Bioscience

Generation of Tooth-like Structures from hU-iPSCs

Recently, Dr. Pei Duanqing's group in Guangzhou Institutes of Biomedicine and Health (GIBH), CAS has confirmed that hU-iPSCs could be an appealing stem cell source for tooth regeneration by a chimeric culture system between human and mouse. It is known that tooth develops from the reciprocal interactions between the dental epithelium and the dental mesenchymal cells. However, the epithelial cells of dental origin are unavailable in adult tooth. Dr. Pei's group succeeded in differentiating the hU-iPSCs into the epithelial sheets, which could replace the dental epithelium and receive the odontogenic signals from the mouse dental mesenchyme for tooth formation. The regenerative tooth-like structures were recovered from the chimeric recombinants in 3 weeks with success rate up to 30% for 8 different iPSC lines. The hU-iPSC derived epithelial sheets differentiated into enamel-secreting ameloblasts in the tooth-like structures, possessing the same chemical composition and similar physical properties such as elastic modulus and hardness found in the regular human tooth. This finding was published on line in Cell Regeneration on June 30, 2013.

New Candidate Drug for Treatment of High Blood Pressure

High blood pressure is a chronic disease commonly occurred, which is also major endangered factor for the cardia-cerebrovascular disease, while the complications caused include principally stroke, myocardial infarction, heart failure and chronic kidney disease. Prof. Lai Renchu and his colleagues of the Research Group for Natural Medicinal Functional Proteomics, Kunming Institute of Zoology in collaboration with Prof. Ding Jiuping of the Huazhong University of Science and Technology found a kind of peptide in human body, which acts selectively on subunit β with good therapeutic effect on high blood pressure. They further verified the therapeutic effects on monkeys, which were used as high blood pressure models, and the result shows that the peptide decreases apparently both the diastolic pressure and the systolic pressure. In the meantime, the blood flow rate is too much decreased. Thus, the peptide might be developed as a new drug for the clinic treatment of the high blood pressure. The relevant result was published by magazine Hypertension.

DCAMKL1 Regulates Osteoblast Function via Repression of Runx2

On Aug. 5 2013, the Journal of Experimental Medicine published a research result entitled ‘Microtubule-Associated Protein DCAMKL1 regulates osteoblast function via repression of Runx2’ from Dr. Zou Weiguo’s group in the Shanghai Institute of Biochemistry and Cell Biology, CAS. The study found that DCAMKL1 protein can inhibit the activity of transcription factor RUNX2 and thus regulate osteoblast function. The osteoblastogenesis from mesenchymal stem cells was intensively enhanced when the researchers knockdown DCAMKL1 protein. Dcamkl1 knockout mice has a phenotype of enhanced osteoblast function, increased bone formation rate and increased bone mineral density. Further molecular mechanism study revealed that DCAMKL1 can improve the tubulin polymerization, thereby inhibiting the activity of major transcription factor RUNX2 during osteoblast differentiation. Various mutations of RUNX2 lead to human autosomal dominant disease -- cleidocranial dysplasia (CCD), which is characterized with clavicle dysplasia and delayed closure of cranial suture. Consistent with this, Runx2 heterozygous mice appeared with the same clavicle, skull dysplasia phenotype, which were CCD patients related and could be partly reversed through knocking out Dcamkl1 gene, further confirming the genetic relationship between Dcamkl1 and Runx2. By successfully applying forward genetics screening, which is used in this study, Dr. Zou’s group has identified a new regulatory factor in osteoblast function and suggested that we may enhance bone strength through the regulation of microtubule polymerization, indicating a new target for osteoporosis treatment. This work is accomplished by the sincere collaboration of researchers from Shanghai Institute of Biochemistry and cell Biology, CAS, Harvard Medical School, Harvard Dental School, Weill Cornell Medical Center, Merck Corporation.