Abstract:

BACKGROUND: CD24 is known as its specific expression on the surface of nucleus pulposus (NP) cells. Whether detecting CD24 expression can be used as a method to identify NP cells remains poorly understood.
OBJECTIVE: To verify whether flow cytometry (FCM) detection of CD24 expression in NP cells is a fast and convenient method to identify NP cells.
METHODS: Human NP cells were isolated and cultured from seven patients who underwent various spinal surgeries via enzyme digestion. Type Ⅱ collagen immunohistochemistry staining was proceeded to the well grown passage 2 NP cells. RT-PCR experiments had been done to measure the mRNA expression of type Ⅱ collagen and SOX9 from the same cell source. Also the positive rates of CD24 were detected by FCM. The correlation among these results from the same sample was analyzed.
RESULTS AND CONCLUSION: Type Ⅱ collagen immunohistochemistry staining results of in vitro cultured passage 2 NP cells was positive. RT-PCR and FCM also acquired positive results. The positive rate of CD24 was above 50%. Extracellular matrix typeⅡcollagen and SOX9 expression of NP cells correlated to positive CD24 results. Detecting CD24 expression using FCM can identify NP cells fast and conveniently.