Stomach clusterin as a gut-derived feeding regulator.

The stomach has emerged as a crucial endocrine organ in the regulation of feeding since the discovery of ghrelin. Gut-derived hormones, such as ghrelin and cholecystokinin, can act through the vagus nerve. We previously reported the satiety effect of hypothalamic clusterin, but the impact of peripheral clusterin remains unknown. In this study, we administered clusterin intraperitoneally to mice and observed its ability to suppress fasting-driven food intake. Interestingly, we found its synergism with cholecystokinin and antagonism with ghrelin. These effects were accompanied by increased c-fos immunoreactivity in nucleus tractus solitarius, area postrema, and hypothalamic paraventricular nucleus. Notably, truncal vagotomy abolished this response. The stomach expressed clusterin at high levels among the organs, and gastric clusterin was detected in specific enteroendocrine cells and the submucosal plexus. Gastric clusterin expression decreased after fasting but recovered after 2 hours of refeeding. Furthermore, we confirmed that stomachspecific overexpression of clusterin reduced food intake after overnight fasting. These results suggest that gastric clusterin may function as a gut-derived peptide involved in the regulation of feeding through the gut-brain axis. [BMB Reports 2024; 57(3): 149-154].

Enhanced neuronal activity by suffruticosol A extracted from Paeonia lactiflora via partly BDNF signaling in scopolamine-induced memory-impaired mice.

Neurodegenerative diseases are explained by progressive defects of cognitive function and memory. These defects of cognition and memory dysfunction can be induced by the loss of brain-derived neurotrophic factors (BDNF) signaling. Paeonia lactiflora is a traditionally used medicinal herb in Asian countries and some beneficial effects have been reported, including anti-oxidative, anti-inflammatory, anti-cancer activity, and potential neuroprotective effects recently. In this study, we found that suffruticosol A is a major compound in seeds of Paeonia lactiflora. When treated in a SH-SY5 cell line for measuring cell viability and cell survival, suffruticosol A increased cell viability (at 20 µM) and recovered scopolamine-induced neurodegenerative characteristics in the cells. To further confirm its neural amelioration effects in the animals, suffruticosol A (4 or 15 ng, twice a week) was administered into the third ventricle beside the brain of C57BL/6 mice for one month then the scopolamine was intraperitoneally injected into these mice to induce impairments of cognition and memory before conducting behavioral experiments. Central administration of suffruticosol A into the brain restored the memory and cognition behaviors in mice that received the scopolamine. Consistently, the central treatments of suffruticosol A showed rescued cholinergic deficits and BDNF signaling in the hippocampus of mice. Finally, we measured the long-term potentiation (LTP) in the hippocampal CA3-CA1 synapse to figure out the restoration of the synaptic mechanism of learning and memory. Bath application of suffruticosol A (40 µM) improved LTP impairment induced by scopolamine in hippocampal slices. In conclusion, the central administration of suffruticosol A ameliorated neuronal effects partly through elevated BDNF signaling.

Augmentation of the RNA m6A reader signature is associated with poor survival by enhancing cell proliferation and EMT across cancer types.

N6-Methyladenosine (m6A) RNA modification plays a critical role in the posttranscriptional regulation of gene expression. Alterations in cellular m6A levels and m6A-related genes have been reported in many cancers, but whether they play oncogenic or tumor-suppressive roles is inconsistent across cancer types. We investigated common features of alterations in m6A modification and m6A-related genes during carcinogenesis by analyzing transcriptome data of 11 solid tumors from The Cancer Genome Atlas database and our in-house gastric cancer cohort. We calculated m6A writer (W), eraser (E), and reader (R) signatures based on corresponding gene expression. Alterations in the W and E signatures varied according to the cancer type, with a strong positive correlation between the W and E signatures in all types. When the patients were divided according to m6A levels estimated by the ratio of the W and E signatures, the prognostic effect of m6A was inconsistent according to the cancer type. The R and especially the R2 signatures (based on the expression of IGF2BPs) were upregulated in all cancers. Patients with a high R2 signature exhibited poor prognosis across types, which was attributed to enrichment of cell cycle- and epithelial-mesenchymal transition-related pathways. Our study demonstrates common features of m6A alterations across cancer types and suggests that targeting m6A R proteins is a promising strategy for cancer treatment.

Hypothalamic Macrophage Inducible Nitric Oxide Synthase Mediates Obesity-Associated Hypothalamic Inflammation.

Obesity-associated metabolic alterations are closely linked to low-grade inflammation in peripheral organs, in which macrophages play a central role. Using genetic labeling of myeloid lineage cells, we show that hypothalamic macrophages normally reside in the perivascular area and circumventricular organ median eminence. Chronic consumption of a high-fat diet (HFD) induces expansion of the monocyte-derived macrophage pool in the hypothalamic arcuate nucleus (ARC), which is significantly attributed to enhanced proliferation of macrophages. Notably, inducible nitric oxide synthase (iNOS) is robustly activated in ARC macrophages of HFD-fed obese mice. Hypothalamic macrophage iNOS inhibition completely abrogates macrophage accumulation and activation, proinflammatory cytokine overproduction, reactive astrogliosis, blood-brain-barrier permeability, and lipid accumulation in the ARC of obese mice. Moreover, central iNOS inhibition improves obesity-induced alterations in systemic glucose metabolism without affecting adiposity. Our findings suggest a critical role for hypothalamic macrophage-expressed iNOS in hypothalamic inflammation and abnormal glucose metabolism in cases of overnutrition-induced obesity.

The Recovery of Beta-Cell Function is Critical for Antidiabetic Outcomes of Gastric Bypass in Asian Subjects with Type 2 Diabetes and a Body Mass Index Below 30.

Type 2 diabetes (T2D) in Asian populations is characterized by a lower body mass index (BMI) than in Caucasian cases. This pilot study investigated antidiabetic outcomes after a Roux-en-Y gastric bypass (RYGB) in Asian subjects with T2D and BMI < 30. Fifteen Koreans with poorly controlled T2D and BMI 23-30 underwent RYGB. Two years after RYGB, seven patients achieved HbA1c < 6.5% without medication (target-achieved). The other cases also showed improved glycemic control. The insulin secretory response during an oral glucose tolerance test was significantly restored in the target-achieved group. Postoperative changes in insulin sensitivity and body weight did not differ between these groups. Beta-cell function improvement is an important determinant of the long-term antidiabetic outcomes of RYGB in Asian subjects with BMI < 30.

mGluR5 in the nucleus accumbens is critical for promoting resilience to chronic stress.

Resilience to aversive events has a central role in determining whether stress leads to the development of depression. mGluR5 has been implicated in the pathophysiology of depression, but the effect of mGluR5 activity on stress resilience remains unexplored. We found that mGluR5(-/-) (also known as Grm5(-/-)) mice displayed more depression-like behaviors (for example, learned helplessness, social withdrawal and anhedonia) than control mice following exposure to various stressful stimuli. Lentiviral 'rescue' of mGluR5 in the nucleus accumbens (NAc) decreased these depression-like behaviors in mGluR5(-/-) mice. In the NAc, ΔFosB, whose induction promotes stress resilience, failed to be upregulated by stress in mGluR5(-/-) mice. Notably, targeted pharmacological activation of mGluR5 in the NAc increased ΔFosB expression. Our findings point to an essential role for mGluR5 in promoting stress resilience and suggest that a defect in mGluR5-mediated signaling in the NAc may represent an endophenotype for stress-induced depression.

GPR30 mediates anorectic estrogen-induced STAT3 signaling in the hypothalamus.

OBJECTIVE: Estrogen plays an important role in the control of energy balance in the hypothalamus. Leptin-independent STAT3 activation (i.e., tyrosine(705)-phosphorylation of STAT3, pSTAT3) in the hypothalamus is hypothesized as the primary mechanism of the estrogen-induced anorexic response. However, the type of estrogen receptor that mediates this regulation is unknown. We investigated the role of the G protein-coupled receptor 30 (GPR30) in estradiol (E2)-induced STAT3 activation in the hypothalamus. MATERIALS/METHODS: Regulation of STAT3 activation by E2, G-1, a specific agonist of GPR30 and G-15, a specific antagonist of GPR30 was analyzed in vitro and in vivo. Effect of GPR30 activation on eating behavior was analyzed in vivo. RESULTS: E2 stimulated pSTAT3 in cells expressing GPR30, but not expressing estrogen receptor ERα and ERß. G-1 induced pSTAT3, and G-15 inhibited E2-induced pSTAT3 in primary cultures of hypothalamic neurons. A cerebroventricular injection of G-1 increased pSTAT3 in the arcuate nucleus of mice, which was associated with a decrease in food intake and body weight gain. CONCLUSIONS: These results suggest that GPR30 is the estrogen receptor that mediates the anorectic effect of estrogen through the STAT3 pathway in the hypothalamus.

Variants of the adiponectin gene and diabetic microvascular complications in patients with type 2 diabetes.

OBJECTIVE: The aim of this study was to examine the association between common polymorphisms of the adiponectin gene (ADIPOQ) and microvascular complications in patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS: Rs2241766 and rs1501299 of ADIPOQ were genotyped in 708 patients with T2DM. Fundus photography, nerve conducting velocity, and urine analysis were performed to check for the presence of microvascular complications including diabetic nephropathy, retinopathy and neuropathy. RESULTS: The prevalence of diabetic nephropathy tended to be different according to rs2241766 genotype (p=0.057) and the GG genotype of rs2241766 was associated with diabetic nephropathy [urine albumin/creatinine ratio (UACR) greater than 30 mg/g] after adjusting for age, sex, body mass index, duration of diabetes, HDL-cholesterol, smoking status, and blood pressure (odds ratio=1.96; 95% confidence interval=1.01-3.82, p=0.049). Also, the G allele of rs2241766 demonstrated a trend to be associated with an increase in UACR (p=0.087). Rs2241766 genotype was not associated with diabetic retinopathy (p=0.955) and neuropathy (p=0.104) or any diabetic microvascular complications (p=0.104). There was no significant association between the rs1501299 genotype of ADIPOQ and the prevalence of diabetic retinopathy and neuropathy or any diabetic microvascular complications even after adjustment. CONCLUSION: These data suggest that the GG genotype at rs2241766 is implicated in the pathogenesis of risk for diabetic nephropathy defined as UACR greater than 30 mg/day in patients with T2DM.

Nationwide survey of acromegaly in South Korea.

CONTEXT: It was previously reported in Korea that there were 1.4 case per million per year of acromegaly. This was low in comparison with the extrapolated values of Western European countries. We expected that the incidence of acromegaly would be much higher now because of recently improved medical facilities, diagnostic tools and coverage of medical insurance to all the population of South Korea. OBJECTIVE: The purpose of this nationwide survey was to examine the incidence and prevalence of patients with acromegaly, mode of treatment and outcome of surgical treatment of recent 5 years. DESIGN AND PATIENTS: We requested and collected the medical records of all possible patients with acromegaly from 74 secondary or tertiary medical institutes in Korea from 2003 to 2007 retrospectively. MEASUREMENTS: Date of diagnosis and treatment, tumour size, pre- and postoperative hormonal level, treatment modality and usage of medication were collected. RESULTS: During 5 years, 1350 patients with acromegaly had been registered. The average annual incidence was 3.9 cases per million during this period, and prevalence had increased up to 27.9 cases per million in 2007. Male/female ratio was 1:1.2, and mean age at diagnosis was 44.1 years. Macroadenoma was dominant (82.9%). Transsphenoidal adenoidectomy was used the most as primary treatment (90.4%). CONCLUSIONS: This Korean acromegaly survey offers a realistic overview of the predominant epidemiological characteristics of acromegaly in Korea. Annual incidence was at a similar level with western countries. Efforts to diagnose and control the disease earlier are recommended.

Wernicke's encephalopathy in advanced gastric cancer.

PURPOSE: With their prolonged survival and malnutrition, cancer patients, and especially gastrointestinal (GI) tract cancer patients, can develop Wernicke's encephalopathy (WE). The aim of this study is to remind physicians of the importance of WE and prompt management in patients with GI tract cancer. MATERIALS AND METHODS: This study is a retrospective review of 2 cases of WE in advanced gastric cancer (AGC) patients, and we review the literature for cases of GI tract cancer related to WE. RESULTS: A 48-year-old female with AGC presented dizziness and diplopia for 5 days and a 20 kg weight loss. Neurologic exam showed nystagmus and gaze disturbance. Her symptoms improved after daily parenteral injection of thiamine 100 mg for 17 days. A 58-year-old female with AGC presented with sudden disorientation, confusion and 15 kg weight loss. Neurologic exam showed gaze limitation and mild ataxia. Despite daily parenteral injection of thiamine 100 mg for 4 days, she died 5 days after the onset of neurologic symptoms. Combining the cases noted in the literature review with our 2 cases, the 7 gastric cancer cases and 2 colorectal cancer cases related to WE showed similar clinical characteristics; 1) a history of long-period malnutrition and weight loss, 2) relatively typical neurologic signs and symptoms and 3) specific magnetic resonance image findings. Except for 2 patients who had irreversible neurologic symptoms, the other 7 patients were improved with prompt thiamine treatment. CONCLUSION: It is important to consider WE in GI tract cancer patients with acute neurologic symptoms and who are in a state of malnutrition. Thiamine should be given as soon as possible when WE is suspected.

Increments of alpha-dystroglycan expression in liver metastasis correlate with poor survival in gastric cancer.

BACKGROUND: Dystroglycan (DG) is a recently focused adhesion molecule with possible roles in cancer development and progression. We investigated correlations between alpha-DG expression and prognosis in gastric carcinoma with liver metastasis. METHODS: For 40 patients with gastric adenocarcinoma and liver-only metastasis, alpha-DG expression was determined by immunohistochemistry in paraffin-embedded surgical specimens of resected stomach tumor, resected liver metastasis, and their normal counterpart tissues. Correlations between alpha-DG expression and prognosis were retrospectively analyzed. RESULTS: alpha-DG expression was higher in primary gastric cancer (P = 0.006) and lower in liver metastasis (P = 0.002) than in each normal counterpart. In primary stomach cancer, patients who had lower alpha-DG expression in tumors than in normal counterparts showed poor overall survival (OS) (P = 0.028). In contrast, in the liver, patients who had higher alpha-DG expression in tumors than in normal counterparts showed poor OS (P = 0.022). Also, higher alpha-DG expression in liver metastasis than in stomach tumors led to poor recurrence-free survival (P = 0.023) and OS (P = 0.056). CONCLUSIONS: This approach may be used to further understanding of the pathogenesis of liver metastasis from gastric cancer. Further studies are warranted to reveal the mechanisms of alpha-DG dysregulation in liver metastasis.