RESUMO
BACKGROUND: Hepatic progenitor cell (HPC) activity and regenerative process that follows pediatric acute liver failure (PALF) is still not well understood. This clinicopathological study was thus conducted with an aim to study the correlation of liver histology and HPC activity with outcomes in PALF. METHODS: All PALF patients with available hepatic histological specimens were included and specimens were analyzed for hepatocyte loss, HPC activity [using cytokeratin (CK) 7, CK19, sex-determining region Y-related high mobility group box(SOX)9 and epithelial cell adhesion molecule (EpCAM)], hepatocyte proliferation (using Ki67), and hepatocyte senescence (using p53 and p21). RESULTS: Ninety-four children were included: 22 (23.4%) survived with native liver (SNL) (i.e., the good outcome group) while rest (i.e., the poor outcome group) either died [33%, 35.1%] or received liver transplant (LT) [39%, 41.5%]. When compared to subjects with poor outcomes, those in the SNL group exhibited significantly less severe hepatocyte loss, fewer HPC/hpf, more proliferating hepatocytes, and less senescent hepatocytes (p < .05). Increasing severity of hepatocyte loss (adjusted OR: 9.95, 95% CI: 4.22-23.45, p < .001) was identified as an independent predictor of poor outcome. Eighty percent children with >50% native hepatocyte loss had poor outcome within 10 days of hospitalization. CONCLUSION: In PALF, more severe hepatocyte loss, higher number of HPC activation, lesser number of proliferating hepatocytes, and greater number of senescent hepatocytes are associated with a poor outcome. Loss of >50% hepatocytes is an independent predictor of poor outcome in PALF.
Assuntos
Falência Hepática Aguda , Transplante de Fígado , Humanos , Criança , Fígado/patologia , Falência Hepática Aguda/cirurgia , Hepatócitos/metabolismo , Hepatócitos/patologia , Células-Tronco/metabolismo , Células-Tronco/patologiaRESUMO
There is an alarming increase in incidence of fatty liver disease worldwide. The fatty liver disease spectrum disease ranges from simple steatosis (NAFL) to steatohepatitis (NASH) which culminates in cirrhosis and cancer. Altered metabolism is a hallmark feature associated with fatty liver disease and palmitic acid is the most abundant saturated fatty acid, therefore, the aim of this study was to compare metabolic profiles altered in hepatocytes treated with palmitic acid and also the differentially expressed plasma metabolites in spectrum of nonalcoholic fatty liver. The metabolites were analyzed by liquid chromatography-mass spectrometry (LC-MS) platform. Hepatocyte cell lines PH5CH8 and HepG2 cells when treated with 400 µM dose of palmitic acid showed typical features of steatosis. Metabolomic analysis of lipid treated hepatocyte cell lines showed differential changes in phenylalanine and tyrosine pathways, fatty acid metabolism and bile acids. The key metabolites tryptophan, kynurenine and carnitine differed significantly between subjects with NAFL, NASH and those with cirrhosis. As the tryptophan-kynurenine axis is also involved in denovo synthesis of NAD+, we found significant alterations in the NAD+ related metabolites in both palmitic acid treated and also fatty liver disease with cirrhosis. The study underscores the importance of amino acid and NAD+supplementation as promising strategies in fatty liver disorder.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , NAD/metabolismo , Aminoácidos/metabolismo , Palmitatos/metabolismo , Cinurenina/metabolismo , Triptofano/metabolismo , Hepatócitos/metabolismo , Cirrose Hepática/patologia , Ácido Palmítico/farmacologia , Ácido Palmítico/metabolismo , Fígado/metabolismoRESUMO
Pregnancy being an immune compromised state, coronavirus disease of 2019 (COVID-19) disease poses high risk of premature delivery and threat to fetus. Plasma metabolome regulates immune cellular responses, therefore we aimed to analyze the change in plasma secretome, metabolome, and immune cells with disease severity in COVID-19 positive pregnant females and their cord blood. COVID-19 reverse transcriptase-polymerase chain reaction positive pregnant females (n = 112) with asymptomatic (Asy) (n = 82), mild (n = 21), or moderate (n = 9) disease, healthy pregnant (n = 18), COVID-19 positive nonpregnant females (n = 7) were included. Eighty-two cord blood from COVID-19 positive and seven healthy cord blood were also analyzed. Mother's peripheral blood and cord blood were analyzed for untargeted metabolome profiling and cytokines by using high-resolution mass spectrometry and cytokine bead array. Immune scan was performed only in mothers' blood by flow cytometry. In Asy severe acute respiratory syndrome coronavirus 2 infection, the amino acid metabolic pathways such as glycine, serine, l-lactate, and threonine metabolism were upregulated with downregulation of riboflavin and tyrosine metabolism. However, with mild-to-moderate disease, the pyruvate and nicotinamide adenine dinucleotide (NAD+ ) metabolism were mostly altered. Cord blood mimicked the mother's metabolomic profiles by showing altered valine, leucine, isoleucine, glycine, serine, threonine in Asy and NAD+ , riboflavin metabolism in mild and moderate. Additionally, with disease severity tumor necrosis factor-α, interferon (IFN)-α, IFN-γ, interleukin (IL)-6 cytokine storm, IL-9 was raised in both mothers and neonates. Pyruvate, NAD metabolism and increase in IL-9 and IFN-γ had an impact on nonclassical monocytes, exhausted T and B cells. Our results demonstrated that immune-metabolic interplay in mother and fetus is influenced with increase in IL-9 and IFN-γ regulated pyruvate, lactate tricarboxylic acid, and riboflavin metabolism with context to disease severity.
Assuntos
COVID-19 , SARS-CoV-2 , Recém-Nascido , Humanos , Feminino , Gravidez , SARS-CoV-2/metabolismo , Gestantes , Interleucina-9 , NAD , Citocinas , Interleucina-6 , Interferon-alfa , Gravidade do Paciente , Imunidade , Piruvatos , Glicina , Lactatos , Riboflavina , Serina , TreoninaRESUMO
Nonalcoholic or metabolic associated fatty liver disease (NAFLD/MAFLD) is a hepatic reflection of metabolic derangements characterized by excess fat deposition in the hepatocytes. Identifying metabolic regulatory nodes in fatty liver pathology is essential for effective drug targeting. Fatty liver is often associated with circadian rhythm disturbances accompanied with alterations in physical and feeding activities. In this regard, both sirtuins and clock machinery genes have emerged as critical metabolic regulators in maintaining liver homeostasis. Knockouts of either sirtuins or clock genes result in obesity associated with the fatty liver phenotype. Sirtuins (SIRT1-SIRT7) are a highly conserved family of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, protecting cells from metabolic stress by deacetylating vital proteins associated with lipid metabolism. Circadian rhythm is orchestrated by oscillations in expression of master regulators (BMAL1 and CLOCK), which in turn regulate rhythmic expression of clock-controlled genes involved in lipid metabolism. The circadian metabolite, NAD+ , serves as a crucial link connecting clock genes to sirtuin activity. This is because, NAMPT which is a rate limiting enzyme in NAD+ biosynthesis is transcriptionally regulated by the clock genes and NAD+ in turn is a cofactor regulating the deacetylation activity of sirtuins. Intriguingly, on one hand the core circadian clock regulates the sirtuin activity and on the other hand the activated sirtuins regulate the acetylation status of clock proteins thereby affecting their transcriptional functions. Thus, the Clock-NAD+-Sirtuin connection represents a novel "feedback loop" circuit that regulates the metabolic machinery. The current review underpins the importance of NAD+ on the sirtuin and clock connection in preventing fatty liver disorder.
Assuntos
Proteínas CLOCK , NAD , Hepatopatia Gordurosa não Alcoólica , Sirtuínas , Proteínas CLOCK/metabolismo , Ritmo Circadiano , Humanos , Fígado/metabolismo , NAD/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Sirtuínas/metabolismoRESUMO
BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are immunosuppressive in nature, originate in the bone marrow, and are mainly found in the blood, spleen, and liver. In fact, liver acts as an important organ for induction and accumulation of MDSCs, especially during infection, inflammation, and cancer. In humans and rodents, models of liver diseases revealed that MDSCs promote regeneration and drive the inflammatory processes, leading to hepatitis, fibrogenesis, and cirrhosis, ultimately resulting in hepatocellular carcinoma. SUMMARY: This brief review is focused on the in-depth understanding of the key molecules involved in the expansion and regulation of MDSCs and their underlying immunosuppressive mechanisms in liver diseases. KEY MESSAGE: Modulated MDSCs can be used for therapeutic purposes in inflammation, cancer, and sepsis.
Assuntos
Hepatopatias , Células Supressoras Mieloides , Neoplasias , Humanos , Inflamação/patologia , Hepatopatias/patologia , Baço/patologiaRESUMO
Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein involved in redox signalling and programmed cell death. The role of AIF has been well recognized in diabetes and obesity. However, the aspect of AIF deficiency in the development of hepatic steatosis and liver injury is unknown. Therefore, in the current study, Harlequin (Hq mutant) mouse with markedly reduced content of AIF was investigated to explore the role of AIF on the initiation of liver injury. The wild type (WT) developed physiological and pathological features of non-alcoholic fatty liver disease (NAFLD) that were not seen in the Hq mice with AIF deficiency, when fed on high fat high fructose (HFHF) diet. Following bile duct ligation (BDL), the liver associated pathological changes were less conspicuous in Hq mice as compared to WT mice. The expression of AIF protein and apoptosis was markedly lesser as compared to their respective control in Hq mice on HFHF diet. Furthermore, the genes involved in fatty acid metabolism were also altered in the group of treated Hq mice. In conclusion, Hq mice failed to develop diet induced hepatic steatosis, suggestive of a role of AIF mediated pathway in the initiation and progression of liver inflammation. Thus, partial loss of AIF appears to be hepatoprotective. SIGNIFICANCE OF THE STUDY: AIF deficiency has multiple roles in altered pathology processes and cellular metabolism, thereby compromising the cellular homeostasis. Considering the molecular functions of AIF in other organ pathology little is known about its role in diet induced liver injury. Hence, the aim of the current study was to investigate the role of AIF deficiency in liver injury and diseases with focus on NAFLD. The study will help to deliniate the mechanisms of NAFLD using Harliquin Mice.
Assuntos
Fator de Indução de Apoptose/metabolismo , Dieta Hiperlipídica , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Fator de Indução de Apoptose/deficiência , Fator de Indução de Apoptose/genética , Linfócitos B/citologia , Linfócitos B/metabolismo , Ductos Biliares/cirurgia , Glicemia/análise , Modelos Animais de Doenças , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/metabolismo , Triglicerídeos/análise , Regulação para CimaRESUMO
BACKGROUND: Endothelial progenitor cells (EPCs) help in neovascularization and endothelial repair during injury. Patients with cirrhosis show increased number and function of EPCs in circulation. METHODS: Since natural killer (NK) cells regulate EPCs, we investigated the relationship between the 2 in alcoholic cirrhosis (AC, n = 50) and severe alcoholic hepatitis (SAH, n = 18) patients and compared with nonalcoholic cirrhosis (n = 15) and healthy controls (HC, n = 30). Levels of systemic inflammatory cytokines were measured, and coculture assays were performed between EPCs and NK cells in contact-dependent and contact-independent manner. NK cell-mediated killing of EPCs was evaluated, and expression of receptors including fractalkine (FKN) on EPCs and its cognate receptor CX3CR1 on NK cells was studied by RT-PCR assays. RESULTS: Patients with SAH had higher regulated on activation, normal T cell expressed and secreted (RANTES) (p = 0.01), vascular endothelial growth factor (VEGF) (p = 0.04), IL-1ß (p = 0.04), and IL-6 (p = 0.00) growth factors and proinflammatory cytokines as compared to AC and HC. Distinct populations of CD31+ CD34+ EPCs with low and high expression of CD45 were significantly lower in SAH than HC (CD45low , p = 0.03; CD45hi , p = 0.04) and AC (CD45low , p = 0.05; CD45hi , p = 0.02). SAH patients, however, showed increased functional capacity of EPCs including colony formation and LDL uptake. NK cells were reduced in SAH compared with AC (p = 0.002), however with higher granzyme ability (p < 0.001 and p = 0.04, respectively). In SAH, EPC-NK cell interaction assays showed that NK cells lysed the EPCs in both contact-dependent and contact-independent assays. Expression of interaction receptor CX3CR1 was significantly higher on NK cells (p = 0.0005), while its cognate receptor, FKN, was increased on EPCs in SAH patients as compared to HC (p = 0.0055). CONCLUSION: We conclude that in SAH, NK cells induce killing of EPCs via CX3CR1/FKN axis that may be one of the key events contributing to disease severity and proinflammatory responses in SAH.
Assuntos
Células Progenitoras Endoteliais/patologia , Hepatite Alcoólica/patologia , Células Matadoras Naturais/patologia , Leucócitos Mononucleares/patologia , Índice de Gravidade de Doença , Adulto , Morte Celular/fisiologia , Movimento Celular/fisiologia , Técnicas de Cocultura , Células Progenitoras Endoteliais/metabolismo , Feminino , Hepatite Alcoólica/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Células Matadoras Naturais/metabolismo , Leucócitos Mononucleares/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/patologia , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: Targeting cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) is difficult because of their similarities with normal stem cells (NSCs). EpCAM can identify CSCs from EpCAM+AFP+HCC cases, but is also expressed on NSCs. We aimed to distinguish the two using integrated protein, mRNA and miRNA profiling. METHODS: iTRAQ based protein profiling and Next Generation Sequencing (NGS) was performed on EpCAM+/EpCAM- cells isolated from HCC (Ep+CSC, Ep- HCC) and EpCAM+ cells from non-cancerous/non-cirrhotic control liver tissues (Ep+NSC). Validations were done using qRT-PCR, flowcytometry and western blotting followed by in vitro and in vivo functional studies. RESULTS: 11 proteins were overexpressed (>3 fold) in Ep+CSCs compared to Ep- HCC and Ep+NSC cells. However, RNA-sequencing confirmed the Ep+CSC specific up-regulation of only HSPA8, HNRNPC, MPST and GAPDH mRNAs among these. Database search combined with miRNA profiling revealed Ep+ CSC specific down-regulation of 29 miRNAs targeting these four genes. Of these, only miR-26b-5p was found to target both HSPA8 and EpCAM. Validation of HSPA8 overexpression and miR-26b-5p down-regulation followed by linear regression analysis established a negative correlation between the two. Functional studies demonstrated that reduced miR-26b-5p expression increased the spheroid formation, migration, invasion and tumourigenicity of Ep+ CSCs. Furthermore, anti-miR-26b-5p increased the number of Ep+ CSCs with a concomitant overexpression of stemness genes and reduction of proapoptotic protein BBC3, which is a known substrate of HSPA8. CONCLUSION: miR-26b-5p imparts metastatic properties and helps in maintenance of Ep+ CSCs via HSPA8. Thus, miR-26b-5p and HSPA8 could serve as molecular targets for selectively eliminating the Ep+ CSC population in human HCCs.
Assuntos
Carcinoma Hepatocelular/patologia , Molécula de Adesão da Célula Epitelial/metabolismo , Proteínas de Choque Térmico HSC70/metabolismo , Neoplasias Hepáticas/patologia , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/patologia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSC70/genética , Humanos , Neoplasias Hepáticas/metabolismo , MicroRNAs/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
The calcineurin-NFAT signaling pathway regulates cell proliferation, differentiation, and development in diverse cell types and organ systems. Deregulation of calcineurin-NFAT signaling has been reported in leukaemias and few solid tumors such as breast and colon. In the present study, we found elevated calcineurin protein levels and phosphatase activity in cervical cancer cell lines and depletion of the same attenuated cell proliferation. Additionally, nuclear levels of NFAT2, a downstream target of calcineurin, viz, was found elevated in human papillomavirus (HPV) infected cells, HeLa and SiHa, compared to the HPV negative cells, HaCaT and C33A, indicative of its higher DNA binding activity. The nuclear levels of both NFAT1 and NFAT3 remain unaltered implicating they have little role in cervical carcinogenesis. Similar to the in vitro studies, the HPV infected human squamous cell carcinoma specimens showed higher NFAT2 levels compared to the normal cervical epithelium. Depletion of NFAT2 by RNAi attenuated growth of SiHa cells. Overexpression of HPV16 oncoproteins viz, E6 and E7 increased NFAT2 expression levels and DNA binding activity, while knockdown of E6 by RNAi decreased the same. Briefly, we now report an activation of calcineurin-NFAT2 axis in cervical cancer and a novel role of HPV oncoprotein in facilitating NFAT2 dependent cell proliferation.
Assuntos
Calcineurina/metabolismo , Carcinoma/metabolismo , Proliferação de Células/fisiologia , Fatores de Transcrição NFATC/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias do Colo do Útero/metabolismo , Carcinogênese/metabolismo , Carcinoma/virologia , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/virologia , Colo do Útero/metabolismo , Colo do Útero/virologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Células HEK293 , Células HeLa , Humanos , Interferência de RNA/fisiologia , Transdução de Sinais/fisiologia , Neoplasias do Colo do Útero/virologiaRESUMO
In multicellular organisms majority of the cells remain in a non-dividing states of either quiescence (reversible) or senescence (irreversible). In the present study, gene expression signatures unique to quiescence and senescence were identified using microarray in osteosarcoma cell line, U2OS. It was noted that certain genes and pathways like NOD pathway was shared by both the growth arrest conditions. A major highlight of the present study was increased expression of number of chemokines and cytokines in both quiescence and senescence. While senescence-associated secretory phenotype (SASP) is well known, the quiescence-associated secretory phenotype (QASP) is relatively unknown and appeared novel in this study. ARID5A, a subunit of SWI/SNF complex was identified as a quiescence associated gene. The endogenous expression of ARID5A increased during serum starved condition of quiescence. Overexpression of ARID5A resulted in more number of cells in G0/G1 phase of cell cycle. Further ARID5A overexpressing cells when subjected to serum starvation showed a pronounced secretory phenotype. Overall, the present work has identified gene expression signatures which can distinguish quiescence from senescence.
Assuntos
Pontos de Checagem do Ciclo Celular/genética , Ciclo Celular/genética , Senescência Celular/genética , Proteínas Nucleares/genética , Biomarcadores/metabolismo , Divisão Celular/genética , Linhagem Celular Tumoral , Citocinas/metabolismo , Proteínas de Ligação a DNA , Humanos , Fenótipo , Transdução de SinaisRESUMO
BACKGROUND: Asialoglycoprotein receptor expression on hepatocytes has been associated with endocytosis, binding and uptake of hepatitis B virus. The role of asialoglycoprotein receptor in hepatitis B virus vertical transmission and its expression on placenta has not yet been studied. PATIENTS AND METHODS: Thirty-four HBsAg+ve and 13 healthy pregnant mothers along with their newborns were enrolled. The former were categorized into transmitting and non-transmitting mothers based on their newborns being hepatitis B surface antigen and hepatitis B virus DNA positive. Expression of asialoglycoprotein receptor and hepatitis B surface antigen in placenta and isoform of asialoglycoprotein receptor on dendritic cell in peripheral and cord blood dendritic cells were analysed using flowcytometry, immune histochemistry, immune florescence and qRT-PCR. RESULTS: Twelve HBsAg+ve mothers transmitted hepatitis B virus to their newborns whereas the rest (n = 22) did not. Hepatitis B virus-transmitting mothers showed increased expression of asialoglycoprotein receptor in trophoblasts of placenta. Immunofluorescence microscopy revealed colocalization of hepatitis B surface antigen and asialoglycoprotein receptor in placenta as well as in DCs of transmitting mothers. There was no significant difference in the expression of asialoglycoprotein receptor on peripheral blood mononuclear cells or chord blood mononuclear cells between the 2 groups. However, hepatitis B virus-transmitting mothers and their HBsAg+ve newborns showed increased mRNA levels of isoform of asialoglycoprotein receptor on dendritic cell in peripheral blood mononuclear cells. Hepatitis B virus-transmitting mothers and their HBsAg+ve newborns showed an increased expression of isoform of asialoglycoprotein receptor on dendritic cell on circulating dendritic cells compared to hepatitis B virus non-transmitting mothers and their negative newborns. CONCLUSIONS: This study revealed that increased expression of asialoglycoprotein receptor in placenta and colocalization with hepatitis B surface antigen strongly indicates its role in intrauterine transmission of hepatitis B virus. Asialoglycoprotein receptor-blocking strategy can be used for therapeutic intervention of vertical transmission.
Assuntos
Receptor de Asialoglicoproteína/análise , Antígenos de Superfície da Hepatite B/sangue , Hepatite B/transmissão , Placenta/imunologia , Complicações Infecciosas na Gravidez/virologia , Adulto , DNA Viral/sangue , Feminino , Hepatite B/congênito , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Leucócitos Mononucleares/química , Masculino , Gravidez , Complicações Infecciosas na Gravidez/sangue , Curva ROC , Adulto JovemRESUMO
Hydrogen peroxide is often required in sublethal, millimolar concentrations to show its oxidant effects on cells in culture as it is easily destroyed by cellular catalase. Previously, we had shown that diperoxovanadate, a physiologically stable peroxovanadium compound, can substitute H2O2 effectively in peroxidation reactions. We report here that peroxovanadate when anchored to polyacrylic acid (PAPV) becomes a highly potent inhibitor of growth of lung carcinoma cells (A549). The early events associated with PAPV treatment included cytoskeletal modifications, increase in GTPase activity of Rac1, accumulation of the reactive oxygen species, and also increase in phosphorylation of H2AX (γH2AX), a marker of DNA damage. These effects persisted even at 24 h after removal of the compound and culminated in increased levels of p53 and p21 together with growth arrest. The PAPV-mediated growth arrest was significantly abrogated in cells pre-treated with the N-acetylcysteine, Rac1 knocked down by siRNA and DPI an inhibitor of NADPH oxidase. In conclusion, our results show that polyacrylate derivative of peroxovanadate efficiently arrests growth of A549 cancerous cells by activating the axis of Rac1-NADPH oxidase leading to oxidative stress and DNA damage.
Assuntos
Resinas Acrílicas/farmacologia , Neoplasias Pulmonares , NADPH Oxidases/metabolismo , Proteínas de Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Vanadatos/farmacologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Dano ao DNA , Humanos , Peróxido de Hidrogênio/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Estresse Oxidativo/efeitos dos fármacosRESUMO
Maintaining the genomic integrity is a constant challenge in proliferating cells. Amongst various proteins involved in this process, Sirtuins play a key role in DNA damage repair mechanisms in yeast as well as mammals. In the present work we report the role of one of the least explored Sirtuin viz., SIRT7, under conditions of genomic stress when treated with doxorubicin. Knockdown of SIRT7 sensitized osteosarcoma (U2OS) cells to DNA damage induced cell death by doxorubicin. SIRT7 overexpression in NIH3T3 delayed cell cycle progression by causing delay in G1 to S transition. SIRT7 overexpressing cells when treated with low dose of doxorubicin (0.25 µM) showed delayed onset of senescence, lesser accumulation of DNA damage marker γH2AX and lowered levels of growth arrest markers viz., p53 and p21 when compared to doxorubicin treated control GFP expressing cells. Resistance to DNA damage following SIRT7 overexpression was also evident by EdU incorporation studies where cellular growth arrest was significantly delayed. When treated with higher dose of doxorubicin (>1 µM), SIRT7 conferred resistance to apoptosis by attenuating stress activated kinases (SAPK viz., p38 and JNK) and p53 response thereby shifting the cellular fate towards senescence. Interestingly, relocalization of SIRT7 from nucleolus to nucleoplasm together with its co-localization with SAPK was an important feature associated with DNA damage. SIRT7 mediated resistance to doxorubicin induced apoptosis and senescence was lost when p53 level was restored by nutlin treatment. Overall, we propose SIRT7 attenuates DNA damage, SAPK activation and p53 response thereby promoting cellular survival under conditions of genomic stress.
Assuntos
Proliferação de Células , Dano ao DNA/genética , Instabilidade Genômica , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Osteossarcoma/patologia , Sirtuínas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose , Western Blotting , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Ciclo Celular , Citometria de Fluxo , Humanos , Camundongos , Células NIH 3T3 , Osteossarcoma/genética , Osteossarcoma/metabolismo , RNA Interferente Pequeno/genética , Sirtuínas/antagonistas & inibidores , Sirtuínas/genética , Células Tumorais CultivadasRESUMO
Cyclosporine A (CsA), a widely used immunosuppressant shows cytotoxic effects by either inducing apoptosis or redirecting the cell towards non-apoptotic cell death. However, there still remains a lacuna in understanding the mechanism of CsA induced non-apoptotic cell death. In the present study we investigated calcineurin dependent or independent cytotoxic effects of CsA, a calcineurin inhibitor, in cervical cancerous SiHa cells. Decreased cell viability and massive cytoplasmic vacuolations were observed in CsA treated SiHa cells, having increased calcineurin activity. Endoplasmic reticulum (ER) stress and unfolded protein response (UPR), accompanied by a decrease in cyclophilin B (ER resident PPIase), preceded the formation of the vacuoles. These vacuoles stained positive for many ER resident markers confirming their ER origin; but the absence of autophagosomal marker, LC3II, ruled out autophagy. Extensively vacuolated cells eventually undergo cell death which lacked the typical apoptotic features, but showed significant decrease in AIP (ALG2 interacting protein) as seen in paraptosis. ER-vacuolation was prevented by cycloheximide and salubrinal thereby indicating requirement of active protein synthesis. Inhibiting calcineurin activity by either Tacrolimus (FK506) or by knockdown of calcineurin B subunit did not result in either ER-stress or cellular vacuolation. However, knockdown of cyclophilin B by siRNA resulted in increased expression of Bip and IRE1α, together with cytoplasmic vacuolation. In conclusion, we report that persistent ER stress due to cyclophilin B inhibition in CsA treated cervical cancer cells caused cellular vacuolation which culminated in a non-apoptotic cell death response similar to paraptosis. Additionally, the paraptotic effects of CsA are independent of calcineurin inhibition.
RESUMO
Sirtuins belong to the family of class III histone deacetylases; its role in neoplasia is controversial as both tumor-suppressive and promoting functions have been reported. There are very few reports available, where expressions of sirtuin isoforms are comprehensively analyzed during neoplasia. Therefore, in the present study, the expression of SIRT1, SIRT2, and SIRT7 during different stages of cervical cancer progression was analyzed. The normal cervical epithelium showed feeble expression of sirtuin isoforms, SIRT1, SIRT2, and SIRT7. A significant increase in SIRT1 expression was noted in the cytoplasm as well as in the nucleus of proliferative layers of cervical epithelium in squamous intraepithelial lesions (SIL); however, in the squamous cell carcinomas (SCC), a heterogeneous pattern of SIRT1 expression varying from low to high was noted. A progressive increase in the expression of both SIRT2 and SIRT7 was noted during cancer progression in the following order: normal < preneoplasia < cancer. Cervical cancer cell lines, HeLa and SiHa, showed higher levels of SIRT1 and SIRT2 in comparison to the immortalized cell counterpart, HaCaT. Specific inhibitors of SIRT1 (Ex527) and SIRT2 (AGK2) impaired the growth of the cervical cancer cells, SiHa, but not of the HaCaT cells. SIRT1 inhibition caused cell death, while SIRT2 inhibition resulted in cell cycle arrest. In conclusion, we report the overexpression of SIRT2 and SIRT7 proteins in cervical cancer and suggest probable application of sirtuin inhibitors as therapeutic targets. Further, a specific increase in the levels of SIRT1 in intraepithelial lesion makes it a promising candidate for identification of preneoplastic changes.
Assuntos
Sirtuína 1/biossíntese , Sirtuína 2/biossíntese , Sirtuínas/biossíntese , Neoplasias do Colo do Útero/genética , Carbazóis/administração & dosagem , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Pontos de Checagem do Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Feminino , Furanos/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Quinolinas/administração & dosagem , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Sirtuína 2/antagonistas & inibidores , Sirtuína 2/genética , Sirtuínas/antagonistas & inibidores , Sirtuínas/genética , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologiaRESUMO
BACKGROUND: Hepatitis B surface antigen (HBsAg) seroconversion is sometimes observed in hepatitis B reactivation (rHBV), probably due to immune resetting and differentiation. AIMS: To investigate sequential immune differentiation and abrogation of tolerance in patients with rHBV who achieved HBsAg seroconversion. METHODS: We included 19 patients with chronic hepatitis B (CHBV; HBV DNA log103-8 ), 67 with rHBV (raised ALT [>5XULN], HBV DNAlog104-8 ) and 10 healthy controls. Immune differentiation, tolerance and functional status of CD4, CD8, T regulatory cells (Tregs), B cells and follicular T helper (Tfh) cells were assessed at baseline and 24 weeks. RESULTS: At 24 weeks, 81% rHBV (n = 67) lost HBV DNA and HBeAg (41%), and 12 (19%) lost HBsAg and made anti-HBs titers >10 IU/ml. rHBV patients had higher Th1/17, TEM , Tfh, Tfh1/17, plasma and ATM B cells, and lower Tregs, Th2, Th17 and TEMRA expression. rHBV showed lower PD1, TIM3, LAG3, SLAM and TOX compared to CHBV. There was a significant increase in CD8, CD8EM, Tfh, Tfh1/17 and plasma B cells in seroconverters than non-seroconverters. At 24 weeks, we also observed increased plasma B cell frequency in seroconverters. While non-seroconverters showed higher expression of PD1, TIM3, LAG3, SLAM and TOX on CD4/CD8 T cells, blockade of PD1, TIM3, LAG3 and CTLA4 significantly enhanced IFN-γ, TNF-α, IL-4 and IL-21 expression on CD4/CD8 and Tfh cells in non-seroconverters. CONCLUSIONS: Non-seroconverters have increased inhibitory markers on CD4/CD8 T cells. There is a critical play of CD8, Tfh and B cells and subsets in seroclearance, along with checkpoint molecules as a potential therapy for non-seroconverters in HBV infection.
Assuntos
Hepatite B Crônica , Hepatite B , Humanos , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B/genética , DNA Viral , Soroconversão , Receptor Celular 2 do Vírus da Hepatite A/uso terapêutico , Hepatite B/tratamento farmacológico , Hepatite B Crônica/tratamento farmacológico , Antígenos E da Hepatite B , Antivirais/uso terapêuticoRESUMO
BACKGROUND: The stoppage of nucleoside analog (NA) can lead to immune flare and loss of HBsAg in a proportion of HBeAg-negative chronic hepatitis B (CHB) patients. HBsAg loss could be improved by instituting Peg-Interferon therapy in those who show an immune flare after the stoppage of NA. We investigated the immune drivers of HBsAg loss in NA-treated HBeAg-negative CHB patients after stopping NAs and administration of Peg-IFN-α2b therapy. METHODS: Fifty-five NA-treated eAg-ve, HBV DNA not detected CHB patients were subjected to stopping NA therapy. Twenty-two (40%) patients relapsed (REL-CHBV) within 6 months (HBV DNA ≥2000 IU/mL, ALT ≥2XULN) and were started on Peg-IFN-α2b (1.5 mcg/kg) for 48 weeks (PEG-CHBV). Cytokine levels, immune responses, and T-cell functionality were assessed. RESULTS: Only 22 (40%) of 55 patients clinically relapsed, of which 6 (27%) cleared HBsAg. None of the 33 (60%) nonrelapsers cleared HBsAg. REL-CHBV patients had significantly increased IL-6 (p=0.035), IFN-γ (p=0.049), Th1/17 (p=0.005), CD4 effector memory (EM) (p=0.01), Tfh1/17 (p=0.005), and mature B cells (p=0.04) compared with CHBV. Six months after Peg-IFN therapy, immune resetting with a significant increase in CXCL10 (p=0.042), CD8 (p=0.01), CD19 (p=0.001), and mature B cells (p=0.001) was observed. HBV-specific T-cell functionality showed increased Tfh-secreting IFN-γ (p=0.001), IL-21 (p=0.001), and TNF-α (p=0.005) in relapsers and IFN-γ-secreting CD4 T cell (p=0.03) in PEG-CHBV. CONCLUSIONS: Stopping NA therapy induces flare in about 40% of HBeAg-negative patients. Peg-IFN therapy given to such patients causes immune restoration with HBsAg loss in one fourth of them.
Assuntos
Antígenos de Superfície da Hepatite B , Hepatite B Crônica , Humanos , Antivirais/uso terapêutico , Antígenos E da Hepatite B , DNA Viral , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Nucleosídeos/uso terapêutico , Nucleotídeos/uso terapêuticoRESUMO
BACKGROUND: Non-alcoholic fatty liver disease is one of the most common causes of chronic liver diseases and occurs even in lean individuals having normal or low body mass index (BMI). Crucial issue is understanding the clinical, pathobiologic and metabolic characteristics in comparison to obese patients. Very few studies have compared clinicopathological characteristics between lean and obese. Published literature is generally in a small cohort of patients, rarely included over-weight as separate category, and most often had non-standardized use of BMI criteria with discordant conclusions. There is very sparse published literature on liver biopsy-confirmed cohort and that to from Asia; also, none had explored the role of mediators such as stellate cells, progenitor cells and macrophages. AIMS: To evaluate the prevalence of NAFLD in lean patients in a large cohort of histology-confirmed NAFLD, and explore clinico-pathological spectrum of lean NAFLD in comparison to over-weight and obese. Also, to investigate role of hepatic stellate cells, macrophage polarization and their relation to hepatic progenitor cells, in particular the relation to fibrosis and to different BMI categories. METHODS: Prospective analysis of eleven-year retrospective cross-sectional data of all consecutive patients of NAFLD diagnosed in the period between the year 2011 and 2021. All histologically confirmed cases of NAFLD fulfilling inclusion and exclusion criteria were stratified to three groups according to BMI based on Asian criteria. Demographic, lab, metabolic, and histological comparisons between lean and overweight-obese patients were performed. Histological grading and staging of NAFLD components were performed by NAS-CRN score. Immunohistochemical and image analysis-based assessment and quantification of stellate cells, progenitor cells, and macrophage polarization was performed. Appropriate statistical methods were applied, and study was approved by the Institutional ethics committee. RESULTS: Lean patients with biopsy-proven diagnosis constituted 21 % (n = 267) of total NAFLD (n = 1273). Other groups were-over-weight patients (232;18.2 %), and the highest were obese patients (774; 60.8 %). 13.9 % of the lean patients with NAFLD were under-weight with BMI<18.5 kg/m2. Lean patients had significantly lower BMI and waist circumference along with lesser fasting glucose levels in comparison to the other groups. Rest of the metabolic parameters were nearly similar. Lean patients showed higher serum ALT levels, and histological characteristics such as ballooning of hepatocytes and steatosis were also more marked in comparison to other groups. Lobular inflammation and advanced fibrosis were significantly less common in lean patients with NASH related cirrhosis found in only 20.9 % of them. Immunophenotypic studies revealed the inter-relationship of HPCs, HSCs, and macrophages was influenced by the stage of fibrosis and not by the BMI. CONCLUSIONS: Prevalence of NAFLD in lean individuals in a histological-confirmed patient cohort was 21 %. (n = 267/1273). Major strengths of this study are large cohort of lean individuals from a single center, inclusion of only histology-confirmed cases, Asia specific BMI criteria usage, comparative clinical, metabolic, immune-morphologic and image analysis-based characterization, inclusion of over-weight in addition to obese patients, and investigating cross-talk of principal patho-physiologic markers.
RESUMO
Decompensated cirrhosis (DC) is susceptible to infections and sepsis. Neutrophils and monocytes provide the first line of defense to encounter infection. We aimed to evaluate proteins related to neutrophils functionality in sepsis. 70 (DC), 40 with sepsis, 30 without (w/o) sepsis and 15 healthy controls (HC) plasma was analyzed for proteomic analysis, cytokine bead array, endotoxin, cell free DNA and whole blood cells were analyzed for nCD64-mHLADR index, neutrophils-monocytes, functionality and QRT-PCR. nCD64-mHLADR index was significantly increased (p < 0.0001) with decreased HLA-DR expression on total monocytes in sepsis (p = 0.045). Phagocytic activity of both neutrophils and monocytes were significantly decreased in sepsis (p = 0.002 and p = 0.0003). Sepsis plasma stimulated healthy neutrophils, showed significant increase in NETs (neutrophil extracellular traps) and cell free DNA (p = 0.049 and p = 0.04) compared to w/o sepsis and HC. Proteomic analysis revealed upregulated- DNAJC13, TMSB4X, GPI, GSTP1, PNP, ANPEP, COTL1, GCA, APOA1 and PGAM1 while downregulated- AHSG, DEFA1,SERPINA3, MPO, MMRN1and PROS1 proteins (FC > 1.5; p < 0.05) associated to neutrophil activation and autophagy in sepsis. Proteins such as DNAJC13, GPI, GSTP1, PNP, ANPEP, COTL1, PGAM1, PROS1, MPO, SERPINA3 and MMRN1 showed positive correlation with neutrophils activity and number, oxidative burst activity and clinical parameters such as MELD, MELD Na and Bilirubin. Proteomic analysis revealed that faulty functionality of neutrophils may be due to the autophagy proteins i.e., DNAJC13, AHSG, TMSB4X, PROS1 and SERPINA3, which can be used as therapeutic targets in decompensated cirrhosis patients with sepsis.