Direct reprogramming of human umbilical vein- and peripheral blood-derived endothelial cells into hepatic progenitor cells

Recent advances have enabled the direct induction of human tissue-specific stem and progenitor cells from differentiated somatic cells. However, it is not known whether human hepatic progenitor cells (hHepPCs) can be generated from other cell types by direct lineage reprogramming with defined transcription factors. Here, we show that a set of three transcription factors, FOXA3, HNF1A, and HNF6, can induce human umbilical vein endothelial cells to directly acquire the properties of hHepPCs. These induced hHepPCs (hiHepPCs) propagate in long-term monolayer culture and differentiate into functional hepatocytes and cholangiocytes by forming cell aggregates and cystic epithelial spheroids, respectively, under three-dimensional culture conditions. After transplantation, hiHepPC-derived hepatocytes and cholangiocytes reconstitute damaged liver tissues and support hepatic function. The defined transcription factors also induce hiHepPCs from endothelial cells circulating in adult human peripheral blood. These expandable and bipotential hiHepPCs may be useful in the study and treatment of human liver diseases.

The conditions to induce human hepatic progenitor cells from other cell types are unclear. Here, the authors reprogram human endothelial cells to hepatic progenitor cells by expressing FOXA3, HNF1A and HNF6, capable of giving rise to hepatocytes and cholangiocytes that reconstitute damaged liver tissues on transplantation.

Inflammatory cytokine-induced expression of vasohibin-1 by rheumatoid synovial fibroblasts

Angiogenesis is an essential event in the development of synovial inflammation in rheumatoid arthritis (RA). The aim of the current study was to investigate the expression of vasohibin-1, a novel endothelium-derived vascular endothelial growth factor (VEGF)-inducible angiogenesis inhibitor, in the RA synovium, and to test the effect of inflammatory cytokines on the expression of vasohibin-1 by RA synovial fibroblasts (RASFs). Synovial tissue samples were obtained at surgery from patients with osteoarthritis (OA) and RA, and subjected to immunohistochemistry to investigate the expression and distribution of vasohibin-1 relevant to the degree of synovial inflammation. In an in vitro analysis, RASFs were used to examine the expression of vasohibin-1 and VEGF mRNA by real-time PCR after stimulation with VEGF or inflammatory cytokines under normoxic or hypoxic conditions. The immunohistochemical results showed that vasohibin-1 was expressed in synovial lining cells, endothelial cells, and synovial fibroblasts. In synovial tissue, there was a significant correlation between the expression of vasohibin-1 and histological inflammation score (p=0.002, r=0.842). In vitro, stimulation with VEGF induced the expression of vasohibin-1 mRNA in RASFs under normoxic conditions, and stimulation with cytokines induced vasohibin-1 mRNA expression under a hypoxic condition. These results suggest that vasohibin-1 was expressed in RA synovial tissue and might be regulated by inflammatory cytokines.

Lower mortality in patients with the DD genotype of the angiotensin-converting enzyme gene after acute myocardial infarction

OBJECTIVE

The angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with different serum ACE concentrations and cardiac ACE activity. We assessed whether the ACE gene I/D polymorphism influenced cardiac mortality in Japanese patients with acute myocardial infarction.

METHODS AND RESULTS

The ACE gene I/D polymorphism was determined in 441 consecutive patients with a first myocardial infarction. There were 69 patients (16%) with the DD genotype, 194 patients (44%) with the ID genotype, and 178 patients (40%) with the II genotype. During a mean follow-up of 9.4 months, there were 49 cardiac deaths (DD, n = 4; ID, n = 26; II, n = 19). The DD genotype was significantly associated with a lower mortality than the other genotypes (p = 0.0363) by Cox regression analysis adjusted for age, sex, site of myocardial infarction, Killip functional class, reperfusion therapy during acute phase, ACE inhibitor use, and beta-blocker use.

CONCLUSIONS

In a selected cohort of Japanese patients, the DD genotype was associated with a significantly lower cardiac mortality after a first myocardial infarction.

[Pathological study of carbohydrate antigens in human lung cancer with monoclonal antibodies]

The expressions of carbohydrate antigens were examined with panel of specific anti-carbohydrate monoclonal antibodies (MAbs) on human lung cancer tissues. The MAbs used were SH1, SH2, SNH3, AH6, CA3F4, TKH2, TKH6 and TKH5 which define Lex, dimeric Lex, sialosyl Lex, Ley, Lea, sialosyl Tn, Tn and fucosyl GM1, respectively. Paraffin-embedded tissue sections (30 squamous cell carcinomas, 30 adenocarcinomas and 27 small cell carcinomas) were tested by immunohistological staining. Evaluation of stained specimens was performed by taking mean value of scores evaluated by three independent examiners. In squamous cell carcinoma, expression of Ley, sialosyl Tn, sialosyl Lex and Lea was significantly higher than other antigens. Lex was also expressed especially in keratinized tissues. In adenocarcinoma, Lea was expressed most remarkably. Sialosyl Lex, Ley, sialosyl Tn were also highly expressed in malignant cells. There was no significant difference in staining patterns between well and poorly differentiated adenocarcinomas. Sialosyl Tn and sialosyl Lex were positive in morphologically normal mucous glands adjacent to tumors. In small cell carcinomas, Ley was expressed more than other types of tumors, whereas Lex and sialosyl Tn were less than others. Tn antigen was observed throughout adenocarcinomas, squamous and small cell carcinomas in a relatively weak manner. Dimeric Lex and fucosyl GM1 antigens were not detected. Most of normal lung sections showed negative staining with those MAbs. These findings indicate that there are differential expressions of certain carbohydrate antigens in different types of human lung cancers based on their origins.