Protein expression pattern of calcium-responsive transactivator in early postnatal and adult testes

Abstract

Calcium-responsive transactivator (CREST), a nuclear protein highly expressed in postmitotic neurons, is involved in the regulation of cell cycle, differentiation and dendritic development of neuronal cells. Its mRNA has been detected in the testis of adult rat, whilst its protein expression and distribution pattern in the testis remain to be elucidated. In this study, we examined the distribution of CREST in the adult testes of both rats and human as well as the expression pattern of CREST in the testes of postnatal developing rats. In the adult testes of both human and rats, immunohistochemical analysis revealed that CREST was selectively distributed in the mature Sertoli cells but not in the spermatogenic cells. In the testes of postnatal developmental rats, CREST was expressed not only in Sertoli cells but also in the gonocytes and spermatogenic cells at the initial stage of spermatogenic cell differentiation. CREST immunoreactivity continued to increase in Sertoli cells during differentiation, reaching its peak in adulthood. However, CREST immunostaining intensity dramatically decreased as the spermatogenic cells differentiate, disappearing in the post-differentiation stage. Furthermore, Brg1 and p300, two CREST-interacting proteins ubiquitously expressed in the body, are found to be colocalized with CREST in the spermatogenic epithelial cells including Sertoli cells. The unique expression pattern of CREST in developing testis suggests that CREST might play regulatory roles in the differentiation of spermatogenic epithelial cells. The Sertoli cell-specific expression of CREST in the adulthood hints that CREST might be a novel biomarker for the mature Sertoli cells.

Transcription factor SS18L1 regulates the proliferation, migration and differentiation of Schwann cells in peripheral nerve injury

“…The SS18L1 protein consists of three functional domains, an N-terminal auto-regulatory domain that suppresses transactivation in the basal state, a central methionine-rich domain involved in protein-protein interaction, and a C-terminal glutamine-rich domain responsible for transactivation ( 13 ). Northern blot, in situ hybridization, immunohistochemistry and Western blotting analysis all showed that the expression of SS18L1 is enriched in the brain ( 14 ). SS18L1 is an essential component of the nBAF neuron-specific chromatin remodeling complex that is related to the chromatin remodeling complex called switch/sucrose non-fermentable (SWI/SNF) ( 15 ).…”

“…It plays an important role for the normal development of the nervous system, such as neuronal growth and differentiation ( 16 ). SS18L1 is involved in cell cycle regulation and differentiation of neurons through switching SWI/SNF by replacing its homologous protein SS18 in the complex ( 14 ). In addition, SS18L1 is shown to bind chromatin remodeling proteins BAF250 and BRG-1, and plays a crucial role in the differentiation and maturation of the spermatogenic epithelial cells ( 14 ).…”

“…SS18L1 is involved in cell cycle regulation and differentiation of neurons through switching SWI/SNF by replacing its homologous protein SS18 in the complex ( 14 ). In addition, SS18L1 is shown to bind chromatin remodeling proteins BAF250 and BRG-1, and plays a crucial role in the differentiation and maturation of the spermatogenic epithelial cells ( 14 ). Furthermore, SS18L1 can interact with histone acetyltransferases p300 and CREB-binding protein (CBP), thus regulating the determination and differentiation of testicular tissues as well as the metabolic remodeling in the later stages of spermatogenesis ( 14 , 17 ).…”

“…In addition, SS18L1 is shown to bind chromatin remodeling proteins BAF250 and BRG-1, and plays a crucial role in the differentiation and maturation of the spermatogenic epithelial cells ( 14 ). Furthermore, SS18L1 can interact with histone acetyltransferases p300 and CREB-binding protein (CBP), thus regulating the determination and differentiation of testicular tissues as well as the metabolic remodeling in the later stages of spermatogenesis ( 14 , 17 ). We have previously shown that the expression of SS18L1 is significantly down-regulated in rat distal sciatic nerve stumps at early time points after peripheral nerve injury ( 12 ), but its role in the peripheral nerve system remains unclear.…”

Protein expression of nucleolar protein 12 in the retina and its implication in protection of retina from UV irradiation damage

“…Immunohistochemistry staining was performed as previously described [ 44 ]. For immunohistochemical detection of NOL12 and ATR in the retina with the ABC method, the rat eyes were collected, fixed with 4% paraformaldehyde, embedded in paraffin, and serially sectioned at a thickness of 8 µm.…”