scholarly journals The small molecule kobusone can stimulate islet β-cell replication in vivo

2021 ◽  
Vol 49 (7) ◽  
pp. 030006052110328
Author(s):  
Jin woo Choi ◽  
Jin-deok Joo ◽  
Jang hyeok In ◽  
Daewoo Kim ◽  
Yongshin Kim ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Body Weight ◽  
Serum Insulin ◽  
Cyclin D3 ◽  
Control Group ◽  
Cell Replication ◽  
Β Cell ◽  
Insulin Levels ◽  
Glucose Levels

Objective To investigate the ability of kobusone to reduce high glucose levels and promote β-cell proliferation. Methods Four-week-old female db/db mice were assigned to the kobusone (25 mg/kg body weight, intraperitoneally twice a day) or control group (same volume of PBS). Glucose levels and body weight were measured twice a week. After 6 weeks, intraperitoneal glucose tolerance tests and immunohistochemical studies were performed, and insulin levels were determined. The expression of mRNAs involved in cell proliferation, such as PI3K, Akt, cyclin D3 and p57Kip 2 , was measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results Kobusone reduced blood glucose levels after 3 weeks and more strongly increased serum insulin levels than the vehicle. Immunohistochemistry illustrated that kobusone increased 5-bromo-2′-deoxyuridine incorporation into islet β-cells, suggesting that it can stimulate islet β-cell replication in vivo. RT-qPCR indicated that kobusone upregulated the mRNA expression of PI3K, Akt, and cyclin D3 and downregulated that of p57Kip2. Conclusion Our findings suggest that kobusone is a potent pancreatic islet β-cell inducer that has the potential to be developed as an anti-diabetic agent.

scholarly journals Insulin Stimulates Primary β-Cell Proliferation via Raf-1 Kinase

Endocrinology ◽  
2008 ◽  
Vol 149 (5) ◽  
pp. 2251-2260 ◽  
Author(s):  
Jennifer L. Beith ◽  
Emilyn U. Alejandro ◽  
James D. Johnson
Keyword(s):  
Cell Proliferation ◽  
Dominant Role ◽  
Cell Mass ◽  
Diabetes Type 2 ◽  
Dominant Negative ◽  
Cell Replication ◽  
Β Cell ◽  
Physiological Control ◽  
Primary Mouse

A relative decrease in β-cell mass is key in the pathogenesis of type 1 diabetes, type 2 diabetes, and in the failure of transplanted islet grafts. It is now clear that β-cell duplication plays a dominant role in the regulation of adult β-cell mass. Therefore, knowledge of the endogenous regulators of β-cell replication is critical for understanding the physiological control of β-cell mass and for harnessing this process therapeutically. We have shown that concentrations of insulin known to exist in vivo act directly on β-cells to promote survival. Whether insulin stimulates adult β-cell proliferation remains unclear. We tested this hypothesis using dispersed primary mouse islet cells double labeled with 5-bromo-2-deoxyuridine and insulin antisera. Treating cells with 200-pm insulin significantly increased proliferation from a baseline rate of 0.15% per day. Elevating glucose from 5–15 mm did not significantly increase β-cell replication. β-Cell proliferation was inhibited by somatostatin as well as inhibitors of insulin signaling. Interestingly, inhibiting Raf-1 kinase blocked proliferation stimulated by low, but not high (superphysiological), insulin doses. Insulin-stimulated mouse insulinoma cell proliferation was dependent on both phosphatidylinositol 3-kinase/Akt and Raf-1/MAPK kinase pathways. Overexpression of Raf-1 was sufficient to increase proliferation in the absence of insulin, whereas a dominant-negative Raf-1 reduced proliferation in the presence of 200-pm insulin. Together, these results demonstrate for the first time that insulin, at levels that have been measured in vivo, can directly stimulate β-cell proliferation and that Raf-1 kinase is involved in this process. These findings have significant implications for the understanding of the regulation of β-cell mass in both the hyperinsulinemic and insulin-deficient states that occur in the various forms of diabetes.

scholarly journals Short-term high-fat feeding induces islet macrophage infiltration and β-cell replication independently of insulin resistance in mice

2016 ◽  
Vol 311 (4) ◽  
pp. E763-E771 ◽  
Author(s):  
David C. Woodland ◽  
Wei Liu ◽  
Jacky Leong ◽  
Mallory L. Sears ◽  
Ping Luo ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Blood Glucose ◽  
Serum Insulin ◽  
Cell Replication ◽  
Fat Pad ◽  
High Fat ◽  
Fasting Serum ◽  
Β Cell ◽  
Short Term ◽  
Insulin Levels

Short-term high-fat consumption stimulates mouse islet β-cell replication through unknown mechanisms. Resident macrophages (MΦs) are capable of secreting various factors involved in islet development and tissue remodeling. We hypothesized that a short-term high-fat diet (HFD) promotes MΦ infiltration in pancreatic islets and that MΦs serve as a regulator of β-cell replication. To test these hypotheses and dissect mechanisms involved in HFD-induced β-cell replication, adult C57BL/6J mice were fed a HFD for 7 days with or without administration of clodronate-containing liposomes, an MΦ-depleting agent. Mouse body and epididymal fat pad weights, and nonfasting blood glucose and fasting serum insulin levels were measured, and pancreatic islet β-cell replication, oxidative stress, and MΦ infiltration were examined. Short-term HFD promoted an increase in body and epididymal fat pad weight and blood glucose levels, along with an increased fasting serum insulin concentration. β-Cell replication, islet MΦ infiltration, and the percentage of inducible NO synthase positive MΦs in the islets increased significantly in mice fed the HFD. Immunofluorescence staining for 8-oxo-2′-deoxyguanosine or activated caspase-3 revealed no significant induction of DNA damage or apoptosis, respectively. In addition, no change in stromal-derived factor 1-expressing cells was found induced by HFD. Despite continuous elevation of nonfasting blood glucose and fasting serum insulin levels, depletion of MΦs through treatments of clodronate abrogated HFD-induced β-cell replication. These findings demonstrated that HFD-induced MΦ infiltration is responsible for β-cell replication. This study suggests the existence of MΦ-mediated mechanisms in β-cell replication that are independent of insulin resistance.

Quantification of the relationship between glycemia and β-cell mass adaptation in vivo

2009 ◽  
Vol 87 (8) ◽  
pp. 602-609 ◽  
Author(s):  
Laura L. Atkinson ◽  
Brian G. Topp ◽  
Jenny Au ◽  
Horatiu V. Vinerian ◽  
Narinder Dhatt ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Cell Mass ◽  
Cell Replication ◽  
Sprague Dawley ◽  
Β Cell ◽  
Insulin Levels ◽  
Hyperglycemic Clamp ◽  
Sprague Dawley Rats ◽  
Significant Difference

β-cell mass dynamics play an important role in the adaptation to obesity, as well as in the pathogenesis of type 2 diabetes. Here we used a 24-hour modified hyperglycemic clamp protocol to investigate the effect of increasing glucose concentrations (15, 20, 25, or 35 mmol/L) on β-cell mass and rates of β-cell replication, death, and neogenesis in 6-week-old Sprague Dawley rats (n = 40). During the first 4 h of glucose infusion, plasma insulin levels rose to an approximate steady state in each group, but by the end of 24 h, there was no difference in insulin levels between any of the groups. There was also no difference in β-cell mass between groups. Mean β-cell replication rates displayed a linear relationship to mean plasma glucose levels in all hyperglycemic animals (r2 = 0.98, p < 0.05). Relative to the uninfused basal control animals, replication rates were significantly reduced in the 15 mmol/L glucose group. The percentage of TUNEL-positive β-cells was not different between groups. There was also no significant difference in markers of neogenesis. Thus, these data demonstrate that hyperglycemia for 24 h had no effect on β-cell mass, death, or neogenesis in 6-week-old Sprague Dawley rats. We demonstrate a linear relationship, however, between hyperglycemia and β-cell replication rates in vivo.

scholarly journals Glucose Regulates Cyclin D2 Expression in Quiescent and Replicating Pancreatic β-Cells Through Glycolysis and Calcium Channels

Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2589-2598 ◽  
Author(s):  
Seth J. Salpeter ◽  
Agnes Klochendler ◽  
Noa Weinberg-Corem ◽  
Shay Porat ◽  
Zvi Granot ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Division ◽  
Glucose Metabolism ◽  
Calcium Channels ◽  
Mrna Levels ◽  
Β Cells ◽  
Β Cell ◽  
Cyclin D2 ◽  
Glucose Levels

Understanding the molecular triggers of pancreatic β-cell proliferation may facilitate the development of regenerative therapies for diabetes. Genetic studies have demonstrated an important role for cyclin D2 in β-cell proliferation and mass homeostasis, but its specific function in β-cell division and mechanism of regulation remain unclear. Here, we report that cyclin D2 is present at high levels in the nucleus of quiescent β-cells in vivo. The major regulator of cyclin D2 expression is glucose, acting via glycolysis and calcium channels in the β-cell to control cyclin D2 mRNA levels. Furthermore, cyclin D2 mRNA is down-regulated during S-G2-M phases of each β-cell division, via a mechanism that is also affected by glucose metabolism. Thus, glucose metabolism maintains high levels of nuclear cyclin D2 in quiescent β-cells and modulates the down-regulation of cyclin D2 in replicating β-cells. These data challenge the standard model for regulation of cyclin D2 during the cell division cycle and suggest cyclin D2 as a molecular link between glucose levels and β-cell replication.

Overtraining of aerobic physical exercise reduce rats (Rattus norvegicus) memory

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Ni Made Ridla Parwata
Keyword(s):  
Body Weight ◽  
Physical Exercise ◽  
Rattus Norvegicus ◽  
Research Method ◽  
Male Rat ◽  
Control Group ◽  
Adult Male Rat ◽  
The Subject ◽  
Heavy Training

Overtraining syndrome is a decrease in physical capacity, emotions and immunity due to training that is too often without adequate periods of rest. Overtraining is often experienced by athletes who daily undergo heavy training with short break periods. This research aims to look at the effect of overtraining aerobic physical exercise on memory in mice. The research method was experimental in vivo with the subject of adult male rat (Rattus Norvegicus) Winstar strain aged 8-10 weeks, body weight 200-250 gr. Divided into three groups, namely the control group, aerobic group and overtraining group. The results of memory tests with water E Maze showed an increase in the duration of travel time and the number of animal errors made by the overtraining group (p = 0.003). This study concludes that overtraining aerobic physical exercise can reduce memory in rat hippocampus.

Lentiviral-Mediated Beclin-1 Overexpression Inhibits Cell Proliferation and Induces Autophagy of Human Esophageal Carcinoma Eca109 Cell Xenograft in Nude Mice

2020 ◽  
Vol 15 (1) ◽  
pp. 70-77
Author(s):  
Junhe Zhang ◽  
Weihua Dong
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Esophageal Carcinoma ◽  
Nude Mice ◽  
Beclin 1 ◽  
Control Group ◽  
Vector Group ◽  
Empty Vector ◽  
Empty Vector Group

Background: Esophageal carcinoma is one of the common malignant tumors in digestive tract. BECLIN-1 is a key gene that regulates autophagy, and its abnormal expression may be related with many human tumors. However, the mechanism of BECLIN-1 in esophageal carcinoma remains unknown. Objective: In this study, we explored the effect of BECLIN-1 overexpression on tumor growth in mice with esophageal carcinoma and its mechanism. Methods: Recombined lentiviral vector containing BECLIN-1 was used to transfect human esophageal carcinoma Eca109 cells and establish stable cell line. qRT-PCR was used to detect BECLIN-1 mRNA level in the transfected Eca109 cells, CCK-8 assay was used to detect cell proliferation. Beclin-1, P62 and LC3-II protein expression levels in Eca109 cells were detected using Western blot analysis. Subcutaneous xenograft nude mice model of human esophageal carcinoma was established, and the tumor growths in Beclin-1 group, control group and empty vector group were monitored. Beclin-1 protein expression in vivo was detected by immunohistochemistry. Results: Beclin-1 mRNA and protein were overexpressed in Eca109 cells. Compared with empty vector group, the growth rate of cells transfected with BECLIN-1 decreased significantly. Compared with the control group and empty vector group, the expression level of P62 protein in beclin-1 group was significantly decreased, while the expression level of LC3-II protein was significantly increased. The tumor growth rate in nude mice of Beclin-1 group was significantly lower than that of the control group and empty vector group, and Beclin-1 protein was mainly expressed in Beclin-1 group in vivo. Conclusion: BECLIN-1 can induce autophagy in esophageal carcinoma Eca109 cells, and it can significantly inhibit the growth of esophageal carcinoma.

scholarly journals NF-κB activity during pancreas development regulates adult β-cell mass by modulating neonatal β-cell proliferation and apoptosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dror Sever ◽  
Anat Hershko-Moshe ◽  
Rohit Srivastava ◽  
Roy Eldor ◽  
Daniel Hibsher ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Developmental Stages ◽  
Cell Mass ◽  
Diabetes Incidence ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Regulatory Circuit ◽  
Proliferation And Apoptosis

AbstractNF-κB is a well-characterized transcription factor, widely known for its roles in inflammation and immune responses, as well as in control of cell division and apoptosis. However, its function in β-cells is still being debated, as it appears to depend on the timing and kinetics of its activation. To elucidate the temporal role of NF-κB in vivo, we have generated two transgenic mouse models, the ToIβ and NOD/ToIβ mice, in which NF-κB activation is specifically and conditionally inhibited in β-cells. In this study, we present a novel function of the canonical NF-κB pathway during murine islet β-cell development. Interestingly, inhibiting the NF-κB pathway in β-cells during embryogenesis, but not after birth, in both ToIβ and NOD/ToIβ mice, increased β-cell turnover, ultimately resulting in a reduced β-cell mass. On the NOD background, this was associated with a marked increase in insulitis and diabetes incidence. While a robust nuclear immunoreactivity of the NF-κB p65-subunit was found in neonatal β-cells, significant activation was not detected in β-cells of either adult NOD/ToIβ mice or in the pancreata of recently diagnosed adult T1D patients. Moreover, in NOD/ToIβ mice, inhibiting NF-κB post-weaning had no effect on the development of diabetes or β-cell dysfunction. In conclusion, our data point to NF-κB as an important component of the physiological regulatory circuit that controls the balance of β-cell proliferation and apoptosis in the early developmental stages of insulin-producing cells, thus modulating β-cell mass and the development of diabetes in the mouse model of T1D.

scholarly journals Anti-Obesity and Anti-Adipogenic Effects of Chitosan Oligosaccharide (GO2KA1) in SD Rats and in 3T3-L1 Preadipocytes Models

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 331
Author(s):  
Jung-Yun Lee ◽  
Tae Yang Kim ◽  
Hanna Kang ◽  
Jungbae Oh ◽  
Joo Woong Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Density Lipoprotein ◽  
Treated Group ◽  
Control Group ◽  
Chitosan Oligosaccharide ◽  
Sd Rats ◽  
Adipogenic Gene

Excess body weight is a major risk factor for type 2 diabetes (T2D) and associated metabolic complications, and weight loss has been shown to improve glycemic control and decrease morbidity and mortality in T2D patients. Weight-loss strategies using dietary interventions produce a significant decrease in diabetes-related metabolic disturbance. We have previously reported that the supplementation of low molecular chitosan oligosaccharide (GO2KA1) significantly inhibited blood glucose levels in both animals and humans. However, the effect of GO2KA1 on obesity still remains unclear. The aim of the study was to evaluate the anti-obesity effect of GO2KA1 on lipid accumulation and adipogenic gene expression using 3T3-L1 adipocytes in vitro and plasma lipid profiles using a Sprague-Dawley (SD) rat model. Murine 3T3-L1 preadipocytes were stimulated to differentiate under the adipogenic stimulation in the presence and absence of varying concentrations of GO2KA1. Adipocyte differentiation was confirmed by Oil Red O staining of lipids and the expression of adipogenic gene expression. Compared to control group, the cells treated with GO2KA1 significantly decreased in intracellular lipid accumulation with concomitant decreases in the expression of key transcription factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (CEBP/α). Consistently, the mRNA expression of downstream adipogenic target genes such as fatty acid binding protein 4 (FABP4), fatty acid synthase (FAS), were significantly lower in the GO2KA1-treated group than in the control group. In vivo, male SD rats were fed a high fat diet (HFD) for 6 weeks to induced obesity, followed by oral administration of GO2KA1 at 0.1 g/kg/body weight or vehicle control in HFD. We assessed body weight, food intake, plasma lipids, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) for liver function, and serum level of adiponectin, a marker for obesity-mediated metabolic syndrome. Compared to control group GO2KA1 significantly suppressed body weight gain (185.8 ± 8.8 g vs. 211.6 ± 20.1 g, p < 0.05) with no significant difference in food intake. The serum total cholesterol, triglyceride, and low-density lipoprotein (LDL) levels were significantly lower in the GO2KA1-treated group than in the control group, whereas the high-density lipoprotein (HDL) level was higher in the GO2KA1 group. The GO2KA1-treated group also showed a significant reduction in ALT and AST levels compared to the control. Moreover, serum adiponectin levels were significantly 1.5-folder higher than the control group. These in vivo and in vitro findings suggest that dietary supplementation of GO2KA1 may prevent diet-induced weight gain and the anti-obesity effect is mediated in part by inhibiting adipogenesis and increasing adiponectin level.

Effect of a Polyphenol-Rich Extract from Aloe vera Gel on Experimentally Induced Insulin Resistance in Mice

2007 ◽  
Vol 35 (06) ◽  
pp. 1037-1046 ◽  
Author(s):  
Yolanda Y. Pérez ◽  
Enrique Jiménez-Ferrer ◽  
Alejandro Zamilpa ◽  
Marcelino Hernández-Valencia ◽  
Francisco J. Alarcón-Aguilar ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Aloe Vera ◽  
Negative Control Group ◽  
Negative Control ◽  
Control Group ◽  
Glucose Levels ◽  
Insulin Tolerance ◽  
Aloe Vera Gel ◽  
Experimentally Induced

Insulin resistance, which precedes type 2 diabetes mellitus (T2DM), is a widespread pathology associated with the metabolic syndrome, myocardial ischemia, and hypertension. Finding an adequate treatment for this pathology is an important goal in medicine. The purpose of the present research was to investigate the effect of an extract from Aloe vera gel containing a high concentration of polyphenols on experimentally induced insulin resistance in mice. A polyphenol-rich Aloe vera extract (350 mg/kg) with known concentrations of aloin (181.7 mg/g) and aloe-emodin (3.6 mg/g) was administered orally for a period of 4 weeks to insulin resistant ICR mice. Pioglitazone (50 mg/kg) and bi-distilled water were used as positive and negative controls respectively. Body weight, food intake, and plasma concentrations of insulin and glucose were measured and insulin tolerance tests were performed. The insulin resistance value was calculated using the homeostasis model assessment for insulin resistance (HOMA-IR) formula. Results showed that the polyphenol-rich extract from Aloe vera was able to decrease significantly both body weight ( p < 0.008) and blood glucose levels ( p < 0.005) and to protect animals against unfavorable results on HOMA-IR, which was observed in the negative control group. The highest glucose levels during the insulin tolerance curve test were in the negative control group when compared to the Aloe vera extract and pioglitazone treated mice ( p < 0.05). In conclusion, Aloe vera gel could be effective for the control of insulin resistance.

scholarly journals Inhibition of MCF-7 breast cancer cell proliferation by 5alpha-dihydrotestosterone; a role for p21(Cip1/Waf1)

2004 ◽  
Vol 32 (3) ◽  
pp. 793-810 ◽  
Author(s):  
MA Greeve ◽  
RK Allan ◽  
JM Harvey ◽  
JM Bentel
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
S Phase ◽  
Cyclin D3 ◽  
P27 Kip1 ◽  
Mcf 7

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.

Sign in / Sign up

Export Citation Format

Share Document