Water and Electrolyte Content in Hypertension in the Skin (WHYSKI) in Primary Aldosteronism.

Background: Primary aldosteronism (PA), the most common curable salt-dependent form of arterial hypertension, features renal K loss and enhanced Na reabsorption. We investigated whether the electrolyte, water, and TonEBP (tonicity-responsive enhancer binding protein)/ (nuclear factor of activated T cells 5) content is altered in the skin of patients with PA and corrected by surgical cure.

Methods: We obtained skin biopsies from 80 subjects: 49 consecutive patients with PA, optimally treated with a mineralocorticoid receptor antagonist; 6 essential hypertensives; and 25 normotensive controls.

Water and Electrolyte Content in Salt-Dependent HYpertension in the SKIn (WHYSKI): Effect of Surgical Cure of Primary Aldosteronism.

Unlabelled:  INTRODUCTION: This study will test the hypothesis that primary aldosteronism (PA) involves alterations in Na, K, and water content in the skin that are corrected by adrenalectomy.

Aim And Methods: In skin biopsies, we will measure the content of Na, K, water, by physical-chemical methods and the osmotic-stress-responsive transcription factor Tonicity-responsive Enhancer Binding Protein (TonEBP, NFAT5) mRNA copy number by droplet digital PCR, in sex-balanced cohorts of 18 -75-year-old consecutive consenting patients with unilateral and bilateral PA, primary (essential) hypertension, and normotension. Before surgery, the patients with unilateral PA will receive the mineralocorticoid receptor antagonist (MRA) canrenone at doses that correct hypokalemia and high blood pressure values.

From the Identification to the Dissection of the Physiological Role of the Mitochondrial Calcium Uniporter: An Ongoing Story.

The notion of mitochondria being involved in the decoding and shaping of intracellular Ca signals has been circulating since the end of the 19th century. Despite that, the molecular identity of the channel that mediates Ca ion transport into mitochondria remained elusive for several years. Only in the last decade, the genes and pathways responsible for the mitochondrial uptake of Ca began to be cloned and characterized.

PKA compartmentalization links cAMP signaling and autophagy.

Autophagy is a highly regulated degradative process crucial for maintaining cell homeostasis. This important catabolic mechanism can be nonspecific, but usually occurs with fine spatial selectivity (compartmentalization), engaging only specific subcellular sites. While the molecular machines driving autophagy are well understood, the involvement of localized signaling events in this process is not well defined.

Compartmentalized Signaling in Aging and Neurodegeneration.

The cyclic AMP (cAMP) signalling cascade is necessary for cell homeostasis and plays important roles in many processes. This is particularly relevant during ageing and age-related diseases, where drastic changes, generally decreases, in cAMP levels have been associated with the progressive decline in overall cell function and, eventually, the loss of cellular integrity. The functional relevance of reduced cAMP is clearly supported by the finding that increases in cAMP levels can reverse some of the effects of ageing.

Intracellular protein kinase CK2 inhibition by ferulic acid-based trimodal nanodevice.

Protein kinase CK2, a pleiotropic and constitutively active kinase, is strictly involved in different diseases, especially in cancer. Many efforts have been carried out to develop specific CK2 inhibitors and recently, it has been evidenced that ferulic acid (FA) represents a promising, albeit cell impermeable, CK2 inhibitor. In the present study, the potential of a nanotechnological approach to cope with intracellular CK2 regulation was explored.

Phosphorylation of p23-1 cochaperone by protein kinase CK2 affects root development in Arabidopsis.

Root growth is a fundamental process in plants and assures nutrient and water uptake required for efficient photosynthesis and metabolism. Postembryonic development of roots is controlled by the functionality of the meristem. Several hormones and signaling molecules regulate the size of the meristem, and among them, auxins play a major role.

Protein kinase CK2 subunits exert specific and coordinated functions in skeletal muscle differentiation and fusogenic activity.

Casein kinase 2 (CK2) is a tetrameric protein kinase composed of 2 catalytic (α and α') and 2 regulatory β subunits. Our study provides the first molecular and cellular characterization of the different CK2 subunits, highlighting their individual roles in skeletal muscle specification and differentiation. Analysis of C2C12 cell knockout for each CK2 subunit reveals that: ) CK2β is mandatory for the expression of the muscle master regulator myogenic differentiation 1 in proliferating myoblasts, thus controlling both myogenic commitment and subsequent muscle-specific gene expression and myotube formation; ) CK2α is involved in the activation of the muscle-specific gene program; and ) CK2α' activity regulates myoblast fusion by mediating plasma membrane translocation of fusogenic proteins essential for membrane coalescence, like myomixer.

Aldosterone Stimulates Its Biosynthesis Via a Novel GPER-Mediated Mechanism.

Context: The G protein-coupled estrogen receptor (GPER) mediates an aldosterone secretagogue effect of 17β-estradiol in human HAC15 adrenocortical cells after estrogen receptor β blockade. Because GPER mediates mineralocorticoid receptor-independent aldosterone effects in other cell types, we hypothesized that aldosterone could modulate its own synthesis via GPER activation.

Methods: HAC15 cells were exposed to aldosterone in the presence or absence of canrenone, a mineralocorticoid receptor antagonist, and/or of the selective GPER antagonist G36.

Methods to Measure Intracellular Ca Concentration Using Ca-Sensitive Dyes.

Ca ion is universally considered the most versatile second messenger responsible for decoding and regulating the majority of the signaling pathways within the cell. The study of intracellular Ca concentration ([Ca]) dynamics is consequently of primary importance for the interpretation of cellular biology. This chapter will present a relatively simple, largely diffused, and nevertheless robust method to measure variations of [Ca] by the use of the Ca-sensitive chemical dye Fura-2.

Recent advances in the molecular mechanism of mitochondrial calcium uptake.

In the last few decades, a large body of experimental evidence has highlighted the complex role for mitochondria in eukaryotic cells: they are not only the site of aerobic metabolism (thus providing most of the ATP supply for endergonic processes) but also a crucial checkpoint of cell death processes (both necrosis and apoptosis) and autophagy. For this purpose, mitochondria must receive and decode the wide variety of physiological and pathological stimuli impacting on the cell. The "old" notion that mitochondria possess a sophisticated machinery for accumulating and releasing Ca , the most common and versatile second messenger of eukaryotic cells, is thus no surprise.

Loss-of-function mutations in the SIGMAR1 gene cause distal hereditary motor neuropathy by impairing ER-mitochondria tethering and Ca2+ signalling.

Distal hereditary motor neuropathies (dHMNs) are clinically and genetically heterogeneous neurological conditions characterized by degeneration of the lower motor neurons. So far, 18 dHMN genes have been identified, however, about 80% of dHMN cases remain without a molecular diagnosis. By a combination of autozygosity mapping, identity-by-descent segment detection and whole-exome sequencing approaches, we identified two novel homozygous mutations in the SIGMAR1 gene (p.

Design, validation and efficacy of bisubstrate inhibitors specifically affecting ecto-CK2 kinase activity.

By derivatizing the purely competitive CK2 inhibitor N1-(4,5,6,7-tetrabromo-1H-benzimidazol-2-yl)-propane-1,3-diamine (K137) at its 3-amino position with a peptidic fragment composed of three or four glutamic or aspartic acid residues, a new family of bisubstrate inhibitors has been generated whose ability to simultaneously interact with both the ATP and the phosphoacceptor substrate-binding sites has been probed by running mixed competition kinetics and by mutational mapping of the kinase residues implicated in substrate recognition. The most effective bisubstrate inhibitor, K137-E4, interacts with three functional regions of the kinase: the hydrophobic pocket close to the ATP-binding site, the basic residues of the p+1 loop that recognizes the acidic determinant at position n+1 and the basic residues of α-helixC that recognize the acidic determinant at position n+3. Compared with the parent inhibitor (K137), K137-E4 is severalfold more potent (IC50 25 compared with 130 nM) and more selective, failing to inhibit any other kinase as drastically as CK2 out of 140 enzymes, whereas 35 kinases are inhibited more potently than CK2 by K137.

Effects of CK2 inhibition in cultured fibroblasts from Type 1 Diabetic patients with or without nephropathy.

CK2 is a multifunctional, pleiotropic protein kinase involved in the regulation of cell proliferation and survival. Since fibroblasts from Type 1 Diabetes patients (T1DM) with Nephropathy exhibit increased proliferation, we studied cell viability, basal CK2 expression and activity, and response to specific CK2 inhibitors TBB (4,5,6,7-tetrabenzotriazole) and CX4945, in fibroblasts from T1DM patients either with (T1DM+) or without (T1DM-) Nephropathy, and from healthy controls (N). We tested expression and phosphorylation of CK2-specific molecular targets.

Chimeric peptides as modulators of CK2-dependent signaling: Mechanism of action and off-target effects.

Protein kinase CK2 is a tetrameric enzyme composed of two catalytic (α/α') and two regulatory (β) subunits. It has a global prosurvival function, especially in cancer, and represents an attractive therapeutic target. Most CK2 inhibitors available so far are ATP-competitive compounds; however, the possibility to block only the phosphorylation of few substrates has been recently explored, and a compound composed of a Tat cell-penetrating peptide and an active cyclic peptide, selected for its ability to bind to the CK2 substrate E7 protein of human papilloma virus, has been developed [Perea et al.

The mitochondrial calcium uniporter controls skeletal muscle trophism in vivo.

Muscle atrophy contributes to the poor prognosis of many pathophysiological conditions, but pharmacological therapies are still limited. Muscle activity leads to major swings in mitochondrial [Ca(2+)], which control aerobic metabolism, cell death, and survival pathways. We investigated in vivo the effects of mitochondrial Ca(2+) homeostasis in skeletal muscle function and trophism by overexpressing or silencing the mitochondrial calcium uniporter (MCU).

Differential phosphorylation of Akt1 and Akt2 by protein kinase CK2 may account for isoform specific functions.

Akt (also known as PKB) is a survival kinase frequently up-regulated in cancer; three isoforms of Akt exist, and among them Akt1 and Akt2 are the most widely and highly expressed. They share the same structure and activation mechanism and have many overlapping functions; nevertheless isoform-specific roles and substrates have been reported, which are expected to rely on sequence diversities. In particular, a special role in differentiating Akt1 and Akt2 isoforms has been assigned to the linker region, a short segment between the PH and the catalytic domains.

Synthesis and properties of a selective inhibitor of homeodomain-interacting protein kinase 2 (HIPK2).

Homeodomain-interacting protein kinase 2 (HIPK2) is a Ser/Thr kinase controlling cell proliferation and survival, whose investigation has been hampered by the lack of specific inhibitors able to dissect its cellular functions. SB203580, a p38 MAP kinase inhibitor, has been used as a tool to inhibit HIPK2 in cells, but here we show that its efficacy as HIPK2 inhibitor is negligible (IC₅₀>40 µM). In contrast by altering the scaffold of the promiscuous CK2 inhibitor TBI a new class of HIPK2 inhibitors has been generated.

Effects of the CK2 inhibitors CX-4945 and CX-5011 on drug-resistant cells.

CK2 is a pleiotropic protein kinase, which regulates many survival pathways and plays a global anti-apoptotic function. It is highly expressed in tumor cells, and is presently considered a promising therapeutic target. Among the many inhibitors available for this kinase, the recently developed CX-4945 and CX-5011 have proved to be very potent, selective and effective in inducing cell death in tumor cells; CX-4945 has recently entered clinical trials.

Protein kinase CK2 accumulation in "oncophilic" cells: causes and effects.

At variance with protein kinases expressed by oncogenes, CK2 is endowed with constitutive activity under normal conditions, and no CK2 gain-of-function mutants are known. Its amount, however, is abnormally high in malignant cells where it appears to be implicated in many of the cell biology phenomena associated with cancer. These observations can be reconciled assuming that tumor cells develop an overdue reliance ("non-oncogene addiction") on abnormally high CK2 level.