scholarly journals Glucocorticoid and progesterone inhibit involution and programmed cell death in the mouse mammary gland.

1995 ◽  
Vol 131 (4) ◽  
pp. 1095-1103 ◽  
Author(s):  
Z Feng ◽  
A Marti ◽  
B Jehn ◽  
H J Altermatt ◽  
G Chicaiza ◽  
...  

Milk production during lactation is a consequence of the suckling stimulus and the presence of glucocorticoids, prolactin, and insulin. After weaning the glucocorticoid hormone level drops, secretory mammary epithelial cells die by programmed cell death and the gland is prepared for a new pregnancy. We studied the role of steroid hormones and prolactin on the mammary gland structure, milk protein synthesis, and on programmed cell death. Slow-release plastic pellets containing individual hormones were implanted into a single mammary gland at lactation. At the same time the pups were removed and the consequences of the release of hormones were investigated histologically and biochemically. We found a local inhibition of involution in the vicinity of deoxycorticosterone- and progesterone-release pellets while prolactin-release pellets were ineffective. Dexamethasone, a very stable and potent glucocorticoid hormone analogue, inhibited involution and programmed cell death in all the mammary glands. It led to an accumulation of milk in the glands and was accompanied by an induction of protein kinase A, AP-1 DNA binding activity and elevated c-fos, junB, and junD mRNA levels. Several potential target genes of AP-1 such as stromelysin-1, c-jun, and SGP-2 that are induced during normal involution were strongly inhibited in dexamethasone-treated animals. Our results suggest that the cross-talk between steroid hormone receptors and AP-1 previously described in cells in culture leads to an impairment of AP-1 activity and to an inhibition of involution in the mammary gland implying that programmed cell death in the postlactational mammary gland depends on functional AP-1.

2008 ◽  
Vol 6 (1) ◽  
pp. nrs.06006 ◽  
Author(s):  
Sivapriya Ramamoorthy ◽  
Zafar Nawaz

Steroid hormone receptors (SHR) belong to a large family of ligand-activated transcription factors that perform their biological functions by enhancing the transcription of specific target genes. The transactivation functions of SHRs are regulated by a specialized group of proteins called coactivators. The SHR coactivators represent a growing class of proteins with various enzymatic activities that serve to modify the chromatin to facilitate the transcription of SHR target genes. The ubiquitin-proteasome pathway enzymes have also been added to the growing list of enzymatic activities that are recruited to the SHR target gene promoters during transcription. One such ubiquitin-proteasome pathway enzyme to be identified and characterized as a SHR coactivator was E6-associated protein (E6-AP). E6-AP is a hect (homologous to E6-associated protein carboxy-terminal domain) domain containing E3 ubiquitin ligase that possesses two independent separable functions; a coactivation function and an ubiquitin-protein ligase activity. Being a component of the ubiquitin-proteasome pathway, it is postulated that E6-AP may orchestrate the dynamics of steroid hormone receptor-mediated transcription by regulating the degradation of the transcriptional complexes. E6-AP has also been shown to be involved in the regulation of various aspects of reproduction such as prostate and mammary gland development. Furthermore, it has been demonstrated that E6-AP expression is down-regulated in breast and prostate tumors and that the expression of E6-AP is inversely associated with that of estrogen and androgen receptors. This review summarizes our current knowledge about the structures, molecular mechanisms, spatiotemporal expression patterns and biological functions of E6-AP.


2021 ◽  
Vol 22 (18) ◽  
pp. 10161
Author(s):  
Tapan Behl ◽  
Piyush Madaan ◽  
Aayush Sehgal ◽  
Sukhbir Singh ◽  
Neelam Sharma ◽  
...  

One of the utmost frequently emerging neurodegenerative diseases, Parkinson’s disease (PD) must be comprehended through the forfeit of dopamine (DA)-generating nerve cells in the substantia nigra pars compacta (SN-PC). The etiology and pathogenesis underlying the emergence of PD is still obscure. However, expanding corroboration encourages the involvement of genetic and environmental factors in the etiology of PD. The destruction of numerous cellular components, namely oxidative stress, ubiquitin-proteasome system (UPS) dysfunction, autophagy-lysosome system dysfunction, neuroinflammation and programmed cell death, and mitochondrial dysfunction partake in the pathogenesis of PD. Present-day pharmacotherapy can alleviate the manifestations, but no therapy has been demonstrated to cease disease progression. Peroxisome proliferator-activated receptors (PPARs) are ligand-directed transcription factors pertaining to the class of nuclear hormone receptors (NHR), and are implicated in the modulation of mitochondrial operation, inflammation, wound healing, redox equilibrium, and metabolism of blood sugar and lipids. Numerous PPAR agonists have been recognized to safeguard nerve cells from oxidative destruction, inflammation, and programmed cell death in PD and other neurodegenerative diseases. Additionally, various investigations suggest that regular administration of PPAR-activating non-steroidal anti-inflammatory drugs (NSAIDs) (ibuprofen, indomethacin), and leukotriene receptor antagonists (montelukast) were related to the de-escalated evolution of neurodegenerative diseases. The present review elucidates the emerging evidence enlightening the neuroprotective outcomes of PPAR agonists in in vivo and in vitro models experiencing PD. Existing articles up to the present were procured through PubMed, MEDLINE, etc., utilizing specific keywords spotlighted in this review. Furthermore, the authors aim to provide insight into the neuroprotective actions of PPAR agonists by outlining the pharmacological mechanism. As a conclusion, PPAR agonists exhibit neuroprotection through modulating the expression of a group of genes implicated in cellular survival pathways, and may be a propitious target in the therapy of incapacitating neurodegenerative diseases like PD.


1998 ◽  
pp. 482-491 ◽  
Author(s):  
W Kiess ◽  
B Gallaher

Apoptosis or programmed cell death is a physiological form of cell death that occurs in embryonic development and during involution of organs. It is characterized by distinct biochemical and morphological changes such as DNA fragmentation, plasma membrane blebbing and cell volume shrinkage. Many hormones, cytokines and growth factors are known to act as general and/or tissue-specific survival factors preventing the onset of apoptosis. In addition, many hormones and growth factors are also capable of inducing or facilitating programmed cell death under physiological or pathological conditions, or both. Steroid hormones are potent regulators of apoptosis in steroid-dependent cell types and tissues such as the mammary gland, the prostate, the ovary and the testis. Growth factors such as epidermal growth factor, nerve growth factor, platelet-derived growth factor (PDGF) and insulin-like growth factor-I act as survival factors and inhibit apoptosis in a number of cell types such as haematopoietic cells, preovulatory follicles, the mammary gland, phaeochromocytoma cells and neurones. Conversely, apoptosis modulates the functioning and the functional integrity of many endocrine glands and of many cells that are capable of synthesizing and secreting hormones. In addition, exaggeration of the primarily natural process of apoptosis has a key role in the pathogenesis of diseases involving endocrine tissues. Most importantly, in autoimmune diseases such as autoimmune thyroid disease and type 1 diabetes mellitus, new data suggest that the immune system itself may not carry the final act of organ injury: rather, the target cells (i.e. thyrocytes and beta cells of the islets) commit suicide through apoptosis. The understanding of how hormones influence programmed cell death and, conversely, of how apoptosis affects endocrine glands, is central to further design strategies to prevent and treat diseases that affect endocrine tissues. This short review summarizes the available evidence showing where and how hormones control apoptosis and where and how programmed cell death exerts modulating effects upon hormonally active tissues.


1996 ◽  
Vol 135 (6) ◽  
pp. 1889-1898 ◽  
Author(s):  
D Schadendorf ◽  
M A Kern ◽  
M Artuc ◽  
H L Pahl ◽  
T Rosenbach ◽  
...  

Human malignant melanoma is notoriously resistant to pharmacological modulation. We describe here for the first time that the synthetic retinoid CD437 has a strong dose-dependent antiproliferative effect on human melanoma cells (IC50: 5 x 10(-6) M) via the induction of programmed cell death, as judged by analysis of cell morphology, electron microscopical features, and DNA fragmentation. Programmed cell death was preceded by a strong activation of the AP-1 complex in CD437-treated cells as demonstrated by gel retardation and chloramphenicol transferase (CAT) assays. Northern blot analysis showed a time-dependent increase in the expression of c-fos and c-jun encoding components of AP-1, whereas bcl-2 and p53 mRNA levels remained constant. CD437 also exhibited a strong growth inhibitory effect on MeWo melanoma cells in a xenograft model. In tissue sections of CD437-treated MeWo tumors from these animals, apoptotic melanoma cells and c-fos overexpressing cells were colocalized by TdT-mediated deoxyuridine triphosphate-digoxigenin nick end labeling (TUNEL) staining and in situ hybridization. Taken together, this report identifies CD437 as a retinoid that activates and upregulates the transcription factor AP-1, leading eventually to programmed cell death of exposed human melanoma cells in vitro and in vivo. Further studies are needed to evaluate whether synthetic retinoids such as CD437 represent a new class of retinoids, which may open up new ways to a more effective therapy of malignant melanoma.


2013 ◽  
Vol 25 (1) ◽  
pp. 248
Author(s):  
A. A. P. Derussi ◽  
A. C. S. Castilho ◽  
R. W. A. Souza ◽  
R. Volpato ◽  
C. R. F. Guaitolini ◽  
...  

The aim of this study was to compare the mRNA levels of hormone receptor for progesterone (PR), oestrogen α (ER-α), oestrogen β (ER-β), and oxytocin (OTR) in canine morulae and blastocysts. Ten healthy mature bitches were inseminated based on monitoring vaginal cytology and progesterone concentration. The first insemination was performed on Day 2 after the preovulatory LH surge (progesterone 4 ng mL–1), and the second was performed 48 h later. All females were submitted to ovariohysterectomy (OVH), and the oviduct as well the uterurs were flushed with PBS solution to obtain the embryos. The females were divided into two groups: Group A (n = 5), morulae were collected 8 days after the LH surge and Group B (n = 5), blastocysts were collected 12 days after the LH surge. The pools (n = 10) of embryos (5 embryos/pool) were stored in RNAlater® (Ambion, Life Technologies, USA) at –80°C. The samples were analysed together. The RNA later was removed used PBS calcium free and the total RNA extraction was performed using the Qiagen RNeasy micro-kit (Hildesheim, Germany). Before reverse-transcription (RT) reaction, the total RNA was treated with DNase I Amplification Grade (Invitrogen Life Technologies, Carlsbad, CA, USA). The gene expression of target genes was assessed by real-time RT-qPCR, using SuperScript III for RT and power SYBR Green PCR Master Mix (Applied Biosystems, USA) for cDNA for PCR. The primers for target genes were designed using the software Primer Express® (Applied Biosystems, USA). The gene expression of target genes was normalized by HPRT gene and the relative abundance of mRNA was determined by the ΔΔct method corrected by amplification efficiency using Pffafl’s equation. The means of mRNA relative abundance were compared by t-test. The PR mRNA expression only in blastocysts is similar to the results obtained by Hou et al. (1997) in rat embryos. It is believed that the absence of PR in the early stages of cleavage is due to the indirect action of progesterone by growth factors produced by the maternal reproductive tract (2). Apparently, ER-β action does not occur in the embryo canine phases analysed; however, the action of ER-α seems related to the deployment signal as seen by Hou et al. (1996) in rats. Similarly to findings in the literature, OTR expression decreased in canine embryonic development. This receptor was produced by blastocysts while present in the uterus, which may represent an incidental mechanism to the embryo control of endometrial receptivity, such as also to prevent the development of endometrial luteolytic mechanism. The variation in hormone receptors gene expression in canine embryos can be influencing the transition from morula to blastocyst. In addition, a hormonal influence on these structures can occur in different ways.


1998 ◽  
Vol 334 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Georgios SABATAKOS ◽  
Gareth E. DAVIES ◽  
Maria GROSSE ◽  
Anthony CRYER ◽  
Dipak P. RAMJI

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the activation of gene expression in the mammary gland during lactation. We have therefore investigated the detailed expression profile of the C/EBP family during lactation and involution of the mouse mammary gland. The expression of C/EBPβ and C/EBPδ mRNA was low during lactation, increased dramatically at the beginning of involution and remained constant thereafter. In contrast, C/EBPα mRNA expression was relatively high during the early stages of lactation, declined to low levels during the late stages of lactation and at the start of involution, and increased again during involution. Electrophoretic mobility-shift assays showed a close correlation between the expression of the C/EBP genes and the functional C/EBP DNA-binding activity and, additionally, demonstrated the participation of heterodimers, formed from among the three proteins, in DNA–protein interactions. The DNA-binding activity of the activator protein 1 (AP1) family of transcription factors was also induced during involution. These results therefore point to potentially important regulatory roles for both the C/EBP and the AP1 family during lactation and involution of the mammary gland.


2007 ◽  
Vol 196 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Scott M MacKenzie ◽  
Deborah Dewar ◽  
William Stewart ◽  
Robert Fraser ◽  
John M C Connell ◽  
...  

Steroid actions on brain tissue have been implicated in processes such as blood pressure regulation and neurodegeneration, including the progression of Alzheimer's disease (AD). mRNAs from all of the genes required for de novo synthesis from cholesterol of aldosterone and corticosterone (equivalent to cortisol in humans) have been identified in rat brain, together with abundant steroid hormone receptors, but the situation in human brain requires clarification. We used real-time RT-PCR to assess whether transcription of 13 steroid-associated genes occurs in human hippocampus and cerebellum, and to identify whether transcription of these genes is significantly altered in cases of AD. Frozen post-mortem samples of hippocampus and cerebellum from patients with AD (n=7) and age-matched controls free from neurological disease at the time of death (n=9) were used. We found all of the genes under investigation to be transcribed within normal and AD hippocampus and cerebellum except for CYP11B1 (11β-hydroxylase), CYP11B2 (aldosterone synthase) and CYP17 (17α-hydroxylase). No significant differences in mRNA levels were observed between the AD tissue and the equivalent control tissue, although significant regional differences in gene transcription were observed between hippocampus and cerebellum in AD and control samples. The absence of key mRNAs from human hippocampus and cerebellum rules out the de novo generation of aldosterone, cortisol or the sex steroids within these regions. However, the pattern of gene expression does suggest that the mineralocorticoid 11-deoxycorticosterone can be generated de novo. There is no evidence of a link between AD and altered steroid biosynthesis within human hippocampus and cerebellum.


2007 ◽  
Vol 6 (10) ◽  
pp. 1745-1757 ◽  
Author(s):  
Nancy Lee ◽  
Sreenivas Gannavaram ◽  
Angamuthu Selvapandiyan ◽  
Alain Debrabant

ABSTRACT In this report, we have characterized two metacaspases of Leishmania donovani, L. donovani metacaspase-1 (LdMC1) and LdMC2. These two proteins show 98% homology with each other, and both contain a characteristic C-terminal proline-rich domain. Both genes are transcribed in promastigotes and axenic amastigotes of L. donovani; however, LdMC1 shows increased mRNA levels in axenic amastigotes. An anti-LdMC antibody was obtained and showed reactivity with a single ∼42-kDa protein band in both promastigote and axenic amastigote parasite whole-cell lysates by Western blotting. Pulse-chase experiments suggest that LdMCs are not synthesized as proenzymes, and immunofluorescence studies show that LdMCs are associated with the acidocalcisome compartments of L. donovani. Enzymatic assays of immunoprecipitated LdMCs show that native LdMCs efficiently cleave trypsin substrates and are unable to cleave caspase-specific substrates. Consistently, LdMC activity is insensitive to caspase inhibitors and is efficiently inhibited by trypsin inhibitors, such as leupeptin, antipain, and N α-tosyl-l-lysine-chloromethyl ketone (TLCK). In addition, our results show that LdMC activity was induced in parasites treated with hydrogen peroxide, a known trigger of programmed cell death (PCD) in Leishmania and that parasites overexpressing metacaspases are more sensitive to hydrogen peroxide-induced PCD. These findings suggest that Leishmania metacaspases are not responsible for the caspase-like activities reported in this organism and suggest a possible role for LdMCs as effector molecules in Leishmania PCD.


2018 ◽  
Vol 86 (4) ◽  
pp. 46 ◽  
Author(s):  
Tatiana Stupina ◽  
Anastasia Balakina ◽  
Tatiana Kondrat’eva ◽  
Galina Kozub ◽  
Natalia Sanina ◽  
...  

NO donating iron nitrosyl complex with 2-aminothiophenyl ligand (2-AmPh complex) was studied for its ability to cause cell death and affect nuclear factor kappa B (NF-κB) signaling. The complex inhibited viability of HeLa cells and induced cell death that was accompanied by loss of mitochondrial membrane potential and characteristic for apoptosis phosphatidylserine externalization. At IC50, 2-AmPh caused decrease in nuclear content of NF-κB p65 polypeptide and mRNA expression of NF-κB target genes encoding interleukin-8 and anti-apoptotic protein BIRC3. mRNA levels of interleukin-6 and anti-apoptotic protein BIRC2 encoding genes were not affected. Our data demonstrate that NO donating iron nitrosyl complex 2-AmPh can inhibit tumor cell viability and induce apoptosis that is preceded by impairment of NF-κB function and suppression of a subset of NF-κB target genes.


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