Construction and expression of retroviral vector pLEGFP-N1-TERT in preparation of seed cells for skin tissue engineering

Objective:To construct the retroviral vector pLEGFP-N1-telomerase reverse transcriptase(TERT)and to investigate the expression of TERT in neonatal mouse bypodermal cells.Methods:The polymerase chain reaction(PCR)-amplified TERT gene was inserted into plasmid pLEGFPN1.The positive clone was identified by restriction enzyme digestion and sequencing,then was transfected into packaging cells to produce retrovirus particles.Neonatal mouse hypodermal cells were infected with the virus to generate a stable cell line.The TERT mRNA expression level,telomerase activity,and enhanced green fluorescent protein(EGFP)expression level were analyzed.Results:Retroviral vector pLEGFP-N1-TERT was constructed successfully,and a stable cell line of neonatal mouse hypodermal cells expressing EGFP was established.Western blot and immunohistochemical assay showed that the expression level of TERT was significantly elevated in the neonatal mouse hypodermal cells.Conclusions:A high titer of retrovirus pLEGFP-N1-TERT mediates high-level expression of the exogenous TERT gene in the neonatal mouse hypodermal cells.This protocol has potential applications for skin tissue engineering and cell transplantation therapy.

The distribution of hair in Han Chinese

Aim: To explore the characteristics of normal hair distribution in Han Chinese. Methods:A total of 146 healthy Han Chinese and 41 patients with androgenetic alopecia (AGA) were selected as research subjects. Digital photographs of the vertex, temporal, and occipital regions were taken after their hair was trimmed. An image analysis software was used to compute the number of follicular units (FUs) and hairs. Results: The mean FU density of the 146 healthy Han Chinese was 74.36 ± 13.33 units/cm2 and their mean hair density was 143.33 ± 28.08 hairs/cm2. There was no significant difference between males and females (P >0.05). The mean FU density in the occipital region of AGA patients was 77.78 ± 2.99 units/cm2 and their mean hair count was 148.12 ± 6.98 hairs/cm2. Both were lower than those of healthy Han Chinese, and the differences were statistically significant (P < 0.001). Two-hair FUs (52.62%) were the predominant type found in Han Chinese. Conclusion: The FU and hair densities of healthy Han Chinese are lower than those of whites and Africans. The study provides hair transplantation surgeons with information on hair distribution in Han Chinese. It also provides a quantitative basis for the area of donor site and transplantation density necessary for hair transplantation surgeries. The research findings provide some theoretical data for the hair distribution characteristics of Han Chinese. These data can contribute to the preoperative assessment, surgery planning, and postoperative outcome evaluation by hair transplantation surgeons.