Anti-fibrogenic analysis of HGF in intractable organ failures: Clinical potential of HGF as regenerative therapy

(1)使用HGF基因疗法改善肝硬变的策略在日本，现在至少有200万人患有顽固性肝病，特别是每年有2万名患者因终末期肝硬变而死亡。因此，建立一种新的治疗方法来克服这种疾病是很重要的。通过动物模型，我们证明了肝细胞生长因子基因的cDNAi转移对于抑制与肝硬变相关的病理状态是有用的。在接受DMN(一种肝脏毒性药物)慢性治疗的大鼠中，随着肝硬变的进展，伴随着肝脏胶原和转化生长因子-β1水平的增加，导致在DMN治疗开始后6周内死亡。另一方面，所有的肝硬变大鼠在转染人HQF基因后仍然“存活”，直到注射DMN后6周。无肝细胞生长因子基因治疗的肝硬变大鼠表现出严重的肝功能衰竭，并伴有转化生长因子-β1和胶原蛋白…的升高。更多的n个级别。相反，在转HGF基因的DMN大鼠中，几乎没有纤维化病变(包括基质过度堆积、肌成纤维细胞增生和转化生长因子-β1水平升高)。这些发现清楚地证明了补充HGF基因对减少人类肝硬变的治疗潜力。(2)HGF对慢性肾功能衰竭进展的抑制作用慢性肾功能衰竭(CRF)的特点是实质肾单位进行性丧失，代表肾纤维化，尤其是在终末期。用ICGN小鼠作为CRF模型，我们发现内源性HGF在抑制CRF的发生和发展中起关键作用：ICGN小鼠表现为肾功能不全，并伴有肾脏HGF水平的降低和肾炎肾脏中转化生长因子-β1和胶原水平的倒数升高。为了阐明内源性HGF水平的降低，我们给肾病ICGN小鼠注射了抗HGF-Ig G。值得注意的是，HGF中和处理导致了转化生长因子-β1水平的过度表达以及内源性HGF表达的下调。此外，HGF中和不仅可抑制肾小管再生，还可抑制肾小管上皮细胞的凋亡。因此，在HGF中和的ICGN小鼠中，肾脏纤维化和功能障碍迅速发展。这些结果表明：1)内源性HGF在减轻CRF相关的病理状态中起关键作用；2)HGF产生的丧失与转化生长因子-β1水平的升高相互作用，是CRF的表现。(3)HGF改善扩张型心肌病模型中的心脏纤维化和功能障碍。在扩张型心肌病的仓鼠模型中，出生后26-32周时出现明显的心脏纤维化和肥大，同时心脏转化生长因子-β1和心钠素水平升高，导致重组HGF治疗仓鼠死亡，心脏转化生长因子-β1和心钠素水平显著抑制，导致心脏功能障碍和纤维化的改善。虽然目前还没有有效的治疗方法来改善终末期心肌病，但这是第一个证明终末期心肌病可逆性的研究。综上所述，HGF可有效改善心肌病的病理状态。较少

(1) Strategies for ameliorating liver cirrhosis using an HGF gene therapyIn Japan, at least two millions of people are now suffering from intractable liver diseases, and especially, twenty thousands patients become lethal a year, because of an end-stage liver cirrhosis. It is therefore important to establish a new therapy for overcoming this disorder. Using an animal model, we demonstrate that HGF cDNA transfection is useful for suppressing liver cirrhosis-related pathological conditions. In rats undergone chronic treatments with DMN (a hepatotoxic drug), liver cirrhosis progresses, accompanied with increases in hepatic collagen and TGF-beta1 levels, leading to be lethal within 6 weeks after onset of the DMN treatments. On the other hand, all of the cirrhotic rats remained "alive" after transfection of human HQF cDNA, even till 6 weeks of the DMN injections. The cirrhotic rats without the HGF gene treatment manifest severe liver failure, accompanied with increased TGF-beta1 and collage … More n levels. In contrast, there were few fibrotic lesions (including matrix over-accumulation, myofibroblast hyperplasia and elevated TGF-beta1 levels) in the HGF cDNA-transfected DMN rats. These findings clearly demonstrate a therapeutic potential of the HGF gene supplement for minimizing liver cirrhosis in humans.(2) Repressive effect of HGF on progression of chronic renal failureChronic renal failure (CRF) is characterized by a progressive loss in parenchymal nephrons and represents renal fibrosis, especially in an end-stage. Using ICGN mice as a spontaneously occurring CRF model, we found that endogenous HGF is critical for suppressing onset and progression of CRF: The ICGN mice manifest renal dysfunction, accompanied with a decrease in renal HGF level, in reciprocal to increases, in TGF-beta1 and collagen levels in the nephritic kidneys. In order to delineate the loss in endogenous HGF levels, we injected an anti-HGF IgG to the nephrotic ICGN mice. Of note, the HGF-neutralizing treatment led to over-expression of TGF-beta1 levels as well as to down-regulation of endogenous HGF expression. Furthermore, HGF-neutralization caused not only suppressed tubular regeneration but also tubular epithelial apoptosis. Consequently, there: was a rapid progression of renal fibrosis and dysfunction in the HGF-neutralized ICGN mice. These findings show that: 1) Endogenous HGF play a key role for lessening CRF-related pathological states; and 2) The loss of HGF production, in reciprocal to increased TGF-beta1 levels, is responsible for manifesting CRF. If so, exogenous HGF supplement should be considered as a new option for cure-oriented therapy of CRF.(3) HGF ameliorated heart fibrosis and dysfunction in a .model of dilative cardiomyopathyIn the hamster model of dilative cardiomyopathy, there was evident cardiac fibrosis and hypertrophy at ages between 26 and 32 weeks after birth, coinciding with increases in heart TGF-beta1 and ANP levels, leading to be lethal When the hamsters were treated with recombinant HGF, cardiac TGF-beta1 and ANP levels were significantly repressed, resulting in improvements in heart dysfunction: and fibrosis. Although there has been no treatment useful for improving end-stage cardiomyopathy, this is the first research demonstrating reversibility of end-stag-related cardiomyopathy. Taken together, HGF was shown to be available for ameliorating pathological states in the cardiomyopathy. Less