Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
2.
iScience ; 26(11): 108159, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37927554

RESUMO

This study investigated and compared the wound healing kinetics of pigmented (PG) and non-pigmented (NP) skin in guinea pigs, focusing on histological and transcriptional changes. Full-thickness wounds created on PG and NP skin were evaluated at various time points post-injury. Fontana-Masson staining and ultrastructural analysis suggested the presence of melanin and melanosomes in PG skin, which coincided with an upregulation of melanogenic genes cKIT, TYR, and DCT. On day 9 post-wound, PG skin exhibited a rapid transition from the inflammatory to proliferative phase, which correlated with the reappearance of epidermal pigmentation whereas the NP skin exhibited a delayed neo-epidermis formation. Furthermore, the study revealed that melanocyte-derived growth factors (conditioned media) positively regulated keratinocyte migration while inhibiting fibroblast differentiation. These effects were more prominent in tyrosine-treated (hyperpigmented) melanocyte-CM as was TGF- ß expression. These findings provide valuable insights into the mechanisms underlying skin repair and pigmentation.

3.
Science ; 380(6649): eabn9257, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37289866

RESUMO

Aging is associated with changes in circulating levels of various molecules, some of which remain undefined. We find that concentrations of circulating taurine decline with aging in mice, monkeys, and humans. A reversal of this decline through taurine supplementation increased the health span (the period of healthy living) and life span in mice and health span in monkeys. Mechanistically, taurine reduced cellular senescence, protected against telomerase deficiency, suppressed mitochondrial dysfunction, decreased DNA damage, and attenuated inflammaging. In humans, lower taurine concentrations correlated with several age-related diseases and taurine concentrations increased after acute endurance exercise. Thus, taurine deficiency may be a driver of aging because its reversal increases health span in worms, rodents, and primates and life span in worms and rodents. Clinical trials in humans seem warranted to test whether taurine deficiency might drive aging in humans.


Assuntos
Envelhecimento , Taurina , Animais , Humanos , Camundongos , Envelhecimento/sangue , Envelhecimento/efeitos dos fármacos , Envelhecimento/metabolismo , Senescência Celular , Haplorrinos , Longevidade/efeitos dos fármacos , Longevidade/fisiologia , Taurina/sangue , Taurina/deficiência , Taurina/farmacologia , Suplementos Nutricionais , Dano ao DNA/efeitos dos fármacos , Telomerase/metabolismo
4.
J Vis Exp ; (194)2023 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154568

RESUMO

The ocular micro-dissection of the rodent eye involves the segmentation of the enucleated eyeball with the attached nictitating membrane, or third eyelid, to obtain the anterior and posterior eyecups. With this technique, the sub-parts of the eye, including the corneal tissue, neural tissue, retinal pigment epithelial (RPE) tissue, and lens, can be obtained for wholemounts, cryo-sectioning, and/or single-cell suspensions of a specific ocular tissue. The presence of the third eyelid presents unique and significant advantages, as it benefits the maintenance of the orientation of the eye, which is important for understanding eye physiology following any localized intervention or in studies involving ocular analysis relating to the eye's spatial topography. In this method, we enucleated the eyeball at the socket along with the third eyelid by carefully and slowly cutting through the extraocular muscles and severing the optic nerve. The eyeball was pierced through the corneal limbus using a microblade. The incision was used as the point of entry, allowing for cutting along the corneal-scleral junction by inserting micro-scissors through the incision point. Small and continuous cuts along the circumference were made until the cups separated. These could be further dissected by gently peeling the translucent layer of the neural retina using Colibri suturing forceps to obtain the neural retina and RPE layers. Further, three/four equidistant cuts were made from the periphery perpendicularly to the optic center until the optic nerve was reached. This opened the hemispherical cups into a floret shape so that they fell flat and could be easily mounted. This technique has been used in our lab for corneal wholemounts and retinal sections. The presence of the third eyelid delineates the nasal-temporal orientation, which allows for the study of various cell therapy interventions post-transplantation and, thus, the targeted physiological validation vital for visualization and accurate representation in such studies.


Assuntos
Cristalino , Microdissecção , Animais , Olho , Retina/cirurgia , Epitélio Pigmentado da Retina , Córnea/cirurgia
5.
ACS Pharmacol Transl Sci ; 6(2): 253-269, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36798477

RESUMO

Advanced glycation end-products (AGEs) form when glucose reacts non-enzymatically with proteins, leading to abnormal protein function, oxidative stress, and inflammation. AGEs are associated with aging and age-related diseases; their formation is aggravated during diabetes. Therefore, drugs preventing AGE formation can potentially treat diabetic complications, positively affecting health. Earlier, we demonstrated that rifampicin and its analogs have potent anti-glycating activities and increase the life span of Caenorhabditis elegans. This study aimed to investigate the effects of rifampicin during hyperglycemia in C. elegans and in a mouse model of obesity-induced type 2 diabetes. The effects of rifampicin were assessed by determining the life span of C. elegans cultured in the presence of glucose and by measuring HbA1c, AGE levels, and glucose excursions in the diabetic mouse model. Our results show that rifampicin protects C. elegans from glucose-induced toxicity and increases life span. In mice, rifampicin reduces HbA1c and AGEs, improves insulin sensitivity, and reduces indications of diabetic nephropathy without inducing hepatotoxicity. Rifampicin quinone, an analog with lower anti-microbial activity, also reduces HbA1c levels, improves glucose homeostasis and insulin sensitivity, and lowers indications of diabetic nephropathy, without adversely affecting the liver of the diabetic mice. Altogether, our results indicate that rifampicin and its analog have protective roles during diabetes without inflicting hepatic damage and may potentially be considered for repositioning to treat hyperglycemia-related complications in patients.

6.
Orphanet J Rare Dis ; 17(1): 378, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253797

RESUMO

BACKGROUND: Retinitis pigmentosa (RP) is a hereditary retinal disease which leads to visual impairment. The onset and progression of RP has physiological consequences that affects the ocular environment. Some of the key non-genetic factors which hasten the retinal degeneration in RP include oxidative stress, hypoxia and ocular inflammation. In this study, we investigated the status of the ocular immune privilege during retinal degeneration and the effect of ocular immune changes on the peripheral immune system in RP. We assessed the peripheral blood mononuclear cell stimulation by retinal antigens and their immune response status in RP patients. Subsequently, we examined alterations in ocular immune privilege machineries which may contribute to ocular inflammation and disease progression in rd1 mouse model. RESULTS: In RP patients, we observed a suppressed anti-inflammatory response to self-retinal antigens, thereby indicating a deviated response to self-antigens. The ocular milieu in rd1 mouse model indicated a significant decrease in immune suppressive ligands and cytokine TGF-B1, and higher pro-inflammatory ocular protein levels. Further, blood-retinal-barrier breakdown due to decrease in the expression of tight junction proteins was observed. The retinal breach potentiated pro-inflammatory peripheral immune activation against retinal antigens and caused infiltration of the peripheral immune cells into the ocular tissue. CONCLUSIONS: Our studies with RP patients and rd1 mouse model suggest that immunological consequences in RP is a contributing factor in the progression of retinal degeneration. The ocular inflammation in the RP alters the ocular immune privilege mechanisms and peripheral immune response. These aberrations in turn create an auto-reactive immune environment and accelerate retinal degeneration.


Assuntos
Degeneração Retiniana , Retinose Pigmentar , Animais , Anti-Inflamatórios , Autoantígenos , Citocinas , Modelos Animais de Doenças , Privilégio Imunológico , Inflamação , Leucócitos Mononucleares/metabolismo , Camundongos , Proteínas de Junções Íntimas
7.
J Cell Physiol ; 237(8): 3164-3180, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35616339

RESUMO

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/metabolismo
8.
Antimicrob Agents Chemother ; 66(3): e0194321, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35041501

RESUMO

Alphaviruses cause animal or human diseases that are characterized by febrile illness, debilitating arthralgia, or encephalitis. Selective estrogen receptor modulators (SERMs), a class of FDA-approved drugs, have been shown to possess antiviral activities against multiple viruses, including hepatitis C virus, Ebola virus, dengue virus, and vesicular stomatitis virus. Here, we evaluated three SERM compounds, namely, 4-hydroxytamoxifen, tamoxifen, and clomifene, for plausible antiviral properties against two medically important alphaviruses, chikungunya virus (CHIKV) and Sindbis virus (SINV). In cell culture settings, these SERMs displayed potent activity against CHIKV and SINV at nontoxic concentrations with 50% effective concentration (EC50) values ranging between 400 nM and 3.9 µM. Further studies indicated that these compounds inhibit a postentry step of the alphavirus life cycle, while enzymatic assays involving purified recombinant proteins confirmed that these SERMs target the enzymatic activity of nonstructural protein 1 (nsP1), the capping enzyme of alphaviruses. Finally, tamoxifen treatment restrained CHIKV growth in the infected mice and diminished musculoskeletal pathologies. Combining biochemical analyses, cell culture-based studies, and in vivo analyses, we strongly argue that SERM compounds, or their derivatives, may provide for attractive therapeutic options against alphaviruses.


Assuntos
Infecções por Alphavirus , Vírus Chikungunya , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Linhagem Celular , Camundongos , Moduladores Seletivos de Receptor Estrogênico/metabolismo , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Proteínas não Estruturais Virais , Replicação Viral
9.
J Clin Invest ; 132(4)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34905510

RESUMO

Through their ability to regulate gene expression in most organs, glucocorticoid (GC) hormones influence numerous physiological processes and are therefore key regulators of organismal homeostasis. In bone, GC hormones inhibit expression of the hormone Osteocalcin for poorly understood reasons. Here, we show that in a classical endocrine feedback loop, osteocalcin in return enhanced the biosynthesis of GC as well as mineralocorticoid hormones (adrenal steroidogenesis) in rodents and primates. Conversely, inactivation of osteocalcin signaling in adrenal glands significantly impaired adrenal growth and steroidogenesis in mice. Embryo-made osteocalcin was necessary for normal Sf1 expression in fetal adrenal cells and adrenal cell steroidogenic differentiation and therefore determined the number of steroidogenic cells present in the adrenal glands of adult animals. Embryonic, not postnatal, osteocalcin also governed adrenal growth, adrenal steroidogenesis, blood pressure, electrolyte equilibrium, and the rise in circulating corticosterone levels during the acute stress response in adult offspring. This osteocalcin-dependent regulation of adrenal development and steroidogenesis occurred even in the absence of a functional hypothalamus/pituitary/adrenal axis and explains why osteocalcin administration during pregnancy promoted adrenal growth and steroidogenesis and improved the survival of adrenocorticotropic hormone signaling-deficient animals. This study reveals that a bone-derived embryonic hormone influences lifelong adrenal functions and organismal homeostasis in the mouse.


Assuntos
Glândulas Suprarrenais/embriologia , Homeostase , Sistema Hipotálamo-Hipofisário/embriologia , Osteocalcina/metabolismo , Sistema Hipófise-Suprarrenal/embriologia , Transdução de Sinais , Animais , Feminino , Glucocorticoides/genética , Glucocorticoides/metabolismo , Macaca mulatta , Camundongos , Camundongos Knockout , Osteocalcina/genética
10.
J Cell Sci ; 134(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34369561

RESUMO

Meta-analysis of transcripts in colon adenocarcinoma patient tissues led to the identification of a DNA damage responsive miR signature called DNA damage sensitive miRs (DDSMs). DDSMs were experimentally validated in the cancerous colon tissues obtained from an independent cohort of colon cancer patients and in multiple cellular systems with high levels of endogenous DNA damage. All the tested DDSMs were transcriptionally upregulated by a common intestine-specific transcription factor, CDX2. Reciprocally, DDSMs were repressed via the recruitment of HDAC1/2-containing complexes onto the CDX2 promoter. These miRs downregulated multiple key targets in the DNA damage response (DDR) pathway, namely BRCA1, ATM, Chk1 (also known as CHEK1) and RNF8. CDX2 directly regulated the DDSMs, which led to increased tumor volume and metastasis in multiple preclinical models. In colon cancer patient tissues, the DDSMs negatively correlated with BRCA1 levels, were associated with decreased probability of survival and thereby could be used as a prognostic biomarker. This article has an associated First Person interview with the first author of the paper.


Assuntos
Adenocarcinoma , Neoplasias do Colo , MicroRNAs , Fator de Transcrição CDX2/genética , Neoplasias do Colo/genética , Dano ao DNA/genética , Proteínas de Ligação a DNA/genética , Humanos , MicroRNAs/genética , Fatores de Transcrição , Ubiquitina-Proteína Ligases
11.
Sci Rep ; 11(1): 3049, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542363

RESUMO

Due to the limited utility of Bacillus Calmette-Guérin (BCG), the only approved vaccine available for tuberculosis, there is a need to develop a more effective and safe vaccine. We evaluated the safety and efficacy of a dry powder aerosol (DPA) formulation of BCG encapsulated alginate particle (BEAP) and the conventional intradermal BCG immunization in infant rhesus macaques (Macaca mulatta). The infant macaques were immunized intratracheally with DPA of BEAP into the lungs. Animals were monitored for their growth, behaviour, any adverse and allergic response. The protective efficacy of BEAP was estimated by the ex-vivo H37Rv infection method. Post-immunization with BEAP, granulocytes count, weight gain, chest radiography, levels of liver secreted enzymes, cytokines associated with inflammation like TNF and IL-6 established that BEAP is non-toxic and it does not elicit an allergic response. The T cells isolated from BEAP immunized animals' blood, upon stimulation with M.tb antigen, secreted high levels of IFN-γ, TNF, IL-6 and IL-2. The activated T cells from BEAP group, when co-cultured with M.tb infected macrophages, eliminated largest number of infected macrophages compared to the BCG and control group. This study suggests the safety and efficacy of BEAP in Non-human primate model.


Assuntos
Vacina BCG/farmacologia , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose/prevenção & controle , Alginatos/química , Alginatos/farmacologia , Animais , Vacina BCG/efeitos adversos , Modelos Animais de Doenças , Humanos , Imunização , Interferon gama/genética , Interleucina-2/genética , Interleucina-6/genética , Macaca mulatta/imunologia , Macaca mulatta/microbiologia , Mycobacterium tuberculosis/patogenicidade , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Tuberculose/genética , Tuberculose/imunologia , Tuberculose/microbiologia , Vacinas contra a Tuberculose/imunologia , Fator de Necrose Tumoral alfa/genética
12.
Cell Biochem Funct ; 39(2): 296-307, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32767404

RESUMO

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 Cima
13.
Stem Cell Res Ther ; 11(1): 412, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32967734

RESUMO

BACKGROUND: Cell therapy is one of the most promising therapeutic interventions for retinitis pigmentosa. In the current study, we aimed to assess if peripheral blood-derived monocytes which are highly abundant and accessible could be utilized as a potential candidate for phenotypic differentiation into neuron-like cells. METHODS: The peripheral blood-derived monocytes were reconditioned phenotypically using extrinsic growth factors to induce pluripotency and proliferation. The reconditioned monocytes (RM) were further incubated with a cocktail of growth factors involved in retinal development and growth to induce retinal neuron-like properties. These cells, termed as retinal neuron-like cells (RNLCs) were characterized for their morphological, molecular and functional behaviour in vitro and in vivo. RESULTS: The monocytes de-differentiated in vitro and acquired pluripotency with the expression of prominent stem cell markers. Treatment of RM with retinal growth factors led to an upregulation of neuronal and retinal lineage markers and downregulation of myeloid markers. These cells show morphological alterations resembling retinal neuron-like cells and expressed photoreceptor (PR) markers. The induced RNLCs also exhibited relative membrane potential change upon light exposure suggesting that they have gained some neuronal characteristics. Further studies showed that RNLCs could also integrate in an immune-deficient retinitis pigmentosa mouse model NOD.SCID-rd1 upon sub-retinal transplantation. The RNLCs engrafted in the inner nuclear layer (INL) and ganglion cell layer (GCL) of the RP afflicted retina. Mice transplanted with RNLCs showed improvement in depth perception, exploratory behaviour and the optokinetic response. CONCLUSIONS: This proof-of-concept study demonstrates that reconditioned monocytes can be induced to acquire retinal neuron-like properties through differentiation using a defined growth media and can be a potential candidate for cell therapy-based interventions and disease modelling for ocular diseases.


Assuntos
Monócitos , Retina , Animais , Diferenciação Celular , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Neurônios
14.
Front Immunol ; 11: 83, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210950

RESUMO

Exhaustion of CD8+ T cells and increased IL-10 production is well-known in chronic viral infections but mechanisms leading to loss of their cytotoxic capabilities and consequent exhaustion remain unclear. Exhausted CD8+T cells also called T suppressors are highly immune suppressive with altered T cell receptor signaling characteristics that mark it exclusively from their cytotoxic counterparts. Our study found that iCa2+ flux is reduced following T cell receptor activation in T suppressor cells when compared to their effector counterpart. Importantly chronic activation of murine cytotoxic CD8+ T cells lead to reduced iCa2+ influx, decreased IFN-γ and enhanced IL-10 production and this profile is mimicked in Tc1 cells upon reduction of iCa2+ flux by extracellular calcium channel inhibitors. Further reduced iCa2+ flux induced ROS which lead to IFN-γ reduction and increased IL-10 producing T suppressors through the STAT3-STAT5 axis. The above findings were substantiated by our human data where reduced iCa2+ flux in chronic Hepatitis infections displayed CD8+ T cells with low IFN-γ and increased IL-10 production. Importantly treatment with an antioxidant led to increased IFN-γ and reduced IL-10 production in human chronic Hep-B/C samples suggesting overall a proximal regulatory role for iCa2+ influx, ROS, and IL-10 in determining the effector/ suppressive axis of CD8+ T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Cálcio/metabolismo , Linfócitos T Citotóxicos/imunologia , Viroses/imunologia , Animais , Antioxidantes/farmacologia , Cálcio/imunologia , Bloqueadores dos Canais de Cálcio/farmacologia , Células Cultivadas , Citotoxicidade Imunológica , Voluntários Saudáveis , Hepatite B/imunologia , Humanos , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-10/metabolismo , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição NFATC/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo
15.
J Vis Exp ; (153)2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31840655

RESUMO

Acute liver failure (ALF) is a clinical condition caused by various etiologies resulting in the loss of metabolic, biochemical, synthesizing, and detoxifying functions of the liver. In most irreversible liver damage cases, orthotropic liver transplant (OLT) remains the only available treatment. To study the therapeutic potential of a treatment for ALF, its prior testing in an animal model of ALF is essential. In the current study, an ALF model in rats was developed by combining 70% partial hepatectomy (PHx) and injections of acetaminophen (APAP) that provides a therapeutic window of 48 h. The median and left lateral lobes of the liver were removed to excise 70% of the liver mass and APAP was given 24 h postsurgically for 2 days. Survival in ALF-induced animals was found to be severely decreased. The development of ALF was confirmed by altered serum levels of the enzymes alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP); changes in prothrombin time (PT); and assessment of the international normalized ratio (INR). Study of the gene expression profile by qPCR revealed an increase in expression levels of genes involved in apoptosis, inflammation, and in the progression of liver injury. Diffused degeneration of hepatocytes and infiltration of immune cells was observed by histological evaluation. The reversibility of ALF was confirmed by the restoration of survival and serum levels of ALT, AST, and ALP after intrasplenic transplantation of syngeneic healthy rat hepatocytes. This model presents a reliable alternative to the available ALF animal models to study the pathophysiology of ALF as well as to evaluate the potential of a novel therapy for ALF. The use of two different approaches also makes it possible to study the combined effect of physical and drug-induced liver injury. The reproducibility and feasibility of current procedure is an added benefit of the model.


Assuntos
Acetaminofen/toxicidade , Modelos Animais de Doenças , Hepatectomia/efeitos adversos , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/etiologia , Fígado/cirurgia , Analgésicos não Narcóticos/toxicidade , Animais , Hepatócitos/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Falência Hepática Aguda/patologia , Masculino , Ratos , Ratos Wistar , Reprodutibilidade dos Testes
16.
J Biol Chem ; 294(12): 4381-4400, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30679313

RESUMO

MicroRNAs of the miR-16 and miR-34 families have been reported to inhibit cell cycle progression, and their loss has been linked to oncogenic transformation. Utilizing a high-throughput, genome-wide screen for miRNAs and mRNAs that are differentially regulated in osteosarcoma (OS) cell lines, we report that miR-449a and miR-424, belonging to the miR-34 and miR-16 families, respectively, target the major S/G2 phase cyclin, cyclin A2 (CCNA2), in a bipartite manner. We found that the 3'-UTR of CCNA2 is recognized by miR-449a, whereas the CCNA2 coding region is targeted by miR-424. Of note, we observed loss of both miR-449a and miR-424 in OS, resulting in derepression of CCNA2 and appearance of aggressive cancer phenotypes. Ectopic expression of miR-449a and miR-424 significantly decreased cyclin A2 levels and inhibited proliferation rate, migratory potential, and colony-forming ability of OS cells. To further probe the roles of miR-449a and miR-424 in OS, we developed an OS mouse model by intraosseous injection of U2OS cells into the tibia bone of NOD-scid mice, which indicated that miR-449a and miR-424 co-expression suppresses tumor growth. On the basis of this discovery, we analyzed the gene expression of human OS biopsy samples, revealing that miR-449a and miR-424 are both down-regulated, whereas cyclin A2 is significantly up-regulated in these OS samples. In summary, the findings in our study highlight that cyclin A2 repression by miRNAs of the miR-16 and miR-34 families is lost in aggressive OS.


Assuntos
Neoplasias Ósseas/genética , Ciclina A2/metabolismo , MicroRNAs/fisiologia , Osteossarcoma/genética , Regiões 3' não Traduzidas , Animais , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Replicação do DNA , Modelos Animais de Doenças , Regulação para Baixo , Fase G1 , Fase G2 , Redes Reguladoras de Genes , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/genética , Osteossarcoma/metabolismo , Osteossarcoma/patologia , RNA Mensageiro/genética , Fase S
17.
Mol Cell Endocrinol ; 482: 70-80, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30579957

RESUMO

The synergistic actions of Testosterone (T) and FSH via testicular Sertoli cells (Sc) regulate male fertility. We have previously reported that the actions of these hormones (T and FSH) in infant monkey testes are restricted only to the expansion of Sc and spermatogonial cells. The robust differentiation of male Germ cells (Gc) occurs after pubertal maturation of testis. The present study was aimed to investigate the molecular basis of the synergy between T and FSH action in pubertal primate (Macaca mulatta) Sc. Using primary Sc culture, we here have demonstrated that T (but not FSH) downregulated AMH and Inhibin-ß-B (INHBB) mRNAs in pubertal Sc. We also found that, prolonged stimulation of T in pubertal Sc significantly elevated the expression of genes involved in FSH signaling pathway like FSH-Receptor (FSHR), GNAS and RIC8B, and this was associated with a rise in cAMP production. T also augmented FSH induced expression of genes like SCF, GDNF, ABP and Transferrin (TF) in pubertal Sc. We therefore conclude that T acts in synergy with FSH signaling in pubertal Sc. Such a coordinated network of hormonal signaling in Sc may facilitate the timely onset of the first spermatogenic wave in pubertal primates and is responsible for quantitatively and qualitatively normal spermatogenesis.


Assuntos
Hormônio Foliculoestimulante/farmacologia , Receptores do FSH/genética , Receptores do FSH/metabolismo , Células de Sertoli/citologia , Testosterona/farmacologia , Animais , Células Cultivadas , Subunidades beta de Inibinas/genética , Macaca mulatta , Masculino , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Maturidade Sexual , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima
18.
Int J Exp Pathol ; 99(1): 46-53, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29656466

RESUMO

Non-alcoholic fatty liver disease (NAFLD)-like conditions enhance the production and action of clotting factors in humans. However, studies examining the effect of NAFLD due to high-fat high-fructose (HFHF) diet in factor VIII-deficient (haemophilia A) animals or patients have not been reported previously. In this study, we investigated the individual role of factor VIII in the progression of diet-induced NAFLD in the factor 8-/- (F8-/- ) mouse model system and its consequences on the haemophilic status of the mice. The F8-/- mice were fed with HFHF diet for 14 weeks. Physiological, biochemical, haematological, molecular, pathological, and immune histochemical analyses were performed to evaluate the effect of this diet. The F8-/- mice developed hepatic steatosis after 14 weeks HFHF diet and displayed lower energy metabolism, higher myeloid cell infiltration in the liver, decreased platelet count, upregulated de novo fatty acid synthesis, lipid accumulation, and collagen deposition. This study helps to understand the role of factor VIII in NAFLD pathogenesis and to analyse the severity and consequences of steatosis in haemophilic patients as compared to normal population. This study suggests that haemophilic animals (F8-/- mice) are highly prone to hepatic steatosis and thrombocytopenia.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Açúcares da Dieta/toxicidade , Fator VIII/genética , Frutose/toxicidade , Hemofilia A/genética , Hepatopatia Gordurosa não Alcoólica/etiologia , Animais , Colágeno/metabolismo , Açúcares da Dieta/administração & dosagem , Modelos Animais de Doenças , Fator VIII/metabolismo , Ácidos Graxos/metabolismo , Frutose/administração & dosagem , Predisposição Genética para Doença , Hemofilia A/sangue , Mediadores da Inflamação/metabolismo , Gotículas Lipídicas/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Knockout , Células Mieloides/metabolismo , Células Mieloides/patologia , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/patologia , Fenótipo , Trombocitopenia/sangue , Trombocitopenia/etiologia , Fatores de Tempo , Triglicerídeos/metabolismo , Aumento de Peso
19.
J Vis Exp ; (132)2018 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-29553548

RESUMO

Partial hepatectomy is a versatile and reproducible method to study liver regeneration and the effect of cell based therapeutics in various pathological conditions. Partial hepatectomy also facilitates the increased engraftment and proliferation of transplanted cells by accelerating neovascularization and cell migration towards the liver. Here, we describe a simple protocol for performing 30% hepatectomy and transplantation of cells in the spleen of a non-obese diabetic/severe combined immunodeficient NOD.SCID (NOD.CB17-Prkdcscid/J) mouse. In this procedure, two small incisions are made. The first incision is to expose and resect the left lobe of the liver, and another small incision is made to expose the spleen for the intrasplenic transplantation of cells. This procedure does not require any specialized surgical skills, and it can be completed in 5-7 minutes with less stress and pain, faster recovery, and better survival. We have demonstrated the transplantation of hepatocytes isolated from a green fluorescent protein (GFP) expressing mouse (Transgenic C57BL/6-Tg (UBC-GFP) 30Scha/J), as well as hepatocyte like cells of human origin (NeoHep) in partially hepatectomized NOD.SCID mice.


Assuntos
Hepatectomia/métodos , Hepatócitos/transplante , Regeneração Hepática/fisiologia , Baço/cirurgia , Animais , Hepatócitos/citologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID
20.
Sci Rep ; 7(1): 10062, 2017 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-28855623

RESUMO

Curcumin has many pharmacological activities despite its poor bioavailability and in vivo stability. Here, we show that a nanoformulated curcumin (PLGA-curcumin) has better therapeutic index than native curcumin in preventing the onset of neurological symptoms and delaying the death of mice in experimental cerebral malaria. Oral PLGA-curcumin was at least as effective as native curcumin at a 15-fold lower concentration in preventing the breakdown of blood-brain barrier and inhibition of brain mRNAs for inflammatory cytokines, chemokine receptor CXCR3 and its ligand CXCL10, with an increase in the anti-inflammatory cytokine IL-10. This was also reflected in serum cytokine and chemokine levels. At equivalent concentrations, a single oral dose of PLGA-curcumin was more effective in inhibiting serum IFNγ levels and enhancing IL-10 levels than native curcumin. Even at low concentrations, PLGA-curcumin was superior to native curcumin in inhibiting the sequestration of parasitized-RBCs and CD8+ T cells in the brain. A single oral dose of 5 mg PLGA-curcumin containing 350 µg of curcumin resulted in 3-4 fold higher concentration and prolonged presence of curcumin in the brain than that obtained with 5 mg of native curcumin, indicating better bioavailability of PLGA-curcumin. PLGA-curcumin has potential as an adjunct drug to treat human cerebral malaria.


Assuntos
Antimaláricos/farmacologia , Encéfalo/efeitos dos fármacos , Curcumina/farmacologia , Malária Cerebral/tratamento farmacológico , Nanopartículas/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Animais , Antimaláricos/química , Disponibilidade Biológica , Encéfalo/parasitologia , Encéfalo/patologia , Linfócitos T CD8-Positivos , Quimiocina CXCL10/genética , Quimiocina CXCL10/imunologia , Curcumina/química , Modelos Animais de Doenças , Portadores de Fármacos , Composição de Medicamentos/métodos , Eritrócitos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Malária Cerebral/genética , Malária Cerebral/parasitologia , Malária Cerebral/patologia , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/metabolismo , Fármacos Neuroprotetores/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/crescimento & desenvolvimento , Plasmodium berghei/patogenicidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Receptores CXCR3/genética , Receptores CXCR3/imunologia , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA