Increased albumin concentration reduces apoptosis and improves functionality of human islets

Area of Science:

• Cell Biology
• Transplantation Immunology

Background:

• Islet transplantation success relies on sufficient islet mass.
• Apoptosis (programmed cell death) is a primary cause of islet cell loss post-isolation.
• Preventing apoptosis is crucial for enhancing islet transplant efficacy.

Purpose of the Study:

• To investigate the effect of elevated human albumin (HA) concentrations on apoptosis in cultured human islets.
• To determine if higher HA levels can mitigate post-isolation islet cell death.

Main Methods:

• Human islets were cultured for 24 hours in CMRL media supplemented with either 1.5% or 5% HA.
• Apoptosis was indirectly assessed by measuring caspase 3 activity and tetramethylrhodamine-ethyl-ester (TMRE) levels.
• Islet function and viability were evaluated post-culture.

Main Results:

• Islets cultured with higher HA concentrations exhibited significantly lower caspase 3 activity (p = 0.011).
• Elevated HA levels correlated with increased insulin secretory capacity (Stimulation Index, p = 0.023).
• Islet viability was improved in higher albumin concentrations.

Conclusions:

• Increased human albumin concentration effectively prevents apoptosis in isolated human islets.
• This protective effect of albumin may enhance islet transplant outcomes by preserving islet mass and function.