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On page 1 showing 1 ~ 20 papers out of 245 papers

Integrated high-throughput analysis identifies Sp1 as a crucial determinant of p53-mediated apoptosis.

  • H Li‎ et al.
  • Cell death and differentiation‎
  • 2014‎

The restoration of p53 tumor suppressor function is a promising therapeutic strategy to combat cancer. However, the biological outcomes of p53 activation, ranging from the promotion of growth arrest to the induction of cell death, are hard to predict, which limits the clinical application of p53-based therapies. In the present study, we performed an integrated analysis of genome-wide short hairpin RNA screen and gene expression data and uncovered a previously unrecognized role of Sp1 as a central modulator of the transcriptional response induced by p53 that leads to robust induction of apoptosis. Sp1 is indispensable for the pro-apoptotic transcriptional repression by p53, but not for the induction of pro-apoptotic genes. Furthermore, the p53-dependent pro-apoptotic transcriptional repression required the co-binding of Sp1 to p53 target genes. Our results also highlight that Sp1 shares with p53 a common regulator, MDM2, which targets Sp1 for proteasomal degradation. This uncovers a new mechanism of the tight control of apoptosis in cells. Our study advances the understanding of the molecular basis of p53-mediated apoptosis and implicates Sp1 as one of its key modulators. We found that small molecules reactivating p53 can differentially modulate Sp1, thus providing insights into how to manipulate p53 response in a controlled way.


Damage effect of interleukin (IL)-23 on oxygen-glucose-deprived cells of the neurovascular unit via IL-23 receptor.

  • M Wang‎ et al.
  • Neuroscience‎
  • 2015‎

Interleukin-23/interleukin-23 receptor (IL-23/IL-23R) has been implicated in many inflammatory diseases. Previous research mainly focused on its ability to induce IL-17 production from T cells. However, few studies have investigated its role in cerebral ischemic injury. The aim of our study was to explore the potential effect of IL-23 on cells of the neurovascular unit (NVU) under an oxygen-glucose deprivation (OGD) condition and the role of IL-23R in IL-23-mediated effect. OGD of primary cells of the NVU and permanent middle cerebral artery occlusion (pMCAO) were used to produce experimental stroke in vitro and in vivo, respectively. IL-23 and IL-23R were detected by immunohistochemistry and western blot in pMCAO mice. Metabolic viability of cultured cells was assessed by MTT assay. The cell-associated proteins (Bcl-2, AQP4 and ET-1) were determined by western blot and enzyme-linked immunosorbent assay (ELISA). Immunofluorescence staining and western blot were used to detect the IL-23R expression. The results showed that the expression of IL-23/IL-23R was elevated in pMCAO mice. IL-23 could aggravate neuron damage, astrocyte swelling, and further impair the integrity of blood-brain barrier induced by OGD. In addition, the effect of IL-23 on cells of the NVU is mediated by IL-23R and is likely IL-23R-expression-level dependent. However, there are no such biological properties for the IL-23p19 subunit alone. Our study provides the first evidence that IL-23 has a toxic effect on cells of the NVU under OGD stress, which is mediated by IL-23R. These results not only help us better understand the role of IL-23/IL-23R in brain ischemia, but also provide a potential therapeutic target in stroke.


Mitochondrial ATAD3A combines with GRP78 to regulate the WASF3 metastasis-promoting protein.

  • Y Teng‎ et al.
  • Oncogene‎
  • 2016‎

AAA domain containing 3A (ATAD3A) is an integral mitochondrial membrane protein with unknown function, although we now show that high-level expression is associated with poor survival in breast cancer patients. Using a mass spectrometry approach we have demonstrated that ATAD3A interacts with the WASF3 metastasis-promoting protein. Knockdown of ATAD3A leads to decreased WASF3 protein levels in breast and colon cancer cells. Silencing ATAD3A also results in loss of both cell anchorage-independent growth and invasion and suppression of tumor growth and metastasis in vivo using immuno-compromised mice. HSP70 is responsible for stabilizing WASF3 in the cytoplasm, but inactivation of HSP70 does not lead to the loss of WASF3 stability at the mitochondrial membrane, where presumably it is protected through its interaction with ATAD3A. In response to endoplasmic reticulum (ER) stress, increases in the GRP78 protein level leads to increased WASF3 protein levels. We also show that ATAD3A was present in a WASF3-GRP78 complex, and suppression of GRP78 led to destabilization of WASF3 at the mitochondrial membrane, which was ATAD3A dependent. Furthermore, ATAD3A-mediated suppression of CDH1/E-cadherin occurs through its regulation of GRP78-mediated WASF3 stability. Proteolysis experiments using isolated mitochondria demonstrates the presence of the N-terminal end of WASF3 within the mitochondria, which is the interaction site with the N-terminal end of ATAD3A. It appears, therefore, that stabilization of WASF3 function occurs through its interaction with ATAD3A and GRP78, which may provide a bridge between the ER and mitochondria, allowing communication between the two organelles. These findings also suggest that pharmacologic inhibition of ATAD3A could be an effective therapeutic strategy to treat human cancer.


Long-term survival among Hodgkin's lymphoma patients with gastrointestinal cancer: a population-based study.

  • P Youn‎ et al.
  • Annals of oncology : official journal of the European Society for Medical Oncology‎
  • 2013‎

The increased risk of gastrointestinal (GI) cancers after Hodgkin's lymphoma (HL) is well established. However, no large population-based study has described the actuarial survival after subsequent GI cancers in HL survivors (HL-GI).


Two-particle Bose-Einstein correlations in pp collisions at [Formula: see text] 0.9 and 7 TeV measured with the ATLAS detector.

  • G Aad‎ et al.
  • The European physical journal. C, Particles and fields‎
  • 2015‎

The paper presents studies of Bose-Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range [Formula: see text] 100 MeV and [Formula: see text] 2.5 in proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. The integrated luminosities are approximately 7 [Formula: see text]b[Formula: see text], 190 [Formula: see text]b[Formula: see text] and 12.4 nb[Formula: see text] for 0.9 TeV, 7 TeV minimum-bias and 7 TeV high-multiplicity data samples, respectively. The multiplicity dependence of the BEC parameters characterizing the correlation strength and the correlation source size are investigated for charged-particle multiplicities of up to 240. A saturation effect in the multiplicity dependence of the correlation source size parameter is observed using the high-multiplicity 7 TeV data sample. The dependence of the BEC parameters on the average transverse momentum of the particle pair is also investigated.


Role of Runx2 phosphorylation in prostate cancer and association with metastatic disease.

  • C Ge‎ et al.
  • Oncogene‎
  • 2016‎

The osteogenic transcription factor, Runx2, is abnormally expressed in prostate cancer (PCa) and associated with metastatic disease. During bone development, Runx2 is activated by signals known to be hyperactive in PCa including the RAS/MAP kinase pathway, which phosphorylates Runx2 on multiple serine residues including S301 and S319 (equivalent to S294 and S312 in human Runx2). This study examines the role of these phosphorylation sites in PCa. Runx2 was preferentially expressed in more invasive PCa cell lines (PC3>C4-2B>LNCaP). Furthermore, analysis using a P-S319-Runx2-specific antibody revealed that the ratio of P-S319-Runx2/total Runx2 as well as P-ERK/total ERK was highest in PC3 followed by C4-2B and LNCaP cells. These results were confirmed by immunofluorescence confocal microscopy, which showed a higher percentage of PC3 cells staining positive for P-S319-Runx2 relative to C4-2B and LNCaP cells. Phosphorylated Runx2 had an exclusively nuclear localization. When expressed in prostate cell lines, wild-type Runx2 increased metastasis-associated gene expression, in vitro migratory and invasive activity as well as in vivo growth of tumor cell xenografts. In contrast, S301A/S319A phosphorylation site mutations greatly attenuated these Runx2 responses. Analysis of tissue microarrays from 129 patients revealed strong nuclear staining with the P-S319-Runx2 antibody in primary PCas and metastases. P-S319-Runx2 staining was positively correlated with Gleason score and occurrence of lymph node metastases while little or no Runx2 phosphorylation was seen in normal prostate, benign prostate hyperplasia or prostatitis indicating that Runx2 S319 phosphorylation is closely associated with PCa induction and progression towards an aggressive phenotype. These studies establish the importance of Runx2 phosphorylation in prostate tumor growth and highlight its value as a potential diagnostic marker and therapeutic target.


Frequent promoter hypermethylation of PTPRT increases STAT3 activation and sensitivity to STAT3 inhibition in head and neck cancer.

  • N D Peyser‎ et al.
  • Oncogene‎
  • 2016‎

Signal transducer and activator of transcription 3 (STAT3) overactivation is a common event in many cancers, including head and neck squamous cell carcinoma (HNSCC), where STAT3 represents a promising therapeutic target. HNSCC is not characterized by frequent kinase mutations, in contrast to some malignancies where mutational activation of kinases upstream of STAT3 is common. Instead, STAT3 may be activated by loss-of-function of negative regulators of STAT3, including by promoter hypermethylation of PTPRT. Here we first analyzed The Cancer Genome Atlas data and determined that the PTPRT promoter is frequently hypermethylated in several cancers, including HNSCC (60.1% of tumors analyzed) in association with downregulation of PTPRT mRNA expression and upregulation of pSTAT3 expression. These findings were confirmed in an independent cohort of HNSCC tumors by methylation-specific PCR and immunohistochemistry. We demonstrate that PTPRT promoter methylation and gene silencing is reversible in HNSCC cells, leading to PTPRT-specific downregulation of pSTAT3 expression. We further show that PTPRT promoter methylation is significantly associated with sensitivity to STAT3 inhibition in HNSCC cells, suggesting that PTPRT promoter methylation may serve as a predictive biomarker for responsiveness to STAT3 inhibitors in clinical development.


The p38α mitogen-activated protein kinase is a key regulator of myelination and remyelination in the CNS.

  • S-H Chung‎ et al.
  • Cell death & disease‎
  • 2015‎

The p38α mitogen-activated protein kinase (MAPK) is one of the serine/threonine kinases regulating a variety of biological processes, including cell-type specification, differentiation and migration. Previous in vitro studies using pharmacological inhibitors suggested that p38 MAPK is essential for oligodendrocyte (OL) differentiation and myelination. To investigate the specific roles of p38α MAPK in OL development and myelination in vivo, we generated p38α conditional knockout (CKO) mice under the PLP and nerve/glial antigen 2 (NG2) gene promoters, as these genes are specifically expressed in OL progenitor cells (OPCs). Our data revealed that myelin synthesis was completely inhibited in OLs differentiated from primary OPC cultures derived from the NG2 Cre-p38α CKO mouse brains. Although an in vivo myelination defect was not obvious after gross examination of these mice, electron microscopic analysis showed that the ultrastructure of myelin bundles was severely impaired. Moreover, the onset of myelination in the corpus callosum was delayed in the knockout mice compared with p38α fl/fl control mice. A delay in OL differentiation in the central nervous system was observed with concomitant downregulation in the expression of OPC- and OL-specific genes such as Olig1 and Zfp488 during early postnatal development. OPC proliferation was not affected during this time. These data indicate that p38α is a positive regulator of OL differentiation and myelination. Unexpectedly, we observed an opposite effect of p38α on remyelination in the cuprizone-induced demyelination model. The p38α CKO mice exhibited better remyelination capability compared with p38α fl/fl mice following demyelination. The opposing roles of p38α in myelination and remyelination could be due to a strong anti-inflammatory effect of p38α or a dual reciprocal regulatory action of p38α on myelin formation during development and on remyelination after demyelination.


Repression of Hox genes by LMP1 in nasopharyngeal carcinoma and modulation of glycolytic pathway genes by HoxC8.

  • Y Jiang‎ et al.
  • Oncogene‎
  • 2015‎

Epstein-Barr virus (EBV) causes human lymphoid malignancies, and the EBV product latent membrane protein 1 (LMP1) has been identified as an oncogene in epithelial carcinomas such as nasopharyngeal carcinoma (NPC). EBV can epigenetically reprogram lymphocyte-specific processes and induce cell immortalization. However, the interplay between LMP1 and the NPC host cell remains largely unknown. Here, we report that LMP1 is important to establish the Hox gene expression signature in NPC cell lines and tumor biopsies. LMP1 induces repression of several Hox genes in part via stalling of RNA polymerase II (RNA Pol II). Pol II stalling can be overcome by irradiation involving the epigenetic regulator TET3. Furthermore, we report that HoxC8, one of the genes silenced by LMP1, has a role in tumor growth. Ectopic expression of HoxC8 inhibits NPC cell growth in vitro and in vivo, modulates glycolysis and regulates the expression of tricarboxylic acid (TCA) cycle-related genes. We propose that viral latency products may repress via stalling key mediators that in turn modulate glycolysis.


Growth hormone secretion is correlated with neuromuscular innervation rather than motor neuron number in early-symptomatic male amyotrophic lateral sclerosis mice.

  • F J Steyn‎ et al.
  • Endocrinology‎
  • 2013‎

GH deficiency is thought to be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, therapy with GH and/or IGF-I has not shown benefit. To gain a better understanding of the role of GH secretion in ALS pathogenesis, we assessed endogenous GH secretion in wild-type and hSOD1(G93A) mice throughout the course of ALS disease. Male wild-type and hSOD1(G93A) mice were studied at the presymptomatic, onset, and end stages of disease. To assess the pathological features of disease, we measured motor neuron number and neuromuscular innervation. We report that GH secretion profile varies at different stages of disease progression in hSOD1(G93A) mice; compared with age-matched controls, GH secretion is unchanged prior to the onset of disease symptoms, elevated at the onset of disease symptoms, and reduced at the end stage of disease. In hSOD1(G93A) mice at the onset of disease, GH secretion is positively correlated with the percentage of neuromuscular innervation but not with motor neuron number. Moreover, this occurs in parallel with an elevation in the expression of muscle IGF-I relative to controls. Our data imply that increased GH secretion at symptom onset may be an endogenous endocrine response to increase the local production of muscle IGF-I to stimulate reinnervation of muscle, but that in the latter stages of disease this response no longer occurs.


MiRNA-296-3p-ICAM-1 axis promotes metastasis of prostate cancer by possible enhancing survival of natural killer cell-resistant circulating tumour cells.

  • X Liu‎ et al.
  • Cell death & disease‎
  • 2013‎

Natural killer (NK) cells are important in host to eliminate circulating tumour cells (CTCs) in turn preventing the development of tumour cells into metastasis but the mechanisms are very poorly defined. Here we find that the expression level of miR-296-3p is much lower in the non-metastatic human prostate cancer (PCa) cell line P69 than that in the highly metastatic cell line M12, which is derived from P69. We demonstrate that miR-296-3p directly targets and inhibits the expression of intercellular adhesion molecule 1 (ICAM-1) in the malignant M12. The data from clinical tissue microarrays also show that miR-296-3p is frequently upregulated and ICAM-1 is reversely downregulated in PCa. Interestingly, ectopic expression of miR-296-3p in P69 increases the tolerance to NK cells whereas knockdown of miR-296-3p in M12 reduces the resistance to NK cells, which both phenotypes can be rescued by re-expression or silencing of ICAM-1 in P69 and M12, respectively. These results are also manifested in vivo by the decrease in the incidence of pulmonary tumour metastasis exhibited by knockdown of miR-296-3p in M12 when injected into athymic nude mice via tail vein, and consistently down-expression of ICAM-1 reverses this to increase extravasation of CTCs into lungs. Above results suggest that this newly identified miR-296-3p-ICAM-1 axis has a pivotal role in mediating PCa metastasis by possible enhancing survival of NK cell-resistant CTC. Our findings provide novel potential targets for PCa therapy and prognosis.


Association between diabetes, diabetes treatment and risk of developing endometrial cancer.

  • J Luo‎ et al.
  • British journal of cancer‎
  • 2014‎

A growing body of evidence suggests that diabetes is a risk factor for endometrial cancer incidence. However, most of these studies used case-control study designs and did not adjust for obesity, an established risk factor for endometrial cancer. In addition, few epidemiological studies have examined the association between diabetes treatment and endometrial cancer risk. The objective of this study was to assess the relationships among diabetes, diabetes treatment and endometrial cancer risk in postmenopausal women participating in the Women's Health Initiative (WHI).


Loss of TACSTD2 contributed to squamous cell carcinoma progression through attenuating TAp63-dependent apoptosis.

  • F Wang‎ et al.
  • Cell death & disease‎
  • 2014‎

Tumor-associated calcium signal transducer 2 (TACSTD2), a calcium signal transducer, is universally expressed in stratified squamous epithelia of many organs, including skin, esophagus and cervix. Although TACSTD2, was reported to be overexpressed in many epithelial tumors, which has increased interest in using it as a molecular target for cancer therapy, the role of TACSTD2 in carcinogenesis of squamous cell carcinoma (SCC) is largely unclear and controversial. To explore the role of TACSTD2, temporal-spatial expression of TACSTD2 was analyzed in both normal and SCC tissues. Our data demonstrate that Tacstd2 expression and membrane localization are tightly associated with stratified epithelial homeostasis, while loss of TACSTD2 was identified in poorly differentiated SCC tissues collected from cervix, esophagus, head and neck. Gradual loss of TACSTD2 was correlated with stepwise progression of SCC. Consistent with these in vivo observations, our data show that inhibition of Tacstd2 expression significantly inhibited chemotherapeutic reagent-induced apoptosis, and TACSTD2 regulated apoptotic gene expression through P63 containing the transactivation domain (TAp63). These findings indicated that loss of TACSTD2 could promote SCC progression and treatment resistance through attenuating chemotherapeutic reagent-induced apoptosis through TAp63, and TACSTD2 could be used as a marker for pathological grading of SCC.


MicroRNA-922 promotes tau phosphorylation by downregulating ubiquitin carboxy-terminal hydrolase L1 (UCHL1) expression in the pathogenesis of Alzheimer's disease.

  • Z-B Zhao‎ et al.
  • Neuroscience‎
  • 2014‎

Decreased levels of soluble ubiquitin carboxy-terminal hydrolase L1 (UCHL1) have been reported in the brains of sporadic Alzheimer's disease (AD) patients, and the introduction of UCHL1 rescued the synaptic and cognitive function of AD model mice. Obviously, a reduction in the levels of UCHL1 may play a role in the pathogenesis of AD. However, the mechanisms underlying the regulation of UCHL1 levels in AD have not been fully elucidated. MicroRNAs (miRs) have been shown to participate in the process of AD. In our study, we discovered that microRNA-922 decreased the levels of UCHL1. Neurofibrillary tangles (NFTs) mainly consisting of the hyperphosphorylated microtubule-associated protein tau are the defining pathological features of AD. In the present study, we found the levels of UCHL1 affected the levels of phosphorylated tau: the phosphorylated tau levels increased after knockdown of UCHL1 expression, and the phosphorylated tau levels decreased when UCHL1 was overexpressed. Furthermore, overexpression of microRNA-922 increased the phosphorylated tau levels. In conclusion, miR-922 increasing the levels of phosphorylated tau by regulating UCHL1 levels contributed to the pathogenesis of AD. Our study partly explained one of the mechanisms underlying the downregulation of UCHL1 levels in AD patients and could enrich the content of tau pathology in the pathogenesis of AD.


Development of a methodology for and assessment of pulsatile luteinizing hormone secretion in juvenile and adult male mice.

  • F J Steyn‎ et al.
  • Endocrinology‎
  • 2013‎

Current methodology to monitor pulsatile LH release in mice is limited by inadequate assay sensitivity, resulting in the need for collection of large blood volumes. Thus, assessment of pulsatile LH secretion in mice remains highly challenging, and observations are limited to adult mice. To address this, we developed a highly sensitive ELISA for assessment of mouse LH concentrations in small fractions of whole blood. We demonstrate that this assay is capable of reliably detecting LH down to a theoretical limit of 0.117 ng/mL in a 2-μL fraction of whole blood. Using an established frequent blood collection procedure, we validated the accuracy of this method by determining the pulsatile LH secretion in early-adult (10 weeks old) C57BL6/J male mice. Data demonstrate regular pulsatile release of LH, with peaks in LH secretion rarely exceeding 3 ng/mL. Moreover, assessment of LH release in Gpr54 knockout mice demonstrates the lack of pulsatile LH release after the loss of kisspeptin-mediated pubertal maturation. We next determined age-associated changes in pulsatile LH secretion by assessment of LH secretion in prepubertal (28 days old) C57BL6/J male mice and repeated assessment in the same mice in adulthood (120 days old). Data demonstrate that the rise in total LH secretion in mice after pubertal maturation occurs along with an overall rise in the pulsatile LH secretion rate. This was coupled with a significant increase in the number of LH secretory events (number of pulses). In addition, we observed a decrease in the clearance (increased half-life) and a decrease in the regularity (approximate entropy) of LH release. This method will be of wide general utility within the field of reproductive biology.


Involvement of miR-30c in resistance to doxorubicin by regulating YWHAZ in breast cancer cells.

  • Y Fang‎ et al.
  • Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas‎
  • 2014‎

MicroRNAs (miRNAs) are small RNA molecules that modulate gene expression implicated in cancer, which play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. The aim of this study was to investigate whether miR-30c mediated the resistance of breast cancer cells to the chemotherapeutic agent doxorubicin (ADR) by targeting tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ). miR-30c was downregulated in the doxorubicin-resistant human breast cancer cell lines MCF-7/ADR and MDA-MB-231/ADR compared with their parental MCF-7 and MDA-MB-231 cell lines, respectively. Furthermore, we observed that transfection of an miR-30c mimic significantly suppressed the ability of MCF-7/ADR to resist doxorubicin. Moreover, the anti-apoptotic gene YWHAZ was confirmed as a target of miR-30c by luciferase reporter assay, and further studies indicated that the mechanism for miR-30c on the sensitivity of breast cancer cells involved YWHAZ and its downstream p38 mitogen-activated protein kinase (p38MAPK) pathway. Together, our findings provided evidence that miR-30c was one of the important miRNAs in doxorubicin resistance by regulating YWHAZ in the breast cancer cell line MCF-7/ADR.


Increased expression of RRM2 by human papillomavirus E7 oncoprotein promotes angiogenesis in cervical cancer.

  • N Wang‎ et al.
  • British journal of cancer‎
  • 2014‎

The purpose of this study was to confirm that RRM2 as a novel target of HPVE7 involved in cervical cancer angiogenesis.


Downregulation of FAP suppresses cell proliferation and metastasis through PTEN/PI3K/AKT and Ras-ERK signaling in oral squamous cell carcinoma.

  • H Wang‎ et al.
  • Cell death & disease‎
  • 2014‎

It is largely recognized that fibroblast activation protein (FAP) is expressed in cancer-associated fibroblasts (CAFs) of many human carcinomas. Furthermore, FAP was recently also reported to be expressed in carcinoma cells of the breast, stomach, pancreatic ductal adenocarcinoma, colorectum, and uterine cervix. The carcinoma cell expression pattern of FAP has been described in several types of cancers, but the role of FAP in oral squamous cell carcinoma (OSCC) is unknown. The role of endogenous FAP in epithelium-derived tumors and molecular mechanisms has also not been reported. In this study, FAP was found to be expressed in carcinoma cells of OSCC and was upregulated in OSCC tissue samples compared with benign tissue samples using immunohistochemistry. In addition, its expression level was closely correlated with overall survival of patients with OSCC. Silencing FAP inhibited the growth and metastasis of OSCC cells in vitro and in vivo. Mechanistically, knockdown of FAP inactivated PTEN/PI3K/AKT and Ras-ERK and its downstream signaling regulating proliferation, migration, and invasion in OSCC cells, as the inhibitory effects of FAP on the proliferation and metastasis could be rescued by PTEN silencing. Our study suggests that FAP acts as an oncogene and may be a potential therapeutic target for patients with OSCC.


Visualisation of Kiss1 Neurone Distribution Using a Kiss1-CRE Transgenic Mouse.

  • S-H Yeo‎ et al.
  • Journal of neuroendocrinology‎
  • 2016‎

Kisspeptin neuropeptides are encoded by the Kiss1 gene and play a critical role in the regulation of the mammalian reproductive axis. Kiss1 neurones are found in two locations in the rodent hypothalamus: one in the arcuate nucleus (ARC) and another in the RP3V region, which includes the anteroventral periventricular nucleus (AVPV). Detailed mapping of the fibre distribution of Kiss1 neurones will help with our understanding of the action of these neurones in other regions of the brain. We have generated a transgenic mouse in which the Kiss1 coding region is disrupted by a CRE-GFP transgene so that expression of the CRE recombinase protein is driven from the Kiss1 promoter. As expected, mutant mice of both sexes are sterile with hypogonadotrophic hypogonadism and do not show the normal rise in luteinising hormone after gonadectomy. Mutant female mice do not develop mature Graafian follicles or form corpora lutea consistent with ovulatory failure. Mutant male mice have low blood testosterone levels and impaired spermatogenesis beyond the meiosis stage. Breeding Kiss-CRE heterozygous mice with CRE-activated tdTomato reporter mice allows fluorescence visualisation of Kiss1 neurones in brain slices. Approximately 80-90% of tdTomato positive neurones in the ARC were co-labelled with kisspeptin and expression of tdTomato in the AVPV region was sexually dimorphic, with higher expression in females than males. A small number of tdTomato-labelled neurones was also found in other locations, including the lateral septum, the anterodorsal preoptic nucleus, the amygdala, the dorsomedial and ventromedial hypothalamic nuclei, the periaquaductal grey, and the mammillary nucleus. Three dimensional visualisation of Kiss1 neurones and fibres by CLARITY processing of whole brains showed an increase in ARC expression during puberty and higher numbers of Kiss1 neurones in the caudal region of the ARC compared to the rostral region. ARC Kiss1 neurones sent fibre projections to several hypothalamic regions, including rostrally to the periventricular and pre-optic areas and to the lateral hypothalamus.


A novel mechanism of memory loss in Alzheimer's disease mice via the degeneration of entorhinal-CA1 synapses.

  • X Yang‎ et al.
  • Molecular psychiatry‎
  • 2018‎

The entorhinal cortex (EC) is one of the most vulnerable brain regions that is attacked during the early stage of Alzheimer's disease (AD). Here, we report that the synaptic terminals of pyramidal neurons in the EC layer II (ECIIPN) directly innervate CA1 parvalbumin (PV) neurons (CA1PV) and are selectively degenerated in AD mice, which exhibit amyloid-β plaques similar to those observed in AD patients. A loss of ECIIPN-CA1PV synapses disables the excitatory and inhibitory balance in the CA1 circuit and impairs spatial learning and memory. Optogenetic activation of ECIIPN using a theta burst paradigm rescues ECIIPN-CA1PV synaptic defects and intercepts the decline in spatial learning and memory. These data reveal a novel mechanism of memory loss in AD mice via the selective degeneration of the ECIIPN-CA1PV pathway.


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