P465L-PPARγ mutation confers partial resistance to the hypolipidaemic action of fibrates

Familial partial lipodystrophic syndrome 3 (FPLD3) is associated with mutations in the transcription factor PPAR. One of these mutations, the P467L, confers a dominant negative effect. We and others have previously investigated the pathophysiology associated to this mutation using a humanised mouse model that recapitulated most of the clinical symptoms observed in human patients under different experimental conditions. One of the key clinical manifestations observed both in humans and mouse models is the ectopic accumulation of fat in the liver. Here, we dissect the molecular mechanisms that contribute to the excessive accumulation of lipids in the liver and characterise the negative effect of this PPAR mutation on the activity of PPAR in vivo when activated by fibrates. P465L mice have increased levels of insulin and free fatty acids (FFA), exhibit decreased levels of Very Low Density Lipoproteins (VLDL) when fed high fat diet (HFD) and partial impaired response to the hypolipidemic action of WY14643. This indicates that the deleterious effects of P465L-PPAR mutation may be augmented by their collateral negative effect on PPAR function.Wellcome Trust, MRC MDU (MC_UU_12012/2), FP7-MITIN (Integration of the System Models of Mitochondrial Function and Insulin Signaling and its Application in the Study of Complex Diseases) (Grant Agreement 223450) and H2020 EPoS (Elucidating Pathways of Steatohepatitis) (Grant Agreement 634413). Disease Model Core, Biochemistry Assay Lab and the Histology Core are funded by MRC_MC_UU_12012/5 and a Wellcome Trust Strategic Award [100574/Z/12/Z

Mechanisms bywhich dietary fatty acids regulate mitochondrial structure-function in health and disease

Mitochondria are the energy-producing organelles within a cell. Furthermore, mitochondria have a role in maintaining cellular homeostasis and proper calcium concentrations, building critical components of hormones and other signaling molecules, and controlling apoptosis. Structurally, mitochondria are unique because they have 2 membranes that allow for compartmentalization. The composition and molecular organization of thesemembranes are crucial to the maintenance and function of mitochondria. In this review, we first present a general overview of mitochondrial membrane biochemistry and biophysics followed by the role of different dietary saturated and unsaturated fatty acids in modulatingmitochondrial membrane structure-function.We focus extensively on long-chain n-3 (ω-3) polyunsaturated fatty acids and their underlyingmechanisms of action. Finally,we discuss implications of understanding molecular mechanisms by which dietary n-3 fatty acids targetmitochondrial structure-function in metabolic diseases such as obesity, cardiac-ischemia reperfusion injury, obesity, type 2 diabetes, nonalcoholic fatty liver disease, and select cancers

Bitter melon reduces head and neck squamous cell carcinoma growth by targeting c-Met signaling.

Head and neck squamous cell carcinoma (HNSCC) remains difficult to treat, and despite of advances in treatment, the overall survival rate has only modestly improved over the past several years. Thus, there is an urgent need for additional therapeutic modalities. We hypothesized that treatment of HNSCC cells with a dietary product such as bitter melon extract (BME) modulates multiple signaling pathways and regresses HNSCC tumor growth in a preclinical model. We observed a reduced cell proliferation in HNSCC cell lines. The mechanistic studies reveal that treatment of BME in HNSCC cells inhibited c-Met signaling pathway. We also observed that BME treatment in HNSCC reduced phosphoStat3, c-myc and Mcl-1 expression, downstream signaling molecules of c-Met. Furthermore, BME treatment in HNSCC cells modulated the expression of key cell cycle progression molecules leading to halted cell growth. Finally, BME feeding in mice bearing HNSCC xenograft tumor resulted in an inhibition of tumor growth and c-Met expression. Together, our results suggested that BME treatment in HNSCC cells modulates multiple signaling pathways and may have therapeutic potential for treating HNSCC

Oral BME administration in Cal27 xenograft nude mice reduces tumor growth.

<p>(A). Cal27 cells were implanted subcutaneously into the flank of athymic nude mice. Tumor bearing mice were randomized into two groups, and water (control) or BME was gavaged orally for 4 weeks (5 day/wk). Down arrow indicates the BME or water gavage start time. Volume of tumor growth was monitored once a week and presented as a mean. Small bar indicates standard error (*, p<0.05). (B). Representative tumors dissected from the control and BME-fed mice are shown. (C). Western blot of c-Met, c-myc and MCM2 in xenograft tumor tissues isolated from both control and BME fed mice. The blot was reprobed with an antibody to GAPDH for comparison of protein load. (D). The immunohistochemical staining for PCNA in representative tumor section of a control and BME-fed mice (magnification, 40×) are shown. (E). A representative tumor section from control or BME-fed mice stained with hematoxylin and eosin (magnification, 40×) are shown. Arrows indicate the mitosis.</p