The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferou...The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions （TJs）, adhesion junctions and gap junctions （GJs）. Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles. The deletion or functional silencing of genes encoding these proteins may disrupt the BTB, which may cause immunological or other damages to meiotic and postmeiotic cells and ultimately lead to spermatogenic arrest and infertility. In this review, we will summarize the findings on the BTB structure and function from genetically-modified mouse models and discuss the future perspectives.展开更多
In the first article of this series, we presented some evidence of hyperforin as an antibiotic, antiprotozoal, antiviral, anticancer, and immunomodulatory substance. In the present article, evidence of the permeabilit...In the first article of this series, we presented some evidence of hyperforin as an antibiotic, antiprotozoal, antiviral, anticancer, and immunomodulatory substance. In the present article, evidence of the permeability of the blood-testis barrier (BTB) and blood-brain barrier (BBB) to hyperforin and its distribution in other organs of the domestic pig (Sus scrofa domesticus) are revealed. Seven-month-old male boars with a body mass of 100 kg were fed a diet containing hyperforin. Organs were surgically removed under anesthesia. Organs were suitable prepared and extracted, and then analyzed using gas chromatography-mass spectrometry with supersonic molecular beams (GC-MS with SMB). The presence of hyperforin was recorded in all organs and body fluids. Special attention was paid to the evaluation of the presence of hyperforin in the brain and testes of experimental animals. The presence of hyperforin in the brain and testes of experimental animals was established by GC-MS with SMB. The results are of interest because penicillin and numerous other antibiotics cannot pass through the BTB or BBB if healthy or non-inflamed, which limits their use in patients with meningitis and gonorrhea. The findings are also of interest in cases of penicillin- and multi-antibiotic-resistant bacterial infections.展开更多
During spermatogenesis, developi ng germ cells that lack the cellular ultrastructures of filopodia and lamellipodia gen erally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to su...During spermatogenesis, developi ng germ cells that lack the cellular ultrastructures of filopodia and lamellipodia gen erally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These in elude the transport of preleptote ne spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell-cell and Sertoli-germ cell in terface also un dergo rapid remodeli ng, invo Iving disassembly and reassembly of cell j un ctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the invoIving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protei n S6 (rpS6, the down stream signali ng protein of mammalian target of rapamycin complex 1 [mTORCl]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mT0RCl/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubulebased cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.展开更多
Studies in international business negotiation acquire unprecedented significance,as globalization closely connects various business fields into a dynamic whole.Cultural factors play a vital role in international busin...Studies in international business negotiation acquire unprecedented significance,as globalization closely connects various business fields into a dynamic whole.Cultural factors play a vital role in international business negotiation.This paper begins with a brief introduction to business negotiation,international business negotiation and significance of cultural barriers to international business negotiation.It then explores two fundamental cultural differences of China and western countries:value differences and thinking-pattern differences,which pose cultural barriers.The author then puts forward three strategies to help remove the cultural barriers and achieve successful negotiations.展开更多
基金This work was supported by the National Basic Research Program （Nos. 2013CB947900, 2013CB945502 and 2014CB943101） of China （973）, by grants from National Natural Science Foundation of China （No. 31371519） and the Knowledge Innovation Program of the Chinese Academy of Sciences （No. KSCX2-EW-R-07）.
文摘The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions （TJs）, adhesion junctions and gap junctions （GJs）. Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles. The deletion or functional silencing of genes encoding these proteins may disrupt the BTB, which may cause immunological or other damages to meiotic and postmeiotic cells and ultimately lead to spermatogenic arrest and infertility. In this review, we will summarize the findings on the BTB structure and function from genetically-modified mouse models and discuss the future perspectives.
文摘In the first article of this series, we presented some evidence of hyperforin as an antibiotic, antiprotozoal, antiviral, anticancer, and immunomodulatory substance. In the present article, evidence of the permeability of the blood-testis barrier (BTB) and blood-brain barrier (BBB) to hyperforin and its distribution in other organs of the domestic pig (Sus scrofa domesticus) are revealed. Seven-month-old male boars with a body mass of 100 kg were fed a diet containing hyperforin. Organs were surgically removed under anesthesia. Organs were suitable prepared and extracted, and then analyzed using gas chromatography-mass spectrometry with supersonic molecular beams (GC-MS with SMB). The presence of hyperforin was recorded in all organs and body fluids. Special attention was paid to the evaluation of the presence of hyperforin in the brain and testes of experimental animals. The presence of hyperforin in the brain and testes of experimental animals was established by GC-MS with SMB. The results are of interest because penicillin and numerous other antibiotics cannot pass through the BTB or BBB if healthy or non-inflamed, which limits their use in patients with meningitis and gonorrhea. The findings are also of interest in cases of penicillin- and multi-antibiotic-resistant bacterial infections.
基金grants from the National Institutes of Health (R01 HD056034 to CYC)the Natural Science Foundation of China (NSFC)(No. 81601264 to LXLand No. 81730042 to RSG).
文摘During spermatogenesis, developi ng germ cells that lack the cellular ultrastructures of filopodia and lamellipodia gen erally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These in elude the transport of preleptote ne spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell-cell and Sertoli-germ cell in terface also un dergo rapid remodeli ng, invo Iving disassembly and reassembly of cell j un ctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the invoIving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protei n S6 (rpS6, the down stream signali ng protein of mammalian target of rapamycin complex 1 [mTORCl]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mT0RCl/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubulebased cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.
文摘Studies in international business negotiation acquire unprecedented significance,as globalization closely connects various business fields into a dynamic whole.Cultural factors play a vital role in international business negotiation.This paper begins with a brief introduction to business negotiation,international business negotiation and significance of cultural barriers to international business negotiation.It then explores two fundamental cultural differences of China and western countries:value differences and thinking-pattern differences,which pose cultural barriers.The author then puts forward three strategies to help remove the cultural barriers and achieve successful negotiations.
