Protective roles of autophagy in retinal pigment epithelium under high glucose condition via regulating PINK1/Parkin pathway and BNIP3L

BACKGROUND: Our study aimed to investigate the roles of autophagy against high glucose induced response in retinal pigment epithelium (ARPE-19 cells). METHODS: The morphological changes and reactive oxygen species (ROS) generation in ARPE-19 cells under high glucose treatment were respectively detected using the transmission electron microscopy and flow cytometry. The expression levels of Parkin, PINK1, BNIP3L, LC3-I and LC3-II in ARPE-19 cells received high glucose treatment were measured by western blot after pretreatment of carbonyl cyanide m-chlorophenylhydrazone (CCCP), 3-methyladenine (3-MA), N-acetyl cysteine (NAC) or cyclosporin A (CsA) followed by high glucose treatment. RESULTS: ARPE-19 cells subjected to high glucose stress showed an obvious reduction in the LC3-I expression and significant increase in the number of autophagosomes, in the intracellular ROS level, and in the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). Pretreatment with CCCP significantly reduced the LC3-I expression and increased the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). ARPE-19 cells pretreated with CsA under high glucose stress showed markedly down-regulated expressions of Parkin, PINK1 and BNIP3L compared with the cells treated with high glucose (p < 0.05). Pretreatment of ARPE-19 cells with NAC or 3-MA under high glucose stress resulted in a marked reduction in the expression levels of PINK1, BNIP3L and LC3-II (p < 0.05). Meanwhile, the expression level of Parkin in the ARPE-19 cells pretreated with NAC under high glucose stress was comparable with that in the control cells. CONCLUSION: Autophagy might have protective roles against high glucose induced injury in ARPE19 cells via regulating PINK1/Parkin pathway and BNIP3L.

Effect of allopurinol on the kidney function, histology and injury biomarker (NGAL, IL 18) levels in uninephrectomised rats subjected to ischaemia-reperfusion injury

PURPOSE: To investigate whether allopurinol exerts a protective effect on kidneys by measuring new kidney injury biomarkers (NGALp, NGALu, KIM 1 and IL 18) and analysing the renal function and histology in uninephrectomised rats subjected to ischaemia-reperfusion injury. METHODS: Thirty two Wistar rats were randomly allocated to four groups: Sham (S): laparotomy; Control (C): laparotomy and ischaemia-reperfusion in the left kidney; Control Allopurinol (CA): laparotomy and allopurinol at a dose of 100mg·kg 1·d 1; and Allopurinol (A): laparotomy ischaemia-reperfusion in the left kidney and allopurinol at a dose of 100mg·kg 1·d 1. The NGALp, NGALu, KIM 1, IL 18 and creatinine levels and the kidney histology were analysed. The significance level was established as p<0.05. RESULTS: Creatinine level increased in all the groups, with A ≈ C > S ≈ CA. The NGALp, NGALu and IL 18 levels exhibited similar behaviour in all the groups. KIM 1 was higher in group A than C and showed intermediate values in groups S and CA. Severity of injury in the left kidney was greater in groups C and A compared to S and CA. CONCLUSION: Allopurinol did not exert protective or damaging effects on the kidneys of rats subjected to ischaemia-reperfusion injury. .

Carcinoma de tireóide pouco diferenciado: novas considerações terapêuticas / Poorly differentiated thyroid carcinomas: new therapeutics considerations

Para a maioria dos carcinomas diferenciados de tireóide, como o papilífero e o folicular, após a tireoidectomia total e 131I para ablação de remanescentes tireoideanos, o tratamento com hormônios tireoideanos para suprimir os níveis de TSH reduz o crescimento de qualquer célula cancerosa remanescente, e o tratamento com radiação específica para as células cancerosas cura ou controla muito bem a doença. Os carcinomas de tireóide são considerados pouco diferenciados quando começam a perder as funções de captação de iodo e a dependência do TSH para crescimento e produção de proteínas tireóide-específicas, como proteína NIS, tireoglobulina e desiodases. Um dos maiores desafios no manejo de pacientes com carcinoma de tireóide derivados das células foliculares é o tratamento de tumores que evoluem apesar da cirurgia, 131I e supressão do TSH com T4. Com o melhor conhecimento da sinalização molecular anormal nas células tireoideanas cancerosas, atualmente novas terapias dirigidas a alvos moleculares específicos envolvidos na transformação neoplásica têm sido utilizadas. Com a identificação das necessidades moleculares críticas para a iniciação, manutenção e progressão tumoral, terapias combinadas com agentes terapêuticos alvo-dirigidos, agindo em cada uma destas etapas, irão melhorar o tratamento do carcinoma pouco diferenciado de tireóide.