Circadian production of melatonin in cartilage modifies rhythmic gene expression.

Endochondral ossification, including bone growth and other metabolic events, is regulated by circadian rhythms. Herein, we provide evidence that melatonin has a direct effect on the circadian rhythm of chondrocytes. We detected mRNA expression of the genes which encode the melatonin-synthesizing enzymes AANAT (arylalkylamine N-acetyltransferase) and HIOMT (hydroxyindole O-methyltransferase), as well as the melatonin receptors MT1 and MT2 in mouse primary chondrocytes and cartilage. Production of melatonin was confirmed by mass spectrometric analysis of primary rat and chick chondrocytes. Addition of melatonin to primary mouse chondrocytes caused enhanced cell growth and increased expression of Col2a1, Aggrecan, and Sox9, but inhibited Col10a1 expression in primary BALB/c mouse chondrocytes. Addition of luzindole, an MT1 and MT2 antagonist, abolished these effects. These data indicate that chondrocytes produce melatonin, which regulates cartilage growth and maturation via the MT1 and MT2 receptors. Kinetic analysis showed that melatonin caused rapid upregulation of Aanat, Mt1, Mt2, and Pthrp expression, followed by Sox9 and Ihh. Furthermore, expression of the clock gene Bmal1 was induced, while that of Per1 was downregulated. Chronobiological analysis of synchronized C3H mouse chondrocytes revealed that melatonin induced the cyclic expression of Aanat and modified the cyclic rhythm of Bmal1, Mt1, and Mt2. In contrast, Mt1 and Mt2 showed different rhythms from Bmal1 and Aanat, indicating the existence of different regulatory genes. Our results indicate that exogenous and endogenous melatonin work in synergy in chondrocytes to adjust rhythmic expression to the central suprachiasmatic nucleus clock.

Endometrial Cancer with Sarcoidosis in Regional Lymph Nodes: A Case Report.

Sarcoidosis is a chronic, multisystemic disease commonly affecting the lungs and lymphatic system and is characterized by the formation of noncaseating granulomas. Although several reports are available on cases developing both sarcoidosis and cancer metachronously, cases of simultaneous diagnosis of these diseases have rarely been reported. A 67-year-old woman diagnosed with endometrial cancer had developed systemic lymph node swelling, including bilateral hilar, paraaortic, and a few pelvic lymph nodes, as observed on preoperative imaging. During surgery, frozen sections of a paraaortic lymph node were examined, revealing noncaseating granulomas compatible with sarcoidosis. Next, modified radical hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy were performed. Postoperative pathological analysis revealed endometrioid adenocarcinoma of the uterus, and no metastasis but noncaseating granulomas were detected in the resected lymph nodes. Postoperatively, we identified cutaneous sarcoidosis and uveitis in the presence of a tuberculin-negative test. On the basis of these findings, we diagnosed the patients with endometrial cancer complicated by sarcoidosis. She underwent adjuvant chemotherapy, and at the 1-year follow-up, the lymph node swelling due to sarcoidosis was stable, and no recurrence of the cancer was observed. This turned out to be a case of early endometrial cancer mimicking advanced cancer by sarcoidosis. Histological confirmation and additional examination for sarcoidosis are necessary in cancer patients suspected of sarcoidosis.

Hamiltonian decomposition for bulk and surface states.

We demonstrate that a tight-binding Hamiltonian with nearest- and next-nearest-neighbor hopping integrals can be decomposed into bulk and boundary parts for honeycomb lattice systems. The Hamiltonian decomposition reveals that next-nearest-neighbor hopping causes sizable changes in the energy spectrum of surface states even if the correction to the energy spectrum of bulk states is negligible. By applying the Hamiltonian decomposition to edge states in graphene systems, we show that the next-nearest-neighbor hopping stabilizes the edge states. The application of Hamiltonian decomposition to a general lattice system is discussed.

Oral progestogen versus intramuscular progesterone for luteal support after assisted reproductive technology treatment: a prospective randomized study.

OBJECTIVES: To evaluate the efficacy of oral progestogen, chlormadinone acetate, and intramuscular (IM) progesterone for luteal support in patients, undergoing assisted reproductive technology (ART) treatment, who were treated with a gonadotropin-releasing hormone agonist (GnRHa). METHODS: This was a prospective randomized study of 40 patients with normal and high response (serum estradiol > 2,000 pg/ml) in GnRHa down-regulation. Patients were randomized to receive either oral chlormadinone acetate or IM progesterone. The outcomes of ART treatment, including pregnancy and embryo implantation rates, were analyzed. RESULTS: There were no significant differences in the clinical pregnancy rates (25 vs. 20%) and in the implantation rates (12.7 vs. 9.1%) of patients who received IM progesterone and oral chlormadinone acetate. Endometrial thickness was also comparable between oral chlormadinone acetate and IM progesterone. CONCLUSION: Oral progestogen, chlormadinone acetate showed a comparable pregnancy rate and live birth rate with IM progesterone as luteal support for the high responders. The optimal methods for luteal support may be dependent on responses to stimulation with gonadotropin, although it is not concluded that oral chlormadinone acetate is recommended as an option for luteal support in high responders.

Neutral endopeptidase expressed by decidualized stromal cells suppresses akt phosphorylation and deoxyribonucleic acid synthesis induced by endothelin-1 in human endometrium.

Endothelin-1 (ET-1) in human endometrium has been proposed to have a potential paracrine role, for its receptors are also present within this tissue. In addition, the expression of ET-1 varies during the menstrual cycle, and therefore, ET-1 may be involved in the cyclic change of the human endometrium, such as proliferation and decidualization. However, neither the inactivation of ET-1 in the endometrium nor the paracrine effect of ET-1 on endometrial cells has been determined. We investigated the production of ET-1 and the presence of neutral endopeptidase (NEP), which cleaves and inactivates ET-1, in primary cultured human endometrial cells. We found primary cultured endometrial epithelial cells, not stromal cells, to be the major source of ET-1. Western blot analysis and RT-PCR demonstrated that NEP was predominantly expressed by endometrial stromal cells. We also demonstrated that ET-1 stimulated the phosphorylation of Akt and DNA synthesis in endometrial stromal cells via the ET(A) receptor and phospahtidylinositol-3 kinase signaling pathways. The effect of ET-1 was regulated by NEP expressed by stromal cells. We also found that conditioned medium containing ET-1 from endometrial epithelial cell culture stimulated phosphorylation of Akt via the ET(A) receptor. In conclusion, ET-1 has a paracrine effect of Akt phosphorylation and cell proliferation on endometrial stromal cells, which occurs via the ET(A) receptor and phospahtidylinositol-3 kinase signaling pathways, and is regulated by cell-surface NEP.

Possible involvement of crosstalk cell-adhesion mechanism by endometrial CD26/dipeptidyl peptidase IV and embryonal fibronectin in human blastocyst implantation.

When human blastocysts hatch through the zona pellucida, gaining the ability to adhere to the endometrium, crosstalk between the embryo and the uterus may represent a successful outcome of their synchronized development and differentiation. CD26/dipeptidyl peptidase IV is known as a marker molecule of the implantation phase endometrium. To study the role of CD26 in implantation, 35 human hatched blastocysts were prepared by enzymatic treatment of expanded blastocysts that had been grown on schedule from frozen-thawed surplus embryos at the 2- or 4-cell stage. The blastocysts were placed on CD26-overexpressing or mock-transfected control monolayer cell cultures. The CD26-overexpression caused significantly higher blastocyst adhesion rate (53.3% versus 25.0%, P < 0.05) and significantly larger outgrowth area of trophectoderm (1.7-fold, P < 0.05). The second part of the present study was to show the expression of fibronectin, a CD26 ligand, in human preimplantation embryos, using the same donated resources. Fibronectin mRNA was detected by RT-PCR from the single hatched blastocyst (2/2) and from the single early blastocyst (3/6) but not from the single morula (0/5) samples. An indirect immunofluorescence technique verified the localization of fibronectin on the surface of the blastocyst. These results indicate that the adhesion mechanism by endometrial CD26 and embryonal fibronectin may be involved in human blastocyst implantation.