Advanced glycation end products facilitate the proliferation and reduce early apoptosis of cardiac microvascular endothelial cells via PKCβ signaling pathway: Insight from diabetic cardiomyopathy

Update on clinical and experimental management of diabetic cardiomyopathy: addressing current and future therapy

Diabetic cardiomyopathy (DCM) is a severe secondary complication of type 2 diabetes mellitus (T2DM) that is diagnosed as a heart disease occurring in the absence of any previous cardiovascular pathology in diabetic patients. Although it is still lacking an exact definition as it combines aspects of both pathologies - T2DM and heart failure, more evidence comes forward that declares DCM as one complex disease that should be treated separately. It is the ambiguous pathological phenotype, symptoms or biomarkers that makes DCM hard to diagnose and screen for its early onset. This re-view provides an updated look on the novel advances in DCM diagnosis and treatment in the experimental and clinical settings. Management of patients with DCM proposes a challenge by itself and we aim to help navigate and advice clinicians with early screening and pharmacotherapy of DCM.

Oxidative stress signaling in the pathogenesis of diabetic cardiomyopathy and the potential therapeutic role of antioxidant naringenin

Diabetes mellitus (DM) is one of the most prevalent metabolic disorders that poses a global threat to human health. It can lead to complications in multiple organs and tissues, owing to its wide-ranging impact on the human body. Diabetic cardiomyopathy (DCM) is a specific cardiac manifestation of DM, which is characterized by heart failure in the absence of coronary heart disease, hypertension and valvular heart disease. Given that oxidative stress is a key factor in the pathogenesis of DCM, intervening to mitigate oxidative stress may serve as a therapeutic strategy for managing DCM. Naringenin is a natural product with anti-oxidative stress properties that can suppress oxidative damage by regulating various oxidative stress signaling pathways. In this review, we address the relationship between oxidative stress and its primary signaling pathways implicated in DCM, and explores the therapeutic potential of naringenin in DCM.

[Effect of dissipating phlegm and blood stasis simultaneously on AGEs/RAGE axis and oxidative stress in rats with diabetic myocardial microangiopathy]

OBJECTIVE

To investigate the effect of dissipating phlegm and blood stasis simultaneously for protecting cardiac microvascular endothelial cells (CMECs) against high glucose-induced injury and the role of AGEs/RAGE axis in the underlying mechanism.

METHODS

The primary CMECs were isolated from rat heart by enzymatic digestion and identified by immunofluorescence assay. The CMECs exposed to 33 mmol/L glucose for 48 h were divided into model group (MC), resolving phlegm (RP) group, dissipating blood stasis (DBS) group, dissipating phlegm and blood stasis (RPDBS) group and ALT-711 group. After treatment with 10% drug-containing serum and ALT-711 for 48 h, the content of AGEs in the cells were measured with ELISA. The expressions of RAGE mRNA and protein were measured with real-time quantitative PCR, immunofluorescence assay and Western blotting; The activity of NADPH oxidase and ROS level were measured by cytochrome c reduction and fluorescent probe DHE.

RESULTS

High glucose exposure significantly increased the content of AGEs, RAGE expressions at the protein and mRNA levels, NADPH oxidase activity and ROS level in the CMECs (P < 0.01). These changes were significantly mitigated by treatments with RP, DBS, RPDBS and ALT-711 (P < 0.01), among which RPDBS caused the most significant decrements in AGEs content, RAGE expression and NADPH oxidase activity (P < 0.01, P < 0.05). The reduction of ROS level in the RPDBS group was significantly greater than that in RP group (P < 0.01), but similar to that in DBS group (P > 0.05).

CONCLUSION

Dissipating phlegm and blood stasis simultaneously can be helpful for prevention and treatment of diabetic myocardial microangiopathy by suppressing the excessive activation of AGEs-RAGE signal axis and oxidative stress, thus protecting CMECs against high glucose-induced damage. Dissipating phlegm and blood stasis simultaneously is better than either of the therapy alone.