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Tightly regulated Ca2+ homeostasis is a prerequisite for proper cardiac function. To dissect the regulatory network of cardiac Ca2+ handling, we performed a chemical suppressor screen on zebrafish tremblor embryos, which suffer from Ca2+ extrusion defects. Efsevin was identified based on its potent activity to restore coordinated contractions in tremblor. We show that efsevin binds to VDAC2, potentiates mitochondrial Ca2+ uptake and accelerates the transfer of Ca2+ from intracellular stores into mitochondria. In cardiomyocytes, efsevin restricts the temporal and spatial boundaries of Ca2+ sparks and thereby inhibits Ca2+ overload-induced erratic Ca2+ waves and irregular contractions. We further show that overexpression of VDAC2 recapitulates the suppressive effect of efsevin on tremblor embryos whereas VDAC2 deficiency attenuates efsevin's rescue effect and that VDAC2 functions synergistically with MCU to suppress cardiac fibrillation in tremblor. Together, these findings demonstrate a critical modulatory role for VDAC2-dependent mitochondrial Ca2+ uptake in the regulation of cardiac rhythmicity.DOI: http://dx.doi.org/10.7554/eLife.04801.001

The therapeutic effect of ShK-170 is mediated by suppression of microglial activation and microglia-mediated neurotoxicity and enhanced neurorestoration by promoting proliferation of neural progenitor cells.

Objective: Esophageal squamous cell carcinoma (ESCC) is one of the most commonly diagnosed cancer types in China. Recent genomic sequencing analysis indicated the over-activation of Hippo/YAP signaling might play important roles for the carcinogenic process and progression for ESCC patients. However, little is known about the molecular mechanisms that controls Hippo signaling activity in ESCC. Our previous studies indicated that PLCE1-an important risk factor for ESCC-linked to ESCC progression through snail signaling, during this period, we found PARK2 was an important downstream target of PLCE1-snail axis. PARK2 was decreased in ESCC human samples, and correlated with good prognosis in ESCC patients. Further research showed that PARK2 could inhibit YAP, which functions as key downstream effectors of the Hippo pathway. Here, we aim to reveal the molecular mechanisms of PARK2 modulated Hippo pathway in ESCC. Methods: To evaluate the function of PARK2 in ESCC, we used a tissue microarray (TMA) of 223 human ESCC patients and immunohistochemistry to analyze the correlation between PARK2 expression and clinicopathologic variables. Depletion of endogenous PARK2 and YAP from ESCC cells using CRISPR/Cas9 technologies. Flow cytometry and EdU cell proliferation assay were used to detect proliferation of ESCC cells. Nude mice subcutaneous injection and Ki-67 staining were used to evaluate tumor growth in vivo . Migration and invasion assays were performed. In addition, lung metastasis models in mice were used to validate the function of PARK2 in vivo . Identification of PARK2 involved in hippo pathway was achieved by expression microarray screening, double immunofluorescence staining and co-immunoprecipitation assays. The RNA-seq analysis results were validated through quantitative real-time PCR (qRT-PCR) analysis. The protein half-life of YAP was analyzed by Cycloheximide assay, and the TEAD activity was detected by Luciferase reporter assays. Results: Clinical sample of ESCC revealed that low PARK2 expression correlated with late tumor stage (P < 0.001), poor differentiation (P < 0.04), lymph node (P < 0.001) and distant metastasis (P = 0.0087). Multivariate Cox proportional regression analysis further revealed that PARK2 expression (P = 0.032) is an independent prognostic factor for the overall survival of ESCC patients. Besides, the immunohistochemistry results showed that PARK2 negatively correlated with YAP protein level (P < 0.001). PARK2 depletion promotes ESCC progression both through Hippo/YAP axis, while PARK2 overexpression suppresses ESCC tumor progression by Hippo signaling. Co-IP and ubiquitination assays revealed that PARK2 could interact with YAP in the cytosol and promotes YAP K48-linked ubiquitination at K90 sites. Conclusion: Clinical sample analysis and mechanistic study have validated PARK2 as a tumor suppressor for ESCC. Multivariate Cox propo...

Six postmenopausal women, who were experiencing frequent hot flashes, had an 8 h continuous recording of skin temperature over the dorsum of the finger as an objective index of hot flashes. Frequent blood samples were obtained during the time of the recording for the measurement of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels. During the 48 h of recording 34 significant temperature elevations were recorded and 32 were associated with a subjective hot flash. 3l pulses of LH release were also observed with 26 occurring simultaneously with the temperature rises. Correlation analysis of simultaneous skin temperature and circulating LH levels showed a significant positive correlation (p less than 0.01). FSH levels showed no consistent relationship with skin temperature. These data suggest that LH or the factors that trigger its pulsatile release are related to the mechanism responsible for the initiation of hot flashes.

To determine which dosage of estrogen might provide physiological replacement and also avoid possible harmful side effects, 21 postmenopausal women were studied before and after the oral administration of conjugated equine estrogens. The dosages studied were 0.15, 0.30, 0.625, and 1.25 mg/day, with each being given for 6 weeks. Fifteen premenopausal women were also studied, and their values were presumed to reflect normal physiological function. Variable responses of the different biochemical and biological markers of the action of estrogen were observed. Both LH and FSH levels showed stepwise decreases with increasing amounts of estrogen, but even 1.25 mg/day did not suppress these hormones to the range found in premenopausal women, suggesting a subphysiological response. The lower dosages of conjugated estrogen had minimal effects on vaginal cytology, with only the 1.25-mg dose changing the maturation index to values similar to those found in premenopausal subjects. The 0.3-mg dose of conjugated estrogen was the lowest amount that resulted in a significant reduction (P < 0.05) of the urinary calcium to creatinine ratio (an index of bone resorption). Liver protein synthesis was the most sensitive parameter to the action of estrogen. Hepatic resoponses were variable depending on which protein was assessed. These data indicate that the oral administration of conjugated equine estrogens results in inconsistent effects. All doses exerted subphysiological, physiological, and pharmacological responses at the different sites of action.

Eighteen female rhesus monkeys subjected to complete or anterior disconnection of the medial basal hypothalamus (MBH) were studied to assess the effects of these deafferentation procedures on GH and cortisol secretion. Basal serum levels of GH were not disturbed or were slightly elevated following complete or anterior MBH disconnection. GH secretion in response to vasopressin administration or insulin hypoglycemia, however, was abolished by complete isolation of the MBH. In contrast, the elevations in serum cortisol concentrations observed in response to these noxious stimuli were not noticeably affected. The normal diurnal rhythm in cortisol secretion remained fully evident following anterior deafferentation, but was severely attenuated or abolished when all neuronal inputs to the MBH were transected. Such observations suggest that the central components of the neuroendocrine systems which regulate basal GH secretion and which subserve stress-induced elevations in cortisol secretion are resident within the MBH-hypophysial unit. In addition, these data indicate that the mechanisms underlying the diurnal rhythm in cortisol secretion, as well as those mediating the discharges of GH in response to vasopressin administration and insulin hypoglycemia, are dependent on the integrity of neuronal connections between the MBH and other hypothalamic and/or extrahypothalamic areas.

In post-partum lactating rats, sucking by the young was associated with high prolactin release and maintenance of lactation but severe inhibition of LH and FSH release and suspension of oestrous cycles. Shortly after the pups were removed on day 22 post partum LH and FSH release returned to normal and oestrous cycles resumed. Twice-daily injections of ergocornine methanesulphonate (ERG) into mothers beginning at 5 or 7 days post partum, resulted in sustained inhibition of prolactin release and diminished mild secretion. By frequent exchange of pups between control and ERG-treated mothers, it was possible to maintain vigorous sucking and almost normal pup growth despite low serum prolactin levels and diminished lactation. In these rats, serum levels of LH remained low during 11 or more days of treatment with ERG, but serum FSH was consistently higher than in untreated control mothers. After 11 or more days of ERG treatment, most rats showed a return to normal LH and FSH release and resumption of oestrous cycles. These results suggest (a) that the sucking stimulus rather than high prolactin levels in the circulation is mainly responsible for inhibition of LH and FSH release during the first 11 days post partum, (b) that the sucking stimulus acts to increase prolactin and inhibit LH release by separate hypothalamic mechanisms, and (c) that administration of ERG results in diminished prolactin release and lactation, and in increased release of FSH and subsequently of LH with earlier resumption of oestrous cycles.