RESUMO
We have shown previously that Clock, microsomal triglyceride transfer protein (MTP), and nocturnin are involved in the circadian regulation of intestinal lipid absorption. Here, we clarified the role of apolipoprotein AIV (apoAIV) in the diurnal regulation of plasma lipids and intestinal lipid absorption in mice. Plasma triglyceride in apoAIV(-/-) mice showed diurnal variations similar to apoAIV(+/+) mice; however, the increases in plasma triglyceride at night were significantly lower in these mice. ApoAIV(-/-) mice absorbed fewer lipids at night and showed blunted response to daytime feeding. To explain reasons for these lower responses, we measured MTP expression; intestinal MTP was low at night, and its induction after food entrainment was less in apoAIV(-/-) mice. Conversely, apoAIV overexpression increased MTP mRNA in hepatoma cells, indicating transcriptional regulation. Mechanistic studies revealed that sequences between -204/-775 bp in the MTP promoter respond to apoAIV and that apoAIV enhances expression of FoxA2 and FoxO1 transcription factors and their binding to the identified cis elements in the MTP promoter at night. Knockdown of FoxA2 and FoxO1 abolished apoAIV-mediated MTP induction. Similarly, knockdown of apoAIV in differentiated Caco-2 cells reduced MTP, FoxA2, and FoxO1 mRNA levels, cellular MTP activity, and media apoB. Moreover, FoxA2 and FoxO1 expression showed diurnal variations, and their expression was significantly lower in apoAIV(-/-) mice. These data indicate that apoAIV modulates diurnal changes in lipid absorption by regulating forkhead transcription factors and MTP and that inhibition of apoAIV expression might reduce plasma lipids.
Assuntos
Apolipoproteínas A/metabolismo , Proteínas de Transporte/metabolismo , Ritmo Circadiano , Fatores de Transcrição Forkhead/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Lipídeos/farmacocinética , Animais , Apolipoproteínas A/genética , Western Blotting , Células CACO-2 , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Ingestão de Alimentos , Enterócitos/metabolismo , Feminino , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/genética , Fator 3-beta Nuclear de Hepatócito/genética , Humanos , Absorção Intestinal , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Immunotherapy drugs are associated with a multitude of immune-related adverse events. We describe a case of cardiac tamponade in a patient with stage IV lung adenocarcinoma, with almost 100% expression of PDL-1, treated with pembrolizumab. The patient is a 62-year-old male who developed worsening shortness of breath after five cycles of pembrolizumab. He was diagnosed with large pericardial effusion on computed tomography chest. Echocardiogram confirmed tamponade physiology. He was treated with discontinuation of pembrolizumab and urgent pericardial window followed by high dose prednisone with tapering. The patient responded very well to the treatment. We have comprehensively reviewed cases of pericardial effusion secondary to either immune mediated mechanisms or pseudoprogression.