The effect of diabetes and poor left ventricular function on bone marrow cell-induced myocardial protection

Area of Science:

• Cardiovascular Biology
• Regenerative Medicine
• Cell Therapy

Background:

• Myocardial protection via ischemic preconditioning (IP) is impaired in patients with diabetes and poor left ventricular (LV) function.
• Bone marrow cells (BMCs) exert paracrine effects that can protect the myocardium.
• The specific cellular or tissue deficits responsible for the loss of myocardial protection in these conditions remain unclear.

Purpose of the Study:

• To investigate if diabetes and poor LV function affect the protective capacity of BMCs on the myocardium.
• To determine whether the loss of protection is attributable to BMCs, the myocardium, or both.
• To elucidate the mechanisms underlying impaired myocardial protection in these patient groups.

Main Methods:

• Co-culture of myocardial tissue with autologous or allogenic BMCs from patients with and without diabetes and with preserved or poor LV function.
• Subjecting co-cultures to ischemia/reoxygenation (I/R) injury.
• Assessing myocardial injury by measuring creatine kinase (CK) release, necrosis, and apoptosis.

Main Results:

• Diabetic myocardium showed no protection from IP or BMC co-incubation, indicating a myocardial deficit.
• Non-diabetic myocardium co-incubated with diabetic BMCs showed reduced injury, suggesting BMCs from diabetic patients retain some protective function.
• BMCs from patients with poor LV function failed to protect either their own or allogenic myocardium, indicating deficits in both BMCs and myocardium.

Conclusions:

• Impaired myocardial protection in patients with poor LV function is primarily due to deficits in both BMCs and the myocardium.
• In diabetic patients, the myocardial deficit, not the BMCs, is responsible for the failure of protection against I/R injury.
• These findings highlight distinct cellular mechanisms underlying myocardial dysfunction in diabetes and heart failure.