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Updated: Jun 26, 2025
High-throughput Functional Screening using a Homemade Dual-glow Luciferase Assay
Published on: June 1, 2014
An shRNA screen in primary human beta cells identifies the serotonin 1F receptor as a negative regulator of survival
Abstract:
Islet transplantation can cure type 1 diabetes, but peri-transplant beta cell death limits this procedure to those with low insulin requirements. Improving human beta cell survival or proliferation may make islet transplantation a possibility for more type 1 patients. To identify novel regulators of beta cell survival and proliferation, we conducted a pooled small hairpin RNA (shRNA) screen in primary human beta cells transplanted into immunocompromised mice. shRNAs targeting several cyclin dependent kinase inhibitors were enriched after transplant. Here, we focused on the Gi/o-coupled GPCR, serotonin 1F receptor ( HTR1F, 5-HT 1F ) which our screen identified as a negative regulator of beta cell numbers after transplant. In vitro , 5-HT 1F knockdown induced human beta cell proliferation but only when combined with harmine and exendin-4. In vivo , knockdown of 5-HT 1F reduced beta cell death during transplant. To demonstrate the feasibility of targeting 5-HT 1F in islet transplant, we identified and validated a small molecule 5-HT 1F antagonist. This antagonist increased glucose stimulated insulin secretion from primary human islets and cAMP accumulation in primary human beta cells. Finally, the 5-HT 1F antagonist improved glycemia in marginal mass, human islet transplants into immunocompromised mice. We identify 5-HT 1F as a novel druggable target to improve human beta cell survival in the setting of islet transplantation.
One Sentence Summary:
Serotonin 1F receptor (5-HT 1F ) negatively regulates insulin secretion and beta cell survival during transplant.
Insights
Targeting the serotonin 1F receptor (5-HT 1F) can improve beta cell survival and proliferation. This discovery offers a new therapeutic strategy to enhance islet transplantation success for type 1 diabetes patients.
Area of Science:
- Endocrinology and Metabolism
- Cell Biology
- Transplantation Immunology
Background:
- Islet transplantation is a potential cure for type 1 diabetes, but limited success is attributed to peri-transplant beta cell death.
- Enhancing human beta cell survival and proliferation is crucial to expand islet transplantation eligibility for more type 1 diabetes patients.
Approach:
- A pooled small hairpin RNA (shRNA) screen was performed on primary human beta cells transplanted into immunocompromised mice to identify novel regulators of beta cell survival and proliferation.
- The study focused on the serotonin 1F receptor (5-HT 1F), identified as a negative regulator of beta cell numbers post-transplant.
- Researchers investigated the effects of 5-HT 1F knockdown in vitro and in vivo, and developed a 5-HT 1F antagonist for therapeutic potential.
Key Points:
- Knockdown of 5-HT 1F in vitro promoted human beta cell proliferation when combined with harmine and exendin-4.
- In vivo, 5-HT 1F knockdown reduced beta cell death following transplantation.
- A novel 5-HT 1F antagonist enhanced glucose-stimulated insulin secretion and cAMP accumulation in human beta cells.
- The 5-HT 1F antagonist improved glycemic control in human islet transplants in mice.
Conclusions:
- The serotonin 1F receptor (5-HT 1F) is identified as a novel, druggable target for improving human beta cell survival.
- Targeting 5-HT 1F presents a promising therapeutic strategy to enhance the efficacy of islet transplantation for type 1 diabetes.
- Further research into 5-HT 1F modulation could significantly advance treatment options for type 1 diabetes.
