Functional membrane microdomains (FMMs) that are mainly composed of scaffold proteins and polyisoprenoids play important roles in diverse cellular physiological processes in bacteria. The aim of this study was to identify the correlation between MK-7 and FMMs and then regulate the MK-7 biosynthesis through FMMs. Firstly, the relationship between FMMs and MK-7 on the cell membrane was determined by fluorescent labeling. Secondly, we demonstrated that MK-7 is a key polyisoprenoid component of FMMs by analyzing the changes in the content of MK-7 on cell membrane and the changes in the membrane order before and after destroying the integrity of FMMs. Subsequently, the subcellular localization of some key enzymes in MK-7 synthesis was explored by visual analysis, and the intracellular free pathway enzymes Fni, IspA, HepT and YuxO were localized to FMMs through FloA to achieve the compartmentalization of MK-7 synthesis pathway. Finally, a high MK-7 production strain BS3AT was successfully obtained. The production of MK-7 reached 300.3 mg/L in shake flask and 464.2 mg/L in 3 L fermenter.
Bacillus subtilis/metabolism* ; Vitamin K 2/metabolism* ; Bioreactors/microbiology* ; Membrane Microdomains/metabolism*

OBJECTIVE: To assess the effect of vitamin K2 in addition to risedronate on postmenopausal osteoporosis METHOD: We enrolled 21 postmenopausal osteoporosis women (age: 65.2+/-7.8 years). Ten subjects received risedronate (35 mg, weekly) and vitamin K2 (45 mg, daily) and eleven subjects only received risedronate. They all received calcium citrate 2,130 mg and vitamin D 600 IU daily. The duration of treatment was 7.7+/-1.4 months. Bone mineral density (BMD) of lumbar spine and both femurs, serum osteocalcin and urine deoxypyridinoline were examined at baseline and after treatment. RESULTS: After treatment, BMD, serum osteocalcin and urine deoxypyridinoline were improved in each group but there was no statistical difference between the groups. CONCLUSION: There was no evidence of the benefit of vitamin K2 in addition to risedronate in bone metabolism on postmenopausal osteoporosis.
Bone Density ; Calcium Citrate ; Female ; Femur ; Humans ; Metabolism ; Osteocalcin ; Osteoporosis, Postmenopausal* ; Risedronate Sodium ; Spine ; Vitamin D ; Vitamin K 2* ; Vitamins*

BACKGROUND: Posttransplant osteoporosis in renal transplant recipient is frequently observed complications, but therapeutic modalities are not clearly elucidated. Recent studies indicate that vitamin K2 also play a role in bone metabolism. Therefore, we performed prospective study to evaluate the effect of vitamin K2 (Menatetrenone(R)) on posttransplant osteroporosis. METHODS: Our study included total 83 patients (40 male, 43 female; age 36.9+/-5.5 years) who received a renal transplant more than 6 months ago. They underwent dual-energy X-ray absorptiometry (DEXA) at lumbar spine and femoral neck. The patients with osteoporosis were treated with vitamin K2 (glakay 15 mg) (group 1) or vitamin D3 with calcium carbonate (group 2). The patients without osteoporosis was observed without any treatment (group 3). After one year, follow-up BMD was performed in all patients. RESULTS: Of 83 patients, 44 patients (53.0%) had osteoporosis and 39 patients (47.0%) had not. In group 1 (N=28), vitamin K2 treatment significantly increased BMD at femoral neck (-3.2+/-0.4 vs 2.6+/-0.6, p<0.05), but there was no increase of BMD at lumbar spine (-2.2+/-1.0 vs 2.2+/-0.9, p>0.05). In group 2 (N=16), there was significant increase in BMD at femoral neck (-3.0+/-0.6 vs -2.5+/-0.8, p< 0.05), but there was no increase of BMD at lumbar spine (-1.8+/-0.7 vs -1.8+/-0.8, p>0.05). Between group 1 and 2, there was no significant difference in BMD change. In group 3, BMD decreased at femoral neck (-1.3+/-0.2 vs -1.5+/-0.2) and lumbar spine (-0.8+/-0.2 vs -1.0+/-0.2) during follow-up period. CONCLUSION: Vitamin K2 (Menatetrenone(R)) is effective in treating osteoporosis at femoral neck and its effectiveness is s imilar with that of using vitamin D3 with calcium carbonate.
Absorptiometry, Photon ; Calcium Carbonate ; Cholecalciferol ; Female ; Femur Neck ; Follow-Up Studies ; Humans ; Male ; Metabolism ; Osteoporosis* ; Prospective Studies ; Spine ; Transplantation* ; Vitamin K 2

Vitamin K2, as well as bisphosphonates, such as etidronate, alendronate, and risedronate, is widely used in the treatment with osteoporosis in Japan. Etidronate increases the lumbar bone mineral density (BMD), and prevents new vertebral fractures, in patients with osteoporosis, while alendronate and risedronate increase the lumbar and femoral neck BMDs, and prevent new vertebral and femoral neck fractures. Vitamin K2 enhances gamma-carboxylation of bone glutamic acid residues and the secretion of osteocalcin, sustains the lumbar BMD, and prevents osteoporotic fractures in patients with osteoporosis. Bisphosphonates, such as alendronate and risedronate, rather than vitamin K2, should be initially chosen for the treatment of osteoporosis, because they are more efficacious than vitamin K2. Available evidence suggest that risedronate prevents deterioration of the connectivity of the trabeculae in ovariectomized rats, whereas vitamin K2 increase the trabecular thickness, and that a combination of risedronate and vitamin K2 has a synergistic effect on preventing the deterioration of trabecular bone architecture induced by estrogen deficiency. Some studies have shown that combined treatment with etidronate and vitamin K2 appears to be more effective than etidronate alone in the prevention of new osteoporotic vertebral fractures. Based on these findings, combined treatment with vitamin K2 and bisphosphonates may be more efficacious in the prevention new vertebral fractures than a single treatment with bisphosphonate in postmenopausal women with osteoporosis. Thus, this combined treatment should be recommended for the treatment of postmenopausal osteoporosis. It is proposed that the role of vitamin K2 should be emphasized, when used in combination with bisphosphonates, especially in patients with vitamin K deficiency.
Aged ; Bone Density/drug effects ; Bone and Bones/drug effects/metabolism ; Diphosphonates/*administration & dosage ; Drug Therapy, Combination ; Female ; Human ; Middle Aged ; Osteoporosis, Postmenopausal/*drug therapy ; Vitamin K 2/*administration & dosage

The study was aimed to investigate the possible mechanism of vitamin K(2) (VK(2)) on myelodysplastic syndrome (MDS) cell line MUTZ-1 in vitro. The flow cytometry was used to analyze apoptosis rate and the change of cell cycle. The expression of apoptosis-related genes bcl-2, survivin and bax were detected by reverse transcription-polymerase chain reaction (RT-PCR). The activity of caspase-3 was detected by chemiluminescence assay. The results indicated that the apoptosis peak on FCM and positive Annexin-V FITC on cell membrane showed that VK(2) induced apoptosis of MUTZ-1 cells in a dose-and-time-dependent manner, S and G(2) cell decrement, G(0)/G(1) cell arrest, VK(2) significantly down-regulated the expression of bcl-2 and survivin, but had no effect on the expression of bax, the activity of caspase-3 was significantly increased. It is concluded that VK(2) induces apoptosis of MUTZ-1 cells through activating caspase-3 pathways and the apoptosis-related genes bcl-2 and survivin may play important roles in the process of apoptosis induction.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Humans ; Inhibitor of Apoptosis Proteins ; Microtubule-Associated Proteins ; biosynthesis ; genetics ; Myelodysplastic Syndromes ; drug therapy ; pathology ; Neoplasm Proteins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Vitamin K 2 ; pharmacology ; bcl-2-Associated X Protein ; biosynthesis ; genetics

Vitamin K2 is widely used for the treatment of osteoporosis in Japan. To understand the effects of vitamin K2 on bone mass and bone metabolism, we reviewed its effects on the development of osteopenia in rats, which characterizes models of osteoporosis. Vitamin K2 was found to attenuate the increase in bone resorption and/or maintain bone formation, reduce bone loss, protect against the loss of trabecular bone mass and its connectivity, and prevent the decrease in strength of the long bone in ovariectomized rats. However, combined treatment of bisphosphonates and vitamin K2 had an additive effect in preventing the deterioration of the trabecular bone architecture in ovariectomized rats, while the combined treatment of raloxifene and vitamin K2 improved the bone strength of the femoral neck. The use of vitamin K2 alone suppressed the increase in trabecular bone turnover and endocortical bone resorption, which attenuated the development of cancellous and cortical osteopenia in orchidectomized rats. In addition, vitamin K2 inhibited the decrease in bone formation in prednisolone-treated rats, thereby preventing cancellous and cortical osteopenia. In sciatic neurectomized rats, vitamin K2 suppressed endocortical bone resorption and stimulated bone formation, delaying the reduction of the trabecular thickness and retarding the development of cortical osteopenia. Vitamin K2 also prevented the acceleration of bone resorption and the reduction in bone formation in tail-suspended rats, which counteracted cancellous bone loss. Concomitant use of vitamin K2 with a bisphosphonate ameliorated the suppression of bone formation and more effectively prevented cancellous bone loss in tail-suspended rats. Vitamin K2 stimulated renal calcium reabsorption, retarded the increase in serum parathyroid hormone levels, and attenuated cortical bone loss primarily by suppressing bone resorption in calcium-deficient rats while maintaining the strength of the long bone in rats with magnesium deficiency. These findings suggest that vitamin K2 may not only stimulate bone formation, but may also suppress bone resorption. Thus, vitamin K2 could regulate bone metabolism in rats, which represented the various models of osteoporosis. However, the effects of vitamin K2 on bone mass and bone metabolism seem to be modest.
Vitamin K 2/chemistry/metabolism/*pharmacology ; Tomography, X-Ray Computed ; Tibia/pathology ; Rats ; Osteoporosis/*drug therapy/*prevention & control ; Male ; Magnesium Deficiency/diagnosis ; Magnesium/metabolism ; Homeostasis ; Female ; *Disease Models, Animal ; Diphosphonates ; Calcium/metabolism ; Bone and Bones/*drug effects/metabolism ; Bone Resorption ; Bone Diseases, Metabolic/*metabolism ; Animals

To study the effects and possible mechanism of Vitamin K(2) (VK(2)) in the treatment of MDS-JSN04 cells, the changes of morphologic features of MDS-JSN04 cells were investigated by cytomorphology, the apoptosis of MDS-JSN04 cells was observed by transmission electron microscope; cellular proliferation was determined by the MTT assay; cell apoptosis, cell cycle shift and expression of myeloid-specific differentiation antigen (CD11b, CD13) were analyzed by flow cytometry (FCM). The expression of apoptosis-related genes bcl-2, survivin and bax were detected by retrotranscriptase polymerase chain reaction (RT-PCR); the activity of caspase-3 was determined by chemiluminescence assay. The results showed that the typical apoptotic morphological features appeared in cells treated with VK(2) for 72 hours; VK(2) induced apoptosis of MDS-JSN04 cells and in a dose-and-time-dependent manner, G(0)/G(1) cell arrest and significantly down-regulated the expression of bcl-2 and survivin, but had no effect on the expression of bax; the activity of caspase-3 significantly increased. It is concluded that VK(2) induces apoptosis of MDS-JSN04 cells through activating caspase-3 pathways and the apoptosis-related genes bcl-2, survivin may play an important role in this process.
Apoptosis ; drug effects ; CD11b Antigen ; analysis ; CD13 Antigens ; analysis ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; Humans ; Inhibitor of Apoptosis Proteins ; Luminescent Measurements ; methods ; Microscopy, Electron, Transmission ; Microtubule-Associated Proteins ; genetics ; Myelodysplastic Syndromes ; genetics ; metabolism ; pathology ; Neoplasm Proteins ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Vitamin K 2 ; pharmacology ; bcl-2-Associated X Protein ; genetics