IV (XXVII) Национальный конгресс эндокринологов с международным участием «ИННОВАЦИОННЫЕ ТЕХНОЛОГИИ В ЭНДОКРИНОЛОГИИ» 22-25 сентября 2021 года МОРФОЛОГИЧЕСКИЕ ОСОБЕННОСТИ Β-И Α-КЛЕТОК ПОДЖЕЛУДОЧНОЙ ЖЕЛЕЗЫ ВОЗРАСТНЫХ КРЫС С САХАРНЫМ ДИАБЕТОМ 2 ТИПА ПРИ ДЛИТЕЛЬНОЙ ТЕРАПИИ РАЗЛИЧНЫМИ ПРЕПАРАТАМИ СУЛЬФОНИЛМОЧЕВИНЫ 1 Тучина Т .

The prostate gland (PG) is a small organ in the male reproductive system that is currently the focus of biomedical research due to its leading position in morbidity and mortality from the tissue-specific cancer prostate cancer (PC). The PG epithelium, which undergoes a cancerous transformation, is formed and functions under the control of androgens. At the beginning of the disease, epithelial cells produce an androgen receptor (AR) and are sensitive to androgen-deprivation therapy. However, such therapy inevitably leads to the transition of the disease to the castration-resistant prostate cancer (CRPC), which manifests itself in metastasis and rapid mortality. In CRPC, the cells of the prostate epithelium change their phenotype, that may be associated with AR mutation and loss the sensitivity to specific therapy. The mechanism of PG phenotypic transformation may be hidden in the interaction and formation of the stromal and epithelial cells, which are evident during the establishment of the primary cultures. The aim of this study was to investigate the generation of human PG stromal cells in primary stromal and organoid cultures. We found that, in contrast to the rapid appearance and formation of a homogeneous population of mesenchymal cells in primary stromal cultures of most tissues, human PG cell cultures are formed initially from epithelial cells. They appear in the second week of cultivation and produce cytokeratins (CKs). A homogeneous population of mesenchymal cells producing vimentin is formed only at the end of the fourth week of cultivation. It is accompanied by the disappearance of epithelial cells. At the same time, some epithelial cells simultaneously produce CKs and vimentin. In PG organoid cultures, there is often a concomitant growth of epithelial, but not mesenchymal, cells on culture plastic. During the cultivation of epithelial cells arising from the organoid cultures, they, like the cells of the primary epithelium, exhibit the ability to spontaneous transformation into mesenchymal cells and simultaneously produce CKs and vimentin. Our data suggest that in primary and organoid PG cultures, stromal cells can be formed from epithelium due to the epithelial-to-mesenchymal transition (EMT). The tendency of PG epithelium toward spontaneous EMT may contribute to the mechanism of high sensitivity of prostate tissue to malignant transformation and metastasis. Understanding this mechanism may contribute to the development of effective antitumor therapy of prostate cancer.

Aim: to study the morphology of pancreatic islet cells in rats aged more than 1 year with experimental type 2 diabetes (T2D) that receive sulphonylureas for a long time.Patients and Methods: albino laboratory rats aged more than 1 year (equal to 40 years in humans) were enrolled in this experimental study. Streptozotocin and nicotinamide were administered to induce T2D (streptozotocin-nicotinamide-induced diabetic rats). The animals were divided into four groups, i.e., healthy controls, T2D with no treatment, T2D treated with glibenclamide, and T2D treated with gliclazide. After the experimental study, immunohistochemistry with the antibodies against insulin, glucagon, and Ki-67 was performed. Morphometric analysis was performed using microphotographs. Insulin-, glucagon- and Ki-67-positive cells in islets were calculated.Results: by the 24th week of the study, the ratio of the total volume of α-cells to islet area in rats receiving glibenclamide was similar compared to diabetic rats receiving no treatment (p=0.75). Meanwhile, the significant reduction in the number of α-cells was reported in rats receiving gliclazide compared to diabetic rats receiving no treatment (p=0.000004). Moreover, the number of α-cells was equal to healthy controls. The total volume of β-cells remained unchanged in rats receiving glibenclamide or gliclazide as compared with diabetic rats with no treatment.Conclusion: our findings demonstrate that older animals (>1 year of age) are characterized by the changes in the ratio of α- and β-cells that are similar to the adults with T2D, i.e., the reduction in the percentage of β-cells and the increase in the percentage of α-cells. Long-term treatment with sulphonylureas does not result in the additional changes in the number and total volume of β-cells (rats receiving sulphonylureas for 24 weeks are similar to T2D rats with no treatment in terms of the volume of β-cells). However, 24-week treatment with gliclazide results in the normalization of the total volume of α-cells, and their number is comparable to healthy controls.KEYWORDS: sulphonylureas, α-cells, β-cells, pancreas, type 2 diabetes. FOR CITATION: Tuchina T.P., Skotnikova K.P., Vtorushina A.A. et al. Morphology of pancreatic endocrine cells in rats with type 2 diabetes after the long-term treatment with sulphonylureas. Russian Medical Inquiry. 2020;4(6):329–333. DOI: 10.32364/2587-6821-2020-4-6-329-333.

Группа препаратов, основанных на инкретиновых эффектах (аналоги глюкагоноподобного пептида-1 аГПП1) и ингибиторы дипептидилпептидазы-4, иДПП4), обладают способностью увеличивать репликацию β -клеток и ингибировать апоптоз. Инкретиномиметики способны влиять на функцию α-клеток, восстанавливая физиологическую регуляцию уровня глюкагона. При этом эффекты инкретиномиметиков на пролиферацию/апоптоз α-клеток изучены недостаточно. В единичных исследованиях отмечено увеличение пролиферации α-клеток, но факторы, определяющие выраженность этих изменений, не установлены. Цель - оценка влияния терапии инкретиномиметиками разной продолжительности на морфологические и функциональные особенности α- и β-клеток поджелудочной железы крыс (12 мес) с сахарным диабетом 2-го типа (СД 2-го типа). Методика. У крыс (возраст 12 мес), находящихся на высокожировой диете, моделировали стрептозотоцин-никотинамид-индуцированный СД 2-го типа. Животные получали инкретиномиметки: агонист рецепторов ГПП1 (лираглутид) или ингибитор ДПП4 (вилдаглиптин) в течение 4,10 и 24 нед. Макроскопически оценивали наличие/отсутствие видимых изменений поджелудочной железы. Парафиновые срезы поджелудочной железы окрашивали гематоксилином и эозином для оценки микроструктуры ткани. Проводили иммуногистохимическое (ИГХ) исследование с применением антител (Abcam) к глюкагону, инсулину в аппарате для ИГХ «Thermo Autostainer 720». После процедуры ИГХ ядра доокрашивали гематоксилином в аппарате для окраски гистологических микропрепаратов LeicaST5020. Результаты. Показано, что без лечения сахарный диабет приводил к снижению числа α- и β- клеток на всех сроках наблюдения. Лечение диабета лираглутидом и вилдаглиптином приводило к восстановлению пула как α-, так и β- клеток. При сравнении групп, получавших терапию и без терапии, с группой контроля значимые отличия сохранялись по количеству как α-, так и β-клеток во все сроки наблюдения. Через 4 нед в группах, получавших лираглутид, количество α-клеток стало сопоставимым с таковым в группе контроля, но количество β-клеток оставалось сниженным. После 10 и 24 нед терапии статистически значимой разницы между группой контроля и животными, получавшими терапию лиралутидом, по количеству как β-, так и α- клеток не выявлено. Заключение. Полученные данные свидетельствуют в пользу того, что терапия инкретиномиметиками способствует восстановлению пула как α-, так и β-клеток поджелудочной железы. Drugs based on incretin effects, including analogs of glucagon-like peptide-1 (GLP1) and dipeptidyl peptidase-4 inhibitors (DPP4), increase replication and inhibit apoptosis of β-cells. Incretin mimetics can influence the function of α-cells thereby restoring physiological regulation of glucagon. However, effects of incretin mimetics on proliferation and apoptosis of α-cells are understudied. A few studies reported increased α-cell proliferation, but the factors determining the degree of these changes were not established. Aim. To evaluate the effect of incretin mimetic treatment of different duration on morphological and functional features of pancreatic α- and β-cells of 12-month-old rats with type 2 diabetes mellitus. Method. Streptozotocin-nicotinamide-induced type 2 diabetes mellitus was modeled in 12-month-old rats receiving a high-fat diet. The rats were treated with incretin mimetics, a GLP-1 receptor antagonist (Liraglutide) or a DPP-4 inhibitor (Vildagliptin) for 4, 10 or 24 weeks. Paraffin sections of the pancreas were stained with hematoxylin-eosin to evaluate the tissue microstructure. An immunohistochemical (IHC) study was performed using glucagon and insulin antibodies (Abcam) with a Thermo Autostainer 720 IHC instrument. After the IHC procedure, nuclei were additionally stained with hematoxylin using a Leica ST5020 stainer for histological micropreparations. Results. Untreated diabetes mellitus resulted in decreased numbers of α- and β-cells at all timepoints of observation. The treatments with Liraglutide and Vildagliptin recovered the pools of α- and β-cells. Significant differences of both treated and untreated diabetic groups from the control group in the number of α- and β-cells remained at all timepoints of observation. In the Liraglutide group at 4 weeks, the number of α-cells became comparable with the control group, but the number of β-cells remained lower. At 10 and 24 weeks of treatment, statistically significant differences between the control group and the Liraglutide or Vildagliptin treatment groups in the number of α- and β-cells were not observed. Conclusion. The results of the study suggested that the incretin mimetic therapy provided recovery of both α and β-cell pools in the pancreas.