scholarly journals Role of AA-NAT and TPH1 in the Ghrelin-Dependent Regulation of Melatonin Secretion in Sheep during Different Seasons: An In Vitro Study

Author(s):  
Katarzyna Kirsz ◽  
Malgorzata Szczesna ◽  
Dorota A. Zieba

Several studies suggests that ghrelin (GHRL) has neurobiological effects that extend beyond control of food intake. Our previous results confirmed that GHRL modulates the secretory activity of the pineal gland (PG) through nocturnal melatonin (MEL) secretion in sheep, the seasonally reproductive animals. Here we investigated the effects of GHRL (10 ng/ml) on the expression of enzymes limiting synthesis of MEL, including tryptophan 5-hydroxylase 1 (TPH1), serotonin N-acetyltransferase (AA-NAT) and its phosphorylated form p31T-AA-NAT in sheep PG explants (n = 72) during the 4-hour incubation in a gas-liquid interface, at a short (SD) and long (LD) photoperiods. After each hour of incubation selected explants were frozen in liquid nitrogen and stored at -80°C for subsequent analysis (real-time PCR, western-blotting, ELISA). Results show that GHRL regulates nightly MEL secretion in a TPH1-independent manner. The factor modulating GHRL activity was photoperiod. During SD photoperiod GHRL significantly reduced the expression of p31T-AA-NAT, AA-NAT and inhibited MEL secretion from PG explants. Whereas, during LD photoperiod no effect of GHRL on MEL secretion and expression of examined enzymes was noted. Studies indicate that GHRL directly affects PG under in vitro conditions and causes MEL secretion in animals which exhibit seasonality in reproductive and metabolic processes.

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2999
Author(s):  
Deborah Reynaud ◽  
Roland Abi Nahed ◽  
Nicolas Lemaitre ◽  
Pierre-Adrien Bolze ◽  
Wael Traboulsi ◽  
...  

The inflammatory gene NLRP7 is the major gene responsible for recurrent complete hydatidiform moles (CHM), an abnormal pregnancy that can develop into gestational choriocarcinoma (CC). However, the role of NLRP7 in the development and immune tolerance of CC has not been investigated. Three approaches were employed to define the role of NLRP7 in CC development: (i) a clinical study that analyzed human placenta and sera collected from women with normal pregnancies, CHM or CC; (ii) an in vitro study that investigated the impact of NLRP7 knockdown on tumor growth and organization; and (iii) an in vivo study that used two CC mouse models, including an orthotopic model. NLRP7 and circulating inflammatory cytokines were upregulated in tumor cells and in CHM and CC. In tumor cells, NLRP7 functions in an inflammasome-independent manner and promoted their proliferation and 3D organization. Gravid mice placentas injected with CC cells invalidated for NLRP7, exhibited higher maternal immune response, developed smaller tumors, and displayed less metastases. Our data characterized the critical role of NLRP7 in CC and provided evidence of its contribution to the development of an immunosuppressive maternal microenvironment that not only downregulates the maternal immune response but also fosters the growth and progression of CC.


2021 ◽  
Vol 8 ◽  
Author(s):  
An Liu ◽  
Wenyuan Shi ◽  
Dongdong Lin ◽  
Haihui Ye

C-type allatostatins (C-type ASTs) are a family of structurally related neuropeptides found in a wide range of insects and crustaceans. To date, the C-type allatostatin receptor in crustaceans has not been deorphaned, and little is known about its physiological functions. In this study, we aimed to functionally define a C-type ASTs receptor in the mud crab, Scylla paramamosian. We showed that C-type ASTs receptor can be activated by ScypaAST-C peptide in a dose-independent manner and by ScypaAST-CCC peptide in a dose-dependent manner with an IC50 value of 6.683 nM. Subsequently, in vivo and in vitro experiments were performed to investigate the potential roles of ScypaAST-C and ScypaAST-CCC peptides in the regulation of ecdysone (20E) and methyl farnesoate (MF) biosynthesis. The results indicated that ScypaAST-C inhibited biosynthesis of 20E in the Y-organ, whereas ScypaAST-CCC had no effect on the production of 20E. In addition, qRT-PCR showed that both ScypaAST-C and ScypaAST-CCC significantly decreased the level of expression of the MF biosynthetic enzyme gene in the mandibular organ, suggesting that the two neuropeptides have a negative effect on the MF biosynthesis in mandibular organs. In conclusion, this study provided new insight into the physiological roles of AST-C in inhibiting ecdysone biosynthesis. Furthermore, it was revealed that AST-C family peptides might inhibit MF biosynthesis in crustaceans.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zonghao Tang ◽  
Jiajie Chen ◽  
Zhenghong Zhang ◽  
Jingjing Bi ◽  
Renfeng Xu ◽  
...  

The increase of oxidative stress is one of the important characteristics of mammalian luteal regression. Previous investigations have revealed the essential role of reactive oxygen species (ROS) in luteal cell death during luteolysis, while it is unknown how ROS is regulated in this process. Considering the decrease of blood flow and increase of PGF2α during luteolysis, we hypothesized that the HIF-1α pathway may be involved in the regulation of ROS in the luteal cell of the late corpus luteum (CL). Here, by using a pseudopregnant rat model, we showed that the level of both HIF-1α and its downstream BNIP3 was increased during luteal regression. Consistently, we observed the increase of autophagy level during luteolysis, which is regulated in a Beclin1-independent manner. Comparing with early (Day 7 of pseudopregnancy) and middle CL (Day 14), the level of ROS was significantly increased in late CL, indicating the contribution of oxidative stress in luteolysis. Inhibition of HIF-1α by echinomycin (Ech), a potent HIF-1α inhibitor, ameliorated the upregulation of BNIP3 and NIX, as well as the induction of autophagy and the accumulation of ROS in luteal cells on Day 21 of pseudopregnancy. Morphologically, Ech treatment delayed the atrophy of the luteal structure at the late-luteal stage. An in vitro study indicated that inhibition of HIF-1α can also attenuate PGF2α-induced ROS and luteal cell apoptosis. Furthermore, the decrease of cell apoptosis can also be observed by ROS inhibition under PGF2α treatment. Taken together, our results indicated that HIF-1α signaling is involved in the regression of CL by modulating ROS production via orchestrating autophagy. Inhibition of HIF-1α could obviously hamper the apoptosis of luteal cells and the process of luteal regression.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Chanwoo Kim ◽  
Hannah Song ◽  
Sandeep Kumar ◽  
Douglas Nam ◽  
Hyuk Sang Kwon ◽  
...  

Atherosclerosis is a multifactorial disease that arises from a combination of endothelial dysfunction and inflammation, occurring preferentially in arterial regions exposed to disturbed flow. Bone morphogenic protein-4 (BMP4) produced by disturbed flow induces inflammation, endothelial dysfunction and hypertension, suggesting the importance of BMPs in vascular biology and disease. BMPs bind to two different types of BMP receptors (BMPRI and II) to instigate intracellular signaling. Increasing evidences suggest a correlative role of BMP4 and atherosclerosis, but the role of BMP receptors especially BMPRII in atherosclerosis is still unclear and whether knockdown of BMPRII is the cause or the consequence of atherosclerosis is still not known. It is therefore, imperative to investigate the mechanisms by which BMPRII expression is modulated and its ramifications in atherosclerosis. Initially, we expected that knockdown of BMPRII will result in loss of pro-atherogenic BMP4 signaling and will thereby prevent atherosclerosis. Contrarily, we found that loss of BMPRII expression causes endothelial inflammation and atherosclerosis. Using BMPRII siRNA and BMPRII +/- mice, we found that BMPRII knockdown induces endothelial inflammation in a BMP-independent manner via mechanisms involving reactive oxygen species (ROS), NFκB, and NADPH oxidases. Further, BMPRII +/- ApoE -/- mice develop accelerated atherosclerosis compared to BMPRII +/+ ApoE -/- mice, suggesting loss of BMPRII may induce atherosclerosis. Interestingly, we found that multiple pro-atherogenic stimuli such as hypercholesterolemia, disturbed flow, pro-hypertensive angiotensin II, and pro-inflammatory cytokine, TNFα, downregulate BMPRII expression in endothelium, while anti-atherogenic stimuli such as stable flow and statin treatment upregulate its expression, both in vivo and in vitro . Moreover, we found that BMPRII expression is significantly diminished in human coronary advanced atherosclerotic lesions. These results suggest that BMPRII is a critical, anti-inflammatory and anti-atherogenic protein that is commonly targeted by multiple pro- and anti-atherogenic factors. BMPRII could be used as a novel diagnostic and therapeutic target in atherosclerosis.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
António Galvão ◽  
Angela Tramontano ◽  
Maria Rosa Rebordão ◽  
Ana Amaral ◽  
Pedro Pinto Bravo ◽  
...  

Metabolic hormones have been associated with reproductive function modulation. Thus, the aim of this study was: (i) to characterize the immunolocalization, mRNA and protein levels of leptin (LEP), Ghrelin (GHR) and respective receptors LEPR and Ghr-R1A, throughout luteal phase; and (ii) to evaluate the role of LEP and GHR on progesterone (P4), prostaglandin (PG) E2and PGF2α, nitric oxide (nitrite), tumor necrosis factor-α(TNF); macrophage migration inhibitory factor (MIF) secretion, and on angiogenic activity (BAEC proliferation), in equine corpus luteum (CL) from early and mid-luteal stages. LEPR expression was decreased in late CL, while GHR/Ghr-R1A system was increased in the same stage. Regarding secretory activity, GHR decreased P4in early CL, but increased PGF2α, nitrite and TNF in mid CL. Conversely, LEP increased P4, PGE2, angiogenic activity, MIF, TNF and nitrite during early CL, in a dose-dependent manner. Thein vitroeffect of LEP on secretory activity was reverted by GHR, when both factors acted together. The present results evidence the presence of LEP and GHR systems in the equine CL. Moreover, we suggest that LEP and GHR play opposing roles in equine CL regulation, with LEP supporting luteal establishment and GHR promoting luteal regression. Finally, a dose-dependent luteotrophic effect of LEP was demonstrated.


Botany ◽  
2009 ◽  
Vol 87 (7) ◽  
pp. 691-701 ◽  
Author(s):  
Man-Ho Oh ◽  
Joan L. Huber ◽  
Wei Shen ◽  
Gurdeep S. Athwal ◽  
Xia Wu ◽  
...  

The 14-3-3 family of proteins are highly conserved signaling proteins in eukaryotes that bind to their client proteins, usually through specific phosphorylated target sequences. While the 14-3-3 proteins are thought to interact with a wide array of cellular proteins, there have been few studies addressing the in-vivo role of 14-3-3. As one approach to study this in-vivo role, we generated transgenic Arabidopsis plants constitutively overexpressing a directed mutant of 14-3-3 isoform ω that inhibits phosphorylated nitrate reductase (pNR) in a largely divalent-cation-independent manner in vitro. The transgenic plants had increased relative phosphorylation of NR at the regulatory Ser-534 site and decreased NR activity measured in the presence of 5 mmol·L–1 MgCl2 relative to nontransgenic plants. In addition, total NR protein was increased and the protein half-life was increased about two-fold. Two-dimensional difference gel electrophoresis analysis of proteins extracted from leaves of plants expressing the mutant 14-3-3 identified numerous cellular proteins that were altered in abundance. In particular, several β-glucosidase and glutathione S-transferase isoforms were decreased in abundance relative to wild type plants suggesting a possible alteration in stress or defense responses.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2743-2743
Author(s):  
Simona Colla ◽  
Nicola Giuliani ◽  
Paola Storti ◽  
Mirca Lazzaretti ◽  
Katia Todoerti ◽  
...  

Abstract Bone marrow (BM) neo-angiogenesis has a critical role in multiple myeloma (MM) progression. It is well established that the angiogenic process in MM is mainly due to an overproduction of pro-angiogenic molecules by MM cells and the BM microenvironment cells. However the molecular mechanisms at the basis of the angiogenic process in MM are currently under investigation. The deregulation of the homeobox genes has been previously associated to tumor progression and neoangiogenesis. Particularly, overexpression of the homeobox HOXB7 is critical in tumor-associated angiogenic switch in solid tumors as breast cancer. Actually the potential role of HOXB7 in MM-induced angiogenesis is not known. In this study we have investigated the expression of HOXB7 by MM and BM microenvironment cells and its potential role in the regulation of the angiogenic process. First, by microarray analysis in a large database of MM patients (n°= 132) we found that HOXB7 was overexpressed by MM cells in about 10% of patients as compared to healthy donors and MGUS subjects. On the other hand HOXB7 mRNA was expressed in 18 out of 23 human myeloma cell lines tested. Moreover, we found that isolated BM mesenchymal (MSC) and osteoblastic (OB) cells, obtained from bone biopsies in a subgroup of MM patients (n°=24) expressed HOXB7 gene by microarray analysis and real time PCR. HOXB7 expression was also investigated at protein level by immunohistochemistry on bone biopsies of MM patients finding that MSC and OB as well as endothelial cells expressed HOXB7 protein mainly at nuclear level. In order to investigate the potential role of HOXB7 in the angiogenic process we enforced HOXB7 expression by lentivirus vectors in MSC using both primary BM MSC and the human MSC cell line HS-5 to obtain a stable transduced cell line. The overexpression of HOXB7 in HOXB7 transduced MSC as compared to the empty vector-transduced MSC cells was confirmed by real time PCR, western blot and immunohistochemistry. By Gene chips U133 plus 2.0 (Affymetrix) we evaluated the gene expression profiling of HOXB7 over-expressing MSC finding that proangiogenic cytokines, metalloproteinases and chemokines were significantly modulated in HOXB7-transduced MSC cells as compared to control cells. Data were validated either by real time PCR or by western blot and by an angiogenesis antibody array showing that bFGF and VEGF production was induced in MSC by HOXB7 overexpression. Consistently, we found that conditioned media of HOXB7-transduced MSC cells significantly stimulated vessel formation as compared to controls using an in vitro angiogenic model. Finally we observed that the angiogenic in vitro differentiation of HOXB7-transduced MSC was significantly increased as compared to controls. In conclusion our data suggest the HOXB7 overexpression in MSC regulates the angiogenic switch and could be a potential therapeutic target in MM-induced angiogenesis.


Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 2966-2975 ◽  
Author(s):  
Kristian Rohde ◽  
Louise Rovsing ◽  
Anthony K. Ho ◽  
Morten Møller ◽  
Martin F. Rath

The cone-rod homeobox (Crx) gene encodes a transcription factor in the retina and pineal gland. Crx deficiency influences the pineal transcriptome, including a reduced expression of arylalkylamine N-acetyltransferase (Aanat), a key enzyme in nocturnal pineal melatonin production. However, previous functional studies on pineal Crx have been performed in melatonin-deficient mice. In this study, we have investigated the role of Crx in the melatonin-proficient rat pineal gland. The current study shows that pineal Crx transcript levels exhibit a circadian rhythm with a peak in the middle of the night, which is transferred into daily changes in CRX protein. The study further shows that the sympathetic innervation of the pineal gland controls the Crx rhythm. By use of adenovirus-mediated short hairpin RNA gene knockdown targeting Crx mRNA in primary rat pinealocyte cell culture, we here show that intact levels of Crx mRNA are required to obtain high levels of Aanat expression, whereas overexpression of Crx induces Aanat transcription in vitro. This regulatory function of Crx is further supported by circadian analysis of Aanat in the pineal gland of the Crx-knockout mouse. Our data indicate that the rhythmic nature of pineal CRX protein may directly modulate the daily profile of Aanat expression by inducing nighttime expression of this enzyme, thus facilitating nocturnal melatonin synthesis in addition to its role in ensuring a correct tissue distribution of Aanat expression.


2018 ◽  
Vol 314 (6) ◽  
pp. G655-G667 ◽  
Author(s):  
Zhao Lei ◽  
Meihong Deng ◽  
Zhongjie Yi ◽  
Qian Sun ◽  
Richard A. Shapiro ◽  
...  

Liver ischemia-reperfusion (I/R) injury occurs through induction of oxidative stress and release of damage-associated molecular patterns (DAMPs), including cytosolic DNA released from dysfunctional mitochondria or from the nucleus. Cyclic guanosine monophosphate–adenosine monophosphate (cGAMP) synthase (cGAS) is a cytosolic DNA sensor known to trigger stimulator of interferon genes (STING) and downstream type 1 interferon (IFN-I) pathways, which are pivotal innate immune system responses to pathogen. However, little is known about the role of cGAS/STING in liver I/R injury. We subjected C57BL/6 (WT), cGAS knockout (cGAS−/−), and STING-deficient (STINGgt/gt) mice to warm liver I/R injury and that found cGAS−/− mice had significantly increased liver injury compared with WT or STINGgt/gt mice, suggesting a protective effect of cGAS independent of STING. Liver I/R upregulated cGAS in vivo and also in vitro in hepatocytes subjected to anoxia/reoxygenation (A/R). We confirmed a previously published finding that hepatocytes do not express STING under normoxic conditions or after A/R. Hepatocytes and liver from cGAS−/− mice had increased cell death and reduced induction of autophagy under hypoxic conditions as well as increased apoptosis. Protection could be restored in cGAS−/− hepatocytes by overexpression of cGAS or by pretreatment of mice with autophagy inducer rapamycin. Our findings indicate a novel protective role for cGAS in the regulation of autophagy during liver I/R injury that occurs independently of STING. NEW & NOTEWORTHY Our studies are the first to document the important role of cGAS in the acute setting of sterile injury induced by I/R. Specifically, we provide evidence that cGAS protects liver from I/R injury in a STING-independent manner.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2450-2450
Author(s):  
Pedro De Alarcon ◽  
Manu Gnanamony ◽  
Jessica Garcia

Abstract Introduction: Iron deficiency (ID) is one of the recognized causes of reactive thrombocytosis in children. Factors that are commonly associated with megakaryopoiesis such as thrombopoietin (TPO), interleukin 6 (IL-6) and IL-11 are not altered in patients with iron deficiency and thrombocytosis suggesting the role of alternate mechanisms in controlling this process. We have previously shown using an ID rat model that ID increased the number of megakaryocytes in the bone marrow. We have also shown an increase in VEGFR (FLT1) and CXCR4 staining in bone marrow slides of ID rats. This data suggests that angiogenesis plays a vital role in the development of reactive thrombocytosis in response to ID. In this report, we have expanded our study to identify specific angiogenic signaling molecules associated with ID and used functional assays to validate it. Methods: For this study, we used the megakaryoblast cell line MEG-01 as an in vitro model of megakaryopoiesis. MEG-01 cells were adapted to grow in chemically defined serum free medium containing iron (iron replete media). For iron deficiency, serum free iron free media was mixed with iron replete media at a 1% v/v concentration (iron deplete media). For our experiments, MEG-01 cells were grown in both iron replete and depleted media for 7 days. Cell viability was measured using the trypan blue exclusion assay. Messenger-RNA expression of iron-related markers (TFR1, TFR2, FLT1, FLT3, FTL, FTH1, TF, HMOX1 and HMOX2) and angiogenic markers (VEGFA, VEGFB, VEGFC, PDGF, ANGPTL1, ANGPTL2, FGF2) was studied using real time PCR. We performed functional validation of angiogenesis with an in vitro tube formation assay using human umbilical vein endothelial (HUVEC) cells. For statistical analysis of the data we performed the t test using graph pad prism software and we considered p<0.05 as statistically significant. Results: In low iron conditions, MEG-01 cells showed a significant increase in FLT1 (4 fold) and FLT3 (3 fold) expression using real time PCR (p<0.001). Iron deficiency also induced a 2 fold increase in the mRNA expression of angiogenic molecules VEGFB, VEGFC, FGF2 and PDGFA (p<0.001). Using the tube formation assay, we also show that conditioned media collected from iron deficient MEG-01 cells induced increased vessel formation in endothelial cells. Conclusion: In this study, we were able to validate our earlier in vivo findings on iron deficiency induced reactive thrombocytosis. We show that cells adapt to low iron conditions by upregulating FLT1, FLT3 and FTL. We also show that several markers in the angiogenesis pathway like VEGFB, VEGFC, FGF2 and PDGFA are upregulated in response to iron deficiency. We were also able to show that an increase in these angiogenic molecules induced increased vessel formation in endothelial cells. This report, along with our previous findings, points to the importance of the angiogenic pathway in reactive thrombocytosis induced by iron deficiency. Disclosures No relevant conflicts of interest to declare.


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