Introduction of a bacterial acetyl-CoA synthesis pathway improves lactic acid production in Saccharomyces cerevisiae.

Acid-tolerant Saccharomyces cerevisiae was engineered to produce lactic acid by expressing heterologous lactate dehydrogenase (LDH) genes, while attenuating several key pathway genes, including glycerol-3-phosphate dehydrogenase1 (GPD1) and cytochrome-c oxidoreductase2 (CYB2). In order to increase the yield of lactic acid further, the ethanol production pathway was attenuated by disrupting the pyruvate decarboxylase1 (PDC1) and alcohol dehydrogenase1 (ADH1) genes. Despite an increase in lactic acid yield, severe reduction of the growth rate and glucose consumption rate owing to the absence of ADH1 caused a considerable decrease in the overall productivity.

Repetitive genomic insertion of gene-sized dsDNAs by targeting the promoter region of a counter-selectable marker.

Genome engineering can be used to produce bacterial strains with a wide range of desired phenotypes. However, the incorporation of gene-sized DNA fragments is often challenging due to the intricacy of the procedure, off-target effects, and low insertion efficiency. Here we report a genome engineering method enabling the continuous incorporation of gene-sized double-stranded DNAs (dsDNAs) into the Escherichia coli genome.

In vivo deletion of CAR resulted in high bone mass phenotypes in male mice.

Constitutive androstane receptor (CAR) was originally identified as xenobiotic sensor that regulates the expression of cytochrome P450 genes. However, recent studies suggest that this nuclear receptor is also involved in the regulation of energy metabolism including glucose and lipid homeostasis. This study investigated the role of CAR in the regulation of bone mass in vivo using CAR(-/-) mice.

The positive association between peripheral blood cell counts and bone mineral density in postmenopausal women.

Purpose: Accumulating evidence has shown a close connection between hematopoiesis and bone formation. Our aim was to evaluate the association between peripheral blood cell counts and bone mineral density (BMD) in a sample of postmenopausal women.

Materials And Methods: Three hundreds thirty eight healthy postmenopausal women who underwent BMD measurement during their health check-up were investigated.

Two-stage pretreatment of rice straw using aqueous ammonia and dilute acid.

Liberation of fermentable sugars from recalcitrant lignocellulosic biomass is one of the key challenges in production of cellulosic ethanol. Here we developed a two-stage pretreatment process using aqueous ammonia and dilute sulfuric acid in a percolation mode to improve production of fermentable sugars from rice straw. Aqueous NH₃ was used in the first stage which removed lignin selectively but left most of cellulose (97%) and hemicellulose (77%).

The prevalence and risk factors of vertebral fractures in Korea.

We investigated the prevalence and risk factors of vertebral fractures in Korea. In a community-based prospective epidemiology study, 1,155 men and 1,529 women (mean age 59 years, range 43-74) were recruited from Ansung, a rural Korean community. Prevalent vertebral fractures were identified on the lateral spinal radiographs at T11 to L4 using vertebral morphometry.

Osteoblast-targeted overexpression of PPARγ inhibited bone mass gain in male mice and accelerated ovariectomy-induced bone loss in female mice.

PPARγ has critical role in the differentiation of mesenchymal stem cells into adipocytes while suppressing osteoblastic differentiation. We generated transgenic mice that overexpress PPARγ specifically in osteoblasts under the control of a 2.3-kb procollagen type 1 promoter (Col.

Transgenic mice overexpressing secreted frizzled-related proteins (sFRP)4 under the control of serum amyloid P promoter exhibit low bone mass but did not result in disturbed phosphate homeostasis.

Secreted frizzled-related protein-4 (sFRP4) is a member of secreted modulators of Wnt signaling pathways and has been recognized to play important role in the pathogenesis of oncogenic osteomalacia as a potential phosphatonin. To investigate the role of sFRP4 in bone biology and phosphorus homeostasis in postnatal life, we generated transgenic mice that overexpress sFRP4 under the control of the serum amyloid P promoter (SAP-sFRP4), which drives transgene expression postnatally. Serum phosphorus level and urinary phosphorus excretion were slightly lower and higher, respectively, in SAP-sFRP4 compared to wild-type (WT) littermate, but the difference did not reach statistical significance.

Pretreatment of rice straw with ammonia and ionic liquid for lignocellulose conversion to fermentable sugars.

Pretreatment technology is a prerequisite to facilitate the release of sugars from a lignocellulosic biomass prior to fermentation. Recently, some pretreatment methods have been tried with ionic liquids, but they were still expensive and unpractical. In this study, an efficient pretreatment method using ammonia and ionic liquid was developed for the recovery of bio-digestible cellulose from a lignocellulosic byproduct, rice straw, and the increase of ionic liquid utilization.

Enhanced mitochondrial biogenesis contributes to Wnt induced osteoblastic differentiation of C3H10T1/2 cells.

Mitochondria play a key role in cell physiology including cell differentiation and proliferation. We investigated the changes of mitochondrial biogenesis during Wnt-induced osteoblastic differentiation of murine mesenchymal C3H10T1/2 cells. Scanning electron microscopy demonstrated that activation of Wnt signaling by Wnt-3A conditioned medicum (CM) resulted in significant increase in the number of mitochondria in C3H10T1/2 cells.

Prevalence and risk factors of osteoporosis in Korea: a community-based cohort study with lumbar spine and hip bone mineral density.

Purpose: To investigate bone mineral density (BMD) profiles, osteoporosis prevalence and risk factors in a community-based cohort in Korea.

Methods: The present study is a cross-sectional study. The study population consisted of 1,547 men and 1991 women aged 40 years and older with BMD measurements using central dual energy X-ray absorptiometry from a prospective community-based cohort.

Silent corticotroph adenomas have unique recurrence characteristics compared with other nonfunctioning pituitary adenomas.

Objective: The prevalence of silent corticotroph adenomas (SCAs) is not rare among nonfunctioning pituitary adenomas (NFPAs); however, it is unknown whether the clinical significance of SCAs differs from that of NFPAs without ACTH immunoreactivity (non-SCAs). Our goal was to compare the clinical characteristics and natural history between patients with SCAs and non-SCAs.

Design/patients: We reviewed the medical records of all patients who underwent transsphenoidal surgery for NFPAs from January 1990 to October 2007 at the Seoul National University Hospital.

Transplantation of mesenchymal stem cells overexpressing RANK-Fc or CXCR4 prevents bone loss in ovariectomized mice.

Osteoporosis is a systemic skeletal disorder characterized by reduced bone mineral density (BMD) and increased risk of fracture. We studied the effects of transplantation of mesenchymal stem cells (MSCs) overexpressing receptor activator of nuclear factor-kappaB (RANK)-Fc and CXC chemokine receptor-4 (CXCR4) using retrovirus on ovariectomy (OVX)-induced bone loss in mice. Ten-week-old adult female C57BL/6 mice were divided into six groups as follows: Sham-operated mice treated with phosphate-buffered saline (PBS) (Sham-op + PBS); OVX mice intravenously transplanted with syngeneic MSCs overexpressing RANK-Fc-DsRED and CXCR4-GFP (RANK-Fc + CXCR4); RANK-Fc-DsRED and GFP (RANK-Fc + GFP); CXCR4-GFP and DsRED (CXCR4 + RED); DsRED and GFP (RED + GFP); or treated with PBS only (OVX + PBS).

Wnt inhibitory factor (WIF)-1 inhibits osteoblastic differentiation in mouse embryonic mesenchymal cells.

Wnt inhibitory factor (WIF)-1 belongs to the members of secreted modulators of Wnt proteins. Secreted frizzled-related proteins (sFRPs), another member of Wnt modulators, have been shown to play differential roles in Wnt signaling depending on the subtypes and cell models. This study was undertaken to investigate the functional role of WIF-1 in osteoblastic differentiation of mouse mesenchymal C3H10T1/2 cells.

Derivation of a new equation for estimating creatinine clearance by using fat-free mass and serum creatinine concentration in Korean patients with type 2 diabetes mellitus.

Aims: Equations to predict creatinine clearance (Ccr) or glomerular filtration rate have limitations in applying to a wide range of ethnicities with different fat-free mass (FFM). We aimed to determine the serum creatinine (Scr) concentrations that indicate renal insufficiency and formulate a new equation to estimate Ccr by a function of FFM in Korean type 2 diabetic patients.

Methods: Ccr was measured in 283 type 2 diabetic patients by 24-h urine collection.

Synergistic effects of sequential treatment with methyl jasmonate, salicylic acid and yeast extract on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures.

To develop an optimal bioprocess for secondary metabolite production and explain the bioprocess at the molecular level, we examine the synergistic effects of sequential treatment with methyl jasmonate (MJ), salicylic acid (SA) and yeast extract (YE) on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures. Serial treatment of MJ, SA and YE at 24h intervals enhanced the accumulation of dihydrosanguinarine (2.5 times) and sanguinarine (5.

Differential induction of protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cultures by methyl jasmonate and yeast extract.

Methyl jasmonate (MJ) and yeast extract (YE) induce protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cell cultures. One hundred microM MJ primarily induced dihydrosanguinarine 509.0+/-7.

Enhanced benzophenanthridine alkaloid production and protein expression with combined elicitor in Eschscholtzia californica suspension cultures.

Production of the benzophenanthridine alkaloids in Eschscholtzia californica suspension cell cultures was optimized by adding 0.5 mg methyl jasmonate (MJ) and 0.02 mg salicylic acid (SA)/g FCW after 7 days cultivation.