Jiyoung Park

Adipocytes represent a major cell type in the mammary tumor microenvironment and are important for tumor growth. Collagen VI (COL6) is highly expressed in adipose tissue, upregulated in the obese state, and enriched in breast cancer lesions and is a stimulator of mammary tumor growth. Here, we have described a cleavage product of the COL6α3 chain, endotrophin (ETP), which serves as the major mediator of the COL6-mediated tumor effects. ETP augmented fibrosis, angiogenesis, and inflammation throu

The past few years have provided substantial evidence for the vital role of the local tumor microenvironment for various aspects of tumor progression. With obesity and its pathophysiological sequelae still on the rise, the adipocyte is increasingly moving center stage in the context of tumor stroma-related studies. To date, we have limited insight into how the systemic metabolic changes associated with obesity and the concomitant modification of the paracrine and endocrine panel of stromal adipo

Glucose-6-phosphate dehydrogenase (G6PD) produces cellular NADPH, which is required for the biosynthesis of fatty acids and cholesterol. Although G6PD is required for lipogenesis, it is poorly understood whether G6PD in adipocytes is involved in energy homeostasis, such as lipid and glucose metabolism. We report here that G6PD plays a role in adipogenesis and that its increase is tightly associated with the dysregulation of lipid metabolism and insulin resistance in obesity. We observed that the

In adipocytes, oxidative stress and chronic inflammation are closely associated with metabolic disorders, including insulin resistance, obesity, cardiovascular disease, and type 2 diabetes. However, the molecular mechanisms underlying these metabolic disorders have not been thoroughly elucidated. In this report, we demonstrate that overexpression of glucose-6-phosphate dehydrogenase (G6PD) in adipocytes stimulates oxidative stress and inflammatory responses, thus affecting the neighboring macrop

Endotrophin is a cleavage product of collagenVIα3 (COL6A3). Here, we explore the relationship between thiazolidinediones (TZDs), endotrophin and cisplatin resistance in the context of a mammary tumour model. COL6A3 levels are increased in response to cisplatin exposure in tumours. Endotrophin, in turn, causes cisplatin resistance. The effects of endotrophin can be bypassed, either through use of COL6 null (COL6(-/-)) mice or by administering TZDs in wild-type mice (leading to a downregulation of

There is growing evidence that obesity is a risk factor of cancer incidence and mortality. Hence, the identification of the mechanistic links between obesity and cancer progression is emerging as a topic of widespread interest. Recently, several groups have addressed the functional roles of leptin, an adipocyte-derived adipokine, for mammary tumor progression. In this issue of Endocrine-Related Cancer, Zheng et al. study the role of leptin on tumor growth in a xenograft model of MMTV-Wnt1-derive

Pyramidal neurons integrate synaptic inputs from basal and apical dendrites to generate stimulus-specific responses. It has been proposed that feed-forward inputs to basal dendrites drive a neuron's stimulus preference, while feedback inputs to apical dendrites sharpen selectivity. However, how a neuron's dendritic domains relate to its functional selectivity has not been demonstrated experimentally. We performed 2-photon dendritic micro-dissection on layer-2/3 pyramidal neurons in mouse primary

Collagen VI (COL6, encoded by the COL6A1, COL6A2, and COL6A3 genes) is an extracellular matrix protein that forms a microfilamentous network in various connective tissues, including skeletal muscle, cartilage, skin and adipose tissue. Among the various tissues, adipose tissue is by far the most abundant source of COL6 microfilaments [1]. Clinically, mutations in COL6 develop mild muscle myopathies (such as Bethlem myopathy and Ullrich congenital muscular dystrophy), with symptoms of muscle weakn

Extracellular matrix dysregulation is associated with chronic liver disease. CollagenVI-alpha3 chain (COL6A3) is a biomarker for hepatic fibrosis and poor prognosis of hepatocellular carcinoma (HCC), but its function in liver pathology remains unknown. High levels of COL6A3 and its cleaved product, endotrophin (ETP) in tumor-neighboring regions are strongly associated with poor prognosis in HCC patients. Here, we report that the high levels of ETP in injured hepatocytes induce JNK-dependent hepa

Highly developed meningeal lymphatics remove waste products from the brain. Disruption of meningeal lymphatic vessels in a mouse model of amyloid pathology (5XFAD) accelerates the accumulation of amyloid plaques in the meninges and brain, and causes learning and memory deficits, suggesting that clearance of toxic wastes by lymphatic vessels plays a key role in neurodegenerative diseases. Here, we discovered that DSCR1 (Down syndrome critical region 1, known also as RCAN1, regulator of calcineuri

Dysregulation of extracellular matrix proteins in obese adipose tissue (AT) induces systemic insulin resistance. The metabolic roles of type VI collagen and its cleavage peptide endotrophin in obese AT are well established. However, the mechanisms regulating endotrophin generation remain elusive. Herein, we identified that several endotrophin-containing peptides (pre-endotrophins) were generated from the COL6A3 chain in a stepwise manner for the efficient production of mature endotrophin, partly