Autopolyploidization is considered to play an important role in plant evolution. In polyploidization, the polyploid evolves from the original diploid cytotype, in which the triploid state is considered to mediate the process (triploid bridge). Nevertheless, the fitness of triploid individuals seems to be too low to facilitate the polyploidization process (triploid block). The evolutionary condition of autopolyploidy was analyzed using a mathematical model focusing on the role of parthenogenesis in triploid and tetraploid individuals. In addition, offspring were assumed to arise by sexual reproduction by conjugations between haploid, diploid, and triploid gametes produced by diploid, tetraploid, and triploid individuals. According to the analysis, even if triploid block suppresses the fitness of sexually produced triploids, the polyploidization process can proceed when parthenogenesis occurs frequently. If only triploids frequently reproduce parthenogenetically, the evolutionary consequences tend to depend on the fitness of the tetraploid individuals. On the basis of a predetermined parameter set, if tetraploid fitness is relatively low, all three ploidies can coexist. Otherwise, tetraploidization occurs. In this case, triploid parthenogenesis promotes not only triploidization but also tetraploidization. However, if both triploids and tetraploids frequently reproduce parthenogenetically, the ploidy levels with the highest fitness are likely to dominate in the population through direct competition among cytotypes.

No abstract

In pancreatic β cells, ABCA1, a 254 kDa membrane protein, affects cholesterol homeostasis and insulin secretion. Angiotensin II, as the main effector of the renin-angiotensin system, decreases glucose-stimulated insulin secretion (GSIS). We examined the effect of angiotensin II on ABCA1 expression in primary pancreatic islets and INS-1 cells. Angiotensin II decreased ABCA1 protein and mRNA; angiotensin II type 1 receptor (AT1R) blockade rescued this ABCA1 repression. In parallel, angiotensin II suppressed the promoter activity of , an effect that was abrogated by PD98095, a specific inhibitor of MAPK kinase (MEK). LXR enhanced promoter activity, and angiotensin II decreased the nuclear abundance of LXR protein. On a chromatin immunoprecipitation assay, LXR mediated the transcription of by directly binding to its promoter. Mutation of the LXR binding site on the promoter cancelled the effect of angiotensin II. Furthermore, angiotensin II induced cholesterol accumulation and impaired GSIS; inhibition of AT1R or MEK pathway reversed these effects. In summary, our study showed that angiotensin II suppressed ABCA1 expression in pancreatic islets and INS-1 cells, indicating that angiotensin II may influence GSIS by regulating ABCA1 expression. Additional research may address therapeutic needs in diseases such as diabetes mellitus.

Background Nonalcoholic fatty liver disease (NAFLD) refers to hepatic steatosis caused by something other than alcoholic liver injury, and often occurs after gastrointestinal surgeries such as pancreatoduodenectomy and gastrectomy. This study aimed to identify the risk factors for NAFLD after gastrectomy for gastric cancer. Methods A total of 721 patients who underwent gastrectomy for gastric cancer and plane abdominal computed tomography (CT) preoperatively and 1 year after surgery were included in this study. NAFLD was defined as having a mean hepatic CT attenuation value of < 40 Hounsfield units. We retrospectively examined the relationship between the onset of NAFLD and clinicopathological findings to identify the risk factors associated with the development of NAFLD after gastrectomy. Results The incidence of postoperative NAFLD was 4.85% (35/721). The univariate analysis identified the following factors as being significantly associated with the incidence of NAFLD: age, preoperative BMI ≥ 25 kg/m 2 , tumor depth of pT3 ≤, lymph node metastasis grade of pN2 ≤, cholecystectomy, D2 lymphadenectomy, adjuvant chemotherapy, high preoperative cholinesterase serum level, and low grade of preoperative FIB-4 index. Adjuvant chemotherapy (p < 0.001) and high preoperative cholinesterase serum level (p = 0.021) were identified as independent risk factors for NAFLD 1 year after gastrectomy. Conclusion Our study showed that adjuvant chemotherapy with S-1 and high level of serum cholinesterase were considered as the risk factors for NAFLD occurring after gastrectomy for gastric cancer.

Context 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors demonstrate anti-metabolic and anti-sarcopenic effects in Cushing’s syndrome (CS) and autonomous cortisol secretion (ACS) patients. Objective To confirm the efficacy and safety of S-707106 (11β-HSD1 inhibitor) administered to CS and ACS patients. Design A 24-week single-center, open-label, single-arm, dose-escalation, investigator-initiated clinical trial on a database. Setting Kyushu University Hospital, Kurume University Hospital, and related facilities. Patients Sixteen patients with inoperable or recurrent CS and ACS, with mildly impaired glucose tolerance. Intervention Oral administration of 200-mg S-707106 after dinner, daily, for 24 weeks. In patients with insufficient improvement in oral glucose tolerance test results at 12 weeks, an escalated dose of S-707106 (200-mg BID) was administered for the residual 12 weeks. Main Outcome Measures The rate of participants responding to glucose tolerance impairment, defined as those showing a 25% reduction in the area under the curve (AUC) of plasma glucose during the 75 g-oral glucose tolerance test at 24 weeks. Results S-707106 administration could not achieve the primary endpoint of this clinical trial (&gt;20% of responsive participants). AUC glucose decreased by -7.1% (SD, 14.8 [90% CI: -14.8– -1.0], P=0.033) and -2.7% (14.5 [-10.2–3.4], P=0.18) at 12 and 24 weeks, respectively. S-707106 administration decreased AUC glucose significantly in participants with a high body mass index. Body fat percentage decreased by -2.5% (1.7 [-3.3– -1.8], P&lt;0.001), and body muscle percentage increased by 2.4% (1.6 [1.7–3.1], P&lt;0.001). Conclusions S-707106 is an effective insulin sensitizer and anti-sarcopenic and anti-obesity medication for these patients.