Inhibition of calcium-sensing receptor by its antagonist promotes gastrointestinal motility in a Parkinson's disease mouse model.

BACKGROUND: The Calcium-sensing receptor (CaSR) participates in the regulation of gastrointestinal (GI) motility under normal conditions and might be involved in the regulation of GI dysmotility in patients with Parkinson's disease (PD). METHODS: CaSR antagonist-NPS-2143 was applied in in vivo and ex vivo experiments to study the effect and underlying mechanisms of CaSR inhibition on GI dysmotility in the MPTP-induced PD mouse model. FINDINGS: Oral intake of NPS-2143 promoted GI motility in PD mice as shown by the increased gastric emptying rate and shortened whole gut transit time together with improved weight and water content in the feces of PD mice, and the lack of influence on normal mice. Meanwhile, the number of cholinergic neurons, the proportion of serotonergic neurons, as well as the levels of acetylcholine and serotonin increased, but the numbers of nitrergic and tyrosine hydroxylase immunoreactive neurons, and the levels of nitric oxide synthase and dopamine decreased in the myenteric plexus in the gastric antrum and colon of PD mice in response to NPS-2143 treatment. Furthermore, the numbers of c-fos positive neurons in the nucleus tractus solitarius (NTS) and cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) increased in NPS-2143 treated PD mice, suggesting the involvement of both the enteric (ENS) and central (CNS) nervous systems. However, ex vivo results showed that NPS-2143 directly inhibited the contractility of antral and colonic strips in PD mice via a non-ENS mediated mechanism. Further studies revealed that NPS-2143 directly inhibited the voltage gated Ca2+ channels, which might, at least in part, explain its direct inhibitory effects on the GI muscle strips. INTERPRETATION: CaSR inhibition by its antagonist ameliorated GI dysmotility in PD mice via coordinated neuronal regulation by both ENS and CNS in vivo, although the direct effects of CaSR inhibition on GI muscle strips were suppressive.

Emergence of ehrlichiosis by a new tick-borne Ehrlichia species in China.

OBJECTIVES: From March to June 2021, the reported number of clinically diagnosed endemic typhus in Anhui and Hubei provinces of China nearly increased four-fold compared with the monthly average numbers in last 5 years. An etiological and epidemiological investigation was initiated. METHODS: The clinical specimens from the reported patients and the potential vector ticks were collected for molecular and serological detection, as well as cell culturing assay to identify the potential pathogen. RESULTS: Polymerase chain reaction and sequence analysis of rrs and groEL showed that the pathogen from these patients was Ehrlichia sp., isolated from Haemaphysalis longicornis attached to these patients. The phylogenetic analysis based on 39 Ehrlichia genomes suggested that it should be taxonomically classified as a novel species, tentatively named "Candidatus Ehrlichia erythraense". A total of 19 of 106 cases were confirmed as Candidatus Ehrlichia erythraense infections by polymerase chain reaction, sequencing, and/or serological tests. The most frequent symptoms were fever (100%), rashes (100%), asthenia (100%), anorexia (100%), and myalgia (79%). CONCLUSION: The occurrence of the disease presenting with fever and rashes in Anhui and Hubei provinces was caused by a novel species of the genus Ehrlichia; physicians need to be aware of this newly-discovered pathogen to ensure appropriate testing, treatment, and regional surveillance.

Polymannuronic acid prebiotic plus Lacticaseibacillus rhamnosus GG probiotic as a novel synbiotic promoted their separate neuroprotection against Parkinson's disease.

Gut microbiota (GM) dysbiosis plays key roles in aggravating Parkinson's disease (PD) and discovery of agents targeting GM may open new avenues for PD therapy. This study aims to investigate the potentially neuroprotective effects and underlying mechanisms of polymannuronic acid (PM) or Lacticaseibacillus rhamnosus GG (LGG), or their combination in a chronic PD mice model. Our results found oral administration of prebiotic PM or LGG separately or in combination for 5 weeks could prevent dopaminergic neuronal loss via improving reduced walking distance and activity or weakened muscle strength in behavior tests by enhancing tyrosine hydroxylase (TH) gene and/or protein expressions in the midbrain and striatum of PD mice. Strikingly, PM and LGG in combination had a much better neuroprotective effects than separate PM or LGG. PM provided neuroprotection via a short chain fatty acids (SCFAs)-mediated anti-inflammation and anti-apoptosis mechanism. The neuroprotective effects of LGG might be associated with its ability to improve the expression of striatal glial cell-derived neurotrophic factor (GDNF) and to increase bacteria abundance of Clostridiales. When PD mice were administered with PM + LGG, PM as prebiotic favored bacterial growth (from Bacilli class to Lactobacillus genus) in the colon, which helped to improve blood brain barrier (BBB) integrity and increase brain-derived neurotrophic factor (BDNF) and GDNF expressions, thereby inhibiting apoptosis in the striatum. In conclusion, PM and LGG in combination promoted their separate neuroprotection against PD. Our study discovered and testified a novel synbiotic that might be one of the ideal oral agents for PD therapy.

[Effects of ARC-hippocampus obestatin neural pathway on gastric motility and gastric emptying in diabetic rats].

Objective: To investigate the obestatin neural projections from arcuate nucleus (ARC) to hippocampus in diabetic rats, and its effects on gastric motility and gastric emptying of rats. Methods: Diabetic model was established by fructose intake combined with streptozotocin injected intraperitoneally in healthy male Wistar rats. Diabetic rats were randomly divided into five groups: control group (NS group), 0.1, 1 and 10 pmol obestatin group, and obestatin + NBI27914 group, with 7 rats in each group. 0.5 µl saline (NS), obestatin (0.1 pmol, 1 pmol, 10 pmol) or the mixture (10 pmol obestatin + 60 pmol NBI27914) was injected into the hippocampus respectively, the gastric motility was recorded immediately after administration, and the gastric emptying was studied 15 min later. ARC-hippocampus obestatin neural pathway and ARC obestatin mRNA expression were compared between normal and diabetic rats with fluorogold (FG) retrograde tracing and immunofluorescence histochemical staining. Results: Compared with normal rats, the number of ARC FG/obestatin double labeled neurons and the expression level of ARC obestatin mRNA were decreased significantly in diabetic rats (P＜0.05); Obestatin could inhibit gastric motility and gastric emptying in a dose-dependent manner (P＜0.05~0.01) and the effects of obestatin could be partially blocked by NBI27914, an antagonist of corticotropin releasing factor receptor 1 (CRFR1) (P＜0.05). Compared with normal rats, the inhibitory effects of obestatin on gastric motility and gastric emptying were significantly decreased in diabetic rats (P＜0.05). Conclusion: There is an obestatin neural pathway between ARC and hippocampus, which participates in the regulation of gastric motility and gastric emptying in diabetic rats, and CRFR1 signal pathway is involved in this process. The damage of this neural pathway may participate in gastric motility dysfunction in early stage of diabetes.

[Effect of orexin-A and orexin-1 receptor antagonist injected into the fourth ventricle of rats on food-intake and spontaneous physical activity].

The present study was aimed to investigate the effects of orexin-A and orexin-1 receptor (OX1R) antagonist injected into the fourth ventricle of rats on food-intake and spontaneous physical activity (SPA). Obese rat model was induced by high fat diet. Different doses of orexin-A or SB334867, an OX1R antagonist, were injected into the fourth ventricle of obese and normal rats respectively. SPA and food intake were monitored for 4 h after injection in both light and dark environment. In the light measurement cycle, different doses of orexin-A significantly stimulated feeding and SPA in all injected rats, and the animals' responses showed a dose-dependent manner (P < 0.05-0.01), and compared with those of normal rats, the orexin-A induced food intake and SPA were more pronounced in obese rats. In the dark measurement cycle, different doses of orexin-A had no obvious effect on food intake and SPA in both normal and obese rats (P > 0.05). In the light cycle, different doses of SB334867 significantly decreased food intake and SPA in all rats during 0-2 h and 2-4 h after injection (P < 0.05), but the food intake and SPA in obese rats were significantly greater than those of normal rats. In the dark cycle, different doses of SB334867 showed no obvious effect on food intake and SPA of normal and obese rats (P > 0.05). These results suggest that fourth cerebral ventricle nuclei may be one target for orexin-A and light condition may play an important role in orexin-A and OX1R physiological functional processes.

The effects of nesfatin-1 in the paraventricular nucleus on gastric motility and its potential regulation by the lateral hypothalamic area in rats.

The current study investigated the effects of nesfatin-1 in the hypothalamic paraventricular nucleus (PVN) on gastric motility and the regulation of the lateral hypothalamic area (LHA). Using single unit recordings in the PVN, we show that nesfatin-1 inhibited the majority of the gastric distention (GD)-excitatory neurons and excited more than half of the GD-inhibitory (GD-I) neurons in the PVN, which were weakened by oxytocin receptor antagonist H4928. Gastric motility experiments showed that administration of nesfatin-1 in the PVN decreased gastric motility, which was also partly prevented by H4928. The nesfatin-1 concentration producing a half-maximal response (EC50) in the PVN was lower than the value in the dorsomedial hypothalamic nucleus, while nesfatin-1 in the reuniens thalamic nucleus had no effect on gastric motility. Retrograde tracing and immunofluorescent staining showed that nucleobindin-2/nesfatin-1 and fluorogold double-labeled neurons were observed in the LHA. Electrical LHA stimulation changed the firing rate of GD-responsive neurons in the PVN. Pre-administration of an anti- nucleobindin-2/nesfatin-1 antibody in the PVN strengthened gastric motility and decreased the discharging of the GD-I neurons induced by electrical stimulation of the LHA. These results demonstrate that nesfatin-1 in the PVN could serve as an inhibitory factor to inhibit gastric motility, which might be regulated by the LHA.

Central nesfatin-1 influences the excitability of ghrelin-responsive gastric distension neurons in the arcuate nucleus and reduces gastric motility in rats.

Although the novel satiety peptide nesfatin-1 has been shown to regulate gastric motility, the underlying mechanisms have yet to be elucidated. The study aimed to explore the effects of nesfatin-1 on ghrelin-responsive gastric distension (GD) neurons in the arcuate nucleus (Arc), and potential regulation mechanisms of gastric motility by the paraventricular nucleus (PVN). Single-unit discharges in the Arc were recorded extracellularly, and gastric motility in conscious rats was monitored during the administration of nesfatin-1 to the Arc or electrical stimulation of the PVN. Retrograde tracing and fluo-immunohistochemistry staining were used to determine NUCB2/nesfatin-1 neuronal projections. Nesfatin-1 inhibited most of the ghrelin-responsive GD-excitatory neurons, but excited ghrelin-responsive GD-inhibitory neurons in the Arc. Gastric motility was significantly reduced by nesfatin-1 administration to the Arc in a dose-dependent manner. The firing activity in the Arc and changes to gastric motility were partly reduced by SHU9119, an antagonist of melanocortin 3/4 receptors. Electrical stimulation of PVN excited most of the ghrelin-responsive GD neurons in the Arc and promoted gastric motility. Nonetheless, pretreatment with an anti-NUCB2/nesfatin-1 antibody in the Arc further increased the firing rate of most of the ghrelin-responsive GD-excitatory neurons and decreased the ghrelin-responsive GD-inhibitory neurons following electrical stimulation of the PVN. Gastric motility was enhanced by pretreatment with an anti-NUCB2/nesfatin-1 antibody in the Arc following PVN stimulation. Furthermore, NUCB2/nesfatin-1/fluorogold double-labeled neurons were detected in the PVN. These results suggest that nesfatin-1 could serve as an inhibitory factor in the Arc to regulate gastric motility via the melanocortin pathway. The PVN could be involved in the regulation of the Arc in gastric activity.

Electrophysiological and behavioral effects of group III metabotropic glutamate receptors on pallidal neurons in normal and parkinsonian rats.

The globus pallidus plays a critical role in movement regulation. Glutamate being an important excitatory neurotransmitter modulates the activity of pallidal neurons through both ionotropic and metabotropic glutamate receptors (mGluRs). Morphological studies have shown that group III mGluRs are generally located presynaptically in the globus pallidus. Up to now, little is known about the in vivo electrophysiological effects of group III mGluRs on the pallidal neurons. This study investigated the electrophysiological and behavioral effects of group III mGluRs on pallidal neurons in both normal and 6-hydroxydopamine (6-OHDA) lesioned parkinsonian rats. Micropressure ejection of group III mGluR agonist, L-2-amino-4-phosphonobutyrate (L-AP4), increased or decreased the firing rate of pallidal neurons in both normal and parkinsonian rats. The L-AP4-induced excitatory effects on the lesioned side of parkinsonian rats (117.4 ± 17.2%) were stronger than that in normal rats (64.3 ± 10.1%). While the proportion of neurons that were unresponsive to L-AP4 on the lesioned side of parkinsonian rats (50%) was more than that of normal rats (13%). Unilateral microinjection of L-AP4 into the globus pallidus induced a contralateral dystonic posturing in the presence of systemic haloperidol administration. The selective group III mGluRs antagonist, (RS)-α-cyclopropyl-4-phosphonophenylglycine, had no effect on pallidal neurons when used alone and could block both L-AP4-induced electrophysiological and behavioral effects. Combining electrophysiological and behavioral findings, we concluded that activation of group III mGluRs modulate the activity of pallidal neurons under both normal and parkinsonian state.

Electrophysiological and behavioral effects of group I metabotropic glutamate receptors on pallidal neurons in rats.

The globus pallidus plays a critical role in movement regulation. Morphological studies have shown that group I mGluRs including mGluR1 and mGluR5 are expressed in the globus pallidus. Up to now, little is known about the in vivo electrophysiological effects of group I mGluRs on the pallidal neurons. The present study investigated the electrophysiological effects of group I mGluRs on the firing rate of pallidal neurons in anesthetized rats. Single unit in vivo extracellular recordings showed that micropressure ejection of group I mGluRs agonist, 3,5-dihydroxyphenylglycine (DHPG), increased the spontaneous firing rate of pallidal neurons. DHPG-induced excitation could be blocked by mGluR1 antagonist, (S)-(+)-α-amino-4-carboxy-2-methylb-enzeneacetic acid (LY367385), but not mGluR5 antagonist, 2-methyl-6-(phenylethynyl)-pyridine (MPEP). LY367385 alone had no effect but MPEP alone increased the excitability of pallidal neurons. Unilateral microinjection of DHPG into the globus pallidus induced a contralateral dystonic posturing in the presence of systemic haloperidol administration and this effect could be blocked by LY367385 but not MPEP. The present in vivo electrophysiological and behavioral studies indicate that group I mGluRs could produce excitatory effect on pallidal neurons via mGluR1, and blockade of mGluR5 also has an excitatory effect on pallidal neurons. Our findings suggest that the effects of globus pallidus in movement regulation is partly mediated by group I mGluRs.

γ-Tocotrienol inhibits angiogenesis of human umbilical vein endothelial cell induced by cancer cell.

Antiangiogenic therapy mediated by food components is an established strategy for cancer chemoprevention. Growth factors play critical roles in tumor angiogenesis. A conditioned medium containing growth factors from human gastric adenocarcinoma SGC-7901 cell conditioned medium was used as an angiogenic stimulus in this study. The purpose of this study was to evaluate the inhibitory effect and possible mechanism of γ-tocotrienol on tumor angiogenesis. The results showed that γ-tocotrienol (10-40 µmol/L) significantly suppressed proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) induced by SGC-7901 cell conditioned medium in a dose-dependent manner. γ-Tocotrienol (800-1200 µg/egg) also inhibited new blood vessel formation on the growing chick embryo chorioallantoic membrane in a dose-dependent manner. Moreover, the inhibitory effects of γ-tocotrienol on HUVECs were correlated with inducing the apoptosis and arresting cell cycle at the G(0)/G(1) phase at a dose of 40 µmol/L γ-tocotrienol. In addition, γ-tocotrienol inhibited angiogenesis in HUVECs by down-regulation of ß-catenin, cyclin D1, CD44, phospho-VEGFR-2 and MMP-9. The antiangiogenic effects of γ-tocotrienol on HUVECs may be attributable to regulation of Wnt signaling by decreasing ß-catenin expression. Thus, our results suggest that γ-tocotrienol has a potential chemopreventive agent via antiangiogenesis.

Growth inhibition effect of ß-catenin small interfering RNA-mediated gene silencing on human colon carcinoma HT-29 cells.

The ß-catenin gene is a critical component of Wnt signaling pathway. Aberrant activation of Wnt/ß-catenin signaling and subsequent upregulation of ß-catenin is related to enhancing cell proliferation and developing colon polyps and colon cancer. In the present study, the effect of ß-catenin knockdown on the growth and survival of the human colon cancer cell line HT-29 was investigated in vitro. The effect of knockdown of ß-catenin on cell proliferation was investigated by MTT assay and colony formation. The cell cycle distribution was investigated by flow cytometry. Apoptosis was measured by nuclear staining and flow cytometry. The change of ß-catenin and related proteins were determined by western blotting and immunofluorescence. The results showed that small interfering RNA directed against ß-catenin markedly inhibited the expression and nuclear translocation of ß-catenin and decreased the expression of known target genes such as cyclin D1 and c-myc; HT-29 cell proliferation was inhibited as indicated by growth reduction, cell cycle arrest in G0/G1 phase, and induction of apoptosis; and the inhibition of cell growth may be associated with switching off cyclin D1 and c-myc expression by small interfering RNA targeted against ß-catenin in colon cancer HT-29 cells.

Effects of beta-ionone on mammary carcinogenesis and antioxidant status in rats treated with DMBA.

Recent chemopreventive studies from our group showed that dietary beta -ionone inhibited 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis by the inhibition of cell proliferation and apoptosis initiation. In this study, we examined the chemopreventive effects of varied doses of dietary beta -ionone on the development and growth of DMBA-induced rat mammary tumors as well as plasma antioxidant status. beta -ionone treatment groups were given 9, 18, and 36 mmol/kg in the AIN76A diet starting 2 wk prior to DMBA administration and continuing for the 24 wk. Results showed that tumor incidence was dose dependently reduced by 35.4, 68.3, and 87.8%, respectively, compared to the positive control. Tumor sizes were dose dependently smaller, and tumor weight was less in each group, each rat, and each tumor compared to the positive control (P < 0.05). A significant decrease in lipid peroxidation was observed in the tumor-induced rats treated with dietary beta -ionone, whereas the plasma activities of antioxidant enzymes such as glutathione peroxidase, glutathione reductase, superoxide dismutase, and the nonenzymatic antioxidant glutathione were increased in the beta -ionone treated rats when compared to control. The levels of catalase and lactate dehydrogenase were remarkably decreased in the beta -ionone treated groups compared to the positive control group. These results suggest that dietary beta -ionone has biologically relevant antioxidant activity and plays a chemopreventive role against DMBA induced mammary gland tumors.

Inhibitory effects of gamma-tocotrienol on invasion and metastasis of human gastric adenocarcinoma SGC-7901 cells.

Natural vitamin E is a mixture of two classes of compounds, tocopherols and tocotrienols. Recent research has revealed that tocotrienols, especially gamma-tocotrienol, exhibit not only the same antioxidant ability as tocopherols, but also remarkable anticancer capacity in cancer cell lines. In this study, the invasion and metastatic capacities of gastric adenocarcinoma SGC-7901 cells and the correlation with antimetastasis mechanisms induced by gamma-tocotrienol were explored. The results showed the inhibitory effects of gamma-tocotrienol at doses of 15, 30, 45 and 60 mumol/L for 48 h on cell migration and cell matrigel invasion; activities of matrix metalloproteinase (MMPs) increased in SGC-7901 cells when compared to the control group (P<.05 or P<.01). An increasing trend in the chemotactic responses to fibronectin (FN) in SGC-7901 cells was found in the gamma-tocotrienol treatments. SGC-7901 cell attachment decreased in the gamma-tocotrienol-treated groups in comparison with the control group (P<.01). The mRNA expressions of MMP-2 and MMP-9 showed that gamma-tocotrienol significantly reduced the matrigel invasion capability through down-regulation of the mRNA expressions of MMP-2 and MMP-9 (P<.01), and up-regulation of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 in SGC-7901 cells by treatment with gamma-tocotrienol for 48 h (P<.05). gamma-Tocotrienol also significantly increased the mRNA expression of nm23-H1 in SGC-7901 cells (P<.01). These findings suggest a potential mechanism of gamma-tocotrienol-mediated antitumor metastasis activity and indicate the role of vitamin E as potential chemopreventative agents against gastric cancer.

Inhibition of proliferation and induction of apoptosis by gamma-tocotrienol in human colon carcinoma HT-29 cells.

OBJECTIVE: gamma-Tocotrienol is a major component of the tocotrienol-rich fraction of palm oil, but there is limited evidence that it has antitumor activity. In particular, the effects of gamma-tocotrienol on human colon carcinoma cells have not been reported. To investigate the chemopreventive effects of gamma-tocotrienol on colon cancer, we examined its capacity to inhibit proliferation and induce apoptosis in HT-29 cells and explored the mechanism underlying these effects. METHODS: We cultured HT-29 cells in the presence of gamma-tocotrienol. The effect of gamma-tocotrienol on cell proliferation was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, mitotic index, and colony formation. The cell-cycle distribution was investigated by flow cytometry. We measured apoptosis by nuclear staining, transmission electron microscopy, and DNA fragmentation. Apoptosis-related proteins and the nuclear factor-kappaB p65 protein were determined by western blotting and immunofluorescence. RESULTS: gamma-Tocotrienol inhibited cell growth and arrested HT-29 cells in G(0)/G(1) phase. The 50% inhibitory concentration was 31.7 micromol/L (48 h). gamma-Tocotrienol-induced apoptosis in HT-29 cells was accompanied by downregulation of Bcl-2, upregulation of Bax, and activation of caspase-3. Furthermore, we found that gamma-tocotrienol reduced the expression level of total nuclear factor-kappaB p65 protein and inhibited its nuclear translocation. CONCLUSION: The results indicated that gamma-tocotrienol inhibits cell proliferation and induces apoptosis in HT-29 cells in a time- and dose-dependent manner, and that this process is accompanied by cell-cycle arrest at G(0)/G(1), an increased Bax/Bcl-2 ratio, and activation of caspase-3. Our data also indicated that nuclear factor-kappaB p65 protein may be involved in these effects.

Genotoxicity of water from the Songhua River, China, in 1994-1995 and 2002-2003: Potential risks for human health.

A previous study showed that the cancer mortalities are higher for residents who lived nearby the Songhua River heavily polluted by organic contamination. It is important to determine its risk of carcinogenic potential. Short-term genotoxic bio-assays using Salmonella, Sister Chromatid Exchange (SCE), and Micronuclei (MN) assays were employed to examine the genotoxic activity of ether extracts of water samples taken from the Songhua River. The results of the Salmonella bioassay indicated that there were indirect frame-shift mutagens in the water samples. A dose-response relationship for the SCE and MN assays was obtained. These results showed that organic extracts of water samples have genotoxic activity and the risk of carcinogenic potential to human health. The mutagenesis of water samples had changed compared to the results in 1994-1995. An increasing trend of risk of carcinogenic potential in the Songhua River after ten years should be noted and needs to be studied further.

[Expression of motilin and its precursor mRNA in normal parenchyma, benign and malignant tumors of human thyroid].

OBJECTIVE: To investigate the expression of motilin and its precursor mRNA in normal human thyroid. To compare the expression differences of motilin and it precursor mRNA between normal thyroid and intestines. To study the expression of motilin and its precursor mRNA in human thyroid tumors and their clinical implications. METHODS: RT-PCR, Southern blot and molecular cloning were used to detect motilin transcript expression in human thyroid and mucous membrane of small intestine. Real-time PCR and immunohistochemical techniques were used to quantify motilin precursor mRNA and motilin peptide in thyroid tissue samples including adenoma, medullary carcinoma, follicular carcinoma, papillary carcinoma and nodular goiter. RESULTS: (1) The expression of motilin and its precursor mRNA in normal human thyroid was primarily in the thyroid C cells. (2) RT-PCR and Southern blot showed that motilin mRNA expressed in human thyroid was identical to that expressed in duodenum with identical sequence deposited in NCBI Genbank of America. (3) Immunohistochemistry, Western blot research and real-time PCR studies showed that motilin and its precursor mRNA were expressed in normal and tumor tissues of human thyroid. Thyroid tumors (acidophilic adenoma, medullary carcinoma, follicular carcinoma, papillary carcinoma and nodular goiter) showed intense and diffuse immunostaining for motilin peptide. Moreover, the expression of motilin and its precursor mRNA in thyroid medullar carcinoma and acidophilic adenoma were significantly higher than those of normal thyroid tissue (P < 0.05). The expression in thyroid follicular and papillary carcinomas were significantly lower than those of normal thyroid tissue (P < 0.05). There was no difference of the expression between nodular goiter and normal thyroid tissue (P > 0.05). CONCLUSIONS: Motilin peptide and its precursor mRNA are expressed in C cells of human thyroid. The sequence of motilin is identical to that expressed in duodenum from NCBI Genbank of America. The expressions of both motilin and its precursor mRNA in thyroid medullary carcinoma and acidophilic adenoma are significantly increased. In contrast, their expressions in thyroid follicular and papillary carcinomas are significantly decreased. Motilin may regulate physiological functions of the thyroid through parafollicular cells. Motilin may be involved in the pathogenesis of medullary carcinoma and acidophilic adenoma of the thyroid.

beta-Ionone suppresses mammary carcinogenesis, proliferative activity and induces apoptosis in the mammary gland of the Sprague-Dawley rat.

beta-Ionone demonstrates potent anticancer activity both in vitro and in vivo. We determined tumor incidence and the number of rats bearing tumors as well as cell proliferation and apoptosis in a rat mammary cancer model induced by 7, 12-dimethylbenz[a]anthracene (DMBA). Rats were fed an AIN-76A diet containing beta-ionone (0, 9, 18 or 36 mmol/kg), starting 2 weeks before DMBA administration and continuing for 24 weeks. A dose-dependent inhibition of mammary carcinogenesis by dietary beta-ionone was observed. Corresponding tumor incidence values were 82.1, 53.3, 25.9 and 10.0% (p < 0.01 or 0.05). Time to tumor appearance increased and tumor multiplicity decreased with increasing dietary beta-ionone. Histopathological and immunohistochemical evaluations of tumors were performed on the 64, 31, 15 and 3 tumors, respectively, identified in rats from the respective groups of 30. The proportions of adenocarcinomas, adenomas and benign masses were equally distributed in the latter group. In proportions within the other groups, the proportions of adenocarcinomas and benign masses decreased and increased with increasing dietary beta-ionone. Proliferating cell nuclear antigen (PCNA), cyclin D1 and Bcl-2 expression decreased, and Bax expression and nuclear fragmentation increased with increasing dietary beta-ionone. These results demonstrate the potent capacity of dietary beta-ionone to suppress DMBA-initiated mammary cancer in rats.

[Inhibitory effect of potential metastasis in SGC-7901 cells induced by beta-ionone].

OBJECTIVE: To determine the effect of beta-ionone on the potential metastasis of human gastric adenocarcinoma cell line SGC-7901 and the underlying mechanism. METHODS: Using curve of cellular growth, Zymograms, and RT-PCR assays, we analyzed the growth rate, the activities of two types IV collagenase of Matrix met alloproteinase 9 (MMP-9) and MMP-2 and the expression of nm23-H1 gene, tissue inhibitor of met alloproteinase 1 (TIMP-1) and TIMP-2 in SGC-7901 cells which were treated with progressively increasing concentrations (25, 50, 100 and 200 micromol/L) of beta-ionone for 24 h and 48 h. RESULTS: The growth of SGC-7901 cells was inhibited by beta-ionone. Eight days after treatment with different concentrations of beta-ionone, as mentioned above, the inhibition rates were 25.93%, 28.21%, 74.36% and 90.11%, respectively compared to the negative control. The estimated IC50 value of beta-ionone for SGC-7901 cells was estimated to be 89 micromol/L; beta-ionone did not show any effect on the activities of MMP-9 and MMP-2 in SGC-7901 cells. However, the expression of nm23-H1, TIMP-1 and TIMP-2 mRNA transcripts gradually increased in response to beta-ionone in a dose-dependent manner. CONCLUSION: beta-ionone can inhibit the growth and proliferation of SGC-7901 cells. It may show some effects on the potential metastasis of SGC-7901 cells indicates by its upregulation of nm23-H1, TIMP-1 and TIMP-2 expression. However, beta-ionone may have no effect on the activities of type IV collagenase in SGC-7901 cells. The mechanism by which beta-ionone inhibits the potential metastasis of SGC-7901 cells needs to be studied further.

[Effect of beta-ionone in human mammary cancer cells (Er-) by MAPK pathway].

OBJECTIVE: To investigate the effect of cell proliferation in human breast cancer cells (MDA-MB 435), which has non-receptor of estrogen (Er), induced by beta-ionone. MDA-MB 435 cells were treated with different beta-ionone concentrations (25, 50, 100 and 200 micromol/L), with a negative control. METHODS: Such as curve of cell growth, cellular mitosis, the clone formatting, DNA synthesis, and western blotting for protein of PCNA and MAPK pathway were employed. RESULTS: beta-ionone inhibited the cell proliferation, cellular mitosis, clone formatting and DNA synthesis and reduced expression of PCNA protein in MDA-MB 435 cells. The inhibitory frequency (IF) showed a dose-dependent responses as the concentrations of beta-ionone increased. Seven days after treatment with various concentrations of beta-ionone, as mentioned above, the inhibition rates were 45.65%, 71.24%, 81.53%, and 84.93%, respectively. Its IC50 value was 42.0 micromol/L for MDA-MB 435 cells. The IF from cellular mitosis of MDA-MB 435 cells treated by beta-ionone were - 34.57%-58.857% at 24 h and - 30.05%-75.12% at 48 h, from the clone formatting assay, - 4.44%-63.79% at 24 h and 6.42%-95.55% at 48 h, from DNA synthesis, 17.00%-57.56% at 24h and 62.25%-78.35% at 48 h. The further study was found that beta-ionone inhibited the expression of PCNA which to be related to cell cycle and reduced ERK, MEK-1 proteins expression and promoted the expression of JNK and MKP-1 proteins related to MAPK pathway in MDA-MB 435 cells. CONCLUSION: beta-ionone could inhibit MDA-MB 435 cells proliferation by regulating MAPKs pathway. It may be one of the effects of beta-ionone in anticancer.

[Effect of motilin receptor agonist-erythromycin on the glucose responsive neurons in hypothalamus of rats].

AIM: In order to explore the mechanism of central motilin-induced feeding behavior, the effects of erythromycin, a motilin receptor agonist, on glucose responsive neurons in hypothalamus were observed. METHODS: Extracellular recordings were made from single neurons in region of lateral hypothalamic area (LHA) and ventromedial hypothalamic nucleus (VMH) in anesthetized rats. On the basis of their responsiveness to intracarotid injection of 0.58 mol/L glucose solution 0.2 ml, glucose-sensitive neurons (GSNs) in LHA and glucoreceptor neurons (GRNs) in VMH were recognized. Effects of intracerebroventricularly (i. c. v.) administration of 4 microg erythromycin on neural activities of glucose responsive neurons and non-glucose responsive neurons were examined. The mixture of EM and GM-109 1 microl were used to GSNs and GRNs which were sensitive to i. c. v. administration of EM. RESULTS: In LHA, EM increased activity of GSNs significantly (P < 0.05 vs non-glucose-sensitive neurons group). Whereas in VMH, EM significantly decreased the activities of GRNs (P < 0.01 vs non-glucoreceptor neurons group). The mixture of EM and GM-109 had no effect on GSNs and GRNs. CONCLUSION: EM, a motilin receptor agonist, can stimulate GSNs in LHA and suppress GRNs in VMH and this may contribute to central motilin's effect on feeding behavior.