Mesenchymal Stem Cell Therapy a1 antitrypsin deficiency

描述(由申请人提供)： α-L抗胰蛋白酶(α-1AT)是一种血浆蛋白，在肝脏中产生，抑制弹性蛋白酶，α-1AT缺乏症是一种常染色体隐性遗传病，在美国约有105人受到影响。α1AT缺乏症的肝损伤是由于突变的α1AT滞留在肝细胞内质网(ER)所致的肝毒性作用，肺气肿是由于肺实质中的弹性组织不受抑制的蛋白分解损伤而引起的。原位肝移植是治疗Alpha1AT介导的肝病的唯一有效方法。如果有可靠的肝细胞来源，可以想象它们可以用来替代宿主肝脏的20%-25%，将血浆α1AT水平提高到10微米以上，并防止由于α1AT缺乏而引起的肺毒性。我们已经鉴定出可以从人、小鼠和大鼠骨髓(BM)培养的多潜能成体祖细胞(MAPC)。单个MAPC在体外可分化为中胚层细胞、神经外胚层样细胞和功能性肝细胞样细胞。当输注IV、IM或SQ时，MAPC不会形成肿瘤，但会根据局部提示分化为造血细胞和肺、肠、肝的上皮细胞。要使MAPC来源的肝细胞适合治疗阿尔法1AT或其他肝脏疾病，还需要更好地描述体外分化过程。此外，我们还需要证明MAPC来源的细胞在体内的功能类似于肝细胞。我们提出了三个目标来确定MAPC来源的肝细胞是否可能是治疗Alpha1AT缺陷介导的肺和/或肝脏疾病的细胞来源。对SA1的研究将进一步证明从骨髓来源的MAPC可以产生肝细胞样细胞，并开发出为培养过程中产生的肝细胞选择祖细胞/前体的方法。这些祖细胞的选择将有两个目的：鉴定从多能成体干细胞向肝细胞的分化，以及产生潜在的细胞来源，用于肝脏疾病的有效移植。SA2中描述的评估球形培养中成熟肝细胞的所有功能的研究应该有助于确认BM MAPC产生的肝细胞与来自初级肝脏的肝细胞相似。对SA3的研究将确定MAPC本身、MAPC来源的肝细胞前体细胞或成熟肝细胞是否能够在体内、在肝细胞死亡的情况下以及在肝功能异常但没有肝细胞死亡的情况下恢复肝功能。这将为未来的研究奠定基础，测试MAPC或MAPC来源的肝细胞前体细胞/肝细胞是否可以作为治疗Alpha1AT的合适细胞来源，Alpha1AT是一种与肺损伤和/或肝功能衰竭相关的单基因缺陷。

DESCRIPTION (provided by applicant): Alpha-l-antitrypsin (alpha1AT) is a plasma protein, produced in the liver that inhibits elastase, alpha1AT-deficiency is an autosomal recessive disorder that affects approximately 105 individuals in the US. Liver injury in alpha1AT-deficiency is caused by the hepatotoxic effects of mutant alpha1AT retained within the endoplasmic reticulum (ER) of hepatocytes, and emphysema by uninhibited proteolytic damage to elastic tissue in the lung parenchyma. Orthoptic liver transplantation is the only curative therapy for alpha1AT-mediated liver disease. If a reliable source of hepatocytes were available, they could conceivably be used to replace 20-25% of the host liver, elevating plasma levels of alpha1AT to greater than 10 muM, and preventing pulmonary toxicity due to alpha1AT-deficiency. We have identified multipotent adult progenitor cells, or MAPC, that can be cultured from human, mouse and rat bone marrow (BM). Single MAPC differentiate into mesodermal, neuroectoderm-like cells and functioning hepatocyte-like cells in vitro. MAPC do not form tumors when infused IV, IM or SQ, but differentiate in response to local cues into hematopoietic cells and epithelium of lung, intestine and liver. For MAPC derived hepatocytes to be suitable for therapy of alpha1AT, or other liver disorders, better characterization of the in vitro differentiation process will be needed. In addition, we will need to demonstrate that MAPC-derived cells function like hepatocytes in vivo. We propose three aims to determine whether MAPC-derived hepatocytes may be a source of cells to treat alpha1AT-deficiency mediated pulmonary and/or liver disease. Studies in SA1 will further demonstrate that hepatocyte like cells can be generated from bone marrow derived MAPC, and develop methods to select progenitors/precursors for hepatocytes generated during culture. Selection of such progenitors will serve two purposes: characterization of differentiation from pluripotent adult stem cells to hepatocytes, and generation of a potential source of cells for effective transplantation in liver disease. Studies described in SA2 that will assess all functions of mature hepatocytes in spheroid cultures should help confirm that hepatocytes generated from BM MAPC are similar to hepatocytes derived from primary liver. Studies in SA3 will establish whether MAPC themselves, MAPC-derived hepatocyte progenitors or mature hepatocytes can restore liver function in vivo, in the setting of hepatocyte cell death and in the setting of abnormal liver function but without liver cell death. This should lay the groundwork for future studies testing whether MAPC or MAPC-derived hepatocyte progenitors/hepatocytes can serve as a suitable source of cells for therapy of alpha1AT, a single gene defect associated with lung damage and/or liver failure.