Abstract 5260: Chemopreventive efficacy of everolimus and naproxen combination against carcinogen induced bladder cancer in F344 rats

Bladder Cancer (BC) is the second common genitourinary cancer with high recurrence and mortality rate due to metastatic muscle invasive BC (MIBC). Since majority of BCs are non-invasive at diagnosis, developing agents that effectively block BC progression may be beneficial for clinical translation. In this study, clinically approved agents, everolimus, mTOR inhibitor, [0.19mg/kg;7x/week (low dose, LD) or 1.33mg/kg;1x or 2X/week (high dose, HD)] at various dosing schedules alone or in combination with naproxen, an NSAID (30mg/kg body weight) intermittent dosing (3 Wks ON/OFF) were tested for efficacy in an N-butyl-N-(4- hydroxybutyl)nitrosamine (BBN)-induced BC rat model. Female F344 rats (8 weeks age; N=30) were gavaged 16 doses of BBN (150mg/dose). Either one-week (early intervention) or 12-weeks (late intervention) after BBN treatment, rats in each group received respective drug treatments by gavage. At 50 weeks age, rats were euthanized, and tissues were analyzed. Results suggest that BBN-exposed rats developed high number of Non-MIBC (NMIBC) and MIBC and had significantly large bladders (430±57mg, Mean±SEM; p<0.0001) compared to normal bladders in vehicle group (68.8±1.3mg). Importantly, there was significant reduction in tumor growth and progression of hyperplasia/papilloma with naproxen alone (3 weeks intermittent dosing) by 70% (129.7±7.7mg; p<0.0001) and 58% (180.8±27.6mg; p<0.001) at early and later interventions respectively compared to untreated BBN-exposed rats. Continuous LD or HD everolimus regimens during early intervention showed significant inhibitory effect on papilloma progression, whereas its delayed administration had modest to insignificant inhibitory effect of papilloma progression to NMIBC/MIBC. Intermittent dosing of naproxen alone inhibited large tumors (>200mg) incidence by 90% (p<0.0001) and by 75% (p<0.0001) with early and late interventions respectively. Early treatment with combinations led to >72% reduction in tumor weight (120.8±7.8mg, 121.8±11.5mg, and 118.6±5.2mg; p<0.0001) while late intervention had 58%-65% tumor reductions (179.6±14.4mg, 150.6±12.6mg, and 172.5±15.6mg; p<0.0005) with the combination dosing regimens. Notably, all 3 regimens of naproxen plus everolimus combinations significantly inhibited large tumor incidence at both early intervention (90%-100%; p<0.0001) and late intervention (60%-70%; p<0.0005), with significant suppression of papilloma progression to NMIBC and MIBC, including squamous cell carcinoma (SCC). Protein biomarker analysis suggested decrease in markers of proliferation, inflammation and mTOR signaling with an increased apoptosis. In summary, our study indicated that naproxen and everolimus combination can prevent bladder cancer progression and warrants further evaluation. (Supported by NCI-PREVENT program 75N91019D00020-75N91020F00003)

Citation Format: Venkateshwar Madka, Gopal Pathuri, Surya P. Singh, Anil Singh, Anh Bao, Nicole Stratton, Stanley Lightfoot, Clinton J. Grubbs, Jennifer Fox, John L. Clifford, Brian Cholewa, Shizuko Sei, CV Rao. Chemopreventive efficacy of everolimus and naproxen combination against carcinogen induced bladder cancer in F344 rats. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5260.

Anisotropic bianchi V cosmological model in Scale Covariant Theory of Gravitation with a time-variable deceleration parameter

In this paper we solve the field equations for Scale covariant theory of gravitation which was introduced by Caunato et al. [1], for Bianchi V line element in the presence of perfect fluid medium. Here the deceleration parameter is considered to be time dependent which gives the average scale factor a ( t ) = [ sinh ⁡ ( β t ) ] 1 / n , where n and β are positive constants. This value of average scale factor is the key expression for solving the field equations. Using the recent observational value of q 0 = - 0.52 - 0.04 + 0.08 and H 0 = 69.2 ± 1.2 derived from BAO/CMB and H(z) data by Santos et al. (2016) [46], we have evaluated three different pairs of ( n , β ) . We observe that the model represents a phase transition from early deceleration to a present accelerating phase for a particular choice of the pair ( n = 2 , β = 92.75 ) . Applying some recently developed diagnostic tools like jerk parameter and statefinders, we find that the derived model is exactly in accordance with standard ΛCDM model. Along with these, many physical, geometric and kinematic properties of the model are thoroughly studied and found consistent with recent observations.

Targeted sequencing of candidate genes of dyslipidemia in Punjabi Sikhs: Population-specific rare variants in GCKR promote ectopic fat deposition

Dyslipidemia is a well-established risk factor for cardiovascular diseases. Although, advances in genome-wide technologies have enabled the discovery of hundreds of genes associated with blood lipid phenotypes, most of the heritability remains unexplained. Here we performed targeted resequencing of 13 bona fide candidate genes of dyslipidemia to identify the underlying biological functions. We sequenced 940 Sikh subjects with extreme serum levels of hypertriglyceridemia (HTG) and 2,355 subjects were used for replication studies; all 3,295 participants were part of the Asian Indians Diabetic Heart Study. Gene-centric analysis revealed burden of variants for increasing HTG risk in GCKR (p = 2.1x10-5), LPL (p = 1.6x10-3) and MLXIPL (p = 1.6x10-2) genes. Of these, three missense and damaging variants within GCKR were further examined for functional consequences in vivo using a transgenic zebrafish model. All three mutations were South Asian population-specific and were largely absent in other multiethnic populations of Exome Aggregation Consortium. We built different transgenic models of human GCKR with and without mutations and analyzed the effects of dietary changes in vivo. Despite the short-term of feeding, profound phenotypic changes were apparent in hepatocyte histology and fat deposition associated with increased expression of GCKR in response to a high fat diet (HFD). Liver histology of the GCKRmut showed severe fatty metamorphosis which correlated with ~7 fold increase in the mRNA expression in the GCKRmut fish even in the absence of a high fat diet. These findings suggest that functionally disruptive GCKR variants not only increase the risk of HTG but may enhance ectopic lipid/fat storage defects in absence of obesity and HFD. To our knowledge, this is the first transgenic zebrafish model of a putative human disease gene built to accurately assess the influence of genetic changes and their phenotypic consequences in vivo.

Targeting the paracrine hormone-dependent guanylate cyclase/cGMP/phosphodiesterases signaling pathway for colorectal cancer prevention

Colorectal cancer (CRC) is one of the leading causes of cancer related-deaths. The risk of development of CRC is complex and multifactorial, and includes disruption of homeostasis of the intestinal epithelial layer mediated though dysregulations of tumor suppressing/promoting signaling pathways. Guanylate cyclase 2C (GUCY2C), a membrane-bound guanylate cyclase receptor, is present in the apical membranes of intestinal epithelial cells and maintains homeostasis. GUCY2C is activated upon binding of paracrine hormones (guanylin and uroguanylin) that lead to formation of cyclic GMP from GTP and activation of downstream signaling pathways that are associated with normal homeostasis. Dysregulation/suppression of the GUCY2C-mediated signaling promotes CRC tumorigenesis. High-calorie diet-induced obesity is associated with deficiency of guanylin expression and silencing of GUCY2C-signaling in colon epithelial cells, leading to tumorigenesis. Thus, GUCY2C agonists, such as linaclotide, exhibit considerable role in preventing CRC tumorigenesis. However, phosphodiesterases (PDEs) are elevated in intestinal epithelial cells during CRC tumorigenesis and block GUCY2C-mediated signaling by degrading cyclic GMP to 5`-GMP. PDE5-specific inhibitors, such as sildenafil, show considerable anti-tumorigenic potential against CRC by amplifying the GUCY2C/cGMP signaling pathway, but cannot achieve complete anti-tumorigenic effects. Hence, dual targeting the elevation of cGMP by providing paracrine hormone stimuli to GUCY2C and by inhibition of PDEs may be a better strategy for CRC prevention than alone. This review delineates the involvement of the GUCY2C/cGMP/PDEs signaling pathway in the homeostasis of intestinal epithelial cells. Further, the events are associated with dysregulation of this pathway during CRC tumorigenesis are also discussed. In addition, current updates on targeting the GUCY2C/cGMP/PDEs pathway with GUCY2C agonists and PDEs inhibitors for CRC prevention and treatment are described in detail.

The Luteinizing Hormone-Testosterone Pathway Regulates Mouse Spermatogonial Stem Cell Self-Renewal by Suppressing WNT5A Expression in Sertoli Cells

Spermatogenesis originates from self-renewal of spermatogonial stem cells (SSCs). Previous studies have reported conflicting roles of gonadotropic pituitary hormones in SSC self-renewal. Here, we explored the role of hormonal regulation of SSCs using Fshb and Lhcgr knockout (KO) mice. Although follicle-stimulating hormone (FSH) is thought to promote self-renewal by glial cell line-derived neurotrophic factor (GDNF), no abnormalities were found in SSCs and their microenvironment. In contrast, SSCs were enriched in Lhcgr-deficient mice. Moreover, wild-type SSCs transplanted into Lhcgr-deficient mice showed enhanced self-renewal. Microarray analysis revealed that Lhcgr-deficient testes have enhanced WNT5A expression in Sertoli cells, which showed an immature phenotype. Since WNT5A was upregulated by anti-androgen treatment, testosterone produced by luteinizing hormone (LH) is required for Sertoli cell maturation. WNT5A promoted SSC activity both in vitro and in vivo. Therefore, FSH is not responsible for GDNF regulation, while LH negatively regulates SSC self-renewal by suppressing WNT5A via testosterone.

Neutralization of Naja naja venom induced lethality, edema and myonecrosis by ethanolic root extract of Coix lacryma-jobi

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Oral administration of ethanolic root extract (ERE) at dose levels 100, 200 and 400 mg/kg effectively inhibits Naja naja venom-induced lethality in mice as well as venom-induced proteolysis, fibrinogenolysis, DNase activity.

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ERE at a dose of 200 mg/kg inhibits myotoxicity induced by Naja naja venom measured by creatine kinase activity in rats.

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Molecular docking studies revealed that stigmasterol isolated from the ERE is probably responsible for inhibition of Naja naja venom PLA₂.

Coix lacryma-jobi, commonly known as job’s tear, is a tall grain-bearing tropical plant of the family Poaceae. The ethanolic root extract (ERE) of the plant was investigated for the first time for anti-venom activity against Indian cobra Naja naja venom.

In-vitro studies were conducted to determine neutralization of phospholipase A₂ (PLA₂) activity of the Naja naja venom by the ERE. ERE showed significant inhibition of PLA₂ activity, which was further confirmed from effective neutralization of human red blood cells (HRBC) lysis induced by the venom. In addition, venom-induced proteolysis, fibrinogenolysis, DNase activity were also neutralized by the ERE, which contained carbohydrates, glycolides, resins and tannins.

Oral administration of ERE at doses levels 100, 200 and 400 mg/kg effectively inhibited Naja naja venom-induced lethality in mice. Myotoxicity induced by Naja naja venom, measured by creatine kinase activity in rats was significantly neutralized by the ERE at a dose of 200 mg/kg.

Stigmasterol, as one of the component isolated from the ERE, was found to have venom phospholipase A₂ inhibition potential, which was confirmed by molecular docking studies with PLA₂. In summary, these studies indicate the ability of ERE of Coix lacryma-jobi to effectively neutralize the toxic effects of the venom is, in part, contributed by the inhibition of PLA₂ activity among other venom-derived factors.

Systemic chromosome instability in Shugoshin-1 mice resulted in compromised glutathione pathway, activation of Wnt signaling and defects in immune system in the lung

Mitotic error-mediated chromosome instability (CIN) can lead to aneuploidy, chromothripsis, DNA damage and/or whole chromosome gain/loss. CIN may prompt rapid accumulation of mutations and genomic alterations. Thus, CIN can promote carcinogenesis. This CIN process results from a mutation in certain genes or environmental challenge such as smoking, and is highly prevalent in various cancers, including lung cancer. A better understanding of the effects of CIN on carcinogenesis will lead to novel methods for cancer prevention and treatment. Previously Shugoshin-1 (Sgo1(-/+)) mice, a transgenic mouse model of CIN, showed mild proneness to spontaneous lung and liver cancers. In this study, adoptive (T/B-cell based) immunity-deficient RAG1(-/-) Sgo1(-/+) double mutant mice developed lung adenocarcinomas more aggressively than did Sgo1(-/+) or RAG1(-/-) mice, suggesting immune system involvement in CIN-mediated lung carcinogenesis. To identify molecular causes of the lung adenocarcinoma, we used systems biology approach, comparative RNAseq, to RAG1(-/-) and RAG1(-/-) Sgo1(-/+). The comparative RNAseq data and follow-up analyses in the lungs of naive Sgo1(-/+) mice demonstrate that, (i) glutathione is depleted, making the tissue vulnerable to oxidative stress, (ii) spontaneous DNA damage is increased, (iii) oncogenic Wnt signaling is activated, (iv) both major branches of the immune system are weakened through misregulations in signal mediators such as CD80 and calreticulin and (v) the actin cytoskeleton is misregulated. Overall, the results show multi-faceted roles of CIN in lung carcinoma development in Sgo1(-/+) mice. Our model presents various effects of CIN and will help to identify potential targets to prevent CIN-driven carcinogenesis in the lung.

Involvement of Luteinizing Hormone in Alzheimer Disease Development in Elderly Women

Alzheimer disease (AD) is a slow progressive neurodegenerative disease that affects more elderly women than elderly men. It impairs memory, typically progresses into multidomain cognitive decline that destroys the quality of life, and ultimately leads to death. About 5.3 million older Americans are now living with this disease, and this number is projected to rise to 14 million by 2050. Annual health-care costs in the United States alone are projected to increase to about US$1.1 trillion by 2050. The initial theory that decreasing estrogen levels leads to AD development in postmenopausal women has been proven inconclusive. For example, Women's Health Research Initiative Memory Study and the population-based nested case-control study have failed to demonstrate that estrogen/progesterone (hormone replacement therapy [HRT]) or estrogen replacement therapy could prevent the cognitive decline or reduce the risk of AD. This led to the realization that AD development could be due to a progressive increase in luteinizing hormone (LH) levels in postmenopausal women. Accordingly, a large number of studies have demonstrated that an increase in LH levels is positively correlated with neuropathological, behavioral, and cognitive changes in AD. In addition, LH has been shown to promote amyloidogenic pathway of precursor protein metabolism and deposition of amyloid β plaques in the hippocampus, a region involved in AD. Cognate receptors that mediate LH effects are abundantly expressed in the hippocampus. Reducing the LH levels by treatment with gonadotropin-releasing hormone agonists could provide therapeutic benefits. Despite these advances, many questions remain and require further research.

Therapeutic Potential of Human Chorionic Gonadotropin Against Painful Bladder Syndrome/Interstitial Cystitis

Painful bladder syndrome/interstitial cystitis is a debilitating chronic bladder disease that primarily affects women. The disease is due to a damage of urothelial cell lining. As a result, potassium particles and other toxic substances in urine can leak into bladder mucosa, causing the symptoms of lower abdominal/pelvic discomfort, pain, increased urination frequency, urgency, nocturia, and so on, all of which can substantially reduce the quality of daily life. There are multiple symptom reliving therapies. Among them, only pentosan polysulfate sodium, sold under the brand name of Elmiron, has been approved for oral use by US Food and Drug Administration. It provides the relief after several months of use. Based on the scientific leads presented in this article, we propose that human chorionic gonadotropin has a therapeutic potential that is worth investigating for the treatment of this disease.

Why are We Waiting to Start Large Scale Clinical Testing of Human Chorionic Gonadotropin for the Treatment of Preterm Births?

Preterm births are an expensive global health problem. Despite the basic science and clinical research advances to better understand and prevent preterm births, the rates are increasing. There are several therapeutic options. While some options such as progestins work for selected women, others such as magnesium sulfate can only be used for delaying births for 24 to 48 hours so that the patients can be treated with corticosteroids to promote fetal lung maturity. Based on the scientific and clinical evidence, we recommend testing human chorionic gonadotropin in a large multicenter, randomized, double-blind, and placebo-controlled clinical trials in women with active preterm labor and those with a previous history of preterm births. Human chorionic gonadotropin is not only inexpensive but also has not shown any side effects so far in the infants or in the mothers.

Therapeutic Potential of Human Chorionic Gonadotropin Against Overactive Bladder

Overactive bladder (OAB) is a common form of urinary incontinence, resulting from spontaneous and random contractions of the urinary bladder. The affected individuals have an uncontrollable urge to urinate and experience incontinence and nocturia, which can greatly reduce the quality of daily life. There are several drugs for the treatment, and all of them have serious side effects. The following findings suggested that human chorionic gonadotropin (hCG) has a therapeutic potential that is worth investigating for the treatment of OAB. The finding are (1) human detrusor muscle contains hCG receptors, (2) detrusor muscle becomes quiescent during pregnancy, (3) hCG can inhibit detrusor muscle contractions induced by cholinergic stimulation in rats, and (4) hCG can mimic the anticholinergic drug on detrusor muscle contractions.

Identification of Immunoreactive Luteinizing Hormone Receptors in the Adrenal Cortex of the Female Rhesus Macaque

Female laboratory macaques were studied under a variety of treatment protocols to determine if immunoreactive luteinizing hormone/gonadal chorionic gonadotropin (LH/CG) receptors were present in the adrenal cortex. All adrenal tissues revealed an absence of immunoreactivity in the in the medulla while staining was present in all three outer zones of the cortex. Increased staining was observed in the zonae reticularis with least staining in the zonae glomerulosa. Moderate and variable staining was found in the zonae fasciculata. These results demonstrate that LH/CG receptors in the adrenal cortex may be more common in higher primates than previously recognized and help explain some aspects of the endocrine changes observed in mid-aged women during the menopausal transition when circulating LH concentrations are rising.

Potential Therapy for Rheumatoid Arthritis and Sjögren Syndrome With Human Chorionic Gonadotropin

Autoimmune diseases such as rheumatoid arthritis (RA) and Sjögren syndrome (SS) ameliorate during pregnancy, through dampening (immunotolerance) of the maternal immune system which protects the fetus from rejection. A large number of studies have shown that human chorionic gonadotropin (hCG) contributes to this tolerance. Studies on animal models have reaffirmed that hCG treatment mimics the benefits of pregnancy. Based on the scientific evidence, randomized clinical trials comparing hCG with current therapies and/or placebo are recommended for RA, SS, and for other autoimmune diseases such as, type 1 diabetes and ankylosing spondylitis, which also get better during pregnancy and hCG treatment seems to help.

Potential Therapy for Neisseria Gonorrhoeae Infections With Human Chorionic Gonadotropin

The scientific evidence suggests that Neisseria gonorrhoeae (NG) infects human fallopian tubes by molecular mimicry in which pathogens act like a ligand to bind to epithelial cell surface human chorionic gonadotrophin (hCG)/luteinizing hormone (LH) receptors. The hCG-like molecule has been identified as ribosomal protein L12 in NG coat surface. Human fallopian tube epithelial cells have been shown to contain functional hCG/LH receptors. As previously shown in human fallopian tube organ and cell culture studies, cellular invasion and infection can be prevented by exposing the cells to excess hCG, which would outnumber and outcompete NG for receptor binding. Based on these data, we suggest testing hCG in clinical trials on infected women.

The Presence of Human Chorionic Gonadotropin/Luteinizing Hormone Receptors in Pancreatic β-Cells

We investigated the possible presence of functional human chorionic gonadotropin (hCG)/luteinizing hormone (LH) receptors in β-cells of pancreas, using a combination of techniques on hCG/LH receptor knockout mice, immortalized rat insulinoma cells, and human pancreatic islets. The results showed the presence of receptors and their activation resulted in a dose-dependent increase in glucose-induced release of insulin. These findings place hCG and LH among the regulators of insulin release with potential implications for insulin-level changes during the periods of altered hCG and LH secretion.

Prophylactic vaccine approach for colon and pancreatic cancers: present and future

Vaccines against cancers have not been as effective as vaccines against infectious diseases. However, recent studies have advanced our understanding of the stages of tumor cell development and of mechanisms of immune surveillance, immune suppression, and of tumor escape from the immune system. The development of animal models that mimic development of human cancers has helped advance the understanding of these processes and is aiding the development of greatly improved vaccines. Here we review the recent progress in developing vaccines and prophylactic approaches for pancreatic and colon cancers. Improved understanding of the expression of various oncogenes and tumor-associated antigens helps in selecting antigenic targets for stage-specific immune prevention. Identification of the earliest alterations in precancerous lesions and selection of epitopes unique to the aberrant cells and capable of triggering strong cytotoxic and helper T cell responses may aid the development of safe and effective vaccines for use in those at high risk of progressing to invasive cancers. The responses can be enhanced with carefully selected adjuvants to boost immunity and by selecting epitopes that are expressed on dendritic cells, thereby promoting T cell responses. Tumor resistance via loss of the targeted antigen can be mitigated by inclusion of multiple tumor epitopes in vaccine constructs. Tumor immune escape can be diminished by targeting various immunosuppressive mechanisms used by different tumors, such as tumor production of immunosuppressive cytokines (e.g., interleukin 10, and Transforming Growth Factor-beta, which can promote activity of immunosuppressive regulatory T cells), or by inhibiting production of inflammatory prostanoids with combined cyclooxygenase/lipoxygenase inhibitors. Finally, prevention of many cancers may be enhanced by carefully selecting and scheduling of vaccine administration in combination with other chemotherapeutic or chemopreventive agents. Preclinical and early clinical trials incorporating these principles are discussed.

Human chorionic gonadotropin triggers angiogenesis via the modulation of endometrial stromal cell responsiveness to interleukin 1: a new possible mechanism underlying embryo implantation

Deep functional changes occurring within the endometrium during implantation are orchestrated by embryonic and maternal signals. Human chorionic gonadotropin (hCG), a major embryonic signal, plays a critical role in the initiation and maintenance of pregnancy. Interleukin (IL) 1, one of the earliest embryonic signals, appears to exert a direct impact on the receptive endometrium and to induce major molecular changes that are essential for embryo implantation. Herein we investigate whether hCG can modulate endometrial stromal cell (ESC) receptivity to IL1 during the implantation window and assess the impact on angiogenesis in vitro. Primary cultures of ESCs from normal fertile women during the implantation window were treated for 24 h with different concentrations of hCG (0-100 ng/ml) and stimulated for 24 h with IL1B (0-0.1 ng/ml). IL1 receptors (IL1Rs), IL1R antagonist (IL1RA), and monocyte chemotactic protein (MCP) 1 were analyzed by real-time PCR, ELISA, and Western blotting. The angiogenic activity in vitro was studied using human microvascular endothelial cell line, scratch wound assay, and cell proliferation via BrdU incorporation into DNA. Human CG induced a dose-dependent imbalance in ESC receptivity to IL1 by significantly upregulating the functional signaling IL1R1 and concomitantly downregulating the decoy inhibitory IL1R2 and IL1RA upon subsequent exposure to IL1B. Prior exposure to hCG amplified MCP1 secretion by ESCs in response to IL1B and triggered the release of angiogenic activity in vitro in which MCP1 appeared to play a significant role. Overexpression of IL1R2 using cell transfection inhibited IL1 and hCG/IL1B-mediated MCP1 secretion. These findings suggest that hCG coordinates embryonic signal interaction with the maternal endometrium, and point to a new possible pathway by which it may promote embryonic growth.

In vitro and in vivo hepatoprotective activity of Cissampelos pareira against carbon-tetrachloride induced hepatic damage

Administration of hydroalcoholic extract of Cissampelos pareira roots (CPRE) and standard drug silymarin in rats showed significant hepatoprotective action against CCl4 induced hepatotoxicity. Elevated serum marker enzymes of AST, ALT, ALP and serum bilirubin were significantly reduced to near normal level in CPRE treated rats. Lipid peroxidation level was decreased significantly in CPRE 100, 200, 400 mg/kg doses treatment groups. In case of antioxidant enzymes SOD, catalase levels were increased significantly after CPRE 200, 400 mg/kg doses, similarly it increased the enzyme levels of GST, GPx, and GSH. CPRE 200, 400 mg/kg decreased cholesterol level, and increased triglyceride level. In vitro hepatoprotective activity of the extract was evaluated at 20, 40, 60, 80 and 100 microg/ml concentration against CCl4 (1%) induced toxicity in freshly isolated rat hepatocytes. HepG2 cells showed significant dose dependent increase in percentage viability at the doses 20, 40, 60, 80 and 100 microg/ml of CPRE compared to CCl4 exposed HepG2 cells. Results of this study strongly demonstrate Cissampelos pariera having good hepatoprotective potential.

Human adrenal LH/hCG receptors and what they could mean for adrenal physiology and pathology

Although the research on the potential regulation of human adrenal cortex by LH and hCG is still in its infancy, the available evidence supports the presence of very low levels of LH/hCG receptors in entire zona reticularis and deeper part of zona fasciculata. The activation of these receptors may lead to an increased secretion of androgens and/or cortisol. The same chronically elevated levels, along with unknown genetic and epigenetic changes, may also lead to the formation of tumors that can secrete all three major classes of adrenal steroid hormones. As shown in murine models, the increased receptor levels often seen in tumors, are probably caused by elevated LH/hCG levels. However, the elevated LH/hCG levels or their receptors alone may not be sufficient for the development of adrenal pathology. Therefore, further studies to advance our current understanding on the pathophysiology of human adrenal hCG/LH receptors are required.

The role of RXFP2 in mediating androgen-induced inguinoscrotal testis descent in LH receptor knockout mice

LH receptor knockout (LhrKO) male mice exhibit a bilateral cryptorchidism resulting from a developmental defect in the gubernaculum during the inguinoscrotal phase of testis descent, which is corrected by testosterone replacement therapy (TRT). In vivo and in vitro experiments were conducted to investigate the roles of the androgen receptor (AR) and RXFP2 signals in regulation of gubernacular development in LhrKO animals. This study demonstrated that AR and RXFP2 proteins were expressed in the gubernaculum during the entire postnatal period. TRT normalized gubernacular RXFP2 protein levels inLhrKO mice. Organ and primary cell cultures of gubernacula showed that 5alpha-dihydrotestosterone (DHT) upregulated the expression of Rxfp2 which was abolished by the addition of an AR antagonist, flutamide. A single s.c. testosterone injection also led to a significant increase in Rxfp2 mRNA levels in a time-dependent fashion in LhrKO animals. DHT, natural and synthetic insulin-like peptide 3 (INSL3), or relaxin alone did not affect proliferation of gubernacular mesenchymal cells, while co-treatments of DHT with either INSL3 or relaxin resulted in an increase in cell proliferation, and they also enhanced the mesenchymal cell differentiation toward the myogenic pathway, which included a decrease in a mesenchymal cell marker, CD44 and the expression of troponin. These effects were attenuated by the addition of flutamide, siRNA-mediated Rxfp2 knockdown, or by an INSL3 antagonist. Co-administration of an INSL3 antagonist curtailed TRT-induced inguinoscrotal testis descent in LhrKO mice. Our findings indicate that the RXFP2 signaling pathway plays an important role in mediating androgen action to stimulate gubernaculum development during inguinoscrotal testis descent.

Adrenocorticotropin-independent Cushing's syndrome in pregnancy related to overexpression of adrenal luteinizing hormone/human chorionic gonadotropin receptors

Cushing's syndrome during pregnancy is rare, and rather than being of pituitary origin most patients exhibit ACTH-independent adrenal hypercortisolism. In some cases the syndrome has spontaneously resolved post partum, suggesting the presence of a pregnancy-associated stimulatory factor(s). We describe a case with aberrant adrenal LH/hCG receptors in a large adrenal tumor as a possible explanation for cortisol hypersecretion and tumor growth in Cushing s syndrome during pregnancy. A 27-yr-old woman presented with hypertension and diabetes mellitus in early pregnancy. Investigations revealed hypercortisolemia, suppressed ACTH-levels, and a 6.4- cm right adrenal tumor. The tumor was successfully removed by laparoscopy at 26th week of pregnancy. Hypercortisolism and hypertension resolved post-operatively. The tumor displayed higher LH/hCG receptor mRNA and protein positivity than adjacent normal adrenal tissue as examined by in situ hybridization and immunocytochemistry. High physiological levels of hCG, in conjunction with aberrant adrenal LH/hCG receptor overexpression, may have contributed to the development of Cushing's syndrome in pregnancy.

Chorionic gonadotropin down-regulates the expression of the decoy inhibitory interleukin 1 receptor type II in human endometrial epithelial cells

Secretion of embryonic IL-1beta seems to be the first response of the blastocyst to receptive endometrium, inducing molecular changes that are essential for attachment of the blastocyst. Here, we report that human chorionic gonadotropin (hCG), a glycoprotein hormone that plays a critical role in the initiation and maintenance of pregnancy, markedly down-regulates the expression of the decoy inhibitory IL-1 receptor type II (IL-1R2) in human endometrial epithelial cells. Treatment with hCG resulted in a dose-dependent decrease in IL-1R2 soluble and membrane bound protein forms and mRNA steady-state levels, whereas no significant effect on the expression of the activating IL-1 receptor type I (IL-1R1) was seen. Cell infection with the wild-type human LH/chorionic gonadotropin receptor corroborated the aforementioned data, whereas cell infection with the constitutively activated LH chorionic gonadotropin receptor led to similar effects on IL-1R2 and IL-1R1 expression without hCG treatment. Cloning of human IL-1R2 gene promoter in the pGL3 luciferase reporter vector and transient transfection experiments further showed a significant dose-dependent diminution of IL-1R2 promoter activity in response to hCG. These data suggest that hCG, by down-regulating the expression of IL-1R2, a potent and specific inhibitor of IL-1, without affecting the expression of the functional activating IL-1R1, diminishes the ability of endometrial epithelial cells to counterbalance the local effects of IL-1, making these cells probably more responsive to the cytokine. In view of IL-1's role as an embryonic signal, these data reveal a new mechanism by which hCG sustains human pregnancy and promotes embryonic growth.

Increases in luteinizing hormone are associated with declines in cognitive performance

Questions surrounding estrogen therapy for post-menopausal cognitive decline and dementia led us to examine the role of luteinizing hormone that becomes elevated after menopause. We examined hippocampal-associated cognitive performance, as measured with the Y-maze task, in two strains of transgenic mice, one (Tg-LHbeta) which over-expresses luteinizing hormone and another (LHRKO), which has increased circulating luteinizing hormone levels, but its receptors are silenced. Our results demonstrate that Tg-LHbeta, but not LHRKO mice, show decreased Y-maze performance when compared to aged-matched wild-type animals. These findings indicate that increased luteinizing hormone levels, in the presence of functional receptors may, at least in part, be responsible for cognitive decline after menopause. As such, modulation of luteinizing hormone or its receptor levels may prove to be useful therapeutic strategies for cognitive decline associated with aging and age-related neurodegenerative diseases such as Alzheimer disease.

The past, present and future of nongonadal LH/hCG actions in reproductive biology and medicine

The past and present published studies reaffirm that nongonadal LH and hCG actions are real and here to stay. These actions have led to a better understanding of the biology of the hormones and more importantly begin to pave the way for novel therapies in reproductive medicine and in other areas.

Upregulation of Placental Indoleamine 2,3-Dioxygenase by Human Chorionic Gonadotropin

We tested the hypothesis that hCG can upregulate human trophoblast indoleamine 2, 3-dioxygenase (INDO), which catalyzes the breakdown of tryptophan in villous circulation. The results revealed that it can. Treatment of human trophoblasts with hCG resulted in a time and dose dependent increase in INDO mRNA and protein levels and its enzyme activity. The hCG effect was hormone specific and required the dimer conformation of hCG. The hCG effect required its receptors and was mediated by a cAMP dependent, but protein kinase A independent, mitogen-activated protein kinase 3/1 (MAPK3/1) signaling mechanism. In summary, the present data demonstrate a novel hCG effect on human placental INDO, which probably plays a key role at maternal fetal interface in preventing fetal rejection.

Cryptorchidism in LhrKO animals and the effect of testosterone-replacement therapy

BACKGROUND

The objective of the current study was to characterize the morphological and genetic basis of cryptorchidism.

METHODS AND RESULTS

We investigated cryptorchidism in LH receptor (Lhr) knockout (LhrKO) mice and how testosterone-replacement therapy (TRT) worked to correct the phenotype. The results revealed that while gubernacular development was indistinguishable between Lhr-null and wild-type animals until 7 days of age, it was subsequently severely impaired in null animals. This was due to a reduction in mesenchymal cell division, differentiation into cremaster muscle cells and their delayed maturation. While transcript levels of Hoxa10, Hoxa11, Desrt and Dll1 were indistinguishable, the levels of Notch1, Numb and Lgr8 in the gubernaculum and Insl3 in the testes were lower in Lhr-null than in wild-type siblings. The TRT, which completed testicular descent into the scrotum, corrected the morphological changes and the expression of Lgr8, Numb and Notch, but not Insl3, to wild-type levels. Transection of the genitofemoral nerve did not prevent the TRT effect.

CONCLUSION

In summary, cryptorchidism in Lhr-null animals was caused by defects in the gubernacular development due to testosterone deficiency. TRT reversed all the morphological and gene expression changes except Insl3, suggesting that testosterone, not INSL3, secreted by Leydig cells, facilitates the completion of testicular descent.

Expression of transcription factor Oct-4 and other embryonic genes in CD133 positive cells from human umbilical cord blood

A significant number of hematopoietic stem/progenitor cells (HSPC) in human umbilical cord blood could serve as a reservoir for the placental vasculature, yet, their morphological and functional features are not completely understood. Here, we describe the characterization of purified CD133(+) progenitor cells from umbilical cord blood, a subset of CD34(+) hematopoietic progenitors that were grown in proliferation medium containing Flt3-ligand, thrombopoietin and stem cell factor. Following isolation and enrichment of the CD133(+) cells by immunomagnetic cell sorting, they remained non-adherent for up to 40 days in culture and expressed different pluripotency markers including Sox-1, Sox-2, FGF-4, Rex-1 and Oct-4.Oct-4 expression was confirmed by laser-assisted single cell picking with subsequent quantitative real-time RT-PCR. The expression of Oct-4 indicates a pluripotent phenotype of CD133(+) cells and appears to be of functional relevance: After three weeks in endothelial differentiation medium, suspended cells became adherent, developed an endothelial cell-like morphology, bound fluoresceine isothiocyanate-labeled Ulex europaeus agglutinin-1, took up acetylated Di-LDL, and expressed other endothelial markers such as PECAM-1 or VEGFR-2. Concomitantly, Oct-4 expression was significantly reduced. Moreover, following treatment with retinoic acid, CD133(+) cells exhibited neural morphology associated with the expression of beta-III-tubulin. CD133(+) cells were found to express the luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor, detected by RT-PCR and immunocytochemistry. The recombinant human chorionic gonadotropin induced proliferation of the CD133(+) cells in a dose-specific manner. Our results indicate that CD133(+) HSPC from umbilical cord blood may have a greater differentiation potential than previously recognized and give rise to proliferative endothelial cells participating in placental vasculogenesis.

Presence of luteinizing hormone/human chorionic gonadotropin receptors in male breast tissues

Receptors for LH/human chorionic gonadotropin (hCG) have been found in a variety of nongonadal tissues including the female breast. Using in situ hybridization and immunohistochemistry, we demonstrated the presence of LH/hCG receptor mRNA and protein in normal male breast tissue obtained at autopsy (n = 4) and archival samples of benign gynecomastia (n = 14) and male breast carcinoma (n = 5). Although the function of these receptors remains to be determined, the findings suggest the possibility that LH and hCG may play a role in the pathogenesis of male breast disorders.

Assisting functional assignment for hypothetical Heamophilus influenzae gene products through structural genomics

The three-dimensional structures of Haemophilus influenzae proteins whose biological functions are unknown are being determined as part of a structural genomics project to ask whether structural information can assist in assigning the functions of proteins. The structures of the hypothetical proteins are being used to guide further studies and narrow the field of such studies for ultimately determining protein function. An outline of the structural genomics methodological approach is provided along with summaries of a number of completed and in progress crystallographic and NMR structure determinations. With more than twenty-five structures determined at this point and with many more in various stages of completion, the results are encouraging in that some level of functional understanding can be deduced from experimentally solved structures. In addition to aiding in functional assignment, this effort is identifying a number of possible new targets for drug development.

Characterization of human chorionic gonadotropin as a novel angiogenic factor

Angiogenesis and vascular remodeling are crucial processes in tumor invasion and metastasis as well as in embryo implantation and normal development of the placenta. We have previously shown that hCG expressed in trophoblast and various malignant tumors promotes cellular motility and that uterine endothelium expresses hCG/LH receptor in vivo. In this study hCG was proposed to promote angiogenesis. A three-dimensional in vitro angiogenesis system consisting of uterine microvascular endothelial cells seeded on microcarriers and entrapped in a fibrin matrix was used to study the influence of hCG on neovascularization. Physiological concentrations of hCG (5-50,000 mU/ml) significantly increased in vitro capillary formation (up to 2.5-fold) and migration of endothelial cells in a Boyden chamber assay (up to 3.6-fold) in a dose-dependent manner, whereas hCG had no effect on cell proliferation. In vivo, hCG induced neovascularization in the chicken chorioallantoic membrane assay comparable to the activity of vascular endothelial growth factor. hCG-secreting tumors (choriocarcinoma, endometrium, and ovarian carcinoma) promoted in vitro neovascularization (up to 3-fold), whereas hCG-neutralizing antibody, pertussis toxin (G protein inhibitor), or GRGDTP peptide (integrin antagonist), respectively, abolished both tumor- and hCG-induced capillary sprout formation. Our data indicate a novel function for hCG in uterine adaptation to early pregnancy as well as in tumor development and underline the importance of hCG as an as yet unrecognized angiogenic factor.

Pregnancy-associated Cushing's syndrome secondary to a luteinizing hormone/human chorionic gonadotropin receptor-positive adrenal carcinoma

Cushing's syndrome occurring during pregnancy is frequently due to an adrenal neoplasm. Adrenal gland tumors occasionally respond to luteinizing hormone (LH) or human chorionic gonadotropin (hCG). We report a case of Cushing's syndrome during and following pregnancy due to an adrenal carcinoma which expressed the LH/hCG receptor. The presence of these receptors may have led to the growth and function of the tumor during pregnancy.

Multiorgan sensitivity to anticarcinogenesis by the organoselenium 1,4-phenylenebis(methylene)selenocyanate

The data in this report clearly indicate that the form (structure) in which selenium is used is the most critical determinant of success in future clinical trials. Synthetic organoselenium compounds can be tailored to achieve greater chemopreventive efficacy with minimal toxic side effects by structural modifications. We demonstrated that 1,4-phenylenebis(methylene)selenocyanate is a powerful chemopreventive agent against the development of experimental colon, mammary, lung, and oral carcinogenesis. On the basis of metabolism studies of organoselenium compounds and those reported in the literature, our working hypothesis is that aromatic selenol intermediates are important entities in cancer chemoprevention. In addition, we suggest that 1,4-phenylenebis(methylene)selenocyanate not only serves as a chemopreventive agent, but it may be valuable in preventing metastatic diseases in future studies in the clinic.

Human umbilical cord and fetal membranes co-express leptin and its receptor genes

Leptin, protein product of the ob gene, not only regulates food intake and energy expenditure but also has a number of other actions in the body. Leptin actions are mediated by its receptors that have either a long or a truncated intracellular domain, which is coupled to signal transduction pathways. Previous studies have demonstrated that human placenta expresses both leptin and its receptors. However, it is not known whether human umbilical cord and fetal membranes are also sites of expression of these molecules. Therefore, the present study investigated leptin and its receptor expression in these tissues from term pregnancy. Reverse-transcription polymerase chain reaction (RT-PCR) amplified expected size fragments of leptin and also its short and long receptor isoforms from umbilical cord and fetal membranes. The authenticity of PCR-amplified fragments was confirmed by Southern blot hybridization with corresponding cDNA probes. Western blotting revealed that the transcripts were translated into 16-kDa leptin, and 125-kDa (long) and 100-kDa (short) leptin receptor isoforms. However, the long form is present in umbilical cord and the short form in the fetal membranes. Immunocytochemistry revealed that leptin and its receptor isoforms were present in endothelial cells and smooth muscle of umbilical veins and artery, myofibroblasts in Wharton's jelly, amnion covering the cord, amnion and chorion in reflected fetal membranes and decidua from membranes. Amnion, however, contained the highest levels of leptin and its receptor immunostaining. In summary, term pregnancy human umbilical cord and fetal membranes co-express leptin and its receptor genes, which supports the hypothesis that leptin is an autocrine and paracrine regulator in these tissues.

Human pineal luteinizing hormone receptors

The presence of luteinizing hormone receptors in human pineal glands from five females and three males, ranging in age from 61-89 yr, was examined by in situ hybridization and immunocytochemistry. The results demonstrated the presence of these receptors at the mRNA and protein levels in all the pineal glands examined. Pineal gland luteinizing hormone receptors could potentially be involved in the regulation of melatonin synthesis.

The role of endothelial cells in the pathogenesis of ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of treatment with fertility drugs. Using human lung microvascular endothelial cells (HUMEC-L) as an in-vitro model of OHSS, we have tested the hypothesis that the endothelium is a target of HCG in the pathogenesis of OHSS. Since OHSS is characterized by increased capillary permeability, we have investigated the production and action of vasoactive agents. When HUMEC-L were cultured with high doses of estradiol (E(2)), no significant changes were observed in the secretion of vascular endothelial growth factor (VEGF), interleukin (IL)-6 or IL-1 beta. However, the addition of HCG resulted in a significant increase in the secretion of VEGF and IL-6. Time-course experiments showed that VEGF was secreted within minutes of HCG addition, whereas IL-6 was significantly increased only after 48 h in culture. The secretion of IL-1 beta was unchanged by these hormonal conditions. The presence of HCG receptors was demonstrated in HUMEC-L in basal conditions as well as after the addition of E(2). The expression of VEGF receptors was also investigated. High doses of E(2) were unable to increase the expression of KDR, flt-1 and sfl-t, but the addition of HCG significantly upregulated the KDR concentration in endothelial cells, while no change was observed for flt. Permeability assays demonstrated that while E(2) alone did not change the arrangement of HUMEC-L in vitro, the presence of HCG caused changes in the actin fibres corresponding to increased capillary permeability. Anti-human VEGF antibodies were able to overcome these changes. In conclusion, these experiments show that the endothelium may be a primary target of HCG, causing an acute release of VEGF and a significant increase in IL-6 and resulting in an autocrine-paracrine action that may increase vascular permeability.

[LH receptors: follicle and endometrium]

LH-receptors are widely distributed in the human body. The talk focussed on ovarian and endometrial receptors. Ovarian LH receptors Uterine LH receptors In conclusion, LH and hCG should no longer be viewed as only gonadal regulating hormones. They have multiple targets in the body. Better understanding of nonclassical actions could lead to novel therapeutic applications of hCG such as prevention of threatened and habitual abortions, preterm labor, etc.

Consequences of targeted inactivation of LH receptors

The inactivation of luteinizing hormone (LH) receptors was neither lethal nor it had any effect on sex differentiation. However, it dramatically reduced the growth and development of gonads and the reproductive tract. As a result, both female and male animals were infertile. Serum LH levels were dramatically elevated, follicle stimulating hormone (FSH) levels moderately elevated in both sexes, estradiol and progesterone levels partially decreased in females, testosterone levels dramatically decreased and estradiol levels moderately increased in males. The knockout of LH receptors had no effect on gonadal FSH receptors in both sexes, progesterone receptors in females and androgen receptors in males. However, estrogen receptor ERalpha and steroidogenic acute regulatory protein decreased and ERbeta increased in both sexes. cDNA expression array analyses revealed that testes were affected more than ovaries and more genes showed an increase rather than a decrease in testes. The affected genes came from many unexpected families. Both null females and males had a decreased density of femur and became obese with age. The ovarian failure in knockout animals could not be reversed by estradiol/progesterone replacement therapy or by PMSG and human chorionic gonadotropin (hCG) injections. Although, testosterone replacement therapy of 30-60-day old null males partially improved spermatogenesis, the animals still remained infertile. A single testosterone injection on postnatal day 1 followed by 21-45-day testosterone replacement therapy beginning at 30 days of age, however, restored fertility. Studies showed that uterus of null animals could not initiate pregnancy even though the size and morphology were greatly improved by estradiol and progesterone replacement therapy. In general, non-gonadal phenotypes in null females and males were not completely reversed by hormone replacement therapy, suggesting that LH signaling could be important for their function. Heterozygous animals were indistinguishable from wild-type animals at 60 days of age. However, as they grew to about 1 year of age, they began to stop cycling, some became extremely obese, showed a decreased density of femur and all animals developed endometrial tumors with a cancer histology. LH receptor-knockout animals will be useful in advancing our present understanding on the importance of classical as well as non-classical actions of LH in the body, in advancing novel therapeutic uses of hCG, and in better understanding and rationalizing the consequences of inactivating type human LH receptor mutations.

Control motifs for intracellular regulatory networks

A number of technological innovations are yielding unprecedented data on the networks of biochemical, genetic, and biophysical reactions that underlie cellular behavior and failure. These networks are composed of hundreds to thousands of chemical species and structures, interacting via nonlinear and possibly stochastic physical processes. A central goal of modern biology is to optimally use the data on these networks to understand how their design leads to the observed cellular behaviors and failures. Ultimately, this knowledge should enable cellular engineers to redesign cellular processes to meet industrial needs (such as optimal natural product synthesis), aid in choosing the most effective targets for pharmaceuticals, and tailor treatment for individual genotypes. The size and complexity of these networks and the inevitable lack of complete data, however, makes reaching these goals extremely difficult. If it proves possible to modularize these networks into functional subnetworks, then these smaller networks may be amenable to direct analysis and might serve as regulatory motifs. These motifs, recurring elements of control, may help to deduce the structure and function of partially known networks and form the basis for fulfilling the goals described above. A number of approaches to identifying and analyzing control motifs in intracellular networks are reviewed.

Two new 2'-oxygenated flavones from Andrographis elongata

Two new 2'-oxygenated flavones, 5,2',6'-trihydroxy-7-methoxyflavone (3) and skullcapflavone I 2'-O-beta-D-(4"-E-cinnamyl) glucopyranoside (5), together with three known flavones, 7-O-methylwogonin (1), skullcapflavone I (2) and skullcapflavone I 2'-O-beta-D-glucopyranoside (4) were isolated from the whole plant of Andrographis elongata, and the structures were elucidated by FAB-MS and one- and two-dimensional (1D- and 2D)-NMR spectral studies including 1H-1H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and rotating frame Overhauser enhancement spectroscopy (ROESY) experiments, and chemical studies.

Prophylactic and curative effects of Bacopa monniera in gastric ulcer models

Bacopa monniera Wettst. (BM, syn. Herpestis monniera L; Scrophulariaceae), is an Ayurvedic drug used as a rasayana. Its fresh juice was earlier reported to have significant antiulcerogenic activity. In continuation, methanolic extract of BM (BME) standardized to bacoside-A content (percentage-38.0 +/- 0.9), when given in the dose of 10-50 mg/kg, twice daily for 5 days, showed dose-dependent anti-ulcerogenic on various gastric ulcer models induced by ethanol, aspirin, 2 h cold restraint stress and 4 h pylorus ligation. BME in the dose of 20 mg/kg, given for 10 days, twice daily showed healing effects against 50% acetic acid-induced gastric ulcers. Further work was done to investigate the possible mechanisms of its action by studying its effect on various mucosal offensive acid-pepsin secretion and defensive factors like mucin secretion, mucosal cell shedding, cell proliferation and antioxidant activity in rats. BME 20 mg/kg showed no effect on acid-pepsin secretion, increased mucin secretion, while it decreased cell shedding with no effect on cell proliferation. BME showed significant antioxidant effect per se and in stressed animals. Thus, the gastric prophylactic and curative effects of BME may be due to its predominant effect on mucosal defensive factors.

Clinical importance of vascular LH/hCG receptors--a review

It was believed for a long time that functional LH/hCG receptors were present only in gonads. Recent studies have demonstrated, however, that these receptors are also present in several nongonadal organs in the human body. Uterus is one of them. Besides two uterine layers, endothelial cells and smooth muscle of blood vessels in the uterus also contain these receptors. In vivo administration of hCG decreased vascular resistance in the human uterus and in vitro treatment increased vasodilatory and decreased vasoconstrictive eicosanoids in the vessels. These findings led us to investigate whether hCG administration to patients with signs of threatened abortion has any beneficial effect. Patients were treated with either magnesium or progesterone and/or hCG. The results showed that the frequency of patients reaching second trimester was higher when hCG was used, which was paralleled by a significant decrease in uterine vascular resistance. Patients who reached term after treatment had decreased incidence of preterm delivery and intrauterine growth retardation. In conclusion, we suggest that uterine vascular LH/hCG receptors play an important role in the peri-implantation period by increasing uterine blood flow through vasodilatation and also perhaps through angiogenesis and trophoblast invasion, resulting in therapeutic benefit.

Neural actions of luteinizing hormone and human chorionic gonadotropin

Luteinizing hormone (LH) and its homologue, human chorionic gonadotropin (hCG), are able to elicit multiple effects in the central nervous system (CNS) through binding to their receptors. Specific receptors for LH/hCG have been identified in the hippocampus, dentate gyrus, hypothalamus, cortex, brain stem, area postrema, cerebellum, choroid plexus, ependymal cells, glial cells, neural retina, pituitary gland, and neuron processes of the spinal cord. Neurotropic effects of LH and hCG have been demonstrated in fetal rat brain, where the expression of LH/hCG receptors is developmentally regulated. Administration of hCG has been found to be beneficial in restoration of transected spinal cord function in rats. In adult rat brain, LH and hCG are involved in the feedback regulation of synthesis and secretion of gonadotropin-releasing hormone (GnRH) in the hypothalamus and LH in the pituitary gland. LH and hCG also induce several behavioral and other changes that are associated with the hippocampus, which contains the highest density of LH/hCG receptors. Many of the behavioral changes induced by hCG in rats parallel those in pregnant women. Some of these behavioral effects are correlated with changes of eicosanoid metabolism induced by LH and hCG in the brain. The LH/hCG receptors present in the choroid plexus, brain vessels, and perihypophyseal vascular complex may be involved in the modulation of transport of LH, hCG, and GnRH into the CNS. Thus, the CNS is one of the specific target tissues for LH and hCG, by which LH/hCG act as pleiotropic hormones that regulate several reproduction-related as well as reproduction-nonrelated functions in the CNS.