RESUMO
AIMS: In a recent genome-wide association study, WD-repeat domain 12 (WDR12) was associated with early-onset myocardial infarction (MI). However, the function of WDR12 in the heart is unknown. METHODS AND RESULTS: We characterized cardiac expression of WDR12, used adenovirus-mediated WDR12 gene delivery to examine effects of WDR12 on left ventricular (LV) remodeling, and analyzed relationship between MI associated WDR12 allele and cardiac function in human subjects. LV WDR12 protein levels were increased in patients with dilated cardiomyopathy and rats post-infarction. In normal adult rat hearts, WDR12 gene delivery into the anterior wall of the LV decreased interventricular septum diastolic and systolic thickness and increased the diastolic and systolic diameters of the LV. Moreover, LV ejection fraction (9.1%, P<0.05) and fractional shortening (12.2%, P<0.05) were declined. The adverse effects of WDR12 gene delivery on cardiac function were associated with decreased cellular proliferation, activation of p38 mitogen-activated protein kinase (MAPK)/heat shock protein (HSP) 27 pathway, and increased protein levels of Block of proliferation 1 (BOP1), essential for ribosome biogenesis. Post-infarction WDR12 gene delivery decreased E/A ratio (32%, P<0.05) suggesting worsening of diastolic function. In human subjects, MI associated WDR12 allele was associated significantly with diastolic dysfunction and left atrial size. CONCLUSIONS: WDR12 triggers distinct deterioration of cardiac function in adult rat heart and the MI associated WDR12 variant is associated with diastolic dysfunction in human subjects.
Assuntos
Insuficiência Cardíaca/metabolismo , Hemodinâmica , Infarto do Miocárdio/metabolismo , Proteínas Nucleares/metabolismo , Regulação para Cima , Adulto , Alelos , Animais , Proteínas de Ciclo Celular , Células Cultivadas , Feminino , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico HSP27/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/genética , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/metabolismo , Proteínas Nucleares/genética , Proteínas de Ligação a RNA , Ratos , Ratos Sprague-Dawley , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
The domains of bispecific diabodies (BsDbs) can be ordered in four different ways; however, the influence of domain order on the cytotoxicity of BsDbs that retarget immune cells against tumor cells had not been addressed. We previously reported the marked antitumor effects of a humanized BsDb that targets epidermal growth factor receptor and CD3 (hEx3-Db). Here, we rearranged the domains of hEx3-Db to examine the influence of domain order on the function of BsDbs. We successfully prepared homogenous dimers of hEx3-Db in all four domain configurations. Interestingly, all three rearranged hEx3s inhibited cancer growth more effectively than did the original hEx3-Db, in which both components were in variable heavy domain (VH)-variable light domain (VL) order (redesignated as hEx3-HL), and the highest effects were observed with hEx3-LH (hEx3-Db with both components in VL-VH order). In addition, hEx3-LH had comparable in vitro growth inhibitory effects to those of the tandem single-chain variable fragment (scFv) format of hEx3-Db (hEx3-tandem scFv (taFv)), which we previously showed to have greater cytotoxicity than does hEx3-HL. Flow cytometry suggested that the enhanced cytotoxicity of hEx3-LH is attributable to structural superiority for cross-linking, similar to that of hEx3-taFv. Furthermore, hEx3-LH inhibited cancer growth in mice more effectively than did hEx3-taFv; this difference may be due to differences in antibody stability. Our results show that merely rearranging the domain order of BsDbs can enhance their effects beyond those with structural format conversion.
Assuntos
Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/uso terapêutico , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Complexo CD3/imunologia , Receptores ErbB/imunologia , Neoplasias/terapia , Animais , Anticorpos Biespecíficos/imunologia , Antineoplásicos/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Camundongos , Neoplasias/imunologia , Multimerização Proteica , Estrutura Terciária de ProteínaRESUMO
Persistent controversy underlies the functional roles of specific p38 MAPK isoforms in cardiac biology and regulation of hypertrophy-associated genes. Here we show that adenoviral gene transfer of p38ß but not p38α increased B-type natriuretic peptide (BNP) mRNA levels in vitro as well as atrial natriuretic peptide mRNA levels both in vitro and in vivo. Overexpression of p38α, in turn, augmented the expression fibrosis-related genes connective tissue growth factor, basic fibroblast growth factor and matrix metalloproteinase-9 both in vitro and in vivo. p38ß-induced BNP transcription was diminished by mutation of GATA-4 binding site, whereas overexpression of MKK6b, an upstream regulator of p38α and p38ß, activated BNP transcription through both GATA-4 and AP-1. Overexpression of MKK3, upstream regulator of p38α, induced BNP transcription independently from AP-1 and GATA-4. These data provide new evidence for diversity in downstream targets and functional roles of p38 pathway kinases in regulation of hypertrophy-associated cardiac genes.