Self-organized insulin-producing β-cells differentiated from human omentum-derived stem cells and their in vivo therapeutic potential

Omentum transplantation for malignant tumors: a narrative review of emerging techniques and clinical applications

Omentum transplantation has emerged as a versatile and effective technique across various surgical disciplines due to its unique properties of immunological surveillance, anti-inflammatory effects, and wound healing promotion. In breast cancer surgeries, it has been utilized to manage locoregional issues and immediate reconstruction, providing satisfactory cosmetic outcomes and minimal complications, particularly in patients who had previously undergone irradiation. For esophageal cancer, omental reinforcement has significantly reduced anastomotic leak rates and postoperative complications, supporting its use in esophagectomy and complex cardiothoracic surgeries. In gynecological surgeries, the use of omental flaps has shown excellent results in neovaginal reconstruction following pelvic exenteration, offering distinct advantages over myocutaneous flaps by reducing morbidity and preserving sexual function. Additionally, omental transposition has proven beneficial in reducing surgical morbidity following radical abdominal hysterectomy and in managing vaginal cuff dehiscence through vaginal approaches. Robotic-assisted omental flap harvesting has enhanced precision and reduced complications in reconstructive surgeries, making it a promising minimally invasive approach in regenerative surgery and complex reconstructions, such as for facial skeleton reconstruction. The omentum has also been beneficial in laparoscopic procedures for pudendal nerve decompression and in managing thoracic aortic graft infections, demonstrating its versatility and effectiveness in various clinical settings. These studies collectively highlight the omentum's significant role in improving surgical outcomes, reducing complications, and enhancing the quality of life for patients, solidifying its place as a valuable tool in modern surgical practice. This article provides a comprehensive narrative review of omentum transplantation in oncology, discussing its current applications and future potential as a standard treatment modality.

Scaffold-free endocrine tissue engineering: role of islet organization and implications in type 1 diabetes

Type 1 diabetes (T1D) is a chronic hyperglycemia disorder emerging from beta-cell (insulin secreting cells of the pancreas) targeted autoimmunity. As the blood glucose levels significantly increase and the insulin secretion is gradually lost, the entire body suffers from the complications. Although various advances in the insulin analogs, blood glucose monitoring and insulin application practices have been achieved in the last few decades, a cure for the disease is not obtained. Alternatively, pancreas/islet transplantation is an attractive therapeutic approach based on the patient prognosis, yet this treatment is also limited mainly by donor shortage, life-long use of immunosuppressive drugs and risk of disease transmission. In research and clinics, such drawbacks are addressed by the endocrine tissue engineering of the pancreas. One arm of this engineering is scaffold-free models which often utilize highly developed cell-cell junctions, soluble factors and 3D arrangement of islets with the cellular heterogeneity to prepare the transplant formulations. In this review, taking T1D as a model autoimmune disease, techniques to produce so-called pseudoislets and their applications are studied in detail with the aim of understanding the role of mimicry and pointing out the promising efforts which can be translated from benchside to bedside to achieve exogenous insulin-free patient treatment. Likewise, these developments in the pseudoislet formation are tools for the research to elucidate underlying mechanisms in pancreas (patho)biology, as platforms to screen drugs and to introduce immunoisolation barrier-based hybrid strategies.

Silencing hsa_circ_0032449 inhibits the pancreatic differentiation of human embryonic stem cells via the hsa_miR-195-5p/CCND1/PI3K/AKT signaling pathway

Stem cell-derived β cells (SC-β cells) differentiated from stem cell-derived pancreatic progenitor (PP) cells are promising tools for enabling normal glucose control of islet transplants and have therapeutic potential for type 1 diabetes treatment. Pancreatic specification is essential for SC-β cell induction in vitro and low-quality PP cells may convert into derivatives of non-pancreatic lineages both in vivo and in vitro, impeding PP-derived β cell safety and differentiation efficiency. Circular RNA (circRNA) commonly determines the fate of stem cells by acting as competing endogenous RNA (ceRNA). Currently, the relationships between endogenous circRNA and pancreatic specification remain elusive. Herein, we used whole transcriptome sequencing analysis and functional experiments to reveal that deficiency of hsa_circ_0032449 resulted in posterior foregut-derived PP cells with a weakened the progenitor state with decreased expression of PDX1, NKX6.1 and CCND1. As differentiation processed into maturation, silencing of hsa_circ_0032449 suppressed PP cell development into functionally mature and glucose-responsive SC-β cells. These SC-β cells exhibited lower serum C-peptide levels compared with those of control groups in nude mice and had difficulties in reversing hyperglycemia in STZ-induced diabetic nude mice. Mechanistically, loss of hsa_circ_0032449 participated in PI3K-AKT signaling transduction by acting as a ceRNA to sponge miR-195-5p and by influencing the expression of the downstream target CCND1 at transcription and translation levels. Overall, our findings identified hsa_circ_0032449 as an essential PP cell-fate specification regulator, indicating a promising potential in clinical applications and basic research.