scholarly journals Deficits in hippocampal neurogenesis in obesity-dependent and -independent type-2 diabetes mellitus mouse models

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jacqueline A. Bonds ◽  
Aashutosh Shetti ◽  
Terilyn K. L. Stephen ◽  
Marcelo G. Bonini ◽  
Richard D. Minshall ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Growth Factor ◽  
Cognitive Decline ◽  
Leptin Receptor ◽  
Memory Function ◽  
Growth Factor Receptor ◽  
Hippocampal Neurogenesis

Abstract Hippocampal neurogenesis plays an important role in learning and memory function throughout life. Declines in this process have been observed in both aging and Alzheimer’s disease (AD). Type 2 Diabetes mellitus (T2DM) is a disorder characterized by insulin resistance and impaired glucose metabolism. T2DM often results in cognitive decline in adults, and significantly increases the risk of AD development. The pathways underlying T2DM-induced cognitive deficits are not known. Some studies suggest that alterations in hippocampal neurogenesis may contribute to cognitive deterioration, however, the fate of neurogenesis in these studies is highly controversial. To address this problem, we utilized two models of T2DM: (1) obesity-independent MKR transgenic mice expressing a mutated form of the human insulin-like growth factor 1 receptor (IGF-1R) in skeletal muscle, and (2) Obesity-dependent db/db mice harboring a mutation in the leptin receptor. Our results show that both models of T2DM display compromised hippocampal neurogenesis. We show that the number of new neurons in the hippocampus of these mice is reduced. Clone formation capacity of neural progenitor cells isolated from the db/db mice is deficient. Expression of insulin receptor and epidermal growth factor receptor was reduced in hippocampal neurospheres isolated from db/db mice. Results from this study warrant further investigation into the mechanisms underlying decreased neurogenesis in T2DM and its link to the cognitive decline observed in this disorder.

Clinical and pathogenetic features of intestinal lesions in patients with type 2 diabetes mellitus

2021 ◽  
Author(s):  
Y. Z. Dynia
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Growth Factor ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Clinical Manifestations ◽  
Intestinal Damage ◽  
Hydrogen Breath Test

Objective — to study the incidence and clinical and pathogenetic features of intestinal injury in patients with type 2 diabetes mellitus. Materials and methods. Examinations involved 138 patients with type 2 diabetes mellitus (DM 2), aged from 39 to 67 years (mean age 53 ± 5 years), including 82 women (59 %) and 56 men (41 %). In addition to general clinical methods, investigations included plasma levels of the transforming growth factor‑b1 (TGF‑b1) and vascular endothelial growth factor (VEGF), the hydrogen breath test with lactulose, endoscopic examination of the intestine with biopsy followed by staining with hematoxylin‑eosin, immunohistochemical determining of claudin‑1 and VEGF, and conduction of PAS‑reaction. Results. Diabetic enterocolopathy (DECP) was diagnosed in 72 (52.2 %) patients with DM 2. Clinical manifestations were nonspecific and similar to those of irritable bowel syndrome (IBS). It has been found that DECP correlates with the duration of the DM 2 course and was diagnosed more often in middle‑aged patients (52.1 ± 4.1 years). In patients with DECP, the increase in the proinflammatory cytokines TGF‑b1 and VEGF significantly exceeded those in IBS patients. Histologically the inflammatory cell infiltration in patients with DECP was more intense and diverse, there were signs of subatrophy of the glands with a relative decrease in the number of vacuoles in the goblet cells. The immunohistochemical study revealed that VEGF in the colon mucosa was visualized mainly in patients with DECP. Moreover, a tendency to a decrease in the claudin‑1 levels was established in these patients. Conclusions. Intestinal damage was revealed in 67.4 % of patients with type 2 diabetes mellitus, and DECP was diagnosed in more than half of patients. Diabetic enterocolopathy had nonspecific clinical symptoms, required differential diagnosis with IBS, and was not always accompanied with abdominal pain. The presence of DECP more often correlated with the bacterial overgrowth syndrome, and levels of proinflammatory cytokines in the blood plasma and intestinal mucosa of these patients was raised.  

Sign in / Sign up

Export Citation Format

Share Document