C-Reactive Protein ; genetics ; metabolism ; Haplotypes ; Humans ; Polymorphism, Single Nucleotide

Thrombophilia that is common among Caucasians is caused by genetic polymorphisms of coagulation factor V Leiden (R506Q) and prothrombin G20210A. Unlike that in Caucasians, thrombophilia that is common in the Japanese and Chinese involve dysfunction of the activated protein C (APC) anticoagulant system caused by abnormal protein S and protein C molecules. Approximately 50% of Japanese and Chinese individuals who develop venous thrombosis have reduced activities of protein S. The abnormal sites causing the protein S molecule abnormalities are distributed throughout the protein S gene, PROS1. One of the most common abnormalities is protein S Tokushima (K155E), which accounts for about 30% of the protein S molecule abnormalities in the Japanese. Whether APC dysfunction occurs in other Asian countries is an important aspect of mapping thrombophilia among Asians. International surveys using an accurate assay system are needed to determine this.
Asian Continental Ancestry Group ; Blood Coagulation ; Blood Proteins/genetics/metabolism ; Humans ; Protein C/genetics/*metabolism ; Protein S/chemistry/genetics/metabolism ; Thrombophilia/epidemiology/*etiology ; Venous Thrombosis/etiology/genetics

Phosphatidylinositol phosphates (PtdInsPs) are ubiquitous membrane phospholipids that play diverse roles in cell growth and differentiation. To clarify the regulation mechanism acting on neurofilament light chain (NF-L) self assembly, we examined the effects of various PtdInsPs on this process. We found that PtdInsPs, including PI(4,5)P2, directly bind to the positively charged Arg54 of murine NF-L, and this binding promotes NF-L self assembly in vitro. Mutant NF-L (R53A/R54A) proteins lacking binding affinity to PtdInsPs did not have the same effect, but the mutant NF-L proteins showed greater self assembly than the wild-type in the absence of any PtdInsP. These results collectively suggest that Arg54 plays a pivotal role in NF-L self assembly by binding with PtdInsPs.
Animals ; Fluorescent Antibody Technique ; Mice ; Mutation/genetics ; Neurofilament Proteins/genetics/*metabolism ; Phosphatidylinositol Phosphates/*metabolism ; Phospholipase C gamma/metabolism ; *Protein Multimerization

The protein C anticoagulant pathway plays a fundamental role in the control of coagulation system and inflammatory response. It has been well established that physiological levels of shear stress induce endothelial structural change and modulate gene and protein expression. However, the role of shear stress in protein C pathway remains unknown. In the present study, we evaluated the effect of shear stress on the activation of protein C as well as on the expression of endothelial protein C receptor (EPCR) and thrombomodulin (TM) in human umbilical vein endothelial cells (HUVECs) which were exposed to TNF-alpha alone, shear stress alone, and TNF-alpha under shear stress. We found: (1) Either TNF-alpha or shear stress alone significantly reduced EPCR expression and protein C activation in HUVECs; and simultaneous exposure of HUVECs to TNF-alpha and shear stress resulted in a further decrease of EPCR expression and protein C activation (P<0.05); (2) Simultaneous exposure of HUVECs to TNF-alpha and shear stress resulted in the increase of soluble EPCR level more significantly than did the exposure of HUVECs to either TNF-alpha or shear stress alone (P<0.05); (3) Shear stress significantly increased TM expression on HUVECs, whereas TNF-alpha inhibited TM expression; shear stress could strongly neutralize TNF-alpha's inhibitive effect on TM expression. We therefore conclude that shear stress may play an important role in protein C pathway, which may be fulfilled by regulating EPCR expression and TM expression in endothelial cells.
Antigens, CD ; genetics ; metabolism ; Biomechanical Phenomena ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Endothelial Protein C Receptor ; Humans ; Protein C ; metabolism ; Receptors, Cell Surface ; genetics ; metabolism ; Shear Strength ; Stress, Mechanical ; Thrombomodulin ; genetics ; metabolism ; Umbilical Veins ; cytology

Animals ; Humans ; Models, Biological ; Oxidative Stress ; genetics ; physiology ; Phosphorylation ; Protein Kinase C ; genetics ; metabolism ; physiology ; Signal Transduction ; genetics ; physiology

OBJECTIVETo study the phenotypes and genotypes of a protein C (PC) deficiency pedigree.

METHODSImmunoassay (ELISA) was used for PC antigen and activated PC (APC) detection, PCR for amplification of the fragment of protein C gene exon II to exon IX, single-strand conformation polymorphism (SSCP) for difference of denatured cDNA and DNA sequencing for gene mutation.

RESULTSFour members in the pedigree were found to be PC antigen levels between 34.3% - 67.8% and PC activity between 22% - 49% which are lower in comparison with normal references (80% - 120% and 70% - 130%, respectively). A G-to-A mutation in exon VII of the protein C gene at 6 219 position was identified in 9 members. This mutation resulted in the substitution of Arg for Gln at 169 amino acid.

CONCLUSIONThe proband is of heterozygosity. The G6219 A mutation in exon VII of the protein C gene leads to the substitution of Arg 169 Gln. This mutation is reported for the first time in China.

Adult ; DNA Mutational Analysis ; Female ; Humans ; Male ; Middle Aged ; Pedigree ; Point Mutation ; Polymerase Chain Reaction ; Protein C ; genetics ; metabolism ; Protein C Deficiency ; congenital ; genetics

Animals ; Bufo bufo ; Caspase 3 ; genetics ; metabolism ; Female ; Immunohistochemistry ; Male ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Spinal Cord ; metabolism ; Spinal Cord Injuries ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

The c-Abl nonreceptor tyrosine kinase is activated in the cellular responses to genotoxic, oxidative and other forms of stress. Using tagged forms of c-Abl, the present studies demonstrate that c-Abl forms homodimers in cells. The results show that the c-Abl N-terminal regions interact with the corresponding C-terminal regions of both partners in the dimmer. Specifically, the c-Abl SH3 domain binds to a proline-rich motif at amino acids 958-982 in the c-Abl C-terminal region. Deletion of the proline-rich motif disrupts dimmer formation. These findings provide the first evidence that c-Abl forms homodimers and indicate that homodimerization can contribute to the regulation of c-Abl activity.
Humans ; Protein Multimerization ; Proto-Oncogene Proteins c-abl ; genetics ; metabolism ; src Homology Domains

OBJECTIVETo investigate the relationship between endothelial protein C receptor(EPCR) gene 6936A/G polymorphism and deep vein thrombosis (DVT).

METHODSThe study group included 65 DVT patients and 71 normal controls. Plasma sEPCR was measured by ELISA. Genomic DNA was extracted by using Genomic Purification Kit. A 315bp EPCR product was amplified by a standard PCR reaction, and the bands were confirmed by direct sequencing after purification.

RESULTS(1) sEPCR levels in healthy controls with 6936AG genotype were significantly higher than that in those with 6936AA genotype \[(0.97 ± 0.32) ng/L vs (0.61 ± 0.24) ng/L, P < 0.01)\], and so did in DVT patients \[(0.87 ± 0.21) ng/L vs (0.50 ± 0.18) ng/L, P < 0.01\]. (2) The sEPCR levels of DVT patients \[(0.68 ± 0.32) ng/L\] were significantly higher than that of healthy controls \[(0.54 ± 0.22) ng/L\](P < 0.05). (3) The distribution of 6936A/G genotype was higher in DVT patients than in healthy controls (P < 0.05). (4) Subjects with 6936A/G had an increased risk of thrombosis (OR = 2.75, 95%CI = 1.04 - 7.30) (P < 0.05).

CONCLUSIONSEPCR gene 6936A/G polymorphism is associated with increased plasma sEPCR levels. The sEPCR levels in DVT patients were significantly higher than that in healthy controls. The subject with 6936AG likely had an increased risk of thrombosis.

Case-Control Studies ; Humans ; Polymorphism, Genetic ; Protein C ; metabolism ; Thrombosis ; Venous Thrombosis ; genetics

The family of voltage-gated potassium Kv2 channels consists of the Kv2.1 and Kv2.2 subtypes. Kv2.1 is constitutively highly phosphorylated in neurons and its function relies on its phosphorylation state. Whether the function of Kv2.2 is also dependent on its phosphorylation state remains unknown. Here, we investigated whether Kv2.2 channels can be phosphorylated by protein kinase C (PKC) and examined the effects of PKC-induced phosphorylation on their activity and function. Activation of PKC inhibited Kv2.2 currents and altered their steady-state activation in HEK293 cells. Point mutations and specific antibodies against phosphorylated S481 or S488 demonstrated the importance of these residues for the PKC-dependent modulation of Kv2.2. In layer II pyramidal neurons in cortical slices, activation of PKC similarly regulated native Kv2.2 channels and simultaneously reduced the frequency of action potentials. In conclusion, this study provides the first evidence to our knowledge that PKC-induced phosphorylation of the Kv2.2 channel controls the excitability of cortical pyramidal neurons.
Action Potentials ; HEK293 Cells ; Humans ; Protein Kinase C/metabolism* ; Pyramidal Cells/enzymology* ; Shab Potassium Channels/genetics*