Efficacy and Safety of Metformin and Atorvastatin Combination Therapy vs. Monotherapy with Either Drug in Type 2 Diabetes Mellitus and Dyslipidemia Patients (ATOMIC): Double-Blinded Randomized Controlled Trial.

Background: It is well known that a large number of patients with diabetes also have dyslipidemia, which significantly increases the risk of cardiovascular disease (CVD). This study aimed to evaluate the efficacy and safety of combination drugs consisting of metformin and atorvastatin, widely used as therapeutic agents for diabetes and dyslipidemia. Methods: This randomized, double-blind, placebo-controlled, parallel-group and phase III multicenter study included adults with glycosylated hemoglobin (HbA1c) levels >7.0% and <10.0%, low-density lipoprotein cholesterol (LDL-C) >100 and <250 mg/dL. One hundred eighty-five eligible subjects were randomized to the combination group (metformin+atorvastatin), metformin group (metformin+atorvastatin placebo), and atorvastatin group (atorvastatin+metformin placebo). The primary efficacy endpoints were the percent changes in HbA1c and LDL-C levels from baseline at the end of the treatment. Results: After 16 weeks of treatment compared to baseline, HbA1c showed a significant difference of 0.94% compared to the atorvastatin group in the combination group (0.35% vs. -0.58%, respectively; P<0.0001), whereas the proportion of patients with increased HbA1c was also 62% and 15%, respectively, showing a significant difference (P<0.001). The combination group also showed a significant decrease in LDL-C levels compared to the metformin group (-55.20% vs. -7.69%, P<0.001) without previously unknown adverse drug events. Conclusion: The addition of atorvastatin to metformin improved HbA1c and LDL-C levels to a significant extent compared to metformin or atorvastatin alone in diabetes and dyslipidemia patients. This study also suggested metformin's preventive effect on the glucose-elevating potential of atorvastatin in patients with type 2 diabetes mellitus and dyslipidemia, insufficiently controlled with exercise and diet. Metformin and atorvastatin combination might be an effective treatment in reducing the CVD risk in patients with both diabetes and dyslipidemia because of its lowering effect on LDL-C and glucose.

Altered Metabolic Phenotypes and Hypothalamic Neuronal Activity Triggered by Sodium-Glucose Cotransporter 2 Inhibition.

BACKGRUOUND: Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are currently used to treat patients with diabetes. Previous studies have demonstrated that treatment with SGLT-2 inhibitors is accompanied by altered metabolic phenotypes. However, it has not been investigated whether the hypothalamic circuit participates in the development of the compensatory metabolic phenotypes triggered by the treatment with SGLT-2 inhibitors. METHODS: Mice were fed a standard diet or high-fat diet and treated with dapagliflozin, an SGLT-2 inhibitor. Food intake and energy expenditure were observed using indirect calorimetry system. The activity of hypothalamic neurons in response to dapagliflozin treatment was evaluated by immunohistochemistry with c-Fos antibody. Quantitative real-time polymerase chain reaction was performed to determine gene expression patterns in the hypothalamus of dapagliflozin-treated mice. RESULTS: Dapagliflozin-treated mice displayed enhanced food intake and reduced energy expenditure. Altered neuronal activities were observed in multiple hypothalamic nuclei in association with appetite regulation. Additionally, we found elevated immunosignals of agouti-related peptide neurons in the paraventricular nucleus of the hypothalamus. CONCLUSION: This study suggests the functional involvement of the hypothalamus in the development of the compensatory metabolic phenotypes induced by SGLT-2 inhibitor treatment.

Exploring the potential hypothalamic role in mediating cisplatin-induced negative energy balance.

Cisplatin is a chemotherapeutic drug commonly used for treating different types of cancer. However, long-term use can lead to side effects, including anorexia, nausea, vomiting, and weight loss, which negatively affect the patient's quality of life and ability to undergo chemotherapy. This study aimed to investigate the mechanisms underlying the development of a negative energy balance during cisplatin treatment. Mice treated with cisplatin exhibit reduced food intake, body weight, and energy expenditure. We observed altered neuronal activity in the hypothalamic nuclei involved in the regulation of energy metabolism in cisplatin-treated mice. In addition, we observed activation of microglia and inflammation in the hypothalamus following treatment with cisplatin. Consistent with this finding, inhibition of microglial activation effectively rescued cisplatin-induced anorexia and body weight loss. The present study identified the role of hypothalamic neurons and inflammation linked to microglial activation in the anorexia and body weight loss observed during cisplatin treatment. These findings provide insight into the mechanisms underlying the development of metabolic abnormalities during cisplatin treatment and suggest new strategies for managing these side effects.

A double-blind, Randomized controlled trial on glucose-lowering EFfects and safety of adding 0.25 or 0.5 mg lobeglitazone in type 2 diabetes patients with INadequate control on metformin and dipeptidyl peptidase-4 inhibitor therapy: REFIND study.

AIMS: To compare the efficacy and safety of adding low-dose lobeglitazone (0.25 mg/day) or standard-dose lobeglitazone (0.5 mg/day) to patients with type 2 diabetes mellitus (T2DM) with inadequate glucose control on metformin and dipeptidyl peptidase (DPP4) inhibitor therapy. MATERIALS AND METHODS: In this phase 4, multicentre, double-blind, randomized controlled, non-inferiority trial, patients with T2DM insufficiently controlled by metformin and DPP4 inhibitor combination therapy were randomized to receive either low-dose or standard-dose lobeglitazone. The primary endpoint was non-inferiority of low-dose lobeglitazone in terms of glycaemic control, expressed as the difference in mean glycated haemoglobin levels at week 24 relative to baseline values and compared with standard-dose lobeglitazone, using 0.5% non-inferiority margin. RESULTS: At week 24, the mean glycated haemoglobin levels were 6.87 ± 0.54% and 6.68 ± 0.46% in low-dose and standard-dose lobeglitazone groups, respectively (p = .031). The between-group difference was 0.18% (95% confidence interval 0.017-0.345), showing non-inferiority of the low-dose lobeglitazone. Mean body weight changes were significantly greater in the standard-dose group (1.36 ± 2.23 kg) than in the low-dose group (0.50 ± 1.85 kg) at week 24. The changes in HOMA-IR, lipid profile and liver enzyme levels showed no significant difference between the groups. Overall treatment-emergent adverse events (including weight gain, oedema and hypoglycaemia) occurred more frequently in the standard-dose group. CONCLUSIONS: Adding low-dose lobeglitazone to metformin and DPP4 inhibitor combination resulted in a non-inferior glucose-lowering outcome and fewer adverse events compared with standard-dose lobeglitazone. Therefore, low-dose lobeglitazone might be one option for individualized strategy in patients with T2DM.

The First Korean Siblings With Adult-Onset 4H Leukodystrophy Related to Nonsynonymous POLR3B Mutations.

Objectives: 4H leukodystrophy is a rare autosomal recessive hypomyelinating disorder characterized by several combinations of motor dysfunction, abnormal dentition, and ophthalmic and endocrine abnormalities. To date, only a single Korean case report of pediatric leukodystrophy caused by the POLR1C sequence variation has been published, while there are no reports on the POLR3B, POLR3A, or POLR3K variants. Methods: Genetic tests of Korean sibling pairs with primary amenorrhea due to normosmic isolated hypogonadotropic hypogonadism and cognitive or behavioral symptoms were performed by whole-exome sequencing (WES). The WES results were validated by direct Sanger sequencing. Results: We identified biallelic variations in the POLR3B gene of p.Tyr685* and p.Tyr746Cys, which have not been associated with 4H leukodystrophy. Both sequence variants lie in the hybrid-binding domain of the protein RPC2. The protein structure analysis predicted that cysteine substitution of the phylogenetically conserved amino acid tyrosine can cause destabilization. Discussion: The siblings reported are the first POLR3B-related hypomyelinating leukodystrophy cases in Korea. Our report expands the mutational spectrum of 4H leukodystrophy and suggests that it is mandatory to consider its diagnostic possibility in adult patients presenting with primary amenorrhea and mild cognitive or behavioral symptoms.

Framingham Risk Score Assessment in Subjects with Pre-diabetes and Diabetes: A Cross-Sectional Study in Korea.

BACKGROUND: This study aimed to evaluate cardiovascular risk in subjects with pre-diabetes and diabetes in Korea. METHODS: In this pan-Korean, non-interventional, cross-sectional study, data were collected from medical records of 10 hospitals between November 2013 and June 2014. Subjects (aged ≥40 years) with medical records of dysglycemia and documentation of total cholesterol level, high-density lipoprotein cholesterol level, systolic blood pressure, and smoking status in the past 6 months were included. The primary endpoint was to determine the Framingham risk score (FRS). The relationships between FRS and cardiovascular risk factors, glycated hemoglobin, and insulin usage were determined by multiple linear regression analyses. RESULTS: Data from 1,537 subjects with pre-diabetes (n=1,025) and diabetes (n=512) were analyzed. The mean FRS (mean±standard deviation) in subjects with pre-diabetes/diabetes was 13.72±8.77. FRS was higher in subjects with diabetes than pre-diabetes (P<0.001). FRS in men with pre-diabetes was comparable to that in women with diabetes (13.80±7.37 vs. 13.35±7.13). FRS was elevated in subjects who consumed alcohol (2.66, P=0.033) and with obesity-class II (6.10, P=0.015) among subjects with diabetes (n=199), and was elevated in patients with left ventricular hypertrophy (11.10, P=0.005), those who consumed alcohol (3.06, P=0.000), were pre-obese (3.21, P=0.002), or were obesity-class I (2.89, P=0.002) among subjects with pre-diabetes (n=306) in comparison to subjects without these coexisting risk factors. CONCLUSION: Overall, Korean subjects with pre-diabetes and diabetes have an increased cardiovascular risk, which is significantly higher in those subjects with diabetes than with pre-diabetes. The present data can be used to develop measures to prevent and manage cardiovascular complications in Koreans with impaired glucose metabolism.

Questionnaire-based Survey of Demographic and Clinical Characteristics, Health Behaviors, and Mental Health of Young Korean Adults with Early-onset Diabetes.

BACKGROUND: The incidence of early-onset diabetes is increasing among young adults. However, there are limited data on the characteristics and management of young Korean adults with diabetes. This study assessed the clinical and demographic characteristics, health behaviors, and mental health among young Korean adults with diabetes mellitus. METHODS: This cross-sectional study included young Korean adults with diabetes (n = 225) with an onset age of 20-39 years from four university hospitals. Demographic characteristics, management of diabetes, and mental health were assessed using a questionnaire survey. RESULTS: Type 2 diabetes was the most common type (73.3%), and 13.8% of participants were classified as other types or unknown. Approximately, 64.7% of participants had a strong family history of diabetes, and 76% had treatment within three months of diagnosis. Approximately, 11.1% of participants had diabetic complications; 39.1% of participants received insulin injections, including oral anti-diabetic medications. Additionally, 30.4% were smokers, and only 28% had active physical activity; 26.5% of participants had >3 hours of screen time. One third of participants never had breakfast, and 60.5% went out to eat at least three times a week. Half of the participants showed moderate to severe stress perception, and 21.4% of patients had moderate to severe levels of depression based on the Korean version of Beck Depression Inventory score. CONCLUSION: Early-onset diabetes was associated with a strong family history and early insulin treatment. Young adults with diabetes had poor health behaviors and frequent mental depression. These findings suggest the necessity of health policies for improving health behaviors and mental distress.

Efficacy and Safety of Treatment with Quadruple Oral Hypoglycemic Agents in Uncontrolled Type 2 Diabetes Mellitus: A Multi-Center, Retrospective, Observational Study.

BACKGROUND: Only few studies have shown the efficacy and safety of glucose-control strategies using the quadruple drug combination. Therefore, the aim of the present study was to investigate the usefulness of the quadruple combination therapy with oral hypoglycemic agents (OHAs) in patients with uncontrolled type 2 diabetes mellitus (T2DM). METHODS: From March 2014 to December 2018, data of patients with T2DM, who were treated with quadruple hypoglycemic medications for over 12 months in 11 hospitals in South Korea, were reviewed retrospectively. We compared glycosylated hemoglobin (HbA1c) levels before and 12 months after quadruple treatment with OHAs. The safety, maintenance rate, and therapeutic patterns after failure of the quadruple therapy were also evaluated. RESULTS: In total, 357 patients were enrolled for quadruple OHA therapy, and the baseline HbA1c level was 9.0%±1.3% (74.9±14.1 mmol/mol). After 12 months, 270 patients (75.6%) adhered to the quadruple therapy and HbA1c was significantly reduced from 8.9%±1.2% to 7.8%±1.3% (mean change, -1.1%±1.2%; P<0.001). The number of patients with HbA1c <7% increased significantly from 5 to 68 (P<0.005). In addition, lipid profiles and liver enzyme levels were also improved whereas no changes in body weight. There was no significant safety issue in patients treated with quadruple OHA therapy. CONCLUSION: This study shows the therapeutic efficacy of the quadruple OHA regimen T2DM and demonstrates that it can be an option for the management of T2DM patients who cannot use insulin or reject injectable therapy.

Combined Effects of Baicalein and Docetaxel on Apoptosis in 8505c Anaplastic Thyroid Cancer Cells via Downregulation of the ERK and Akt/mTOR Pathways.

BACKGROUND: Anaplastic thyroid cancer (ATC) is one of the most lethal human malignancies. Docetaxel, a microtubule stabilizer, is a common chemotherapeutic agent used to treat various metastatic cancers. However, prolonged use results in various side effects and drug resistance. Flavonoids, such as baicalein, are accepted chemotherapeutic and dietary chemopreventive agents with many advantages, such as greater accessibility, affordability, and lower toxicity, compared with traditional chemotherapy agents. In this study, we evaluated whether baicalein enhances the effects of docetaxel on apoptosis and metastasis in 8505c ATC cells. METHODS: The 8505c cells were treated with baicalein or docetaxel individually and in combination. Cell viability was measured by MTT (thiazolyl blue tetrazolium bromide) assay, and apoptosis was detected by fluorescence microscopy of Hoechst-stained cells. The expression of apoptotic (Bax and caspase-3), anti-apoptotic (Bcl-2), angiogenic (vascular endothelial growth factor [VEGF], transforming growth factor ß [TGF-ß], E-cadherin, and N-cadherin), and signaling (extracellular signal-regulated kinase [ERK] mitogen activated protein kinase [MAPK], Akt, and mammalian target of rapamycin [mTOR]) proteins was determined by Western blot analysis. RESULTS: The combination of baicalein (50 or 100 µM) and docetaxel (10 nM) significantly inhibited proliferation and induced apoptosis compared with monotherapies. The combination treatment significantly inhibited the expression of Bax, caspase-3, VEGF, TGF-ß1, E-cadherin, N-cadherin, and mTOR, but decreased the expression of Bcl-2 and significantly decreased the phosphorylation of ERK and Akt. CONCLUSION: The combination of baicalein and docetaxel effectively induced apoptosis and inhibited metastasis in 8505c cells through downregulation of apoptotic and angiogenic protein expression and blocking of the ERK and Akt/mTOR pathways in 8505c cells. These results suggest that baicalein enhances the anticancer effects of docetaxel in ATC.

A 52-week extension study of switching from gemigliptin vs sitagliptin to gemigliptin only as add-on therapy for patients with type 2 diabetes who are inadequately controlled with metformin alone.

We investigated the long-term efficacy and safety of gemigliptin and the efficacy and safety of gemigliptin treatment after once-daily treatment with sitagliptin 100 mg, in patients with type 2 diabetes. This was a 28-week extension of a 24-week, randomized, double-blind, parallel study of gemigliptin or sitagliptin added to ongoing metformin therapy. After randomization to sitagliptin 100 mg qd (S), gemigliptin 25 mg bid (G1) or gemigliptin 50 mg qd (G2) and after completing 24 weeks of treatment, 118 patients switched from gemigliptin 25 mg bid to 50 mg qd (G1/G2), 111 patients continued gemigliptin 50 mg qd (G2/G2) and 106 patients switched from sitagliptin 100 mg qd to gemigliptin 50 mg qd (S/G2). All 3 treatments reduced glycated haemoglobin (HbA1c) (S/G2,-0.99% [95% CI -1.25%, -0.73%]; G1/G2, -1.11% [95% CI -1.33%, -0.89%]; G2/G2, -1.06% [95% CI -1.28%, -0.85%]). The percentage of patients achieving HbA1c < 6.5% was 27.6% in the G1/G2 group at both Week 24 and Week 52, and ranged from 27.3% to 32.7% in the G2/G2 group (difference in proportions, 5% [95% CI -6%, 17%]), while it increased from 6.8% to 27.3% from Week 24 to Week 52 in the S/G2 group (difference in proportions, 20% [95% CI 7%, 34%]). Addition of gemigliptin 50 mg qd to metformin was shown to be efficacious for 52 weeks. Switching from sitagliptin 100 mg to gemigliptin 50 mg showed consistent glyacemic control over the previous treatment.

Visfatin Triggers Anorexia and Body Weight Loss through Regulating the Inflammatory Response in the Hypothalamic Microglia.

Visfatin is an adipokine that is secreted from adipose tissue, and it is involved in a variety of physiological processes. In particular, visfatin has been implicated in metabolic diseases, such as obesity and type 2 diabetes, which are directly linked to systemic inflammation. However, the potential impacts of visfatin on the hypothalamic control of energy homeostasis, which is involved in microglial inflammation, have not fully been investigated. In this study, we found that treatment with exogenous recombinant visfatin protein led to the activation of the inflammatory response in a microglial cell line. In addition, we observed that central administration of visfatin led to the activation of microglia in the hypothalamus. Finally, we found that visfatin reduced food intake and body weight through activating POMC neurons in association with microglia activation in mice. These findings indicate that elevation of central visfatin levels may be associated with homeostatic feeding behavior in response to metabolic shifts, such as increased adiposity following inflammatory processes in the hypothalamus.

Osteopontin levels in patients with papillary thyroid cancer according to the presence of Hashimoto's thyroiditis.

BACKGROUND: Human papillary thyroid carcinoma (PTC) is often associated with Hashimoto's thyroiditis (HT); their coexistence improves PTC prognosis. Osteopontin, a secreted glycoprotein, plays a role in cell survival, immunity, and tumor progression, its expression being associated with a poor prognosis and metastasis in several malignancies. Osteopontin overexpression correlates with aggressive clinicopathological features in PTC. Lymph node metastases and large tumor size positively correlate with osteopontin positivity. This study aimed to: (1) confirm osteopontin overexpression in human PTC samples; (2) compare osteopontin expression levels in PTC cases with and without HT; and (3) identify correlations between tumor aggressiveness and osteopontin expression levels. MATERIALS AND METHODS: Plasma osteopontin was assessed in 45 patients with PTC, 22 patients with PTC and HT, and 24 healthy controls by enzyme-linked immunosorbent assay. Thyroid tissue osteopontin mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction and Western blotting, respectively. RESULTS: Plasma osteopontin levels were significantly higher in PTC patients than in healthy controls. Plasma osteopontin, tissue osteopontin mRNA, and tissue osteopontin protein levels were significantly lower in patients with PTC and HT than in those with PTC alone. In advanced disease stage cases, osteopontin mRNA and protein expression levels were lower in patients with PTC and HT than in those with PTC alone. However, the osteopontin expression level was not significantly associated with the TNM stage. CONCLUSIONS: Plasma osteopontin, tissue osteopontin mRNA, and tissue osteopontin protein levels were significantly lower in patients with PTC and HT than in those with PTC alone, suggesting that HT attenuates PTC aggressiveness through negative regulation of osteopontin expression.

A case of cavernous sinus thrombophlebitis and meningitis as a complication in osteopetrosis.

Osteopetrosis is a rare genetic bone disease characterized by increased bone density but prone to breakage due to defective osteoclastic function. Among two primary types of autosomal dominant osteopetrosis (ADO), osteopetrosis type II is characterized by sclerosis of bones, predominantly involving the spine, the pelvis, and the skull base. Fragility of bones and dental abscess are leading complications. This report presents a case of osteopetrosis in a 52-years-old female, which was complicated by the development of cavernous sinus thrombophlebitis and meningitis. She was suffered from multiple fractures since one year ago. Laboratory data revealed elevated serum levels of tartrate resistant acid phosphatase (TRAP) without carbonic anhydrase II DNA mutation. A thoracolumbar spine X-ray showed, typical findings of ADO type II (ADO II; Albers-Schönberg disease), prominent vertebral endplates so called the 'rugger jersey spine'. Her older sister also showed same typical spine appearance. We report a case of ADO II with cavernous sinus thrombophlebitis and meningitis that was successfully treated with long-term antibiotics with right sphenoidotomy.

Curcumin Enhances Docetaxel-Induced Apoptosis of 8505C Anaplastic Thyroid Carcinoma Cells.

BACKGROUND: Anaplastic thyroid cancer (ATC) is one of the most aggressive malignancies in humans, and its progression is poorly controlled by existing therapeutic methods. Curcumin has been shown to suppress inflammation and angiogenesis. In this study, we evaluated whether curcumin could augment docetaxel-induced apoptosis of ATC cells. We also analyzed changes in nuclear factor κB (NF-κB) and cyclooxygenase-2 (COX-2) expression levels to delineate possible mechanisms of their combined action. METHODS: ATC cells were cultured and treated with curcumin and docetaxel alone or in combination. The effects on cell viability were determined by MTS assay. Apoptosis was assessed by annexin V staining and confirmed by flow cytometric analysis. Caspase, COX-2, NF-κB levels were assayed by Western blotting. RESULTS: Curcumin combined with docetaxel led to lower cell viability than treatment with docetaxel or curcumin alone. Annexin V staining followed by flow cytometric analysis demonstrated that curcumin treatment enhanced the docetaxel-induced apoptosis of ATC cells. Additionally, curcumin inhibited docetaxel-induced p65 activation and COX-2 expression. CONCLUSION: We conclude that curcumin may enhance docetaxel's antitumor activity in ATC cells by interfering with NF-κB and COX-2. Our results suggest that curcumin may emerge as an attractive therapeutic candidate to enhance the antitumor activity of taxanes in ATC treatment.

Safety and efficacy of modern insulin analogues.

BACKGROUND: A1chieve® was a noninterventional study evaluating the clinical safety and efficacy of biphasic insulin aspart 30, insulin detemir, and insulin aspart. METHODS: Korean type 2 diabetes patients who have not been treated with the study insulin or have started it within 4 weeks before enrollment were eligible for the study. The patient selection and the choice of regimen were at the discretion of the physician. The safety and efficacy information was collected from the subjects at baseline, week 12, and week 24. The number of serious adverse drug reactions (SADRs) was the primary endpoint. The changes of clinical diabetic markers at week 12 and/or at week 24 compared to baseline were the secondary endpoints. RESULTS: Out of 4,058 exposed patients, 3,003 completed the study. During the study period, three SADRs were reported in three patients (0.1%). No major hypoglycemic episodes were observed and the rate of minor hypoglycemic episodes marginally decreased during 24 weeks (from 2.77 to 2.42 events per patient-year). The overall quality of life score improved (from 66.7±15.9 to 72.5±13.5) while the mean body weight was slightly increased (0.6±3.0 kg). The 24-week reductions in glycated hemoglobin, fasting plasma glucose and postprandial plasma glucose were 1.6%±2.2%, 2.5±4.7 mmol/L, and 4.0±6.4 mmol/L, respectively. CONCLUSION: The studied regimens showed improvements in glycemic control with low incidence of SADRs, including no incidence of major hypoglycemic episodes in Korean patients with type 2 diabetes.

Effects of rosiglitazone on inflammation in Otsuka long-evans Tokushima Fatty rats.

BACKGROUND: Inflammation plays a role in the response to metabolic stress in type 2 diabetes. However, the effects of rosiglitazone on inflammation of skeletal muscle have not been fully examined in type 2 diabetes. METHODS: We investigated the effects of the insulin-sensitizing anti-diabetic agent, rosiglitazone, on the progression of skeletal muscle inflammation in Otsuka Long-Evans Tokushima Fatty (OLETF) type 2 diabetic rats. We examined the expression of serologic markers (serum glucose, insulin and free fatty acid) and inflammatory cytokines (tumor-necrosis factor-alpha, interleukin [IL]-1beta and IL-6) in OLETF rats from early to advanced diabetic stage (from 28 to 40 weeks of age). RESULTS: Serum glucose and insulin concentrations were significantly decreased in rosiglitazone-treated OLETF rats compared to untreated OLETF rats. Rosiglitazone treatment significantly decreased the concentrations of serum inflammatory cytokines from 28 to 40 weeks of age. The mRNA expression of various cytokines in skeletal muscle was reduced in rosiglitazone-treated OLETF rats compared with untreated OLETF rats. Furthermore, rosiglitazone treatment resulted in the downregulation of ERK1/2 phosphorylation and NF-kappaB expression in the skeletal muscle of OLETF rats. CONCLUSION: These results suggest that rosiglitazone may improve insulin sensitivity with its anti-inflammatory effects on skeletal muscle.

Thyroid transcription factor-1 exhibits osmosensitive transcription in brain-derived cell lines.

Thyroid transcription factor-1 (TTF-1) belongs to the Nkx family of homeodomain-containing proteins and regulates expression of several important genes in the brain. Our previous studies showed that TTF-1 plays an important role in water homeostasis in the subfornical organ of rats and is involved in cerebrospinal fluid formation by regulation of aquaporin-1 transcription in the choroid plexus. In this study, we examined changes in TTF-1 transcription in response to hypertonicity using promoter assays. TTF-1 was synthesized in several osmosensitive regions of the rat brain. TTF-1 promoter activity was diminished by treatment with hypertonic solutions in a time- and dose-dependent manner in brain-derived cell lines. Additionally, TTF-1 was involved in the regulation of angiotensinogen (Aogen) transcription under a hyperosmotic condition through specific binding domains in the Aogen promoter. These results suggest a possible role of TTF-1 in brain fluid homeostasis in response to changes in the osmotic environment.

Thyroid transcription factor-1 facilitates cerebrospinal fluid formation by regulating aquaporin-1 synthesis in the brain.

In the brain, aquaporin-1 (AQP-1), a water channel for high osmotic water permeability, is mainly expressed in the apical membrane of the ventricular choroid plexus and regulates formation of cerebrospinal fluid (CSF). Although the physiology of AQP-1 has been the subject of several publications, much less is known about the trans-acting factors involved in the control of AQP-1 gene expression. Here we report that TTF-1, a homeodomain-containing transcriptional regulator, is coexpressed with AQP-1 in the rat brain choroid plexus and enhances AQP-1 gene transcription by binding to conserved core TTF-1-binding motifs in the 5'-flanking region of the AQP-1 gene. Intracerebroventricular administration of an antisense TTF-1 oligodeoxynucleotide significantly decreased AQP-1 synthesis and reduced CSF formation. In addition, blockade of TTF-1 synthesis increased survival of the animals following acute water intoxication-induced brain edema. These results suggest that TTF-1 is physiologically involved in the transcriptional control of AQP-1, which is required for CSF formation.

TTF-1, a homeodomain-containing transcription factor, regulates feeding behavior in the rat hypothalamus.

TTF-1 is a member of the NKx family of homeodomain genes, and is required for morphogenesis and fetal diencephalon development. Our previous studies have shown that TTF-1 expression is maintained in some regions of the postnatal rat brain and transactivates the gene expression of several neuropeptides. In this study, a potential role for TTF-1 in the regulation of feeding behavior was identified. Immunohistochemical analysis showed that TTF-1 is present in several hypothalamic nuclei of the adult rat brain involved in the control of feeding behavior. Food deprivation for two days markedly increased the hypothalamic levels of TTF-1 mRNA and protein. Intracerebroventricular administration of an antisense TTF-1 oligodeoxynucleotide significantly decreased TTF-1 protein abundance in the hypothalamus. This TTF-1 decrease was followed by a significant decrease in neuropeptide Y mRNA content and an increase in proopiomelanocortin mRNA content, and in turn resulted in a decrease of the animal's food intake and body weight. These results suggest a novel role for TTF-1 in the regulation of feeding behavior in the rat hypothalamus.