Analysis of circulating metabolites to differentiate Parkinson's disease and essential tremor.

Parkinson's disease (PD) and essential tremor (ET) are two common adult-onset tremor disorders in which prevalence increases with age. PD is a neurodegenerative condition with progressive disability. In ET, neurodegeneration is not an established etiology.

Hydrogen sulfide facilitates reprogramming and trans-differentiation in 3D dermal fibroblast.

The efficiency of cell reprogramming in two-dimensional (2D) cultures is limited. Given that cellular stemness is intimately related to microenvironmental changes, 3D cell cultures have the potential of overcoming this limited capacity by allowing cells to self-organize by aggregation. In 3D space, cells interact more efficiently, modify their cellular topology, gene expression, signaling, and metabolism.

3-Mercaptopyruvate sulfurtransferase disruption in dermal fibroblasts facilitates adipogenic trans-differentiation.

Transitioning from a differentiated state to a higher-order of plasticity, by partial rather than full reactivation of pluripotency genes, might be a better approach in regenerative medicine. Hydrogen sulfide plays a crucial role in the maintenance and differentiation of mesenchymal stem cells (MSC) that have the potential to differentiate to a diverse group of mesenchymally derived cells. It was shown that these cells show a heavy reliance on cystathionine-β-synthase (CBS)-derived hydrogen sulfide (HS) during differentiation.

Replicative senescence is distinguishable from DNA damage-induced senescence by increased methylation of promoter of rDNA and reduced expression of rRNA.

Human fibroblasts become senescent after a limited number of replications or by diverse stresses, such as DNA damage. However, replicative and damage induced senescence are indistinguishable in respect to proliferation cessation and expression of senescence markers, senescence-associated β-galactosidase, p16 and p21. Here, we show that senescence types can be distinguished by reduced levels of 18S, 5.

Homocysteine in Chronic Kidney Disease.

Hyperhomocysteinemia occurs in chronic- and end-stage kidney disease at the time when dialysis or transplant becomes indispensable for survival. Excessive accumulation of homocysteine (Hcy) aggravates conditions associated with imbalanced homeostasis and cellular redox thereby resulting in severe oxidative stress leading to oxidation of reduced free and protein-bound thiols. Thiol modifications such as N-homocysteinylation, sulfination, cysteinylation, glutathionylation, and sulfhydration control cellular responses that direct complex metabolic pathways.

Dedifferentiation of cancer cells following recovery from a potentially lethal damage is mediated by H2S-Nampt.

Recently, we reported that cancer cells that recover from a potentially lethal damage gain new phenotypic features comprised of mitochondrial structural remodeling associated with increased glycolytic dependency and drug resistance. Here, we demonstrate that a subset of cancer cells, upon recovery from a potentially lethal damage, undergo dedifferentiation and express genes, which are characteristic of undifferentiated stem cells. While these cells are competent in maintaining differentiated progeny of tumor, they also exhibit transdifferentiation potential.

A H2S-Nampt dependent energetic circuit is critical to survival and cytoprotection from damage in cancer cells.

We recently demonstrated that cancer cells that recover from damage exhibit increased aerobic glycolysis, however, the molecular mechanism by which cancer cells survive the damage and show increased aerobic glycolysis remains unknown. Here, we demonstrate that diverse cancer cells that survive hypoxic or oxidative damage show rapid cell proliferation, and develop tolerance to damage associated with increased production of hydrogen sulfide (H2S) which drives up-regulation of nicotinamide phosphoribosyltransferase (Nampt). Consistent with existence of a H2S-Nampt energetic circuit, in damage recovered cancer cells, H2S, Nampt and ATP production exhibit a significant correlation.

Cancer cells recovering from damage exhibit mitochondrial restructuring and increased aerobic glycolysis.

Instead of relying on mitochondrial oxidative phosphorylation, most cancer cells rely heavily on aerobic glycolysis, a phenomenon termed as "the Warburg effect". We considered that this effect is a direct consequence of damage which persists in cancer cells that recover from damage. To this end, we studied glycolysis and rate of cell proliferation in cancer cells that recovered from severe damage.

p53-mediated regulation of neuronal differentiation via regulation of dual oxidase maturation factor 1.

The p53 transcription factor is involved in cell cycle, apoptosis and differentiation. However, the mechanism of p53 mediated differentiation is not fully understood. Here, we show that recently discovered dual oxidase maturation factor 1 (DUOXA1), which was implicated in neuronal differentiation, is regulated by p53 and may be an important factor in neuronal differentiation.

Mammalian numb-interacting protein 1/dual oxidase maturation factor 1 directs neuronal fate in stem cells.

In this study, we describe a role for the mammalian Numb-interacting protein 1 (Nip1) in regulation of neuronal differentiation in stem cells. The expression of Nip1 was detected in the developing mouse brain, embryonic stem cells, primary neuronal stem cells, and retinoic acid-treated P19 embryonal carcinoma cells. The highest expression of Nip1 was observed in undifferentiated neuronal stem cells and was associated with Duox1-mediated reactive oxygen species ROS production.

NIP1/DUOXA1 expression in epithelial breast cancer cells: regulation of cell adhesion and actin dynamics.

DUOXA1/NIP1, originally identified as a Numb-interacting protein, was recently shown to function as a maturation factor for the dual oxidase 1(DUOX1). In this study, we identified DUOXA1/NIP1 expression in breast cancer cells, observed high expression of DUOXA1 in non-invasive MCF7 cells and low expression in highly metastatic cells with impaired p53 functions linking the expression of DUOXA1 with p53. An inhibition of cell proliferation associated with upregulation of p21(Cip1/WAF1) was observed in MDA-MB-231 cells following transfection of DUOXA1.

SAP binds to CD22 and regulates B cell inhibitory signaling and calcium flux.

The signaling lymphocyte activation molecule (SLAM)-associated protein (SAP or SH2D1A) is an important regulator of immune function which, when mutated or deleted, causes the X-linked lymphoproliferative syndrome (XLP). Because B cell lymphoma is a major phenotype of XLP, it is important to understand the function of SAP in B cells. Here we report that SAP is expressed endogenously in mouse splenic B cells, is inducibly expressed in the human BJAB cells, and co-localizes and interacts with CD22.

Stimulation of phosphoinositide 3-kinase/Akt signaling by copper and zinc ions: mechanisms and consequences.

The phosphoinositide 3'-kinase (PI3K)/Akt signaling cascade controls cellular processes such as apoptosis and proliferation. Moreover, it is a mediator of insulin effects on target cells and as such is a major regulator of fuel metabolism. The PI3K/Akt cascade was demonstrated to be activated by stressful stimuli, including heat shock and reactive oxygen species (ROS).

P53 mediated regulation of metallothionein transcription in breast cancer cells.

Recent studies have shown that only breast cancer epithelial cells with intact p53 can induce metallothionein (MT) synthesis after exposure to metals. In this study, the potential role of p53 on regulation of MT was investigated. Results demonstrate that zinc and copper increased metal response elements (MREs) activity and MTF-1 expression in p53 positive MN1 and parental MCF7 cells.

The role of SLAM family receptors in immune cell signaling.

The signaling lymphocyte-activating molecule (SLAM) family immunoreceptors are expressed in a wide array of immune cells, including both T and B lymphocytes. By virtue of their ability to transduce tyrosine phosphorylation signals through the so-called ITSM (immunoreceptor tyrosine-based switch motif) sequences, they play an important part in regulating both innate and adaptive immune responses. The critical role of the SLAM immunoreceptors in mediating normal immune reactions was highlighted in recent findings that SAP, a SLAM-associated protein, modulates the activities of various immune cells through interactions with different members of the SLAM family expressed in these cells.

Interaction of metallothionein with tumor suppressor p53 protein.

Previous reports have shown that metallothionein (MT) may modulate p53 activity through zinc exchange. However, little is known on a direct interaction between MT and p53 in cells. The results demonstrate an interaction between MT and p53 can occur in vitro.

Inhibition of extracellular signal regulated kinase (ERK) leads to apoptosis inducing factor (AIF) mediated apoptosis in epithelial breast cancer cells: the lack of effect of ERK in p53 mediated copper induced apoptosis.

Recent studies have shown that MEK/ERK-mediated signals play a major role in regulation of activity of p53 tumor suppressor protein. In this study, we investigated whether or not there is functional interaction between p53 and MEK/ERK pathways in epithelial breast cancer cells exposed to copper or zinc. We demonstrated that expression of wild-type p53 induced by copper or zinc significantly reduced phosphorylation of extracellular signal regulated kinase (ERK) in epithelial breast cancer MCF7 cells.

Copper ions strongly activate the phosphoinositide-3-kinase/Akt pathway independent of the generation of reactive oxygen species.

Copper is implicated in metabolic disorders, such as Wilson's disease or Alzheimer's disease. Analysis of signaling pathways regulating cellular survival and function in response to a copper stress is crucial for understanding the pathogenesis of such diseases. Exposure of human skin fibroblasts or HeLa cells to Cu(2+) resulted in a dose- and time-dependent activation of the antiapoptotic kinase Akt/protein kinase B, starting at concentrations as low as 3 microM.