Gaucher disease carrier with gestational thrombocytopenia and anemia: a case report.

BACKGROUND: Gaucher disease is an autosomal recessive inborn error of metabolism that causes disorders of blood, bone, and central nervous system as well as hepatosplenomegaly. We present the case of a carrier of Gaucher disease with gestational thrombocytopenia and anemia that required blood transfusion therapy. CASE PRESENTATION: A 24-year-old Nepalese primipara was diagnosed with idiopathic thrombocytopenia at 12 weeks of gestation. Her platelet count had reduced to 30,000/µL at 21 weeks of gestation, and the hemoglobin content reduced to 7.6 g/dL at 27 weeks of gestation. As she did not respond to any medication, blood transfusion was performed. A female infant weighing 2677 g was delivered vaginally at 39 weeks of gestation. On the 78th day of puerperium, the platelet count of the mother recovered to 101,000/µL, and the hemoglobin content recovered to 12.5 g/dL. The infant had convulsions, respiratory depression, wheezing, systemic purpura, and exfoliation of the epidermis at birth. The infant was diagnosed with Gaucher disease at 37 days of age and passed away at 82 days of age. Subsequently, the parents were diagnosed as carriers of Gaucher disease. CONCLUSION: As carriers of this disease do not usually show symptoms, it is imperative to provide information regarding disease management for future pregnancies.

Critical role of TRPC1-mediated Ca²âº entry in decidualization of human endometrial stromal cells.

Decidualization is an ovarian steroid-induced remodeling/differentiation process of uterus essential for embryo implantation and placentation. Here, we investigated the possible involvement of enhanced Ca²âº dynamics in the decidualization process in human endometrial stromal cells (hESC) in its connection with a recently emerging nonvoltage-gated Ca²âº entry channel superfamily, the transient receptor potential (TRP) protein. Combined application of 17ß-estradiol (E2) (10 nM) and progesterone (P4) (1 µM) for 7-14 d resulted in morphological changes of hESC characteristic of decidualization (i.e. cell size increase), whereas sole application of E2 exerted little effects. A 7- to 14-d E2/P4 treatment greatly increased the expression level of decidualization markers IGF binding protein-1 (IGFBP-1) and prolactin and also up-regulated the expression of TRPC1, a canonical TRP subfamily member that has been implicated in store-operated Ca²âº influx (SOC) in other cell types. In parallel with this up-regulation, SOC activity in hESC, the nuclear translocation of phosphorylated cAMP responsive element binding protein (p-CREB) and the expression of Forkhead box protein 01 were enhanced significantly. Small interfering RNA knockdown of TRPC1 counteracted the E2/P4-induced up-regulation of IGFBP-1 and prolactin and enhancement of SOC activity together with the inhibition of hESC size increase, p-CREB nuclear translocation, and FOXO1 up-regulation. Coadministration of SOC inhibitors SK&F96365 or Gd³âº with E2/P4 also suppressed the up-regulation of IGFBP-1 and hESC size increase. Similar inhibitory effects were observed with extracellularly applied TRPC1 extracellular loop 3-directed antibody, which is known to bind a near-pore domain of TRPC1 channel and block its Ca²âº transporting activity. These results strongly suggest that up-regulation of TRPC1 protein and consequent enhancement of SOC-mediated Ca²âº influx may serve as a crucial step for the decidualization process of hESC probably via p-CREB-dependent transcriptional activity associated with FOXO1 activation.

Counteracting effect of TRPC1-associated Ca2+ influx on TNF-α-induced COX-2-dependent prostaglandin E2 production in human colonic myofibroblasts.

TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E(2) (PGE(2)) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca(2+). In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca(2+)-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca(2+) influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd(3+)-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca(2+) influx by TNF-α, whereas potentiated TNF-α induced PGE(2) production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca(2+) influx, and COX-2-dependent PGE(2) production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE(2) production without affecting TRPC1 expression and the Ca(2+) influx. Finally, the suppression of store-dependent Ca(2+) influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE(2) production, respectively, at the downstream of TRPC1-associated Ca(2+) influx.

Mechanosensitive TRP channels in cardiovascular pathophysiology.

Transient receptor potential (TRP) proteins constitute a large non-voltage-gated cation channel superfamily, activated polymodally by various physicochemical stimuli, and are implicated in a variety of cellular functions. Known activators for TRP include not only chemical stimuli such as receptor stimulation, increased acidity and pungent/cooling agents, but temperature change and various forms of mechanical stimuli such as osmotic stress, membrane stretch, and shear force. Recent investigations have revealed that at least ten mammalian TRPs exhibit mechanosensitivity (TRPC1, 5, 6; TRPV1, 2, 4; TRPM3, 7; TRPA1; TRPP2), but the mechanisms underlying it appear considerably divergent and complex. The proposed mechanisms are associated with lipid bilayer mechanics, specialized force-transducing structures, biochemical reactions, membrane trafficking and transcriptional regulation. Many of mechanosensitive (MS)-TRP channel likely undergo multiple regulations via these mechanisms. In the cardiovascular system in which hemodynamic forces constantly operate, the impact of mechanical stress may be particularly significant. Extensive morphological and functional studies have indicated that several MS-TRP channels are expressed in cardiac muscle, vascular smooth muscle, endothelium and vasosensory neurons, each differentially contributing to cardiovascular (CV) functions. To further complexity, the recent evidence suggests that mechanical stress may synergize with neurohormonal mechanisms thereby amplifying otherwise marginal responses. Furthermore, the currently available data suggest that MS-TRP channels may be involved in CV pathophysiology such as cardiac arrhythmia, cardiac hypertrophy/myopathy, hypertension and aneurysms. This review will overview currently known mechanisms for mechanical activation/modulation of TRPs and possible connections of MS-TRP channels to CV disorders.

Synergistic activation of vascular TRPC6 channel by receptor and mechanical stimulation via phospholipase C/diacylglycerol and phospholipase A2/omega-hydroxylase/20-HETE pathways.

TRPC6 is a non-voltage-gated Ca(2+) entry/depolarization channel associated with vascular tone regulation and remodeling. Expressed TRPC6 channel responds to both neurohormonal and mechanical stimuli, the mechanism for which remains controversial. In this study, we examined the possible interactions of receptor and mechanical stimulations in activating this channel using the patch clamp technique. In HEK293 cells expressing TRPC6, application of mechanical stimuli (hypotonicity, shear, 2,4,6-trinitrophenol) caused, albeit not effective by themselves, a prominent potentiation of cationic currents (I(TRPC6)) induced by a muscarinic receptor agonist carbachol. This effect was insensitive to a tarantula toxin GsMTx-4 (5 mumol/L). A similar extent of mechanical potentiation was observed after activation of I(TRPC6) by GTPgammaS or a diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol (OAG). Single TRPC6 channel activity evoked by carbachol was also enhanced by a negative pressure added in the patch pipette. Mechanical potentiation of carbachol- or OAG-induced I(TRPC6) was abolished by small interfering RNA knockdown of cytosolic phospholipase A(2) or pharmacological inhibition of omega-hydroxylation of arachidonic acid into 20-HETE (20-hydroxyeicosatetraenoic acid). Conversely, direct application of 20-HETE enhanced both OAG-induced macroscopic and single channel TRPC6 currents. Essentially the same results were obtained for TRPC6-like cation channel in A7r5 myocytes, where its activation by noradrenaline or Arg8 vasopressin was greatly enhanced by mechanical stimuli via 20-HETE production. Furthermore, myogenic response of pressurized mesenteric artery was significantly enhanced by weak receptor stimulation dependently on 20-HETE production. These results collectively suggest that simultaneous operation of receptor and mechanical stimulations may synergistically amplify transmembrane Ca(2+) mobilization through TRPC6 activation, thereby enhancing the vascular tone via phospholipase C/diacylglycerol and phospholipase A(2)/omega-hydroxylase/20-HETE pathways.

Nitric oxide-cGMP-protein kinase G pathway negatively regulates vascular transient receptor potential channel TRPC6.

We investigated the inhibitory role of the nitric oxide (NO)-cGMP-protein kinase G (PKG) pathway on receptor-activated TRPC6 channels in both a heterologous expression system (HEK293 cells) and A7r5 vascular myocytes. Cationic currents due to TRPC6 expression were strongly suppressed (by approximately 70%) by a NO donor SNAP (100 microm) whether it was applied prior to muscarinic receptor stimulation with carbachol (CCh; 100 microm) or after G-protein activation with intracellular perfusion of GTPgammaS (100 microm). A similar extent of suppression was also observed with a membrane-permeable analogue of cGMP, 8Br-cGMP (100 microm). The inhibitory effects of SNAP and 8Br-cGMP on TRPC6 channel currents were strongly attenuated by the presence of inhibitors for guanylyl cyclase and PKG such as ODQ, KT5823 and DT3. Alanine substitution for the PKG phosphorylation candidate site at T69 but not at other sites (T14A, S28A, T193A, S321A) of TRPC6 similarly attenuated the inhibitory effects of SNAP and 8Br-cGMP. SNAP also significantly reduced single TRPC6 channel activity recorded in the inside-out configuration in a PKG-dependent manner. SNAP-induced PKG activation stimulated the incorporation of (32)P into wild-type and S321A-mutant TRPC6 proteins immunoprecipitated by TRPC6-specific antibody, but this was greatly attenuated in the T69A mutant. SNAP or 8Br-cGMP strongly suppressed TRPC6-like cation currents and membrane depolarization evoked by Arg(8)-vasopressin in A7r5 myocytes. These results strongly suggest that TRPC6 channels can be negatively regulated by the NO-cGMP-PKG pathway, probably via T69 phosphorylation of the N-terminal. This mechanism may be physiologically important in vascular tissues where NO is constantly released from vascular endothelial cells or nitrergic nerves.