2.Functional analysis of functional membrane microdomains in the biosynthesis of menaquinone-7.
Yajun DONG ; Shixiu CUI ; Yanfeng LIU ; Jianghua LI ; Guocheng DU ; Xueqin LÜ ; Long LIU
Chinese Journal of Biotechnology 2023;39(6):2215-2230
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*
4.Serum vitamin K2 level and its association with bone metabolism markers in 1 732 children.
Chinese Journal of Contemporary Pediatrics 2022;24(10):1130-1135
OBJECTIVES:
To study the level of serum vitamin K2 (VitK2) and its association with bone metabolism markers osteocalcin (OC), type I procollagen amino-terminal peptide (PINP), and type I collagen carboxy-terminal peptide (CTX) in children.
METHODS:
A prospective analysis was performed on 1 732 children who underwent routine physical examination from October 2020 to October 2021. The serum levels of VitK2 and 25-hydroxy vitamin D [25(OH)D] were measured. According to age, they were divided into four groups: <1 year, 1-3 years group, >3-6 years group, and >6-14 years. A total of 309 children with 25(OH)D≥50 nmol/L were screened out, and serum levels of OC, PINP, and CTX were measured to investigate the correlation of the serum levels of OC, PINP, and CTX with serum VitK2 levels in different age groups.
RESULTS:
The prevalence rate of serum VitK2 deficiency was 52.31% (906/1 732). The VitK2 deficiency group had higher prevalence rates of overweight/obesity and growth pain (≥3 years of age) than the normal VitK2 group (P<0.05). There were differences in the prevalence rate of serum VitK2 deficiency (P<0.0083) and the serum level of VitK2 (P<0.05) between the 1-3 years group and the >6-14 years group. The <1 year group had a higher serum level of CTX and a lower serum level of PINP than the >3-6 years group and the >6-14 years group (P<0.05). The <1 year group had a lower serum level of OC than the >6-14 years group (P<0.05). Serum VitK2 level was positively correlated with OC level (rs=0.347, P<0.01), and CTX level was negatively correlated with PINP level (rs=-0.317, P<0.01).
CONCLUSIONS
Serum VitK2 deficiency may be associated with overweight/obesity. Serum VitK2 may affect the level of OC and even bone health.
Child
;
Humans
;
Infant
;
Biomarkers/metabolism*
;
Collagen Type I/metabolism*
;
Obesity/complications*
;
Osteocalcin/metabolism*
;
Overweight/complications*
;
Peptide Fragments/metabolism*
;
Peptides/metabolism*
;
Procollagen/metabolism*
;
Vitamin K/blood*
;
Child, Preschool
;
Adolescent
;
Bone and Bones/metabolism*
5.Cell Cycle Arrest and Apoptosis Induced by Atovaquone in Non-Hodgkin's Lymphoma Raji Cells.
Chun-Yang CHEN ; Xing SHEN ; Shuang XING ; Xue-Wen ZHANG ; Gang JIANG ; Zu-Yin YU
Journal of Experimental Hematology 2022;30(6):1746-1751
OBJECTIVE:
To investigate the effect of atovaquone on the cell cycle and apoptosis of non-Hodgkin's lymphoma Raji cells, and clarify the related mechanisms.
METHODS:
MTT assay and trypan blue dye exclusion method were used to evaluate the effect of atovaquone on the proliferation of Raji cells. After the cells were stained by PI staining, the cell cycle distribution was detected by flow cytometry. Cell apoptosis was analyzed by Annexin V/PI double binding assay. The intracellular alterations of reactive oxygen species were detected by 2', 7'-dichlorofluorescein diacetate (DCFH-DA). The protein expression of cell cycle and apoptosis related molecules were detected by Western blot.
RESULTS:
Various concentrations of atovaquone (5-40 μmol/L) inhibited the growth of Raji cells in a concentration-dependent manner (r=0.951). The proliferation of Raji cells was significantly inhibited after treated by atovaquone (20 and 30 μmol/L) for 24, 48 and 72 h, which showed statistically different with that in the control group (P<0.01, P<0.001, P<0.001). G1 phase arrest (P<0.01, P<0.001) and apoptosis (P<0.01) of Raji cells was induced by atovaquone (20 and 30 μmol/L) significantly for 24 h and 48 h, respectively. The expression of p-JAK2 and p-STAT3(Y705) protein were down-regulated significantly induced by atovaquone (P<0.001, P<0.05). Furthermore, atovaquone treatment could induce the decreasing of antiapoptotic protein Mcl-1, Bcl-2, and Bcl-xl expression level (P<0.05) and increasing of cleaved caspase-3 protein expression level. In addition, atovaquone could also induce the down-regulation of c-Myc (P<0.001, P<0.01) and cell cycle related molecules Cyclin D1, CDK4, and CDK6 (P<0.01, P<0.05) protein expression.
CONCLUSION
Atovaquone effectively inhibits cell proliferation and induces cell cycle arrest and apoptosis by suppression of STAT3 signaling pathway in Raji cells. It can be a potential therapeutic agent against non-Hodgkin's lymphoma.
Humans
;
Atovaquone/pharmacology*
;
Cell Cycle Checkpoints
;
Apoptosis
;
Lymphoma, Non-Hodgkin
6.Jug-PLGA-NPs, a New Form of Juglone with Enhanced Efficiency and Reduced Toxicity on Melanoma.
Wu-Heng YUE ; Lan-Qun QIN ; Juan CAI ; Rui MEI ; Han-Qing QIAN ; Zheng-Yun ZOU
Chinese journal of integrative medicine 2022;28(10):909-917
OBJECTIVE:
To verrify the anti-tumor efficacy and toxicity between juglone (Jug) and Jug-loaded PLGA nanoparticles (Jug-PLGA-NPs).
METHODS:
Jug-PLGA-NPs were prepared by ultrasonic emulsification. The anti-tumor activity of Jug (2, 3, 4 µg/mL) and Jug-PLGA-NPs (Jug: 2, 3, 4 µg/mL) in vitro was measured by MTT assay and cell apoptosis analysis. The distribution, anti-tumor effect and biological safety in vivo was evaluated on A375 nude mice.
RESULTS:
With the advantage of good penetration and targeting properties, Jug-PLGA-NPs significantly inhibited proliferation and migration of melanoma cells both in vitro and in vivo (P<0.05 or P<0.01) with acceptable biocompatibility.
CONCLUSIONS
Jug can inhibit the growth of melanoma but is highly toxic. With the advantage of sustained release, tumor targeting, anti-tumor activity and acceptable biological safety, Jug-PLGA-NPs provide a new pharmaceutical form for future application of Jug.
Animals
;
Cell Line, Tumor
;
Delayed-Action Preparations/therapeutic use*
;
Drug Carriers/therapeutic use*
;
Melanoma/pathology*
;
Mice
;
Mice, Nude
;
Nanoparticles
;
Naphthoquinones
;
Particle Size
;
Polylactic Acid-Polyglycolic Acid Copolymer/therapeutic use*
7.A case of bromadiolone poisoning leading to digestive tract, abdominal hemorrhage and secondary paralytic ileus.
Hong Fan CHEN ; Zhi Jian ZHANG ; Cheng Jin YOU ; Li CHEN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2022;40(9):707-709
Bromadiolone, commonly known as super warfarin, is a long-acting coumarin dicoumarin rodenticide. The mechanism of bromadiolone is mainly to inhibit vitamin K1 epoxide reductase and affect the synthesis of coagulation factors Ⅱ, Ⅶ, Ⅸ and Ⅹ, which causes blood coagulation dysfunction and systemic multiple organ hemorrhage. Here, we report of a case of bromadiolone poisoning patient who had digestive tract, abdominal hemorrhage, as well as secondary paralytic ileus. After blood product transfusion and vitamin K1 supplementation, the patient was discharged after the physical condition was improved. It's suggestied that clinicians should pay attention to rare complications to prevent missed diagnosis when treating other bromadiolone poisoning.
4-Hydroxycoumarins
;
Blood Coagulation Factors
;
Dicumarol
;
Hemorrhage
;
Humans
;
Intestinal Pseudo-Obstruction/chemically induced*
;
Oxidoreductases
;
Rodenticides
;
Vitamin K 1
;
Warfarin
8.Juglone induces proliferation inhibition and apoptosis of cervical cancer cells via promoting c-Myc ubiquitination.
Xing Yu ZHAO ; Kun YANG ; Zi Tong SONG ; Han HE ; Wei ZHANG
Journal of Southern Medical University 2022;42(7):1026-1031
OBJECTIVE:
To observe the expression of c-Myc protein in cervical cancer HeLa cells and explore the effect of juglone on the proliferation and apoptosis of HeLa cells by affecting c-Myc ubiquitination.
METHODS:
HeLa cells treated with different concentrations (0, 10, 20, or 50 μmol/L) of juglone or with 20 μmol/L juglone for different time lengths were examined for expression of c-Myc protein with Western blotting. The half-life of c-Myc protein was determined using cycloheximide (CHX) and c-Myc protein degradation was detected using coimmunoprecipitation. We also assessed the effects of 20 μmol/L juglone combined with 0, 1.0 or 2.0 μmol/L MG132 (a proteasome inhibitor) on c-Myc expression. The effects of 20 μmol/L juglone on the proliferation and apoptosis of HeLa cells with RNA interference-mediated knockdown of c-Myc were evaluated with MTT assay and flow cytometry.
RESULTS:
Treatment with juglone significantly lowered c-Myc protein expression in HeLa cells in a concentration-and time-dependent manner (P < 0.05). Juglone obviously shortened the half-life of c-Myc protein, and the addition of MG132 significantly up-regulated the expression level of c-Myc protein (P < 0.05). Juglone treatment also promoted ubiquitination of c-Myc protein in HeLa cells. Compared with the cells transfected with a negative control construct, the cells transfected with si-c-Myc showed significantly decreased proliferation inhibition and a lowered cell rate with early apoptosis after juglone treatment (P < 0.05).
CONCLUSION
Juglone inhibits proliferation and promotes apoptosis of HeLa cells by affecting the ubiquitination of c-Myc protein.
Apoptosis
;
Cell Proliferation
;
Female
;
HeLa Cells
;
Humans
;
Naphthoquinones
;
Ubiquitination
;
Uterine Cervical Neoplasms/genetics*
9.Advances in metabolic engineering for vitamins production.
Yanyan WANG ; Linxia LIU ; Zhaoxia JIN ; Dawei ZHANG
Chinese Journal of Biotechnology 2021;37(5):1748-1770
Vitamins are organic substances that are essential for the maintenance of life activities. Generally, vitamins need to be obtained from the diet or from some synthetic source as the body cannot synthesize vitamins, or the amounts of the synthesized vitamins are insufficient. At present, vitamins are widely used in medicine, food additives, feed additives, cosmetics and other fields, and the global demand for vitamins is constantly growing. Vitamins can be produced from chemical or microbial synthesis. Chemical synthesis usually requires harsh reaction conditions, produces serious wastes, and creates great potential safety hazard. In contrast, microbial synthesis of vitamins is greener, safer, and requires much less energy input. This review summarizes the advances in metabolic engineering for vitamins production in the past 30 years, with a focus on production of water-soluble vitamins (vitamins B1, B2, B3, B5, B6, B7, B9, B12 and vitamin C precursors) and lipid-soluble vitamins (vitamin A, precursors of vitamin D, vitamin E and vitamin K). Moreover, the bottlenecks for fermentative production of vitamins are discussed, and future perspectives for developing next generation vitamins producing strains using synthetic biotechnology are prospected.
Biotechnology
;
Metabolic Engineering
;
Vitamin A
;
Vitamin K
;
Vitamins/analysis*

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