS via a TLR4-TIR domain-containing adapter-inducing interferon-ß-dependent pathway, which in turn modulates the transcription of tumor suppressor scaffold/matrix attachment region-binding protein 1 (SMAR1, also known as BANP). ChIP analysis showed that TOPORS binds on the SMAR1 promoter and its occupancy increases upon LPS treatment. A previous study from our laboratory revealed that SMAR1 acts as a repressor of signal transducer and activator of transcription 3 (STAT3) transcription. Tumor growth, as well as tumor-associated macrophage polarization, depends on the status of the STAT1:STAT3 ratio. LPS-induced SMAR1 expression decreases STAT3 expression and also skews the macrophage polarization toward M1 phenotype. In contrast, LPS failed to polarize tumor-associated macrophages to M1 phenotype in a SMAR1-silenced condition, which shows the involvement of SMAR1 in dictating the fate of colorectal cancer progression. Identification of the molecular mechanism behind LPS-mediated tumor regression would be crucial for designing cancer treatment strategies involving bacterial components.


Assuntos
Neoplasias Colorretais , Receptor 4 Toll-Like , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Proteínas de Ciclo Celular/metabolismo , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
7.
J Tradit Complement Med ; 11(6): 481-492, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34765512

RESUMO

BACKGROUND AND AIM: Epithelial ovarian cancer has the deadliest prognosis amongst gynaecological cancers, warranting an unmet need for newer drug targets. Based on its anticancer as well as abortifacient potential, Moringa oleifera Lam. root was hypothesized to have some implications in follicle stimulating hormone receptor (FSHR) dependent cancers like epithelial ovarian cancer. EXPERIMENTAL PROCEDURE: Effect of Moringa oleifera Lam. root extract (MRE) was studied in epithelial ovarian cancer cell line through in vitro studies viz. MTT assay, clonogenic assay, cell cycle analysis, flow cytometry, western blot analysis, immunocytochemical analysis of FSHRand c-Myc expression and in vivo studies viz. effect of MRE in mice model of ovarian carcinoma. The structure of the active compound of MRE was elucidated following solvent extraction, purification through column chromatography, preparative TLC and bioactivity guided structural identification through 1H-NMR, 13C-NMR, DEPT-135, ESIMS,FT-IR spectrophotometry, UV-vis-NIR spectrophotometry and DFT study. RESULTS AND CONCLUSION: Crude MRE displayed cytotoxic activity, induced apoptosis, and attenuated expression of FSHR and c-Myc in ovarian cancer cell line OAW42. MRE also attenuated expression of CD31, FSHR, and c-Myc in tumour xenograft mouse model. Finally, the active compound purified from ethyl acetate-n-hexane subfraction ofMRE, that attenuated viability of ovarian carcinoma cell lines and reduced FSHR and c-Myc expression, was identified as a naturally hydrated-trifattyglyceride, showing aDFT-optimized folded amphipathic structure for easy transportation through hydrophilic and hydrophobic regions in a biological system, indicating its immense therapeutic relevance in epithelial ovarian carcinoma.

8.
Int J Biochem Cell Biol ; 141: 106085, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34551340

RESUMO

One of the hallmarks of a cancer cell is the ability for indefinite proliferation leading to the immortalization of the cell. Activation of several signaling pathways leads to the immortalization of cancer cells via the reactivation of enzyme telomerase (hTERT). hTERT is active in germ cells, stem cells and also cancer cells. An earlier report from our lab suggests that SMAR1, a tumor suppressor protein, is significantly downregulated in the higher grades of colorectal cancers. Our study identifies SMAR1 as a transcriptional repressor of hTERT. We find that SMAR1 interacts with HDAC1/mSin3a co-repressor complex at the hTERT promoter and brings about HDAC1-mediated transcriptional repression of the promoter. Most solid tumors including colorectal cancer reactivate hTERT expression as it confers several advantages to the cancer cells like increased proliferation and angiogenesis. One of these non-canonical functions of hTERT is inducing the pool of cancer stem cell population. We find that in the CD133HighCD44High cancer stem cells population, SMAR1 expression is highly diminished leading to elevated hTERT expression. We also find that knockdown of SMAR1 promotes total CD133+CD44+ population and impart enhanced sphere-forming ability to the colorectal cancer cells. SMAR1 also inhibits invasion and metastasis in colorectal cancer cell lines via repression of hTERT. Our study provides evidence that downregulation of SMAR1 causes activation of hTERT leading to an increase in the cancer stem cell phenotype in colorectal cancer cells.


Assuntos
Proteínas de Ciclo Celular , Células-Tronco Neoplásicas , Proteínas de Ligação a DNA
9.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1866(12): 159045, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34450266

RESUMO

Adipogenesis is described as the process of conversion of pre-adipocytes into differentiated lipid-laden adipocytes. Adipogenesis is known to be regulated by a myriad of transcription factors and co-regulators. However, there is a dearth of information regarding the mechanisms that regulate these transcription factors and hence control adipogenesis. PPARγ is the master transcriptional regulator of adipogenesis and its expression is essential for adipocyte differentiation. Herein, we identified that scaffold/matrix attachment region-binding protein 1 (SMAR1) negatively regulates adipogenesis. We observed that SMAR1 gets downregulated during adipocyte differentiation and knockdown of SMAR1 promotes lipid accumulation and adipocyte differentiation. Mechanistically, we have shown that SMAR1 suppresses PPARγ through recruitment of the HDAC1/mSin3a repressor complex to the PPARγ promoter. We further identified cell division cycle 20 (cdc20) mediated proteasomal degradation of SMAR1 during adipogenesis. Moreover, knockdown of cdc20 resulted in stabilization of SMAR1 and a reduction in adipocyte differentiation. Taken together, our observations suggest that SMAR1 functions as a negative regulator of adipogenesis by inhibiting PPARγ expression in differentiating adipocytes.


Assuntos
Adipogenia/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Histona Desacetilase 1/genética , Proteínas Nucleares/genética , PPAR gama/genética , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Proteínas Cdc20/genética , Diferenciação Celular/genética , Montagem e Desmontagem da Cromatina/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Metabolismo dos Lipídeos/genética , Camundongos
10.
Mol Cancer Res ; 19(10): 1635-1650, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34257080

RESUMO

Regulation of cancer stemness has recently emerged as a new gain-of-function (GOF) property of mutant p53. In this study, we identify miR-324-5p as a critical epigenetic regulator of cancer stemness and demonstrate its role in mediating GOF-mutant p53-driven stemness phenotypes. We report that miR-324-5p is upregulated in human cancer cell lines and non-small cell lung carcinoma (NSCLC) tumors carrying TP53 GOF mutations. Mechanistically, we show that GOF mutant p53 upregulates miR-324-5p expression via c-Myc, an oncogenic transcription factor in cancer cells. Our experimental results suggest that miR-324-5p-induced CSC phenotypes stem from the downregulation of CUEDC2, a downstream target gene of miR-324-5p. Accordingly, CUEDC2 complementation diminishes elevated CSC marker expression in miR-324-5p-overexpressing cancer cells. We further demonstrate that mutant p53 cancer cells maintain a low level of CUEDC2 that is rescued upon miR-324-5p inhibition. Importantly, we identify CUEDC2 downregulation as a novel characteristic feature of TP53-mutated human cancers. We show that activation of NF-κB due to downregulation of CUEDC2 by miR-324-5p imparts stemness in GOF mutant p53 cancer cells. Finally, we provide evidence that TP53 mutations coupled with high miR-324-5p expression predict poor prognosis in patients with lung adenocarcinoma. Thus, our study delineates an altered miR-324-5p-CUEDC2-NF-κB pathway as a novel regulator of GOF mutant p53-driven cancer stemness. IMPLICATIONS: Our findings implicate miRNA-324-5p as a novel epigenetic modifier of human cancer stemness.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Mutação com Ganho de Função/genética , MicroRNAs/genética , Células-Tronco Neoplásicas/patologia , Proteína Supressora de Tumor p53/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/genética , NF-kappa B/genética , Oncogenes/genética , Transdução de Sinais/genética
11.
iScience ; 24(6): 102573, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34142060

RESUMO

Unfolding followed by fibrillation of insulin even in the presence of various excipients grappled with restricted clinical application. Thus, there is an unmet need for better thermostable, nontoxic molecules to preserve bioactive insulin under varying physiochemical perturbations. In search of cross-amyloid inhibitors, prion-derived tetrapeptide library screening reveals a consensus V(X)YR motif for potential inhibition of insulin fibrillation. A tetrapeptide VYYR, isosequential to the ß2-strand of prion, effectively suppresses heat- and storage-induced insulin fibrillation and maintains insulin in a thermostable bioactive form conferring adequate glycemic control in mouse models of diabetes and impedes insulin amyloidoma formation. Besides elucidating the critical insulin-IS1 interaction (R4 of IS1 to the N24 insulin B-chain) by nuclear magnetic resonance spectroscopy, we further demonstrated non-canonical dimer-mediated conformational trapping mechanism for insulin stabilization. In this study, structural characterization and preclinical validation introduce a class of tetrapeptide toward developing thermostable therapeutically relevant insulin formulations.

12.
Cancer Metab ; 9(1): 16, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863392

RESUMO

BACKGROUND: Highly proliferating cancer cells exhibit the Warburg effect by regulation of PKM alternative splicing and promoting the expression of PKM2. Majority of the alternative splicing events are known to occur in the nuclear matrix where various MARBPs actively participate in the alternative splicing events. SMAR1, being a MARBP and an important tumor suppressor, is known to regulate the splicing of various cancer-associated genes. This study focuses on the regulation of PKM alternative splicing and inhibition of the Warburg effect by SMAR1. METHODS: Immunohistochemistry was performed in breast cancer patient samples to establish the correlation between SMAR1 and PKM isoform expression. Further, expression of PKM isoforms upon modulation in SMAR1 expression in breast cancer cell lines was quantified by qRT-PCR and western blot. The acetylation status of PTBP1 was estimated by immunoprecipitation along with its enrichment on PKM pre-mRNA by CLIP in SMAR1 knockdown conditions. The role of SMAR1 in tumor metabolism and tumorigenesis was explored by in vitro enzymatic assays and functional assays upon SMAR1 knockdown. Besides, in vivo tumor formation by injecting adeno-SMAR1-transduced MDA-MB-231 cells in NOD/SCID mice was performed. RESULTS: The expression profile of SMAR1 and PKM isoforms in breast cancer patients revealed that SMAR1 has an inverse correlation with PKM2 and a positive correlation with PKM1. Further quantitative PKM isoform expression upon modulation in SMAR1 expression also reflects that SMAR1 promotes the expression of PKM1 over tumorigenic isoform PKM2. SMAR1 deacetylates PTBP1 via recruitment of HDAC6 resulting in reduced enrichment of PTBP1 on PKM pre-mRNA. SMAR1 inhibits the Warburg effect, tumorigenic potential of cancer cells, and in vivo tumor generation in a PKM2-dependent manner. CONCLUSIONS: SMAR1 regulates PKM alternative splicing by causing HDAC6-dependent deacetylation of PTBP1, resulting in reduced enrichment of PTBP1 on PKM pre-mRNA. Additionally, SMAR1 suppresses glucose utilization and lactate production via repression of PKM2 expression. This suggests that tumor suppressor SMAR1 inhibits tumor cell metabolism and tumorigenic properties of cancer cells via regulation of PKM alternative splicing.

13.
Sci Signal ; 13(654)2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082288

RESUMO

The high abundance of drug efflux pumps in cancer stem cells (CSCs) contributes to chemotherapy resistance. The transcriptional regulator SMAR1 suppresses CSC expansion in colorectal cancer, and increased abundance of SMAR1 is associated with better prognosis. Here, we found in breast tumors that the expression of SMAR1 was decreased in CSCs through the cooperative interaction of the pluripotency factors Oct4 and Sox2 with the histone deacetylase HDAC1. Overexpressing SMAR1 sensitized CSCs to chemotherapy through SMAR1-dependent recruitment of HDAC2 to the promoter of the gene encoding the drug efflux pump ABCG2. Treating cultured CSCs or 4T1 tumor-bearing mice with the nonsteroidal anti-inflammatory drug aspirin restored SMAR1 expression and ABCG2 repression and enhanced tumor sensitivity to doxorubicin. Our findings reveal transcriptional mechanisms regulating SMAR1 that also regulate cancer stemness and chemoresistance and suggest that, by restoring SMAR1 expression, aspirin might enhance chemotherapeutic efficacy in patients with stem-like tumors.


Assuntos
Aspirina/farmacologia , Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Células-Tronco Neoplásicas/metabolismo , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Humanos , Células MCF-7 , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
14.
BMC Mol Cell Biol ; 21(1): 61, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807076

RESUMO

An amendment to this paper has been published and can be accessed via the original article.

15.
Front Immunol ; 11: 1949, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849654

RESUMO

After the 1918 flu pandemic, the world is again facing a similar situation. However, the advancement in medical science has made it possible to identify that the novel infectious agent is from the coronavirus family. Rapid genome sequencing by various groups helped in identifying the structure and function of the virus, its immunogenicity in diverse populations, and potential preventive measures. Coronavirus attacks the respiratory system, causing pneumonia and lymphopenia in infected individuals. Viral components like spike and nucleocapsid proteins trigger an immune response in the host to eliminate the virus. These viral antigens can be either recognized by the B cells or presented by MHC complexes to the T cells, resulting in antibody production, increased cytokine secretion, and cytolytic activity in the acute phase of infection. Genetic polymorphism in MHC enables it to present some of the T cell epitopes very well over the other MHC alleles. The association of MHC alleles and its downregulated expression has been correlated with disease severity against influenza and coronaviruses. Studies have reported that infected individuals can, after recovery, induce strong protective responses by generating a memory T-cell pool against SARS-CoV and MERS-CoV. These memory T cells were not persistent in the long term and, upon reactivation, caused local damage due to cross-reactivity. So far, the reports suggest that SARS-CoV-2, which is highly contagious, shows related symptoms in three different stages and develops an exhaustive T-cell pool at higher loads of viral infection. As there are no specific treatments available for this novel coronavirus, numerous small molecular drugs that are being used for the treatment of diseases like SARS, MERS, HIV, ebola, malaria, and tuberculosis are being given to COVID-19 patients, and clinical trials for many such drugs have already begun. A classical immunotherapy of convalescent plasma transfusion from recovered patients has also been initiated for the neutralization of viremia in terminally ill COVID-19 patients. Due to the limitations of plasma transfusion, researchers are now focusing on developing neutralizing antibodies against virus particles along with immuno-modulation of cytokines like IL-6, Type I interferons (IFNs), and TNF-α that could help in combating the infection. This review highlights the similarities of the coronaviruses that caused SARS and MERS to the novel SARS-CoV-2 in relation to their pathogenicity and immunogenicity and also focuses on various treatment strategies that could be employed for curing COVID-19.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Pneumonia Viral/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Animais , Apresentação de Antígeno/imunologia , Antivirais/uso terapêutico , Betacoronavirus/química , COVID-19 , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Citocinas/biossíntese , Genoma Viral , Humanos , Evasão da Resposta Imune , Imunização Passiva/métodos , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Pandemias , Filogenia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Síndrome Respiratória Aguda Grave/virologia , Linfócitos T/imunologia , Replicação Viral
16.
Front Immunol ; 11: 807, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508811

RESUMO

Unlike organ transplants where an immunosuppressive environment is required, a successful pregnancy involves an extremely robust, dynamic, and responsive maternal immune system to maintain the development of the fetus. A specific set of hormones and cytokines are associated with a particular stage of pregnancy. Any disturbance that alters this fine balance could compromise the development and function of the placenta. Although there are numerous underlying causes of pregnancy-related complications, untimely activation of Toll-like receptors (TLR), primarily TLR4, by intrauterine microbes poses the greatest risk. TLR4 is an important Pattern Recognition Receptor (PRR), which activates both innate and adaptive immune cells. TLR4 activation by LPS or DAMPs leads to the production of pro-inflammatory cytokines via the MyD88 dependent or independent pathway. Immune cells modulate the materno-fetal interface by TLR4-mediated cytokine production, which changes at different stages of pregnancy. In most pregnancy disorders, such as PTB, PE, or placental malaria, the TLR4 expression is upregulated in immune cells or in maternal derived cells, leading to the aberrant production of pro-inflammatory cytokines at the materno-fetal interface. Lack of functional TLR4 in mice has reduced the pro-inflammatory responses, leading to an improved pregnancy, which further strengthens the fact that abnormal TLR4 activation creates a hostile environment for the developing fetus. A recent study proposed that endothelial and perivascular stromal cells should interact with each other in order to maintain a homeostatic balance during TLR4-mediated inflammation. It has been reported that depleting immune cells or supplying anti-inflammatory cytokines can prevent PTB, PE, or fetal death. Blocking TLR4 signaling or its downstream molecule by inhibitors or antagonists has proven to improve pregnancy-related complications to some extent in clinical and animal models. To date, there has been a lack of knowledge regarding whether TLR4 accessories such as CD14 and MD-2 are important in pregnancy and whether these accessory molecules could be promising drug targets for combinatorial treatment of various pregnancy disorders. This review mainly focuses on the activation of TLR4 during pregnancy, its immunomodulatory functions, and the upcoming advancement in this field regarding the improvement of pregnancy-related issues by various therapeutic approaches.


Assuntos
Imunomodulação/efeitos dos fármacos , Malária/metabolismo , Troca Materno-Fetal/imunologia , Plasmodium , Pré-Eclâmpsia/metabolismo , Nascimento Prematuro/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Feminino , Feto/imunologia , Humanos , Lipopolissacarídeos/farmacologia , Malária/parasitologia , Camundongos , Placenta/imunologia , Placenta/parasitologia , Gravidez , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/antagonistas & inibidores
18.
Front Cell Dev Biol ; 8: 602994, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33409278

RESUMO

Genome organization plays a crucial role in gene regulation, orchestrating multiple cellular functions. A meshwork of proteins constituting a three-dimensional (3D) matrix helps in maintaining the genomic architecture. Sequences of DNA that are involved in tethering the chromatin to the matrix are called scaffold/matrix attachment regions (S/MARs), and the proteins that bind to these sequences and mediate tethering are termed S/MAR-binding proteins (S/MARBPs). The regulation of S/MARBPs is important for cellular functions and is altered under different conditions. Limited information is available presently to understand the structure-function relationship conclusively. Although all S/MARBPs bind to DNA, their context- and tissue-specific regulatory roles cannot be justified solely based on the available information on their structures. Conformational changes in a protein lead to changes in protein-protein interactions (PPIs) that essentially would regulate functional outcomes. A well-studied form of protein regulation is post-translational modification (PTM). It involves disulfide bond formation, cleavage of precursor proteins, and addition or removal of low-molecular-weight groups, leading to modifications like phosphorylation, methylation, SUMOylation, acetylation, PARylation, and ubiquitination. These chemical modifications lead to varied functional outcomes by mechanisms like modifying DNA-protein interactions and PPIs, altering protein function, stability, and crosstalk with other PTMs regulating subcellular localizations. S/MARBPs are reported to be regulated by PTMs, thereby contributing to gene regulation. In this review, we discuss the current understanding, scope, disease implications, and future perspectives of the diverse PTMs regulating functions of S/MARBPs.

19.
RSC Adv ; 11(2): 960-977, 2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-35423713

RESUMO

COVID-19 has emerged as a pandemic affecting about 213 countries in all the continents of the globe, resulting in more than 37.8 million individuals getting infected and over 1.08 million deaths worldwide, jeopardizing global human health and the economy. This presents an urgent need to develop therapies that target the SARS-CoV2 virus specifically. This review aims at presenting the available information on the coronavirus disease 2019 along with various drugs that are having widespread use until a vaccine candidate is available to aid in the development of therapeutic strategies against COVID-19.

20.
Front Cell Dev Biol ; 8: 619888, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33511131

RESUMO

Obesity is one of the biggest public health concerns identified by an increase in adipose tissue mass as a result of adipocyte hypertrophy and hyperplasia. Pertaining to the importance of adipose tissue in various biological processes, any alteration in its function results in impaired metabolic health. In this review, we discuss how adipose tissue maintains the metabolic health through secretion of various adipokines and inflammatory mediators and how its dysfunction leads to the development of severe metabolic disorders and influences cancer progression. Impairment in the adipocyte function occurs due to individuals' genetics and/or environmental factor(s) that largely affect the epigenetic profile leading to altered gene expression and onset of obesity in adults. Moreover, several crucial aspects of adipose biology, including the regulation of different transcription factors, are controlled by epigenetic events. Therefore, understanding the intricacies of adipogenesis is crucial for recognizing its relevance in underlying disease conditions and identifying the therapeutic interventions for obesity and metabolic syndrome.

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