Neurogranin is expressed in mammalian skeletal muscle and inhibits calcineurin signaling and myoblast fusion.

Calcineurin is a Ca2+/calmodulin (CaM)-dependent phosphatase that plays a critical role in promoting the slow fiber phenotype and myoblast fusion in skeletal muscle, thereby making calcineurin an attractive cellular target for enhancing fatigue resistance, muscle metabolism, and muscle repair. Neurogranin (Ng) is a CaM-binding protein thought to be expressed solely in brain and neurons, where it inhibits calcineurin signaling by sequestering CaM, thus lowering its cellular availability. Here, we demonstrate for the first time the expression of Ng protein and mRNA in mammalian skeletal muscle. Both protein and mRNA levels are greater in slow-oxidative compared with fast-glycolytic muscles. Coimmunoprecipitation of CaM with Ng in homogenates of C2C12 myotubes, mouse soleus, and human vastus lateralis suggests that these proteins physically interact. To determine whether Ng inhibits calcineurin signaling in muscle, we used Ng siRNA with C2C12 myotubes to reduce Ng protein levels by 60%. As a result of reduced Ng expression, C2C12 myotubes had enhanced CaM-calcineurin binding and calcineurin signaling as indicated by reduced phosphorylation of nuclear factor of activated T cells and increased utrophin mRNA. In addition, calcineurin signaling affects the expression of myogenin and stabilin-2, which are involved in myogenic differentiation and myoblast fusion, respectively. Here, we found that both myogenin and stabilin-2 were significantly elevated by Ng siRNA in C2C12 cells, concomitantly with an increased fusion index. Taken together, these results demonstrate the expression of Ng in mammalian skeletal muscle where it appears to be a novel regulator of calcineurin signaling.

Intra-arterial stem cell therapy modulates neuronal calcineurin and confers neuroprotection after ischemic stroke.

Aim: Calcineurin (CaN) is a threonine/phosphatase which play roles in neuronal homeostasis. Ischemic stroke induces hyperactivation of CaN which further triggers apoptotic signaling. CaN inhibition has limited therapeutic output and neurotoxicity due to its intricate roles in the neuronal network and requires a strategic modulation. Intra-arterial (IA) mesenchymal stem cells (MSCs) have shown to interact with the milieu in a paracrine manner as compared to CaN inhibitors to ameliorate the neuronal damage triggered by ischemia/reperfusion injury. The present study investigates the role of IA MSCs in modulating neuronal CaN after stroke onset. Materials and methods: To validate, middle-aged ovariectomized female rats exposed to MCAo (90 min) were treated with IA MSCs (1 × 105 MSCs) or phosphate-buffered saline (PBS) at 6 hours to check CaN expression in different groups.Tests for assessing functional and motor coordination were performed along with biochemical estimations. Furthermore, an inhibition study by non-selective inhibitor of neuronal calcium channel, flunarizine, was performed to explore the possible underlying mechanism by which IA MSCs may interact with CaN. Results: The study suggests that IA MSCs seemingly reduce the expression of CaN after ischemic stroke. IA MSCs have shown to improve the functional outcome and normalize oxidative parameters. Conclusion: Our study provides a preliminary evidence of role of IA MSCs in modulating CaN expression.

An insight into new strategies to combat antifungal drug resistance.

Invasive fungal infections especially in immunocompromised patients represent a dominating cause of mortality. The most commonly used antifungal agents can be divided into three broad categories, including triazoles, echinocandins and polyenes. Antifungal resistance is on the increase, posing a growing threat to the stewardship of immunocompromised patients with fungal infections. The paucity of currently available antifungals leads to the rapid emergence of drug resistance and thus aggravates the refractoriness of invasive fungal infections. Therefore, deep exploration into mechanisms of drug resistance and search for new antifungal targets are required. This review highlights the therapeutic strategies targeting Hsp90, calcineurin, trehalose biosynthesis and sphingolipids biosynthesis, in an attempt to provide clinical evidence for overcoming drug resistance and to form the rationale for combination therapy of conventional antifungals and agents with novel mechanisms of action. What's more, this review also gives a concise introduction of three new-fashioned antifungals, including carboxymethyl chitosan, silver nanoparticles and chromogranin A-N46.

Methamphetamine toxicity-induced calcineurin activation, nuclear translocation of nuclear factor of activated T-cells and elevation of cyclooxygenase 2 levels are averted by calpastatin overexpression in neuroblastoma SH-SY5Y cells.

Methamphetamine (METH) is an addictive stimulant drug that has many negative consequences, including toxic effects to the brain. Recently, the induction of inflammatory processes has been identified as a potential contributing factor to induce neuronal cell degeneration. It has been demonstrated that the expression of inflammatory agents, such as cyclooxygenase 2 (COX-2), depends on the activation of calcineurin (CaN) and nuclear factor of activated T-cells (NFAT). Moreover, the excessive elevation in cytosolic Ca2+ levels activates the cell death process, including calpain activation in neurons, which was diminished by the overexpression of the calpain inhibitor protein, calpastatin. However, it is unclear whether calpain mediates CaN-NFAT activation in the neurotoxic process. In the present study, we observed that the toxic high dose of METH-treated neuroblastoma SH-SY5Y cells significantly decreased cell viability but increased apoptotic cell death, the active cleaved form of calcineurin, the nuclear translocation of NFAT, and COX-2 levels. Nevertheless, these toxic effects were diminished in METH-treated calpastatin-overexpressing SH-SY5Y cells. These findings might emphasize the role of calpastatin against METH-induced toxicity by a mechanism related to calpain-dependent CaN-NFAT activation-induced COX-2 expression.

Reduced Cardiac Calcineurin Expression Mimics Long-Term Hypoxia-Induced Heart Defects in Drosophila.

BACKGROUND: Hypoxia is often associated with cardiopulmonary diseases, which represent some of the leading causes of mortality worldwide. Long-term hypoxia exposures, whether from disease or environmental condition, can cause cardiomyopathy and lead to heart failure. Indeed, hypoxia-induced heart failure is a hallmark feature of chronic mountain sickness in maladapted populations living at high altitude. In a previously established Drosophila heart model for long-term hypoxia exposure, we found that hypoxia caused heart dysfunction. Calcineurin is known to be critical in cardiac hypertrophy under normoxia, but its role in the heart under hypoxia is poorly understood. METHODS AND RESULTS: In the present study, we explore the function of calcineurin, a gene candidate we found downregulated in the Drosophila heart after lifetime and multigenerational hypoxia exposure. We examined the roles of 2 homologs of Calcineurin A, CanA14F, and Pp2B in the Drosophila cardiac response to long-term hypoxia. We found that knockdown of these calcineurin catalytic subunits caused cardiac restriction under normoxia that are further aggravated under hypoxia. Conversely, cardiac overexpression of Pp2B under hypoxia was lethal, suggesting that a hypertrophic signal in the presence of insufficient oxygen supply is deleterious. CONCLUSIONS: Our results suggest a key role for calcineurin in cardiac remodeling during long-term hypoxia with implications for diseases of chronic hypoxia, and it likely contributes to mechanisms underlying these disease states.

Extensive alternative splicing transitions during postnatal skeletal muscle development are required for calcium handling functions.

Postnatal development of skeletal muscle is a highly dynamic period of tissue remodeling. Here, we used RNA-seq to identify transcriptome changes from late embryonic to adult mouse muscle and demonstrate that alternative splicing developmental transitions impact muscle physiology. The first 2 weeks after birth are particularly dynamic for differential gene expression and alternative splicing transitions, and calcium-handling functions are significantly enriched among genes that undergo alternative splicing. We focused on the postnatal splicing transitions of the three calcineurin A genes, calcium-dependent phosphatases that regulate multiple aspects of muscle biology. Redirected splicing of calcineurin A to the fetal isoforms in adult muscle and in differentiated C2C12 slows the timing of muscle relaxation, promotes nuclear localization of calcineurin target Nfatc3, and/or affects expression of Nfatc transcription targets. The results demonstrate a previously unknown specificity of calcineurin isoforms as well as the broader impact of alternative splicing during muscle postnatal development.

Calcineurin Dysregulation Underlies Spinal Cord Injury-Induced K+ Channel Dysfunction in DRG Neurons.

Dysfunction of the fast-inactivating Kv3.4 potassium current in dorsal root ganglion (DRG) neurons contributes to the hyperexcitability associated with persistent pain induced by spinal cord injury (SCI). However, the underlying mechanism is not known. In light of our previous work demonstrating modulation of the Kv3.4 channel by phosphorylation, we investigated the role of the phosphatase calcineurin (CaN) using electrophysiological, molecular, and imaging approaches in adult female Sprague Dawley rats. Pharmacological inhibition of CaN in small-diameter DRG neurons slowed repolarization of the somatic action potential (AP) and attenuated the Kv3.4 current. Attenuated Kv3.4 currents also exhibited slowed inactivation. We observed similar effects on the recombinant Kv3.4 channel heterologously expressed in Chinese hamster ovary cells, supporting our findings in DRG neurons. Elucidating the molecular basis of these effects, mutation of four previously characterized serines within the Kv3.4 N-terminal inactivation domain eliminated the effects of CaN inhibition on the Kv3.4 current. SCI similarly induced concurrent Kv3.4 current attenuation and slowing of inactivation. Although there was little change in CaN expression and localization after injury, SCI induced upregulation of the native regulator of CaN 1 (RCAN1) in the DRG at the transcript and protein levels. Consistent with CaN inhibition resulting from RCAN1 upregulation, overexpression of RCAN1 in naive DRG neurons recapitulated the effects of pharmacological CaN inhibition on the Kv3.4 current and the AP. Overall, these results demonstrate a novel regulatory pathway that links CaN, RCAN1, and Kv3.4 in DRG neurons. Dysregulation of this pathway might underlie a peripheral mechanism of pain sensitization induced by SCI.SIGNIFICANCE STATEMENT Pain sensitization associated with spinal cord injury (SCI) involves poorly understood maladaptive modulation of neuronal excitability. Although central mechanisms have received significant attention, recent studies have identified peripheral nerve hyperexcitability as a driver of persistent pain signaling after SCI. However, the ion channels and signaling molecules responsible for this change in primary sensory neuron excitability are still not well defined. To address this problem, this study used complementary electrophysiological and molecular methods to determine how Kv3.4, a voltage-gated K+ channel robustly expressed in dorsal root ganglion neurons, becomes dysfunctional upon calcineurin (CaN) inhibition. The results strongly suggest that CaN inhibition underlies SCI-induced dysfunction of Kv3.4 and the associated excitability changes through upregulation of the native regulator of CaN 1 (RCAN1).

The effect of RCAN1 on the biological behaviors of small cell lung cancer.

Bone is the third most common site of cancer metastasis. In total, 30%-40% of lung cancer cases can develop skeletal metastasis for which no effective therapy in clinic is available. RCAN1 (regulator of calcineurin 1) is an important regulator in angiogenesis which is vital to tumor growth. In this study, we investigated the changes of biological behaviors in SBC-5 and SBC-3 cells after the RCAN1 expression level was changed. Briefly, overexpression of RCAN1 significantly attenuated their malignancy, including decreased ability of proliferation, colony formation, migration, invasion, and bone adherence. Furthermore, the cell cycle progression was impeded. Although the opposite changes were observed in SBC-3 cells after the RCAN1 expression was suppressed by RNA interference, the apoptosis rate was not affected by the expression level of RCAN1 in these cells. So, our research revealed that RCAN1 was involved in the development of small cell lung cancer, and it might be a cancer-inhibiting gene for the formation of bone metastases in small cell lung cancer.

Elucidation of the calcineurin-Crz1 stress response transcriptional network in the human fungal pathogen Cryptococcus neoformans.

Calcineurin is a highly conserved Ca2+/calmodulin-dependent serine/threonine-specific protein phosphatase that orchestrates cellular Ca2+ signaling responses. In Cryptococcus neoformans, calcineurin is activated by multiple stresses including high temperature, and is essential for stress adaptation and virulence. The transcription factor Crz1 is a major calcineurin effector in Saccharomyces cerevisiae and other fungi. Calcineurin dephosphorylates Crz1, thereby enabling Crz1 nuclear translocation and transcription of target genes. Here we show that loss of Crz1 confers phenotypes intermediate between wild-type and calcineurin mutants, and demonstrate that deletion of the calcineurin docking domain results in the inability of Crz1 to translocate into the nucleus under thermal stress. RNA-sequencing revealed 102 genes that are regulated in a calcineurin-Crz1-dependent manner at 37°C. The majority of genes were down-regulated in cna1Δ and crz1Δ mutants, indicating these genes are normally activated by the calcineurin-Crz1 pathway at high temperature. About 58% of calcineurin-Crz1 target genes have unknown functions, while genes with known or predicted functions are involved in cell wall remodeling, calcium transport, and pheromone production. We identified three calcineurin-dependent response element motifs within the promoter regions of calcineurin-Crz1 target genes, and show that Crz1 binding to target gene promoters is increased upon thermal stress in a calcineurin-dependent fashion. Additionally, we found a large set of genes independently regulated by calcineurin, and Crz1 regulates 59 genes independently of calcineurin. Given the intermediate crz1Δ mutant phenotype, and our recent evidence for a calcineurin regulatory network impacting mRNA in P-bodies and stress granules independently of Crz1, calcineurin likely acts on factors beyond Crz1 that govern mRNA expression/stability to operate a branched transcriptional/post-transcriptional stress response network necessary for fungal virulence. Taken together, our findings reveal the core calcineurin-Crz1 stress response cascade is maintained from ascomycetes to a pathogenic basidiomycete fungus, but its output in C. neoformans appears to be adapted to promote fungal virulence.

Exploring Regulatory Mechanisms of Atrial Myocyte Hypertrophy of Mitral Regurgitation through Gene Expression Profiling Analysis: Role of NFAT in Cardiac Hypertrophy.

BACKGROUND: Left atrial enlargement in mitral regurgitation (MR) predicts a poor prognosis. The regulatory mechanisms of atrial myocyte hypertrophy of MR patients remain unknown. METHODS AND RESULTS: This study comprised 14 patients with MR, 7 patients with aortic valve disease (AVD), and 6 purchased samples from normal subjects (NC). We used microarrays, enrichment analysis and quantitative RT-PCR to study the gene expression profiles in the left atria. Microarray results showed that 112 genes were differentially up-regulated and 132 genes were differentially down-regulated in the left atria between MR patients and NC. Enrichment analysis of differentially expressed genes demonstrated that "NFAT in cardiac hypertrophy" pathway was not only one of the significant associated canonical pathways, but also the only one predicted with a non-zero score of 1.34 (i.e. activated) through Ingenuity Pathway Analysis molecule activity predictor. Ingenuity Pathway Analysis Global Molecular Network analysis exhibited that the highest score network also showed high association with cardiac related pathways and functions. Therefore, 5 NFAT associated genes (PPP3R1, PPP3CB, CAMK1, MEF2C, PLCE1) were studies for validation. The mRNA expressions of PPP3CB and MEF2C were significantly up-regulated, and CAMK1 and PPP3R1 were significantly down-regulated in MR patients compared to NC. Moreover, MR patients had significantly increased mRNA levels of PPP3CB, MEF2C and PLCE1 compared to AVD patients. The atrial myocyte size of MR patients significantly exceeded that of the AVD patients and NC. CONCLUSIONS: Differentially expressed genes in the "NFAT in cardiac hypertrophy" pathway may play a critical role in the atrial myocyte hypertrophy of MR patients.

Effect of the knockdown of Cabin1 on p53 in glomerular podocyte.

Calcineurin binding protein 1 (Cabin1) is a natural inhibitor of calcineurin (CN). Moreover, Cabin1 retards tumor cell apoptosis by regulating p53. This study was designed to observe the expression of Cabin1 during podocyte injury, as well as its relationship with p53. Sprague-Dawley rats were used for the establishment of 5/6 nephrectomized rat model. Sham-operated rats underwent ventral laparotomy without nephrectomy. Then, rats were sacrificed at 8 and 12 weeks after nephrectomy. WT-1, a podocyte nuclear protein, was used for indicating the localization of Cabin1 in glomeruli. As tacrolimus protects podocyte via inhibiting AngiotensinII (AngII) induced CN activation. Cultured podocytes were injured by AngII or restored by tacrolimus. The protein expression and localization was detected by western blot or immunofluorescence staining. Cabin1 was knocked down by siRNA in cultured podocytes. In 5/6 nephrectomized rats, the colocalization of Cabin1 and WT-1 became more obviously in podocyte nuclei. Cabin1 protein was markedly increased in rats at 8 and 12 weeks after nephrectomy, as well as in AngII injured podocytes at 48 h (0.99 ± 0.12 in AngII group versus 0.80 ± 0.16 in control group). Cabin1 and p53 colocalized in cultured podocyte nuclei, p53 expression was significantly decreased (0.21 ± 0.05 in siRNA group versus 0.31 ± 0.05 in negative control group) after Cabin1 was being knocked down. In conclusion, Cabin1 expression significantly increases during podocyte injury. Knockdown of Cabin1 induces p53 expression decrease in cultured podocyte. Cabin1 may provide a new target to investigate podocyte injury.

MicroRNA-30 family members regulate calcium/calcineurin signaling in podocytes.

Calcium/calcineurin signaling is critical for normal cellular physiology. Abnormalities in this pathway cause many diseases, including podocytopathy; therefore, understanding the mechanisms that underlie the regulation of calcium/calcineurin signaling is essential. Here, we showed that critical components of calcium/calcineurin signaling, including TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3, are the targets of the microRNA-30 family (miR-30s). We found that these 5 genes are highly expressed as mRNA, but the level of the proteins is low in normal podocytes. Conversely, protein levels were markedly elevated in podocytes from rats treated with puromycin aminonucleoside (PAN) and from patients with focal segmental glomerulosclerosis (FSGS). In both FSGS patients and PAN-treated rats, miR-30s were downregulated in podocytes. In cultured podocytes, PAN or a miR-30 sponge increased TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3 expression; calcium influx; intracellular Ca2+ concentration; and calcineurin activity. Moreover, NFATC3 nuclear translocation, synaptopodin degradation, integrin ß3 (ITGB3) activation, and actin fiber loss, which are downstream of calcium/calcineurin signaling, were induced by miR-30 reduction but blocked by the calcineurin inhibitor FK506. Podocyte-specific expression of the miR-30 sponge in mice increased calcium/calcineurin pathway component protein expression and calcineurin activity. The mice developed podocyte foot process effacement and proteinuria, which were prevented by FK506. miR-30s also regulated calcium/calcineurin signaling in cardiomyocytes. Together, our results identify miR-30s as essential regulators of calcium/calcineurin signaling.

Investigation of genes encoding calcineurin B-like protein family in legumes and their expression analyses in chickpea (Cicer arietinum L.).

Calcium ion (Ca2+) is a ubiquitous second messenger that transmits various internal and external signals including stresses and, therefore, is important for plants' response process. Calcineurin B-like proteins (CBLs) are one of the plant calcium sensors, which sense and convey the changes in cytosolic Ca2+-concentration for response process. A search in four leguminous plant (soybean, Medicago truncatula, common bean and chickpea) genomes identified 9 to 15 genes in each species that encode CBL proteins. Sequence analyses of CBL peptides and coding sequences (CDS) suggested that there are nine original CBL genes in these legumes and some of them were multiplied during whole genome or local gene duplication. Coding sequences of chickpea CBL genes (CaCBL) were cloned from their cDNAs and sequenced, and their annotations in the genome assemblies were corrected accordingly. Analyses of protein sequences and gene structures of CBL family in plant kingdom indicated its diverse origin but showed a remarkable conservation in overall protein structure with appearance of complex gene structure in the course of evolution. Expression of CaCBL genes in different tissues and in response to different stress and hormone treatment were studied. Most of the CaCBL genes exhibited high expression in flowers. Expression profile of CaCBL genes in response to different abiotic stresses and hormones related to development and stresses (ABA, auxin, cytokinin, SA and JA) at different time intervals suggests their diverse roles in development and plant defence in addition to abiotic stress tolerance. These data not only contribute to a better understanding of the complex regulation of chickpea CBL gene family, but also provide valuable information for further research in chickpea functional genomics.

Calcineurin downregulation in the amygdala is sufficient to induce anxiety-like and depression-like behaviors in C57BL/6J male mice.

BACKGROUND: The calcium-dependent phosphatase calcineurin is highly expressed in the amygdala, a brain area important for behaviors related to mood disorders and anxiety. Organ transplant patients are administered the calcineurin inhibitor cyclosporine A (CsA) chronically and demonstrate an increased incidence of anxiety and mood disorders. It is therefore important to determine whether chronic blockade of calcineurin may contribute to symptoms of anxiety and depression in these patients. METHODS: Pharmacological (CSA) and viral-mediated gene transfer (adeno-associated viral expression of short hairpin RNA [shRNA]) approaches were used to inhibit calcineurin activity systemically or selectively in the amygdala of the mouse brain to determine the role of calcineurin in behaviors related to anxiety and depression. RESULTS: Systemic inhibition of calcineurin activity with CsA or local downregulation of calcineurin levels in the amygdala using adeno-associated viral-delivered shRNAs targeting calcineurin B increased measures of anxiety-like behavior in the elevated plus maze, the light/dark box, and the open field test. A decrease in locomotor activity was also observed in mice treated systemically with CsA. In the forced swim model of depression-like behavior, both systemic CsA treatment and shRNA-mediated calcineurin blockade in the amygdala significantly increased immobility. CONCLUSIONS: Taken together, these data demonstrate that decreasing calcineurin activity in the amygdala increases anxiety-like behaviors and to some extent depression-like behaviors. These studies suggest that chronic administration of CsA to organ transplant patients could have significant effects on anxiety and mood and this should be recognized as a potential clinical consequence of treatment to prevent transplant rejection.

Ovarian cancer G protein-coupled receptor 1 is involved in acid-induced apoptosis of endplate chondrocytes in intervertebral discs.

Ovarian cancer G protein-coupled receptor 1 (OGR1) has been shown to be a receptor for protons. We investigated the role of proton-sensing G protein-coupled receptors in the apoptosis of endplate chondrocytes induced by extracellular acid. The expression of proton-sensing G protein-coupled receptors was examined in rat lumbar endplate chondrocytes. Knockdown of OGR1 was achieved by transfecting chondrocytes with specific short hairpin RNA (shRNA) for OGR1. Apoptotic changes were evaluated by DNA fragmentation ELISA, electron microscopy, and flow cytometry. Intracellular calcium ([Ca(2+) ]i) was analyzed with laser scanning confocal microscopy. The mechanism of OGR1 in acid-induced apoptosis of endplate chondrocytes was also investigated. We found that OGR1 was predominantly expressed in rat endplate chondrocytes, and its expression was highly upregulated in response to acidosis. Knocking down OGR1 with shRNAs effectively attenuated acid-induced apoptosis of endplate chondrocytes and increased [Ca(2+) ]i. Blocking OGR1-mediated [Ca(2+) ]i elevation inhibited acid-induced calcium-sensitive proteases such as calpain and calcineurin, and also inhibited the activation of Bid, Bad, and Caspase 3 and cleavage of poly (ADP-ribose) polymerase (PARP). OGR1-mediated [Ca(2+) ]i elevation has a crucial role in apoptosis of endplate chondrocytes by regulating activation of calcium-sensitive proteases and their downstream signaling.

A yeast chemical genetics approach identifies the compound 3,4,5-trimethoxybenzyl isothiocyanate as a calcineurin inhibitor.

The phosphatase enzyme calcineurin controls gene expression in a variety of biological contexts however few potent inhibitors are currently available. A screen of 360 plant extracts for inhibition of calcineurin-dependent gene expression in the model organism Saccharomyces cerevisiae identified the compound 3,4,5-trimethoxybenzyl isothiocyanate as an inhibitor. The compound was subsequently shown to inhibit human calcineurin via a mixed inhibition mechanism. To gain further mechanistic insight a yeast haploinsufficiency screen of 1152 deletion strains was carried out using a novel liquid medium screening method. The resulting haploinsufficiency profile is similar to that reported for the known calcineurin inhibitor FK506.

Downregulation of CPPED1 expression improves glucose metabolism in vitro in adipocytes.

We have previously demonstrated that the expression of calcineurin-like phosphoesterase domain containing 1 (CPPED1) decreases in adipose tissue (AT) after weight reduction. However, the function of CPPED1 in AT is unknown. Therefore, we investigated whether the change in CPPED1 expression is connected to changes in adipocyte glucose metabolism. First, we confirmed that the expression of CPPED1 decreased after weight loss in subcutaneous AT. Second, the expression of CPPED1 did not change during adipocyte differentiation. Third, CPPED1 knockdown with small interfering RNA increased expression of genes involved in glucose metabolism (adiponectin, adiponectin receptor 1, and GLUT4) and improved insulin-stimulated glucose uptake. To conclude, CPPED1 is a novel molecule involved in AT biology, and CPPED1 is involved in glucose uptake in adipocytes.

[Expression profile of calcineurin pathway genes in myocardium tissues in relation to ischemic heart remodeling in humans].

Calcineurin pathway plays the critical role in the cardiac remodeling of various origin, development of chambers dilatation and progression of heart failure. Components of calcineurin pathway are involved in myocardium hypertrophy regulation, angiogenesis and apoptosis. Results of quantitative expression profiling study of main calcineurin pathway genes PPP3CA, PPP3R1, PPP3CB, GATA4 and NFATC4 in myocardium of right atrium auricle of patients with a coronary heart disease, exposed to various types of surgical treatments depending on weight of a clinical finding (surgical reconstruction of the geometry of left ventricle (LV) (postinfarction aneurysm) or coronary artery bypass grafting in case of unaltered morphology of LV) are presented. In patients with sizable postinfarction LV dilatation (n = 21) expression level of calcineurin catalytic subunit genes PPP3CA and PPP3CB was 1.3 and 1.6 times lower (p = 0.018 and 0.023, accordingly) compared to patients with unaltered shape of the heart (n = 34). Expression level of PPP3R1 gene encoding calcineurin regulatory subunit B and GATA4 and NFATC4 genes for transcription factors did not differ in studied subgroups of patients. Thus, lower expression of PPP3CA and PPP3CB genes in atrium myocardium can be related to expressed postinfarction LV remodeling. Further studies of relation quantitative expression profiling of calcineurin pathway genes with the level of damage of myocardium is essential what may have important outcome for the prevention of adverse events of cardiosurgical treatments in patients with postinfarction remodeling.

Loss of calcineurin in the spinal dorsal horn contributes to neuropathic pain, and intrathecal administration of the phosphatase provides prolonged analgesia.

Calcineurin (protein phosphatase 3) regulates synaptic plasticity in the brain. The development of neuropathic pain appears dependent on some of the same mechanisms that underlie brain synaptic plasticity. In this study, we examined whether calcineurin regulates chronic constriction injury (CCI)-elicited plasticity in the spinal dorsal horn. CCI animals exhibited mechanical and thermal hypersensitivity 7 days after ligation of the sciatic nerve. Neither control uninjured nor sham-operated animals exhibited pain behavior. Calcineurin activity and content of its Aα isoform were significantly decreased in the ipsilateral postsynaptic density (PSD) of dorsal horn neurons in CCI animals. Calcineurin activity and content in the contralateral PSD of CCI animals or either side of the dorsal horn in sham animals were not modified. The pain behavior in CCI animals was attenuated by intrathecal application of exogenous calcineurin. The treatment was long-lasting as a single injection provided analgesia for 4 days by restoring the phosphatase's activity and Aα content in the PSD. No signs of toxicity were detected up to 14 days after the single intrathecal injection. Intrathecal application of the calcineurin inhibitor FK-506 elicited pain behavior in control uninjured animals and significantly reduced calcineurin activity in the PSD. CCI may elicit neuropathic pain at least in part as a result of the loss of calcineurin-mediated dephosphorylation in the dorsal horn. Addition of the phosphatase by intrathecal injection reverses the injury-elicited loss and provides prolonged pain relief. Clinical therapy with calcineurin may prove to be a novel, effective, and safe approach in the management of well-established neuropathic pain.

Cell-specific expression of calcineurin immunoreactivity within the rat basolateral amygdala complex and colocalization with the neuropeptide Y Y1 receptor.

Neuropeptide Y (NPY) produces potent anxiolytic effects via activation of NPY Y1 receptors (Y1r) within the basolateral amygdaloid complex (BLA). The role of NPY in the BLA was recently expanded to include the ability to produce stress resilience and long-lasting reductions in anxiety-like behavior. These persistent behavioral effects are dependent upon activity of the protein phosphatase, calcineurin (CaN), which has long been associated with shaping long-term synaptic signaling. Furthermore, NPY-induced reductions in anxiety-like behavior persist months after intra-BLA delivery, which together indicate a form of neuronal plasticity had likely occurred. To define a site of action for NPY-induced CaN signaling within the BLA, we employed multi-label immunohistochemistry to determine which cell types express CaN and if CaN colocalizes with the Y1r. We have previously reported that both major neuronal cell populations in the BLA, pyramidal projection neurons and GABAergic interneurons, express the Y1r. Therefore, this current study evaluated CaN immunoreactivity in these cell types, along with Y1r immunoreactivity. Antibodies against calcium-calmodulin kinase II (CaMKII) and GABA were used to identify pyramidal neurons and GABAergic interneurons, respectively. A large population of CaN immunoreactive cells displayed Y1r immunoreactivity (90%). Nearly all (98%) pyramidal neurons displayed CaN immunoreactivity, while only a small percentage of interneurons (10%) contained CaN immunoreactivity. Overall, these anatomical findings provide a model whereby NPY could directly regulate CaN activity in the BLA via activation of the Y1r on CaN-expressing, pyramidal neurons. Importantly, they support BLA pyramidal neurons as prime targets for neuronal plasticity associated with the long-term reductions in anxiety-like behavior produced by NPY injections into the BLA.