Protective effects of Lycium barbarum polysaccharide on male sexual dysfunction and fertility impairments by activating hypothalamic pituitary gonadal axis in streptozotocin-induced type-1 diabetic male mice
Guang-Jiang Shi, Jie Zheng, Jing Wu, Hai-Qi Qiao, Qing Chang, Yang Niu, Tao Sun, Yu-Xiang Li, Jian-Qiang Yu
Vol 64 No. 9
Diabetes-associated male sexual dysfunction and fertility impairments are both common clinical complications with limited therapeutic options; hence it seriously affects the quality of life of the patients, in particular, the patients of reproductive age. Lycium barbarum polysaccharide (LBP) has long being believed to maintain and to promote reproductive functions in the traditional medical practice in China. The current study was to investigate if LBP may contribute to recovery of male sexual dysfunction and fertility impairments in diabetic individuals. The effects of LBP on sexual behaviors and histological changes of testis were studied in the type-1 diabetes male mice induced by intra-peritoneal (i.p.) injection of streptozotocin (STZ). After oral administration of LBP (10, 20 or 40 mg/kg), sildenafil citrate (SC, 5 mg/kg) or saline for 62 consecutive days, the typical abnormal changes in the sperm parameters, in relative weight of reproductive organs and in morphology of testis were observed in diabetic mice. LBP treatment of the diabetic mice considerably reversed those changes and Johnsen’s testicular score, serum testosterone (T), follicular stimulating hormone (FSH) and luteinizing hormone (LH) level were also increased to different degrees. Moreover, our data have also shown that a marked improvement in sexual behavior and fertility level after administration of LBP (40 mg/kg) compared to the diabetic group. These results suggested that LBP can exert functional recovery of male sexual dysfunction and fertility damages induced by diabetes in male mice, which is likely to be mediated through regulating the hypothalamus- pituitary-gonadal axis endocrine activity.
Stefan Amisten, Israa Mohammad Al-Amily, Arvind Soni, Ross Hawkes, Patricio Atanes, Shanta Jean Persaud, Patrik Rorsman, Albert Salehi
Vol 64 No. 3
Pancreatic islets express high levels of the orphan G-protein coupled receptor C5C (GPRC5C), the function of which remains to be established. Here we have examined the role of GPRC5C in the regulation of insulin secretion and β-cell survival and proliferation using human and mouse pancreatic islets. The expression of GPRC5C was analysed by RNA-sequencing, qPCR, western blotting and confocal microscopy. Insulin secretion and cell viability were determined by RIA and MTS assays, respectively. GPRC5C mRNA expression and protein level were reduced in the islets from type-2 diabetic donors. RNA sequencing in human islets revealed GPRC5C expression correlated with the expression of genes controlling apoptosis, cell survival and proliferation. A reduction in Gprc5c mRNA and protein expression was observed in islets isolated from old mice (>46 weeks of age) compared to that in islets from newborn (<3 weeks) mice. Down-regulation of Gprc5c led to both moderately reduced glucose-stimulated insulin release and also reduced cAMP content in mouse islets. Potentiation of glucose-stimulated insulin secretion concomitant with enhanced islet cAMP level by all-trans retinoic acid (ATRA) was attenuated upon Gprc5c-KD. ATRA also increased [Ca+2]i in Huh7-cells. Gprc5c over expression in Huh7 cells was associated with increased ERK1/2 activity. Gprc5c-KD in clonal MIN6c4 cells reduced cell proliferation and in murine islets increased apoptosis and the sensitivity of primary islet cells to a cocktail of pro-apoptotic cytokines. Our results demonstrate that agents activating GPRC5C represent a novel modality for the treatment and/or prevention of diabetes by restoring and/or maintaining functional β-cell mass.
Takahiro Takase, Akinobu Nakamura, Hideaki Miyoshi, Chiho Yamamoto, Tatsuya Atsumi
Vol 64 No. 3
In this study, we investigated the ameliorating effects of ipragliflozin on fatty liver in patients with type 2 diabetes. The factors that influenced the amelioration of fatty liver were also examined. Analysis included data of 21 Japanese patients with type 2 diabetes obtained from our prospective observational study. After obtaining patients’ informed consent, once-daily ipragliflozin (50 mg/day) was given for 16 weeks. In addition to several clinical parameters, body composition was also compared before and after 16 weeks of treatment. The extent of fatty liver was estimated using a fatty liver index (FLI). After 16 weeks, FLI significantly decreased, from 70.1 ± 19.4 to 60.3 ± 25.5 (p = 0.0009) as well as levels of fasting plasma glucose (FPG), HbA1c, body weight, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and fat mass. To reveal the factors influencing the FLI changes observed on ipragliflozin treatment, correlations between changes in FLI and several other measured parameters were examined. Changes in FPG (correlation coefficient = 0.4683, p = 0.0323) and HbA1c (correlation coefficient = 0.4383, p = 0.0469) showed significant positive correlations with changes in FLI. On the other hand, no correlations of changes in FLI were observed with body weight, VAT, SAT nor fat mass. In conclusion, ipragliflozin ameliorated FLI in Japanese patients with type 2 diabetes. Improvement in FLI was associated with that of glucose intolerance.
Yudai Okano, Tetsurou Satoh, Kazuhiko Horiguchi, Minoru Toyoda, Aya Osaki, Shunichi Matsumoto, Takuya Tomaru, Yasuyo Nakajima, Sumiyasu Ishii, Atsushi Ozawa, Nobuyuki Shibusawa, Takehiro Shimada, Tetsuya Higuchi, Kazuaki Chikamatsu, Masanobu Yamada
Vol 63 No. 10
The anti-programmed cell death-1 monoclonal antibody (mab), nivolumab has recently been approved for the treatment of unresectable or metastatic malignant melanoma and non-small-cell lung cancers in Japan. Ipilimumab, an anti-cytotoxic T lymphocyte antigen-4 mab for malignant melanoma that was approved earlier than nivolumab in Western countries, is known to frequently cause endocrine immune-related adverse events such as hypophysitis and thyroid dysfunction. We herein report a patient with advanced melanoma who appeared to develop hypophysitis as a consequence of the inhibition of PD-1 by nivolumab. One week after the 6th administration of nivolumab, the patient developed progressive fatigue and appetite loss. Laboratory data on admission for the 7th administration of nivolumab showed eosinophilia and hyponatremia. Since ACTH and cortisol levels were low, nivolumab was discontinued and a large dose of hydrocortisone (100 mg/d) was promptly administered intravenously. A magnetic resonance imaging scan revealed the mild enlargement of the anterior pituitary gland and thickening of the stalk with homogenous contrast. A detailed assessment of anterior pituitary functions with hypothalamic hormone challenges showed that hormonal secretions other than ACTH and TSH were normal. With a replacement dose of hydrocortisone (20 mg/d), the 7th administration of nivolumab was completed without exacerbating the patient’s general condition. The present report provides the first detailed endocrinological presentation of nivolumab-induced hypophysitis showing the enlargement of the pituitary gland and stalk in a malignant melanoma patient in Japan. Oncologists and endocrinologists need to be familiar with potentially life-threatening hypophysitis induced by immune-checkpoint inhibitors.
Chiho Yamamoto, Hideaki Miyoshi, Kota Ono, Hajime Sugawara, Reina Kameda, Mei Ichiyama, Kohei Yamamoto, Hiroshi Nomoto, Akinobu Nakamura, Tatsuya Atsumi
Vol 63 No. 6
To investigate if ipragliflozin, a novel sodium-glucose co-transporter 2 inhibitor, alters body composition and to identify variables associated with reductions in visceral adipose tissue in Japanese patients with type 2 diabetes mellitus. This prospective observational study enrolled Japanese participants with type 2 diabetes mellitus. Subjects were administered ipragliflozin (50 mg/day) once daily for 16 weeks. Body composition, visceral adipose tissue volume and plasma variables were measured at 0, 8, and 16-weeks. The subjects’ lifestyle habits including diet and exercise were evaluated at baseline and 16 weeks. The primary endpoint was defined as the decrease of visceral adipose tissue mass. Twenty-four of 26 enrolled participants completed the study. The visceral adipose tissue decreased significantly (110 ± 33 to 101 ± 36 cm2, p = 0.005) as well as other parameters for metabolic insufficiency including hemoglobin A1c. Seventy-one % of the total body weight reduction (-2.49 kg) was estimated by a decrease in fat mass (-1.77 kg), and the remaining reduction (22%) by water volume (-0.55 kg). A minor but significant reduction in the skeletal muscle index was also observed. Correlation analyses were performed to identify variables associated with changes in visceral adipose tissue and the only significant variable identified was diet therapy (Spearman’s r = -0.416, p = 0.043). Ipragliflozin significantly decreased visceral adipose tissue, and improved parametres for metabolic dysfunction. Adequate diet therapy would be necessary to induce and enhance the therapeutic merit.
Chih-Chun Chang, Keng-Yang Lin, Kang-Yu Peng, Yuan-Ji Day, Li-Man Hung
Vol 63 No. 2
Studies on resveratrol in a wide range of concentrations on obese mice and adipose cells are necessary to comprehend its range of diverse and contradictory effects. In this study, we examined the anti-obesity effects of resveratrol on high-fat diet (HFD)-induced obese mice at dosages ranging from 1 to 30 mg/kg treatment for 10 wk. We also evaluated the effects of resveratrol on cytotoxicity, proliferation, adipogenic differentiation, and lipolysis of 3T3-L1 cells at concentrations ranging from 0.03 to 100 μM. In HFD obese mice, resveratrol treatment for 10 wk without decreased calories intake significantly attenuated HFD-induced weight gain in a dose-dependent manner. Resveratrol treatment also protected against HFD-induced lipid deposition in adipose tissues and liver. In cultured 3T3-L1 preadipocytes, high dosage (10 to 100 μM) resveratrol treatment produced cytotoxicity in both preadipocytes and mature adipocytes. In contrast, low concentration resveratrol treatment (1 to 10 μM) significantly inhibited the capacity of 3T3-L1 cells differentiated into mature adipocytes. Low dose resveratrol treatment also downregulated peroxisome proliferator-activated receptor gamma (PPARγ) and perilipin protein expressions in differentiated adipocytes. Additionally, tumor necrosis factor alpha (TNFα)-induced lipolysis was inhibited by low concentration resveratrol treatment in mature adipocytes. At concentrations of 10-100 μM, resveratrol exerted cytotoxicity. In contrast, at concentrations of 1-10 μM resveratrol inhibited adipogenic differentiation in preadipocytes and suppressed lipolysis in mature adipocytes. Our results suggest that resveratrol possessed anti-obesity effects by induction of cytotoxicity at high dosage and that it influences preadipocyte differentiation and mature adipocyte lipolysis at low concentration.
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