Metabolic profiles in heart failure due to non-ischemic cardiomyopathy at rest and under exercise.

Aims: Identification of metabolic signatures in heart failure (HF) patients and evaluation of their diagnostic potential to discriminate HF patients from healthy controls during baseline and exercise conditions.

Methods: Plasma samples were collected from 22 male HF patients with non-ischemic idiopathic cardiomyopathy and left ventricular systolic dysfunction and 19 healthy controls before (t0), at peak (t1) and 1 h after (t2) symptom-limited cardiopulmonary exercise testing. Two hundred fifty-two metabolites were quantified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC)-MS/MS-based metabolite profiling.

Impact of short-term intake of red wine and grape polyphenol extract on the human metabolome.

Red wine and grape polyphenols are considered to promote cardiovascular health and are involved in multiple biological functions. Their overall impact on the human metabolome is not known. Therefore, exogenous and endogenous metabolic effects were determined in fasting plasma and 24 h urine from healthy male adults consuming a mix of red wine and grape juice extracts (WGM) for 4 days in a placebo-controlled, crossover study.

Distinct neuropathologic phenotypes after disrupting the chloride transport proteins ClC-6 or ClC-7/Ostm1.

The proteins ClC-6 and ClC-7 are expressed in the endosomal-lysosomal system. Because Clcn6-deficient mice display some features of neuronal ceroid lipofuscinosis (NCL), CLCN6 may be a candidate gene for novel forms of NCL. Using landmarks of disease progression from NCL mouse models as a guide, we examined neuropathologic alterations in the central nervous system of Clcn6(-/-), Clcn7(-/-), andgl mice.

Metabolite profiling identifies candidate markers reflecting the clinical adaptations associated with Roux-en-Y gastric bypass surgery.

Background: Roux-en-Y gastric bypass (RYGB) surgery is associated with weight loss, improved insulin sensitivity and glucose homeostasis, and a reduction in co-morbidities such as diabetes and coronary heart disease. To generate further insight into the numerous metabolic adaptations associated with RYGB surgery, we profiled serum metabolites before and after gastric bypass surgery and integrated metabolite changes with clinical data.

Methodology And Principal Findings: Serum metabolites were detected by gas and liquid chromatography-coupled mass spectrometry before, and 3 and 6 months after RYGB in morbidly obese female subjects (n = 14; BMI = 46.

Lysosomal degradation of endocytosed proteins depends on the chloride transport protein ClC-7.

Mutations in either ClC-7, a late endosomal/lysosomal member of the CLC family of chloride channels and transporters, or in its beta-subunit Ostm1 cause osteopetrosis and lysosomal storage disease in mice and humans. The severe phenotype of mice globally deleted for ClC-7 or Ostm1 and the absence of storage material in cultured cells hampered investigations of the mechanism leading to lysosomal pathology in the absence of functional ClC-7/Ostm1 transporters. Tissue-specific ClC-7-knockout mice now reveal that accumulation of storage material occurs cell-autonomously in neurons or renal proximal tubular cells lacking ClC-7.

Lysosomal storage disease upon disruption of the neuronal chloride transport protein ClC-6.

Mammalian CLC proteins function as Cl(-) channels or as electrogenic Cl(-)/H(+) exchangers and are present in the plasma membrane and intracellular vesicles. We now show that the ClC-6 protein is almost exclusively expressed in neurons of the central and peripheral nervous systems, with a particularly high expression in dorsal root ganglia. ClC-6 colocalized with markers for late endosomes in neuronal cell bodies.

Detection of tripeptidyl peptidase I activity in living cells by fluorogenic substrates.

Tripeptidyl peptidase I (TPP-I) is a lysosomal peptidase with unclear physiological function. TPP-I deficiency is associated with late-infantile neuronal ceroid lipofuscinosis (NCL), a fatal neurodegenerative disease of childhood that is characterized by loss of neurons and photoreceptor cells. We have developed two novel fluorogenic substrates, [Ala-Ala-Phe]2-rhodamine 110 and [Arg-Nle-Nle]2-rhodamine 110, that are cleaved by TPP-I in living cells.

ClC-7 requires Ostm1 as a beta-subunit to support bone resorption and lysosomal function.

Mutations in ClC-7, a late endosomal/lysosomal member of the CLC family of chloride channels and transporters, cause osteopetrosis and lysosomal storage disease in humans and mice. Severe osteopetrosis is also observed with mutations in the OSTM1 gene, which encodes a membrane protein of unknown function. Here we show that both ClC-7 and Ostm1 proteins co-localize in late endosomes and lysosomes of various tissues, as well as in the ruffled border of bone-resorbing osteoclasts.

The state of the actin cytoskeleton determines its association with gephyrin: role of ena/VASP family members.

The role the cytoskeleton plays in generating and/or maintaining gephyrin-dependent receptor clusters at inhibitory synapses is poorly understood. Here, the effects of actin cytoskeleton disruption were investigated in eGFP-gephyrin-transfected cells and hippocampal neurons. While gephyrin was not associated with microfilaments in transfected cells, it colocalized with G-actin and cytochalasin-D-induced F-actin patches.

Physiological functions of CLC Cl- channels gleaned from human genetic disease and mouse models.

The CLC gene family encodes nine different Cl() channels in mammals. These channels perform their functions in the plasma membrane or in intracellular organelles such as vesicles of the endosomal/lysosomal pathway or in synaptic vesicles. The elucidation of their cellular roles and their importance for the organism were greatly facilitated by mouse models and by human diseases caused by mutations in their respective genes.

Loss of the chloride channel ClC-7 leads to lysosomal storage disease and neurodegeneration.

ClC-7 is a chloride channel of late endosomes and lysosomes. In osteoclasts, it may cooperate with H(+)-ATPases in acidifying the resorption lacuna. In mice and man, loss of ClC-7 or the H(+)-ATPase a3 subunit causes osteopetrosis, a disease characterized by defective bone resorption.

Ion channels: function unravelled by dysfunction.

Ion channels allow the passage of specific ions and electrical charge. Plasma membrane channels are, for example, important for electrical excitability and transepithelial transport, whereas intracellular channels have roles in acidifying endosomes or in releasing Ca(2+) from stores. The function of several channels emerged from mutations in humans or mice.

Gephyrin interacts with Dynein light chains 1 and 2, components of motor protein complexes.

The clustering of glycine receptors and major subtypes of GABA(A) receptors at inhibitory synapses is mediated by the tubulin-binding protein gephyrin. In an attempt to identify additional components of inhibitory postsynaptic specializations, we performed a yeast two-hybrid screen using gephyrin as bait. Multiple positive clones encoded either the dynein light chain-1 (Dlc-1), also known as dynein LC8 and protein inhibitor of neuronal nitric oxide synthase, or its homolog Dlc-2.