Nonclinical and quality assessment of cell therapy products: Report on the 4th Asia Partnership Conference of Regenerative Medicine, April 15, 2021.

The 4th Asia Partnership Conference of Regenerative Medicine (APACRM) was held online on April 15, 2021, to promote regulatory harmonization of regenerative medicine products throughout Asia. Recognizing domestic regulatory guidelines within each country and region, and their underpinning rationales, is an important initial step toward a convergence of regulations. The 4th APACRM consisted of an open dialog with regulatory agencies regarding nonclinical and quality settings for cell therapy products (CTPs) through industry presentations and panel discussions with regulatory agencies.

Non-clinical assessment of cell therapy products: the perspective from five Asian countries/regions based on regulatory guidelines and the underpinning rationales.

Background Aims: Cell-based regenerative medicine is an innovative field that can potentially alter the overall survival and quality of life of patients with devastating diseases. Several cell therapy products (CTPs) have been approved within the last two decades, and more are under development. The establishment of an effective developmental strategy in accordance with the regulatory bodies of each country/region is crucial for fast delivery of each respective CTP.

A Novel Immunomodulatory Mechanism Dependent on Acetylcholine Secreted by Human Bone Marrow-derived Mesenchymal Stem Cells.

Background And Objectives: Mesenchymal stem cells (MSCs) are used to treat autoimmune or inflammatory diseases. Our aim was to determine the immunomodulatory mechanisms elicited by MSCs during inflammation.

Methods And Results: We cocultured MSCs with peripheral blood mononuclear cells for a mixed lymphocyte reaction or stimulated them by phytohemagglutinin.

Specific PERK inhibitors enhanced glucose-stimulated insulin secretion in a mouse model of type 2 diabetes.

Background: We have reported that partial PERK attenuation using PERK inhibitors (PI) enhanced glucose-stimulated insulin secretion (GSIS) from pancreatic islets and mice through induction of ER chaperone BIP. Therefore, we investigated if PI would have the same effects in a diabetic condition as well.

Methods: GSK2606414 was treated to mouse islets under 20-mM glucose and 0.

Suppression of ROS Production by Exendin-4 in PSC Attenuates the High Glucose-Induced Islet Fibrosis.

Pancreatic stellate cells (PSCs) play a major role to fibrotic islet destruction observed in diabetic patients and animal model of diabetes. Exendin-4 (Ex-4) is a potent insulinotropic agent and has been approved for the treatment of type 2 diabetes. However, there have been no reports demonstrating the effects of Ex-4 on pancreatic islet fibrosis.

Preadipocyte factor 1 induces pancreatic ductal cell differentiation into insulin-producing cells.

The preadipocyte factor 1 (Pref-1) is involved in the proliferation and differentiation of various precursor cells. However, the intracellular signaling pathways that control these processes and the role of Pref-1 in the pancreas remain poorly understood. Here, we showed that Pref-1 induces insulin synthesis and secretion via two independent pathways.

Autophagy deficiency in β cells blunts incretin-induced suppression of glucagon release from α cells.

Incretin-based therapy such as GLP-1 receptor agonists and DPP-4 inhibitors for type 2 diabetes mellitus is characterized by glucose-dependent insulin secretion and glucose-inhibited glucagon secretion. Recently, autophagy deficiency in islet β cells has been shown to contribute to the pathogenesis of type 2 diabetes mellitus however, with the role of incretin has not been established. To evaluate the role of autophagy in incretin effects, 8-week-old male β cell-specific Atg7 knockout (Atg7(Δβ cell)) mice and wild-type mice were administered vildagliptin for 12 weeks.

Long-term Efficacy and Biocompatibility of Encapsulated Islet Transplantation With Chitosan-Coated Alginate Capsules in Mice and Canine Models of Diabetes.

Background: Clinical application of encapsulated islet transplantation is hindered by low biocompatibility of capsules leading to pericapsular fibrosis and decreased islet viability. To improve biocompatibility, we designed a novel chitosan-coated alginate capsules and compared them to uncoated alginate capsules.

Methods: Alginate capsules were formed by crosslinking with BaCl2, then they were suspended in chitosan solution for 10 minutes at pH 4.

Successful xenotransplantation with re-aggregated and encapsulated neonatal pig liver cells for treatment of mice with acute liver failure.

Background: Hepatocyte transplantation is a promising therapy for acute liver failure. Cell therapy using xenogeneic sources has emerged as an alternative treatment for patients with organ failure due to the shortage of transplantable human organs. The purpose of this study was to improve the survival of mice with acute liver failure by transplanting encapsulated neonatal pig re-aggregated liver cells (NPRLC).

Reversal of Hypoglycemia Unawareness with a Single-donor, Marginal Dose Allogeneic Islet Transplantation in Korea: A Case Report.

Pancreatic islet transplantation is a physiologically advantageous and minimally invasive procedure for the treatment of type 1 diabetes mellitus. Here, we describe the first reported case of successful allogeneic islet transplantation alone, using single-donor, marginal-dose islets in a Korean patient. A 59-yr-old patient with type 1 diabetes mellitus, who suffered from recurrent severe hypoglycemia, received 4,163 islet equivalents/kg from a single brain-death donor.

The Paradoxical Effects of AMPK on Insulin Gene Expression and Glucose-Induced Insulin Secretion.

The activation of AMP-activated protein kinase (AMPK) is known to repress the expression of the insulin gene and glucose-stimulated insulin secretion (GSIS). However, the mechanisms by which this occurs, as well as the effects of AMPK activation on glucolipotoxicity-induced β-cell dysfunction, have not been elucidated. To investigate the effects of 5-amino-4-imidazolecarboxamide ribonucleotide (AICAR) and peroxisome proliferator-activated receptorγ-coactivator-1α (PGC-1α) on β-cell-specific genes under glucolipotoxic conditions, we performed real-time PCR and measured insulin secretion by primary islets.

Antifibrotic effect of rapamycin containing polyethylene glycol-coated alginate microcapsule in islet xenotransplantation.

Islet microencapsulation is an attractive strategy for the minimization or avoidance of life-long immunosuppression after transplantation. However, the clinical implementation of this technique is currently limited by incomplete biocompatibility. Thus, the aim of the present study was to demonstrate the improved biocompatibility of rapamycin-containing polyethylene glycol (Rapa-PEG)-coating on alginate microcapsules containing xenogeneic islets.

Metformin alleviates hepatosteatosis by restoring SIRT1-mediated autophagy induction via an AMP-activated protein kinase-independent pathway.

Metformin activates both PRKA and SIRT1. Furthermore, autophagy is induced by either the PRKA-MTOR-ULK1 or SIRT1-FOXO signaling pathways. We aimed to elucidate the mechanism by which metformin alleviates hepatosteatosis by examining the molecular interplay between SIRT1, PRKA, and autophagy.

Targeting PGC-1α to overcome the harmful effects of glucocorticoids in porcine neonatal pancreas cell clusters.

Background: Peroxisome proliferator-activated receptor gamma-coactivator-1α (PGC-1α) has recently been implicated as a crucial factor in the glucocorticoid-suppressed expansion and transdifferentiation of porcine neonatal pancreatic cell clusters (NPCCs). However, the molecular mechanism has not been clarified.

Methods: We investigated whether the suppression of PGC-1α expression protects against β-cell dysfunction induced by dexamethasone (Dx) treatment in vitro and in vivo and determined the mechanism of action of PGC-1α in porcine NPCCs.

Generation of functional insulin-producing cells from neonatal porcine liver-derived cells by PDX1/VP16, BETA2/NeuroD and MafA.

Surrogate β-cells derived from stem cells are needed to cure type 1 diabetes, and neonatal liver cells may be an attractive alternative to stem cells for the generation of β-cells. In this study, we attempted to generate insulin-producing cells from neonatal porcine liver-derived cells using adenoviruses carrying three genes: pancreatic and duodenal homeobox factor1 (PDX1)/VP16, BETA2/NeuroD and v-maf musculo aponeurotic fibrosarcoma oncogene homolog A (MafA), which are all known to play critical roles in pancreatic development. Isolated neonatal porcine liver-derived cells were sequentially transduced with triple adenoviruses and grown in induction medium containing a high concentration of glucose, epidermal growth factors, nicotinamide and a low concentration of serum following the induction of aggregation for further maturation.

A case of cystoid macular edema associated with Paclitaxel chemotherapy.

We encountered a patient with cystoid macular edema (CME) secondary to paclitaxel use. A 57-year-old man presented with gradual decreased bilateral vision. His chemotherapeutic regimen consisted of bevacizumab, paclitaxel (175 mg/m(2) for 5 months), and carboplatin.

Both sitagliptin analogue & pioglitazone preserve the beta-cell proportion in the islets with different mechanism in non-obese and obese diabetic mice.

In this study, the effects of sitagliptin analogue (SITA) or pioglitazone (PIO) treatment on glucose homeostasis and Β-cell dynamics in animal models of type 2 diabetes--Akita and db/db mice were evaluated. After 4-6 weeks of treatment, both SITA and PIO were shown to lower non-fasting glucose levels and reduced glycemic excursion in the intraperitoneal glucose tolerance test. In addition, both drugs preserved normal islet structure and the proportion of Β-cells in the islets.

Expression of Stat3 and indoleamine 2, 3-dioxygenase in cornea keratocytes as factor of ocular immune privilege.

Purpose: Ocular immune privilege is a multifactorial phenomenon evolutionally selected to prevent immunogenic inflammation from disrupting the visual axis and causing blindness. Here, we investigated the role of signal transducers and activators of transcription (Stat3) and indoleamine 2,3-dioxygenase (IDO) in ocular immune privilege in corneal stromal cells.

Methods: Human keratocytes were isolated and cultured in vitro, and Stat3 and IDO expression on keratocytes was investigated by reverse transcription polymerase chain reaction (RT-PCR).

Adenoviruses Expressing PDX-1, BETA2/NeuroD and MafA Induces the Transdifferentiation of Porcine Neonatal Pancreas Cell Clusters and Adult Pig Pancreatic Cells into Beta-Cells.

Background: A limitation in the number of insulin-producing pancreatic beta-cells is a special feature of diabetes. The identification of alternative sources for the induction of insulin-producing surrogate beta-cells is a matter of profound importance. PDX-1/VP16, BETA2/NeuroD, and MafA overexpression have been shown to influence the differentiation and proliferation of pancreatic stem cells.

Rapamycin suppresses the expansion and differentiation of porcine neonatal pancreas cell clusters.

Background: The role of rapamycin in pancreas stem cells remains to be clearly elucidated. Herein, we evaluated the effects of rapamycin on porcine neonatal pancreas cell clusters (NPCCs), which primarily comprised pancreatic precursors, and attempted to find an intracellular mechanism about the harmful effects of rapamycin.

Methods: Porcine NPCCs were treated with rapamycin in a monolayer, and the apoptosis and proliferation were determined via caspase-3 assay and H-thymidine uptake analysis.

Suppression of peroxisome proliferator-activated receptor gamma-coactivator-1alpha normalizes the glucolipotoxicity-induced decreased BETA2/NeuroD gene transcription and improved glucose tolerance in diabetic rats.

Peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1alpha) is significantly elevated in the islets of animal models of diabetes. However, the molecular mechanism has not been clarified. We investigated whether the suppression of PGC-1alpha expression protects against beta-cell dysfunction in vivo and determined the mechanism of action of PGC-1alpha in beta-cells.

cAMP induces neuronal differentiation of mesenchymal stem cells via activation of extracellular signal-regulated kinase/MAPK.

Mesenchymal stem cells are able to trans-differentiate into nonmesodermal lineage cells. Here, we identified downstream signaling molecules required for acquisition of neuron-like traits by mesenchymal stem cells following the elevation of intracellular cAMP levels. We found that forskolin induced neuron-like morphology and expression of neuron-specific enolase and neurofilament-200 in mesenchymal stem cells.