A method for stimulating the differentiation of human pluripotent stem cells (hPSCs) into kidney lineages remains to be developed. Most cells in kidney are derived from an embryonic germ layer known as intermediate mesoderm (IM). Here we show the establishment of an efficient system of homologous recombination in hPSCs by means of bacterial artificial chromosome (BAC)-based vectors and single nucleotide polymorphism (SNP) array-based detection. This system allowed us to generate human induced pluripotent stem cell (hiPSC) lines containing green fluorescence protein (GFP) knocked into OSR1, a specific marker for IM. We have also established a robust induction protocol for IM, which produces up to 90% OSR1+ cells. These human IM cells can differentiate into multiple cell types of IM-derived organs in vitro and in vivo, thereby supplying an unprecedented system to elucidate the mechanisms of IM development and potentially providing a cell source for regenerative therapies of the kidney.
Historically, the genus Nannochloris has been classified using the morphology of cell division, although the mechanics of division remain relatively poorly understood. Nannochloris bacillaris reproduces by binary fission. Microscopic observation with fluorescein isothiocyanate‐phalloidin showed that actin filaments localized near the nucleus and appeared as a ring‐ or beltlike structure in the septum‐forming area in the middle of the cell during cell division. In primitive unicellular Chlorophyta such as N. bacillaris, actin is also thought to play important roles in nuclear migration and cell division. The N. bacillaris actin gene has three exons and two introns defined by two exon–intron junctions with splice site consensus sequences. The two introns are located at codons specifying amino acids 3/4 and 47/48. One of these, intron position 3/4, is conserved in the actin gene of Saccharomyces cerevisiae. The actin gene product was predicted to be 378 amino acids long with an estimated molecular weight of 42 kDa. There is only one copy of the actin gene in the N. bacillaris genome. Nannochloris bacillaris has 14 chromosomes that range in size from 230 kb to 3000 kb, and the total size of the genome was estimated to be 20.3 Mb. The actin gene is on either chromosome XI or XII. In a phylogenetic tree based on the actin gene sequence, N. bacillaris diverged before the divergence of Volvox, Chlamydomonas, and higher plants, and very shortly after the radiation of the Rhodophyta.
Pseudomonas sp. A-01, isolated as a strain with chitosan-degrading activity, produced a 28 kDa chitosanase. Following purification of the chitosanase (Cto1) and determination of its N-terminal amino acid sequence, the corresponding gene (cto1) was cloned by a reverse-genetic technique. The gene encoded a protein, composed of 266 amino acids, including a putative signal sequence (1-28), that showed an amino acid sequence similar to known family-46 chitosanases. Cto1 was successfully overproduced and was secreted by a Brevibacillus choshinensis transformant carrying the cto1 gene on expression plasmid vector pNCMO2. The purified recombinant Cto1 protein was stable at pH 5-8 and showed the best chitosan-hydrolyzing activity at pH 5. Replacement of two acidic amino acid residues, Glu23 and Asp41, which correspond to previously identified active centers in Streptomyces sp. N174 chitosanase, with Gln and Asn respectively caused a defect in the hydrolyzing activity of the enzyme.
In this study, we induced differentiation of CPT II-deficient hiPSCs into mature myocytes in a highly efficient and reproducible manner and recapitulated some aspects of the disease phenotypes of CPT II deficiency in the myocyte disease models. This approach addresses the challenges of modeling the abnormality of FAO in CPT II deficiency using iPSC technology and has the potential to revolutionize translational research in this field.
Cardiovascular complications are the leading cause of death in autosomal dominant polycystic kidney disease (ADPKD), and intracranial aneurysm (ICA) causing subarachnoid hemorrhage is among the most serious complications. The diagnostic and therapeutic strategies for ICAs in ADPKD have not been fully established. We here generated induced pluripotent stem cells (iPSCs) from seven ADPKD patients, including four with ICAs. The vascular cells differentiated from ADPKD-iPSCs showed altered Ca2+ entry and gene expression profiles compared with those of iPSCs from non-ADPKD subjects. We found that the expression level of a metalloenzyme gene, matrix metalloproteinase (MMP) 1, was specifically elevated in iPSC-derived endothelia from ADPKD patients with ICAs. Furthermore, we confirmed the correlation between the serum MMP1 levels and the development of ICAs in 354 ADPKD patients, indicating that high serum MMP1 levels may be a novel risk factor. These results suggest that cellular disease models with ADPKD-specific iPSCs can be used to study the disease mechanisms and to identify novel disease-related molecules or risk factors.
Background There is a lack of evidence that multidrug use triggers adverse events. Therefore, the main purpose of this study was to clarify the relationship between the total number of drugs and number of high-risk prescriptions administered to Japanese elderly patients. Methods Using hospital electronic medical records (EMR), we evaluated the prescriptions of outpatients aged 65 years or older. We defined prescriptions of potentially inappropriate medications (PIMs) and overlapping prescription of drugs with the same mechanism of action (DSAs) as high-risk prescriptions. We analyzed the relationship among total number of drugs and high-risk prescriptions. In addition, we performed a secondary research to determine whether the hospitalization rate and concomitant medication contents differ depending on the high-risk prescriptions. Results Data for 13,630 outpatients were analyzed. A significant positive correlation between the numbers of total drugs and PIMs was found. The prescription frequency of individual PIMs rose as the total number of prescription drugs increased. The odds ratio (OR) of overlapping DSAs was significantly higher in patients using 5 or more drugs. In addition, there were significantly more prescriptions of laxatives among patients with overlapping prescriptions of anticholinergic drugs. The use of almost all PIMs was not an independent risk factor for hospitalization; instead, the number of PIMs was an independent risk factor for hospitalization [OR 1.18 (95% CI, 1.12–1.26)]. Conclusions The number of PIMs and overlapping DSAs were high in patients receiving multidrug treatment. To avoid adverse events and hospitalization, it might be useful to review prescriptions and consider the number of PIMs and overlapping DSAs.
Copy number alterations detected by comparative genomic hybridization (CGH) can lead to the identification of novel cancer‐related genes. We analyzed chromosomal aberrations in a set of 100 human primary colorectal cancers (CRCs) using CGH and found a solute carrier (SLC) 7A1 gene, which encodes cationic amino acid transporter 1 (CAT1) with 14 putative transmembrane domains, in a chromosome region (13q12.3) with a high frequency of gene amplifications. SLC7A1/CAT1 is a transporter responsible for the uptake of cationic amino acids (arginine, lysine, and ornithine) essential for cellular growth. Microarray and PCR analyses have revealed that mRNA transcribed from CAT1 is overexpressed in more than 70% of human CRC samples, and RNA interference–mediated knockdown of CAT1 inhibited the cell growth of CRCs. Rats were immunized with rat hepatoma cells expressing CAT1 tagged with green fluorescent protein (GFP), and rat splenocytes were fused with mouse myeloma cells. Five rat monoclonal antibodies (mAbs) (CA1 ~ CA5) reacting with HEK293 cells expressing CAT1‐GFP in a GFP expression–dependent manner were selected from established hybridoma clones. Novel anti‐CAT1 mAbs selectively reacted with human CRC tumor tissues compared with adjacent normal tissues according to immuno‐histochemical staining and bound strongly to numerous human cancer cell lines by flow cytometry. Anti‐CAT1 mAbs exhibited internalization activity, antibody‐dependent cellular cytotoxicity, and migration inhibition activity against CRC cell lines. Furthermore, CA2 inhibited the in vivo growth of human HT29 and SW‐C4 CRC tumors in nude mice. This study suggested CAT1 to be a promising target for mAb therapy against CRCs.
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