Estrogen Injection Research Articles

Clusterin from endometrial glands plays a critical role in decidualization via Trem2

BackgroundDecidualization is a critical step in establishing pregnancy in mammals. Successful decidualization depends on intricate gland-stromal crosstalk. Clusterin (Clu) is a ubiquitously secreted protein in physiological fluids that is involved in numerous physiological functions. However, the role of Clu in decidualization is not fully understood.ResultsIn this study, we examined the expression pattern of Clu during early pregnancy in mice and explored its potential function in decidualization. Our results revealed that Clu was expressed in the uterine glands on Days 1–2 of early pregnancy and on Days 5–8 during decidualization after embryo implantation, as well as in glands at the interimplantation site. Additionally, ovariectomized mice exhibited significant upregulation of Clu expression in the uterine glands 3 h after in vivo estrogen injection. Trem2, a receptor for Clu, was detected in the decidual region of mice on Days 5–8 of early pregnancy, where it mediates Clu to regulate the decidual region. Furthermore, we observed that recombinant CLU protein increased the expression of the decidualization marker molecules insulin-like growth factor binding protein 1 (IGFBP1) and prolactin (PRL) in decidual cells. However, this upregulation was not observed when Trem2 expression was inhibited with siRNA.ConclusionsUterine gland-derived Clu, a new paracrine modulator, may participate in early pregnancy by influencing the decidualization process mediated by Trem2 in mice.

A Novel Intravaginal Contraceptive Plug for Cats: A Preliminary Biocompatibility Assessment on Haematology and Vaginal Swab.

This preliminary study evaluated the biocompatibility of a novel degradable intravaginal plug contraceptive composed of PEG 4000 and chitosan in cats using haematological profiling and vaginal cytology. Five healthy, non-pregnant female cats were fully anaesthetised and fitted with an intravaginal plug (10 × 0.3 mm) using an applicator, following oestrogen administration 3 h prior. Blood samples were collected from the cephalic vein on days 0 (pre-insertion) and 3 and 7 (post-insertion). Vaginal cytology examinations were conducted on day 0 (pre- and post-oestrogen injection) and days 1, 3 and 7 post-insertion. Haematological parameters, including red blood cell count, haemoglobin levels, haematocrit values, total white blood cell count and differentiation, showed no significant changes after contraceptive insertion (p > 0.05). Vaginal cytology indicated an acute inflammatory response in one out of five subjects on day three post-insertion. The distribution of vaginal epithelial cells (parabasal, intermediate and superficial) remained unaffected by contraception. Oestrogen injection resulted in the dominance of superficial cells up to day 7 of observation (p < 0.05). Overall, PEG 4000 and chitosan-based intravaginal plug contraceptives demonstrated sufficient biocompatibility, indicating their potential as viable contraceptive options for feline use.

The hyperplasia of the mammary gland effect of the Mongolian Remedy RuXian-I in rats reduced by estrogen and progesterone via inhibition of MAPK and NF-κB pathways

Background: The aim of the present study was to evaluate whether the HMG (Hyperplasia of the Mammary Gland) effect of RuXian-I in estrogen- and progestogen- induced HMG rats is mediated through the activation of MAPK (Mitogen activated protein kinase) and NF-κB signaling pathways. Materials and methods: Fifty virgin female Wistar rats were randomly divided into in control and HMG, RuXian-I (0.75 g·kg−1, 1.5 g·kg−1, 3 g·kg−1, respectively) groups, 10 in each. Injections of estrogen and progestogen were given to establish rat models of HMG and RuXian-I at the same time. Changes in nipple heights were measured; pathologic changes of HMG in rats were also observed under a light microscope; the phosphorylation levels of MAPK and NF κB and the expression levels of TNF-α and IL-1β were measured. Results: Compared with the control group, the nipple diameters and height were increased significantly, the numbers of MG lobules were increased, there were changes in breast histopathology, the levels of TNF-α and IL-1β increased significantly, and MAPK and NF-κB were activated in HMG rats. Compared with the HMG model group, the increased nipple height was decreased, the numbers of MG lobules were reduced, the degree of HMG in rats was alleviated obviously, and the phosphorylation level of MAPK and NF-κB and cytokines TNF- α and IL-1β levels in serum were decreased by RuXian-I treatment. Conclusion: Those results suggest RuXian-I has protective and therapeutic effects on HMG rats induced by estrogen and progestogen and is likely to activate MAPK and NF-κB signaling pathways.

Molecular biological marker BCL-2: testis analysis in prenatal injection of estrogen to white laboratory mice

Immunohistochemical study is one of the modern methods of disease diagnostics used in practical veterinary practice, as well as in scientific developments in differential diagnostics of animal diseases of tumour and non-tumour nature. Prenatal influence of estrogens results in reproductive system disorders in an adult organism which is accompanied by parallel growth of steroid dependent cancers of the offspring: testicles and ovaries. The aim of the study was to perform immunohistochemical analysis of Bcl-2 marker during prenatal exposure to different doses of the synthetic estrogen analogue Sinestrol in the testes of the offspring of white non-pedigreed laboratory mice. After fertilization, the pregnant females were divided into 3 groups, one intact and two experimental groups. The intact group was unaffected (n = 10). The first experimental group, C-25 (n = 13), was injected with the estrogen drug Sinestrol in the form of a 2 % oil solution at a dose of 25 g/kg. The second experimental group (n = 13) was given the estrogen preparation Sinestrol in the form of 2 % oil solution in a dose of 40 mkg/kg. When the offspring reached sexual maturity, they were removed from the experiment. Immunohistochemical analysis was carried out on sections from paraffin blocks of testes of progeny intended for standard morphological study, the marker of apoptosis inhibitor Bcl-2 was determined on indices of cellular elements of male glands of progeny: spermatogonia, spermatocytes, sperm-tides, spermatozoa and Leydig cells. Expression of Bcl-2 marker upon exposure to the synthetic drug Sinestrol at doses of 25 and 40 g/kg showed that the number of positively stained cells in spermatogonia increased by 8.6 and 9.4 % respectively compared to the intact group. When the intact group was compared with experimental groups C-25 and C-40, the expression of Bcl-2 marker in spermatocyte cells and spermatozoa showed no difference, a slight increase in positively stained cells in spermatids was observed. Bcl-2 marker expression rate in experimental groups C 25 and C-40 decreased in Leydig cells by 56.0 (P 0.05) and 60.0 % (P 0.05), respectively. Administration of the synthetic estrogen analogue Sinestrol during fetal gland initiation resulted in impaired morphology in the testes in adulthood. The expression index of Bcl-2 marker in experimental groups C-25 and C-40 decreased in Leydig cells, resulting in apoptotic cell death, which is responsible for production of male sex hormone testosterone. The results can be used to select optimal doses of the synthetic estrogen analogue Sinestrol in the prenatal period.

Single neonatal estrogen implant sterilizes female animals by decreasing hypothalamic KISS1 expression

Reproductive sterilization by surgical gonadectomy is strongly advocated to help manage animal populations, especially domesticated pets, and to prevent reproductive behaviors and diseases. This study explored the use of a single-injection method to induce sterility in female animals as an alternative to surgical ovariohysterectomy. The idea was based on our recent finding that repetitive daily injection of estrogen into neonatal rats disrupted hypothalamic expression of Kisspeptin (KISS1), the neuropeptide that triggers and regulates pulsatile secretion of GnRH. Neonatal female rats were dosed with estradiol benzoate (EB) either by daily injections for 11 days or by subcutaneous implantation of an EB-containing silicone capsule designed to release EB over 2–3 weeks. Rats treated by either method did not exhibit estrous cyclicity, were anovulatory, and became infertile. The EB-treated rats had fewer hypothalamic Kisspeptin neurons, but the GnRH-LH axis remained responsive to Kisspeptin stimulation. Because it would be desirable to use a biodegradable carrier that is also easier to handle, an injectable EB carrier was developed from PLGA microspheres to provide pharmacokinetics comparable to the EB-containing silicone capsule. A single neonatal injection of EB-microspheres at an equivalent dosage resulted in sterility in the female rat. In neonatal female Beagle dogs, implantation of an EB-containing silicone capsule also reduced ovarian follicle development and significantly inhibited KISS1 expression in the hypothalamus. None of the treatments produced any concerning health effects, other than infertility. Therefore, further development of this technology for sterilization in domestic female animals, such as dogs and cats is worthy of investigation.

Estrogen modulation of cortical spreading depression

Background and aimsCortical spreading depression (CSD), a transient neuronal and glial depolarization that propagates slowly across the cerebral cortex, is the putative electrophysiological event underlying migraine aura and a headache trigger. Migraine is three times more prevalent in women than men, linked to circulating female hormones. High estrogen levels or estrogen withdrawal may be a migraine trigger for many women. We, therefore, aimed to examine whether sex, gonadectomy, and female hormone supplementation and withdrawal affect the susceptibility to CSD.MethodsTo determine CSD susceptibility, we recorded the frequency of CSDs triggered during 2-h topical KCl application in intact or gonadectomized female and male rats, without or with estradiol or progesterone supplementation via daily intraperitoneal injections. Estrogen or progesterone treatment followed by withdrawal was studied in a separate cohort. To take the first step towards identifying potential mechanisms, we studied glutamate and GABAA receptor binding using autoradiography.ResultsThe CSD frequency in intact female rats was higher than intact male and ovariectomized rats. We did not detect a change in CSD frequency during different stages of the estrous cycle in intact females. Daily estrogen injections for three weeks did not change CSD frequency. However, one-week estrogen withdrawal after two weeks of treatment significantly increased CSD frequency compared with the vehicle group in gonadectomized females. The same protocol of estrogen treatment and withdrawal was ineffective in gonadectomized males. In contrast to estrogen, daily progesterone injections for three weeks elevated CSD susceptibility, and one-week withdrawal after two weeks of treatment partially normalized this effect. Autoradiography did not reveal significant changes in glutamate or GABAA receptor binding density after estrogen treatment and withdrawal.ConclusionsThese data suggest that females are more susceptible to CSD, and sexual dimorphism is abrogated by gonadectomy. Moreover, estrogen withdrawal after prolonged daily treatment enhances CSD susceptibility. These findings may have implications for estrogen-withdrawal migraine, although the latter tends to be without aura.

Morphology of the testes of animals during estrogen injection in the prenatal period

The aim of the study was to investigate the morphological changes in the testes of the offspring of white non-pedigreed laboratory mice when the synthetic oestrogen analogue synestrol was prenatally injected to the mother. After fertilization, the females were divided into 2 groups which received a single intramuscular injection of the synthetic oestrogen analogue synestrol on day E 11.5 of gestation at the same time of the day. The intact group was not exposed to any treatment. The experimental group was exposed to synestrol, a synthetic oestrogen analogue, as a 2% oil solution at a dose of 40 µg/kg (C-40). The results of morphometric analysis of testes of descendants of white outbred laboratory mice after prenatal single injection of synthetic oestrogen analogue synestrol in a dose of 40 µg/kg showed morphological changes in the organ parenchyma, manifested as decrease in mean number of Sertoli cells (C-40) 17.4±1.1 compared to intact group 20.8±1.9; decrease in mean number of spermatogonia (C-40) 24.4±1.1 compared to intact group, decrease in mean number of spermatozoa (C-40) 178.0±4.2 compared to intact group 196.6±5.3. There was observed a change in the endocrine apparatus of testes, expressed as a decrease in the mean area of Leydig cell nuclei in the intact group of 6,72±1,78. Prenatal effects of synestrol revealed in an experimental model, allow us to use it to search for means of postnatal developmental testicular dysfunction correction as well as to develop optimal doses of oestrogenic preparations during pregnancy.

Huayu Sanjie Enema Liquid Relieves Pain in Endometriosis Model Rats by Inhibiting Inflammation, Peripheral Sensitization, and Pelvic Adhesion.

The objective of this study is to observe the effect of relieving pain of Huayu Sanjie enema liquid (HYSJ-EL) on endometriosis model rats and to explore its mechanism of action. Of 24 female Sprague Dawley rats, six were randomly selected as the sham operation group (normal control group). The remaining rats were used to establish rat models of endometriosis through autologous endometrial transplantation combined with estrogen injection. Successfully modeled rats were randomly divided into the model, indomethacin (Western medicine group), and HYSJ-EL (Chinese herbs group) treatment groups. The thermal pain threshold of rats was measured, and hematoxylin and eosin staining was used to observe pathological changes after sampling. Serum levels of prostaglandin E2 (PGE2), interleukin-6 (IL-6), macrophage inflammatory protein-2 (MIP-2), plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor-β (TGF-β) were measured using an enzyme-linked immunosorbent assay (ELISA). Furthermore, the protein and mRNA expression levels of transient receptor potential vanilloid-1 (TRPV1) and tumor necrosis factor-α (TNF-α) in the endometrium and endometriotic lesions were measured using Western blotting and quantitative real-time PCR assays, respectively. Compared to the model group, the heat pain threshold of rats in the HYSJ-EL group was significantly increased (P < 0.01), and the serum levels of PGE2, IL-6, MIP-2, PAI-1, and TGF-β were significantly decreased (P < 0.01), as well as the expression of TRPV1 and TNF-α protein and mRNA in the tissue of the ectopic lesion was significantly decreased (P < 0.05). These results indicate that the Huayu Sanjie enema liquid exerts analgesic effects on endometriosis by inhibiting inflammation, peripheral nerve sensitization, and pelvic adhesion.

Estrogen enhanced the expression of IL-17 by tissue-resident memory γδT cells from uterus via interferon regulatory factor 4.

Tissue-resident memory γδT cells at mucosal and epithelial sites play an important role for pathogen clearance, immunosurveillance, and participating in physiological processes. Different from other barrier sites, the immune cells in uterus face the protection against infections and tolerate an allogeneic fetus during a successful pregnancy. In the previous study, we found that tissue-resident memory γδT cells were enriched both in human and murine uterus and highly expressed IL-17 that promoted the invasion of trophocytes in vitro. In the current study, we found that γδT cells in uterus but not in blood or spleens expressed higher levels of estrogen receptors. The injection of estrogen into mice increased the proportion of γδT cells in uterus but not in spleens in vivo via CXCR3-CXCL10 chemokine axis. In addition, we found that estrogen enhanced the production of IL-17 but not IFN-γ in vivo and in vitro via interferon regulatory factor 4 but not RORγt and pSTAT3 at mRNA and protein levels. The analysis of cell transcriptome sequence further identified multiple differentially expressed genes between estrogen and control γδT cells. Our study demonstrated that estrogen directly act on γδT cells in uterus to enhance the production of IL-17 that might promote the invasion of trophocytes. Furthermore, our study might provide a new idea that estrogen increased the prevalence of autoimmune diseases in women by enhancing γδT cell-derived IL-17 production in uterus and uncover the critical pathological roles for estrogen in the development of autoimmune diseases.

Dose-Dependent Effects of Royal Jelly on Estrogen- and Progesterone-Induced Mammary Gland Hyperplasia in Rats.

Royal jelly (RJ) has a wide range of biological functions, its effect on hyperplasia of the mammary gland (HMG) in mammals is unclear. This study aims to investigate the effect of RJ on HMG and the dose-response relationship of RJ in the treatment of HMG. HMG rats are induced by intramuscular injection of estrogen (E2) and progesterone, and are treated with different doses of RJ (100, 200, 400, and 800 mg kg-1 d-1 ). As a result, RJ improves the expansion of acinar and breast tissue ducts, particularly at 100 and 800 mg kg-1 d-1 . These two doses also inhibit serum E2 and prolactin (PRL) secretion and increase serum progesterone secretion and the expression of estrogen receptor (ER)-β in the breast tissue. In addition, 800 mg kg-1 d-1 decrease and increase the mRNA expression of, respectively, hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary GnRH receptors (GnRH-R). The lowest dosage (100 mg kg-1 d-1 ) increases GnRH-R mRNA expression as well. However, the effects of 200 and 400 mg kg-1 d-1 RJ on the reproductive parameters of HMG are not significant, implying a dose-dependent effect. RJ regulates endocrine dyscrasia in HMG rats and improves the breast tissue structure, indicating its potential in the prevention and treatment on HMG.

A high dose of estrogen can improve renal ischemia-reperfusion-induced pulmonary injury in ovariectomized female rats.

Renal ischemia-reperfusion injury (RIRI) as a pathological process induces remote organ injury such as lung complications and it is regulated in a hormone-dependent manner. This study investigates the effect of estrogen on RIR-induced pulmonary injury in ovariectomized (OV) rats. A total of 60 female Wistar rats were divided into six groups: (i) intact sham, (ii) OV sham, (iii) OV sham + estradiol valerate (E), (iv) intact ischemia, (v) OV ischemia, and (vi) OV ischemia + E. Bilateral ischemia was performed for 45min in all groups except sham. Before the ischemia, OV groups received an intramuscular (i.m.) injection of E. After reperfusion, blood samples were collected for serum analysis and kidney and lung tissue were separated for pathological experiment and malondialdehyde (MDA) and nitrite measurement. The left lung was weighed to measure pulmonary edema. Estrogen deficiency caused a greater increase in blood urea nitrogen and creatinine levels during IRI. Ischemia reduced nitrite of serum and lung tissue. The increased level of MDA during ischemia, returned to normal levels via estrogen injection. The severity of renal and lung damage in ischemic groups increased significantly, and estrogen improved this injury. Estrogen as an antioxidant agent can reduce oxidative stress and may improve renal function and ameliorating lung damage caused by RIR.

Expression and Regulation of CD73 during the Estrous Cycle in Mouse Uterus.

Cluster of differentiation 73 (CD73, also known as ecto-5′-nucleotidase) is an enzyme that converts AMP into adenosine. CD73 is a surface enzyme bound to the outside of the plasma membrane expressed in several cells and regulates immunity and inflammation. In particular, it is known to inhibit T cell-mediated immune responses. However, the regulation of CD73 expression by hormones in the uterus is not yet clearly known. In this study, we investigated the expression of CD73 in ovariectomized mice treated with estrogen or progesterone and its regulation in the mouse uterus during the estrous cycle. The level of CD73 expression was dynamically regulated in the uterus during the estrous cycle. CD73 protein expression was high in proestrus, estrus, and diestrus, whereas it was relatively low in the metestrus stage. Immunofluorescence revealed that CD73 was predominantly expressed in the cytoplasm of the luminal and glandular epithelium and the stroma of the endometrium. The expression of CD73 in ovariectomized mice was gradually increased by progesterone treatment. However, estrogen injection did not affect its expression. Moreover, CD73 expression was increased when estrogen and progesterone were co-administered and was inhibited by the pretreatment of the progesterone receptor antagonist RU486. These findings suggest that the expression of CD73 is dynamically regulated by estrogen and progesterone in the uterine environment, and that there may be a synergistic effect of estrogen and progesterone.

Calcifications due to estrogen injections.

Calcifications due to estrogen injections.

A Rare Case of Autoimmune Progesterone Disease

Background: Autoimmune progesterone disease is a rare disease, with fewer than 200 reported cases. Unfortunately, there are no published estimates of incidence or prevalence.Clinical Case: A 24 year-old woman with no significant past medical history presented with sudden and new onset swelling of the lips which was unresponsive to Benadryl and prednisone. Swelling eventually progressed into blistering over the lips, oral, pharyngeal mucosa and tongue. She was admitted to the hospital for suspicion of Steven Johnson syndrome and was discharged after resolution of skin and oral lesions following treatment. She presented again in 3 months with full body rash and blisters now involving oral and vaginal mucosa. She underwent biopsy of these lesions during this admission and findings were suspicious for drug eruption vs erythema multiforme. Unfortunately, inciting drug or event could not be associated even with pathological diagnosis. She continued to have mucocutaneous flare every month for the next 8 months with multiple hospitalizations and was treated with antibiotics during these admissions. Over the course of her evaluation, it was noted that her symptoms seemed to coincide with her menstrual cycles. Her IUD was removed and she was started on OCPs but her symptoms persisted without any improvement. She underwent intradermal progesterone challenge test at tertiary center for ongoing cyclical dermatitis and tested positive for progesterone sensitivity. She was diagnosed with Autoimmune Progesterone dermatitis. She had to ultimately undergo total abdominal hysterectomy and bilateral salphingo-oophorectomy as she failed OCPs and had adverse effects to progesterone desensitization including full body rash and blisters. Post operatively, she has been started on IM depot injections of estrogen and vaginal estrogen cream.Conclusion: Autoimmune progesterone disease also known as progesterone dermatitis or progesterone hypersensitivity is not associated with other autoimmune diseases and usually affects women of reproductive age. It is a rare disorder with variable presentation and often overlaps with other forms of dermatosis. It is commonly underdiagnosed or misdiagnosed and appropriate treatment is often delayed. High clinical suspicion for symptoms of cyclical nature is necessary for making the diagnosis.

Echotexture Analysis of Prostate Parenchyma for Detection of Benign Prostatic Hyperplasia in Dogs

Ultrasonography is one of the most common methods for the diagnosis of prostate disorders, such as benign prostatic hyperplasia (BPH), in dogs. Changes in the echotexture are one of the indicators used to diagnose prostate disorders. The purpose of this study was to investigate the changes occurred in the dogs’ prostate echotexture during the induction of BPH using image analysis. Twenty sexually mature male intact mixed-breed dogs were selected and divided randomly into control and BPH-induced groups. BPH was induced using testosterone and estrogen injections for 63 days. The ultrasound imaging of the dogs’ prostate was performed during the induction of BPH on days 0, 21, 42, and 63. The echotexture of the prostate parenchyma was analyzed using the Image J software. Then, the changes in the echotexture and its correlation and linear regression with the prostate volume and canine prostate specific esterase (CPSE) concentration were evaluated by statistical tests. The prostate parenchyma echotexture did not show any significant changes during the induction of BPH and in comparison with that of the control group. While prostate volume and CPSE concentration increased significantly, indicating that BPH was induced in the dogs. There was no significant correlation and linear regression between the prostate echotexture and prostate volume or between the CPSE concentration and prostate echotexture. According to the results, the alteration in the prostate parenchymal echotexture did not occur in the early stages of induced BPH, but significant changes occurred in the prostate volume and CPSE concentration during those early stages.

P2X3 receptor expression in dorsal horn of spinal cord and pain threshold after estrogen therapy for prevention therapy in neuropathic pain

IntroductionNeuropathic pain may arise from conditions that affecting the central or peripheral nervous system. This study was held to determine the difference P2X3 receptor expression in the dorsal horn of the spinal cord and pain threshold after estrogen therapy in neuropathic pain. MethodsThis study design was an experimental research laboratory. The 24 mice samples divided into negative control group, positive control, and treatment groups. The treatment groups were given subcutaneous injections of estrogen 0.4 ml and also examined for the onset of thermal hyperalgesia in every rat. On day 15, an autopsy was performed on rats, and the spine was taken. The spinal cord was stained by hematoxylin-eosin, and the expression of P2X3 receptors was investigated. P2X3 receptor expression was examined in the dorsal horn on each sample. ResultsFrom 24 subjects of the study revealed an increase in the onset of thermal hyperalgesia on the estrogen group compared with the placebo group, a higher start. This study also obtained a decrease in the expression of P2X3 on the therapy group compared to the positive control group with significant differences. Statistical test results revealed the appearance of the P2X3 estrogen group had a substantial difference with the placebo group (p = 0.000) and the mean of the negative control group (p = 0.030). The placebo group had a significant difference from the negative control group (p = 0.035). ConclusionEstrogen could decrease the expression of P2X3 receptors and prolonged the onset of thermal hyperalgesia. So, both of these explained that estrogen has a role in preventing the occurrence of neuropathic pain after peripheral nerve lesions.

Impact of estrogen therapy on temporomandibular joints of rats: Histological and hormone analytical study

ObjectivesThis research aims to evaluate the effects of estrogen deficiency and replacement on the TMJ structures of rats. The considerable similarities in the anatomical features of rats and humans make rats a suitable model for human scientific studies. MethodsA clinical trial was conducted on 18 female Sprague-Dawley rats grouped into three categories. The GI group included 6 female rats labelled as the control group, the GII group consisted of 6 females that received ovariectomies, and the GIII group had 6 ovariectomised females that were injected with estrogen replacement therapy in a science laboratory at King Abdulaziz University. ANOVA and Tukey HSD post hoc tests were used to determine any significant differences between the levels of estrogen among the three groups. ResultsThe results indicate that some TMJ structures, including the articular disc and condylar cartilaginous layer, were degraded after estrogen deficiency. However, there was a slight improvement in the cartilaginous layer thickness and proliferation of chondroid cells after estrogen replacement therapy. Estrogen level was reduced in the ovariectomized rats, and while estrogen injections increased blood hormone levels, the levels did not reach those of the control group. ConclusionEstrogen deficiency degraded some TMJ structures, and there is only a slight recovery after estrogen replacement therapy.

Autophagy and multivesicular body formation in blastocysts during the experimental diapause in mice

In experimentally induced diapause model in mice, blastocysts remain dormant for an extended period but resume implantation competency upon estrogen injection. The underlying mechanism by which extended longevity of dormant blastocysts is maintained is unclear. We have previously shown that dormant blastocysts, during experimentally induced diapause, exhibit heightened autophagic activation. Activation of autophagy appears to be a crucial adaptive response for survival in the unfavorable uterine environment, as inhibiting autophagy reduces the survival rate of dormant blastocysts. As a unique cell biological change occurring following estrogen supplementation to activate dormant blastocysts, multivesicular bodies (MVBs) accumulate in the trophectoderm. In various cellular contexts, autophagy and MVB formation are linked cell biological phenomena. Herein, we discuss the implications of these cell biological changes in dormant and activated blastocysts.

Unravelling fatty liver haemorrhagic syndrome: 2. Inflammation and pathophysiology

ABSTRACT To study the role of inflammation in the pathophysiology of the fatty liver haemorrhagic syndrome (FLHS), mature laying hens were treated with oestrogen (β-oestradiol-17-dipropionate or E2) and challenged with lipopolysaccharide (LPS). Oestrogen injections induced FLHS, but the incidence and severity of the condition was increased with a combination of E2 & LPS. Hepatic mRNA levels of the genes encoding key regulators of inflammation, such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-18 (IL-18), were evaluated. The expression of IL-6 mRNA in hepatocytes of all treated groups (E2, LPS and E2 & LPS hens) was elevated from 6-fold to 56-fold (P < 0.01), when compared to baseline and control values, with the highest fold change at 3 h post-treatment. The mRNA levels for IL-1β were better expressed at 24 h post-treatments with E2, LPS and E2 & LPS. The expression of IL-18 mRNA in the liver tissue was lower than IL-1β and IL-6 mRNA in all treated birds. At 24 h post-treatment, total white blood cell (WBC) counts and fibrinogen levels were elevated (P < 0.05) in E2-, LPS- and E2- & LPS-treated hens. Histologically, livers of hens from E2- and E2- & LPS-treated groups revealed inflammatory alterations with areas showing mononuclear aggregations, vacuolar fatty degeneration of hepatocytes, and increased sinusoidal congestion and haemorrhages. It was concluded that liver lipid accumulation and injury were associated with incidences of local (hepatic) and systemic inflammation, which could have initiated liver blood vessel and capsule rupture and, subsequently, the onset of FLHS.

Unravelling fatty liver haemorrhagic syndrome: 1. Oestrogen and inflammation

ABSTRACT Previous studies have implicated oestrogen as a factor in the induction of fatty liver haemorrhagic syndrome (FLHS). In this study, a refined laying hen model was employed to permit further investigations. Intramuscular (i.m.) injections of exogenous oestrogen as β-estradiol-17-dipropionate (E2) (5 mg/kg BW) were given every 4 days for 20 days to 30-week-old hens fed either ad libitum or with restricted feed intake. Elevated (P < 0.01) plasma oestrogen concentrations produced significant macroscopic and microscopic hepatic alterations. Hens in the E2-treated ad libitum fed (EAL) group experienced a higher incidence of FLHS than hens in the E2-treated restricted feed intake group, showing that birds with a higher feed intake are more at risk of developing FLHS. Histological examination of livers revealed that hens in the E2-treated ad libitum fed group had consistent and severe fat infiltration in the liver, and fat vacuolization within hepatocytes. Fat accumulation and fat droplets were found not only in the cytoplasm of hepatocytes but also in liver sinusoids. White blood cell counts and fibrinogen concentrations were altered (P < 0.01) in hens treated with E2 when compared with controls. Plasma fibrinogen concentrations were altered over time, and correlated with white blood cell counts (Pearson’s correlation r = 0.96; P = 0.001). Hens treated with E2 had increased (P < 0.01) levels of cholesterol and triglycerides, confirming that E2 induced hypercholesterolaemia and hypertriglyceridaemia. It was concluded that E2 successfully induced FLHS in hens, with typical systemic and hepatic events resulting from a disturbance in lipid metabolism and chronic low-grade inflammation.