Erratum to: Stomach clusterin as a gut-derived feeding regulator.

[Erratum to: BMB Reports 2024; 57(3): 149-154, PMID: 37817436, PMCID: PMC10979347] The BMB Reports would like to correct in BMB Rep. 57(3):149-154, titled "Stomach clusterin as a gut-derived feeding regulator". This research was supported by the Creative-Pioneering Researchers Program through Seoul National University.

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.

Circulating blood eNAMPT drives the circadian rhythms in locomotor activity and energy expenditure.

Nicotinamide adenine dinucleotide (NAD) is an essential cofactor of critical enzymes including protein deacetylase sirtuins/SIRTs and its levels in mammalian cells rely on the nicotinamide phosphoribosyltransferase (NAMPT)-mediated salvage pathway. Intracellular NAMPT (iNAMPT) is secreted and found in the blood as extracellular NAMPT (eNAMPT). In the liver, the iNAMPT-NAD axis oscillates in a circadian manner and regulates the cellular clockwork.

Eupatilin Promotes Cell Death by Calcium Influx through ER-Mitochondria Axis with SERPINB11 Inhibition in Epithelial Ovarian Cancer.

Ovarian cancer is the leading cause of gynecological cancer-related mortality. The anticancer effect of eupatilin, a family of flavonoids, is known in many cancer types, but it is unclear what mechanism it plays in ovarian cancer. In this study, eupatilin promoted cell death of ovarian cancer cells by activating caspases, cell cycle arrest, reactive oxygen species (ROS) generation, calcium influx, disruption of the endoplasmic reticulum (ER)-mitochondria axis with SERPINB11 inhibition, and downregulation of phosphoinositide 3-kinase (PI3K) and mitogen activated protein kinase (MAPK) pathways.

Reversion of in vivo fibrogenesis by novel chromone scaffolds.

Background: Myofibroblasts are known to play a key role in the development of idiopathic pulmonary fibrosis (IPF). Two drugs, pirfenidone and nintedanib, are the only approved therapeutic options for IPF, but their applications are limited due to their side effects. Thus, curative IPF drugs represent a huge unmet medical need.

Role of Angptl4/Fiaf in exercise-induced skeletal muscle AMPK activation.

Angiopoietin-like protein 4 (Angptl4)/fasting-induced adipose factor (Fiaf) expression levels are increased by exercise in skeletal muscle. We have previously shown that Angptl4 regulates food intake and energy expenditure via modulation of hypothalamic AMP-activated protein kinase (AMPK) activity. AMPK is an important signaling molecule that integrates skeletal muscle metabolism during exercise.

Distinct Ultradian Rhythms in Plasma Clusterin Concentrations in Lean and Obese Korean Subjects.

Background: Blood levels of many hormones show rhythmic fluctuations with variable duration of cycles. Clusterin/apolipoprotein J is a glycoprotein which is highly expressed in the plasma and has modulatory roles in immune and inflammatory reactions, neurobiology, lipid metabolism, and leptin signaling. In this study, we examined the diurnal fluctuations of plasma clusterin concentrations in lean and obese young men.

Development of a mouse IgA monoclonal antibody-based enzyme-linked immunosorbent sandwich assay for the analyses of RBP4.

Elevated circulating Retinol-binding protein 4 (RBP4) has been associated with insulin resistance, dyslipidemia, and hypertension. However, many commonly used RBP4 ELISAs have limited dynamic range. We therefore developed an enzyme-linked immunosorbent sandwich assay (ELISA) employing a novel immunoglobulin A (IgA)-type capture mAb called AG102 instead of IgG subtypes, which was selected for its stability, capture efficiency, and specificity for human RBP 4.

Angiopoietin-like peptide 4 regulates insulin secretion and islet morphology.

Insulin secretion from pancreatic islet β-cells is primarily regulated by the blood glucose level, and also modulated by a number of biological factors produced inside the islets or released from remote organs. Previous studies have shown that angiopoietin-like protein 4 (Angptl4) controls glucose and lipid metabolism through its actions in the liver, adipose tissue, and skeletal muscles. In this present study, we investigated the possible role of Angptl4 in the regulation of insulin secretion from pancreatic islets.

Preadipocyte factor 1 induces pancreatic ductal cell differentiation into insulin-producing cells.

The preadipocyte factor 1 (Pref-1) is involved in the proliferation and differentiation of various precursor cells. However, the intracellular signaling pathways that control these processes and the role of Pref-1 in the pancreas remain poorly understood. Here, we showed that Pref-1 induces insulin synthesis and secretion via two independent pathways.

The ratio of skeletal muscle mass to visceral fat area is a main determinant linking circulating irisin to metabolic phenotype.

Background: The aims of this study were to investigate whether circulating irisin is associated with favorable metabolic parameters and how the association differs according to body composition in humans.

Methods: A total of 424 subjects (233 men and 191 women), aged 23-73 years (mean age 47.1 years), were enrolled from the Seoul Metro City Diabetes Prevention Program.

Extracellular Vesicles as Drug Delivery Vehicles for Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic, systemic and progressive autoimmune disease of connective tissues common in middle age. Dysregulation of the tissue homeostasis involving inflammation is the hallmark of disease pathogenesis, inducing autoimmune insults that frequently lead to permanent disability. Although the advent of immunosuppressive and anti-inflammatory drugs and, more recently, pathogenic TNF-TNF-R axis-targeting biologics significantly delayed progressive joint destruction with significant reduction of disability and physical improvement, a large proportion of RA patients failed to respond to the treatment.

Massive elimination of multinucleated osteoclasts by eupatilin is due to dual inhibition of transcription and cytoskeletal rearrangement.

Osteoporosis is an aging-associated disease requiring better therapeutic modality. Eupatilin is a major flavonoid from plants such as and which has been reported to possess various beneficial biological effects including anti-inflammation, anti-tumor, anti-cancer, anti-allergy, and anti-oxidation activity. Complete blockade of RANK-dependent osteoclastogenesis was accomplished upon stimulation prior to the receptor activator of nuclear factor κB (RANK)-ligand (RANKL) treatment or post-stimulation of bone marrow macrophages (BMCs) in the presence of RANKL with eupatilin.

Progranulin and a five transmembrane domain-containing receptor-like gene are the key components in receptor activator of nuclear factor κB (RANK)-dependent formation of multinucleated osteoclasts.

Homeostatic bone remodeling is vital to maintain healthy bone tissue. Although the receptor activator of nuclear factor κB ligand (RANKL)/RANK axis is considered the master regulator of osteoclastogenesis, the underlying mechanisms including cell fusion remain incompletely defined. Here, we introduce a new axis in the formation of multinucleated cells via RANK signaling: the progranulin (PGRN)/PIRO (PGRN-induced receptor-like gene during osteoclastogenesis) axis.

Regulation of energy balance by the hypothalamic lipoprotein lipase regulator Angptl3.

Hypothalamic lipid sensing is important for the maintenance of energy balance. Angiopoietin-like protein 3 (Angptl3) critically regulates the clearance of circulating lipids by inhibiting lipoprotein lipase (LPL). The current study demonstrated that Angptl3 is highly expressed in the neurons of the mediobasal hypothalamus, an important area in brain lipid sensing.

Plasma clusterin (ApoJ) levels are associated with adiposity and systemic inflammation.

Obesity and insulin resistance are hallmarks of the metabolic syndrome, which is associated with low-grade chronic inflammation. Clusterin/apolipoprotein J is an abundant plasma chaperone protein that has recently been suggested as a potential biomarker that reflects the inflammatory process in Alzheimer's disease. In the present study, we investigated anthropometric and clinical factors affecting the plasma levels of clusterin in healthy Korean subjects.

Association of urinary RBP4 with insulin resistance, inflammation, and microalbuminuria.

Objective: Serum concentrations of retinol-binding protein 4 (RBP4) are elevated in type 2 diabetes and associated with the severity of insulin resistance; however, there are few data about the relationship between urinary RBP4 levels and metabolic parameters. We assessed urinary RBP4 as a new biomarker by establishing its relationship with clinical parameters associated with insulin resistance and urinary albumin excretion.

Design And Methods: We measured RBP4 in the serum and urine of 689 subjects with diverse glucose tolerance status.

Identification of adipokine clusters related to parameters of fat mass, insulin sensitivity and inflammation.

In obesity, elevated fat mass and ectopic fat accumulation are associated with changes in adipokine secretion, which may link obesity to inflammation and the development of insulin resistance. However, relationships among individual adipokines and between adipokines and parameters of obesity, glucose metabolism or inflammation are largely unknown. Serum concentrations of 20 adipokines were measured in 141 Caucasian obese men (n = 67) and women (n = 74) with a wide range of body weight, glycemia and insulin sensitivity.

Clusterin/ApoJ enhances central leptin signaling through Lrp2-mediated endocytosis.

Hypothalamic leptin signaling plays a central role in maintaining body weight homeostasis. Here, we show that clusterin/ApoJ, recently identified as an anorexigenic neuropeptide, is an important regulator in the hypothalamic leptin signaling pathway. Coadministration of clusterin potentiates the anorexigenic effect of leptin and boosts leptin-induced hypothalamic Stat3 activation.

Implication of circulating irisin levels with brown adipose tissue and sarcopenia in humans.

Context: Irisin is an exercise-induced novel myokine that drives brown-fat-like conversion of white adipose tissue and has been suggested to be a promising target for the treatment of obesity-related metabolic disorders.

Objective: To assess the association of circulating irisin concentrations with brown adipose tissue (BAT) and/or sarcopenia in humans.

Setting And Design: We examined irisin levels in 40 BAT-positive and 40 BAT-negative women detected by (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET).

Implications of C1q/TNF-related protein-3 (CTRP-3) and progranulin in patients with acute coronary syndrome and stable angina pectoris.

Background: C1q/TNF-related protein-3 (CTRP-3), an adiponectin paralog, and progranulin were recently identified as novel adipokines which may link obesity with glucose dysregulation and subclinical inflammation. We analyzed the relationship between CTRP-3, progranulin and coronary artery disease (CAD) in Korean men and women.

Methods: Circulating CTRP-3 and progranulin levels were examined in 362 Korean adults with acute coronary syndrome (ACS, n = 69), stable angina pectoris (SAP, n = 85), and control subjects (n = 208) along with various kinds of cardiometabolic risk factors.

Urinary adiponectin concentration is positively associated with micro- and macro-vascular complications.

Background: A relationship between plasma adiponectin level and a number of metabolic conditions, including insulin resistance, obesity, and type 2 diabetes, has been reported. This study aimed to assess whether urinary adiponectin concentration is correlated with vascular complications.

Methods: The study comprised 708 subjects who enrolled in the Seoul Metro City Diabetes Prevention Program and were carefully monitored from September 2008 to December 2008.

Salsalate and adiponectin ameliorate hepatic steatosis by inhibition of the hepatokine fetuin-A.

Fetuin-A was recently identified as a novel hepatokine which is associated with obesity, insulin resistance and non-alcoholic fatty liver disease. Salsalate, a prodrug of salicylate with an anti-inflammatory effect and lower side effect profile, significantly lowers glucose and triglyceride levels, and increased adiponectin concentrations in randomized clinical trials. In this study, we examined the effects and regulatory mechanisms of salsalate and full length-adiponectin (fAd) on fetuin-A expression, steatosis and lipid metabolism in palmitate-treated HepG2 cells.

Salsalate and Adiponectin Improve Palmitate-Induced Insulin Resistance via Inhibition of Selenoprotein P through the AMPK-FOXO1α Pathway.

Selenoprotein P (SeP) was recently identified as a hepatokine that induces insulin resistance (IR) in rodents and humans. Recent clinical trials have shown that salsalate, a prodrug of salicylate, significantly lowers blood glucose levels and increases adiponectin concentrations. We examined the effects of salsalate and full length-adiponectin (fAd) on the expression of SeP under hyperlipidemic conditions and explored their regulatory mechanism on SeP.