CharacterizationofCre recombinase mouselines enabling cell type-specific targeting of postnatal intervertebral discs
JOURNAL OF CELLULAR PHYSIOLOGY
Authors: Zheng, Yixin; Fu, Xuejie; Liu, Qingbai; Guan, Shengqi; Liu, Cunchang; Xiu, Chunmei; Gong, Tingting; Jin, Hongting; Saijilafu; Zhang, Zunyi; Chen, Di; Chen, Jianquan
Abstract
Cre/loxP technology is an important tool for studying cell type-specific gene functions. Cre recombinase mouse lines, including Agc1-CreER(T2), Col2a1-Cre; Col2a1-CreER(T2), Shh-Cre, Shh-CreER(T2), and Osx-Cre, have been proven to be valuable tools to elucidate the biology of long bones, yet the information for their activity in postnatal intervertebral disc (IVD) tissues was very limited. In this study, we used R26-mTmG fluorescent reporter to systematically analyze cell specificity and targeting efficiency of these six mouse lines in IVD tissues at postnatal growing and adult stages. We found that Agc1-CreER(T2) is effective to direct recombination in all components of IVDs, including annulus fibrosus (AF), nucleus pulposus (NP), and cartilaginous endplate (CEP), upon tamoxifen induction at either 2 weeks or 2 months of ages. Moreover, Col2a1-Cre targets most of the cells in IVDs, except for some cells in the outer AF (OAF) and NP. In contrast, the activity of Col2a1-CreER(T2) is mainly limited to the IAF of IVD tissues at either stage of tamoxifen injection. Similarly, Shh-Cre directs recombination specifically in all NP cells, whereas Shh-CreER(T2) is active only in a few NP cells when tamoxifen is administered at either stage. Finally, Osx-Cre targets cells in the CEP, but not in the NP or AF of IVDs tissues at these two stages. Thus, our data demonstrated that all these Cre lines can direct recombination in IVD tissues at postnatal stages with different cell type specificity and/or targeting efficiency, and can, therefore, serve as valuable tools to dissect cell type-specific gene functions in IVD development and homeostasis.
Are Specific Gene Expressions of Extracellular Matrix and Nucleus Pulposus Affected by Primary Cell Cultures Prepared from Intact or Degenerative Intervertebral Disc Tissues?
TURKISH NEUROSURGERY
Authors: Karaarslan, Numan; Yilmaz, Ibrahim; Ozbek, Hanefi; Yasar Sirin, Duygu; Kaplan, Necati; Akyuva, Yener; Gonultas, Aylin; Ates, Ozkan
Abstract
AIM: To determine the gene expression patterns of nucleus pulposus (NP) in cell cultures obtained from degenerated or intact tissues. MATERIAL and METHODS: Whereas 12 of the cases were diagnosed with lumbar disc herniation and had undergone lumbar microdiscectomy, 12 cases had undergone traumatic intervertebral discectomy and corpectomy, along with discectomy after spinal trauma. NP-specific markers and gene expressions of the reagents of the extracellular matrix in the experimental setup were tested at the 0th, 24th, and 48th hours by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Visual evaluations were simultaneously made in all samples using invert and fluorescence microscopy. Vitality and proliferation analyses were evaluated by UV spectrophotometer. As a method of statistical evaluation, Spearman was used for categorical variants, and the Pearson correlation was used for variants with numerical and plain distribution. RESULTS: No association was found either between the tissue type and times (r=0.000; p=1.000) or between the region that the tissue was obtained from and hypoxia transcription factor-1 alpha (HIF-1 alpha) gene expression (r=0.098; p=0.245). There was no correlation between cell proliferation and chondroadherin (CHAD) expression or between type II collagen (COL2A1) and CHAD gene expressions. It was found that CHAD and HIF-1 alpha gene expressions and HIF-1 alpha and COL2A1 gene expressions affected cell proliferation. CONCLUSION: Cell culture setups are of paramount importance because they may influence the pattern of changes in the gene expressions of the cells used in these setups.