Clinical Progress and Preclinical Insights Into Umbilical Cord Blood Transplantation Improvement

Tailoring cell therapies for diabetic metabolic phenotypes: a comparative study on the efficacy of various umbilical cord-derived cell regimens

Given the high heterogeneity of type 2 diabetes mellitus (T2DM), it is imperative to develop personalized stem cell infusion regimen for targeted metabolic phenotype in order to ensure optimal therapeutic efficacy. In this study, we conducted a comparative analysis of 4 infusion regimens involving single and repeated infusions of human umbilical cord Wharton's jelly-derived MSCs (hucMSCs), single infusions of umbilical cord blood mononuclear cells (UCB), and sequential infusions of hucMSCs and UCB in T2DM rats. Results showed all 4 infusion regimens exhibited comparable efficacy in lowering fasting blood glucose levels and suppressing glucagon secretion. Single and double infusions of hucMSCs exhibited a tendency to migrate to the liver, thereby better at ameliorating hepatic glucose metabolism by enhancing glycogen synthesis and storage, promoting glycolysis, inhibiting gluconeogenesis, and improving insulin signal transduction. The sequential infusion of hucMSCs and UCB demonstrated specific cell tropism toward the pancreas, leading to prolonged glucose-lowering effects following a glucose tolerance test, restoration of early-phase insulin secretion, stimulation of islet beta cell proliferation and improvement in the beta/alpha ratio. Multiple injections, regardless of cell type, reduced the expression of systemic chronic inflammatory markers such as IL-1β, IL-6, IL-17, IL-22, and IFN-γ. Finally, a single dose of UCB exhibited a greater tendency to target visceral fat and enhanced effectiveness in regulating levels of total cholesterol and triglycerides. In conclusion, our study provided personalized stem cell regimens for diverse T2DM metabolic phenotypes, thereby offering improved treatment alternatives for future clinical trials and applications.

Repurposing the prostaglandin analogue treprostinil and the calcium-sensing receptor modulator cinacalcet to revive cord blood as an alternate source of hematopoietic stem and progenitor cells for transplantation

Objective

The expanding field of hematopoietic cell transplantation (HCT) for non-malignant diseases, including those amenable to gene therapy or gene editing, faces challenges due to limited donor availability and the toxicity associated with cell collection methods. Umbilical cord blood (CB) represents a readily accessible source of hematopoietic stem and progenitor cells (HSPCs); however, the cell dose obtainable from a single cord blood unit is frequently insufficient. This limitation can be addressed by enhancing the potency of HSPCs, specifically their capacity to reconstitute hematopoiesis. In our study, we investigated the combined effects of treprostinil, a prostaglandin analog, and cinacalcet, a calcium-sensing receptor modulator, on the reconstitution of hematopoiesis.

Methods

A Lineage Cell Depletion Kit was employed to isolate lineage-negative (lin-) HSPCs from mouse bone marrow. A Human CB CD34 Positive Selection Kit was utilized to isolate CD34+ cells from the CB of healthy donors. In vitro, the effects of treprostinil, cinacalcet, and their combination on the migration, adhesion, and differentiation of HSPCs were assessed. In vivo, homing and engraftment were examined. Eight-week-old female and male C57BL/6J, BALB/c, or female NSG mice served as recipient models.

Results

When administered concomitantly, treprostinil and cinacalcet exhibited mutual antagonism: the survival of recipient animals was lower when both drugs were administered together compared to either agent alone. Conversely, a sequential regimen involving priming with treprostinil/forskolin followed by cinacalcet treatment in vivo enhanced survival, irrespective of whether hematopoiesis was reconstituted by human or murine HSPCs. In vitro assays demonstrated enhanced migration and adhesion in response to the presence of treprostinil and cinacalcet, suggesting potential synergistic effects. Colony formation confirmed synergism.

Conclusion

Augmenting the bone marrow reconstitution potential of HSPCs with treprostinil and cinacalcet shows promise for rescuing patients undergoing HCT. This approach is particularly beneficial for those patients at high risk of transplant failure due to limited numbers of available HSPCs. Furthermore, enhancing the potency of HSPCs has the potential to alleviate the burden and risks associated with HSPC donation, as it would reduce the number of cells needed for collection.

Advances in hematopoietic stem cells ex vivo expansion associated with bone marrow niche

Hematopoietic stem cells (HSCs) are an ideal source for the treatment of many hematological diseases and malignancies, as well as diseases of other systems, because of their two important features, self-renewal and multipotential differentiation, which have the ability to rebuild the blood system and immune system of the body. However, so far, the insufficient number of available HSCs, whether from bone marrow (BM), mobilized peripheral blood or umbilical cord blood, is still the main restricting factor for the clinical application. Therefore, strategies to expand HSCs numbers and maintain HSCs functions through ex vivo culture are urgently required. In this review, we outline the basic biology characteristics of HSCs, and focus on the regulatory factors in BM niche affecting the functions of HSCs. Then, we introduce several representative strategies used for HSCs from these three sources ex vivo expansion associated with BM niche. These findings have deepened our understanding of the mechanisms by which HSCs balance self-renewal and differentiation and provided a theoretical basis for the efficient clinical HSCs expansion.

Umbilical cord blood derived cell expansion: a potential neuroprotective therapy

Umbilical cord blood (UCB) is a rich source of beneficial stem and progenitor cells with known angiogenic, neuroregenerative and immune-modulatory properties. Preclinical studies have highlighted the benefit of UCB for a broad range of conditions including haematological conditions, metabolic disorders and neurological conditions, however clinical translation of UCB therapies is lacking. One barrier for clinical translation is inadequate cell numbers in some samples meaning that often a therapeutic dose cannot be achieved. This is particularly important when treating adults or when administering repeat doses of cells. To overcome this, UCB cell expansion is being explored to increase cell numbers. The current focus of UCB cell expansion is CD34+ haematopoietic stem cells (HSCs) for which the main application is treatment of haematological conditions. Currently there are 36 registered clinical trials that are examining the efficacy of expanded UCB cells with 31 of these being for haematological malignancies. Early data from these trials suggest that expanded UCB cells are a safe and feasible treatment option and show greater engraftment potential than unexpanded UCB. Outside of the haematology research space, expanded UCB has been trialled as a therapy in only two preclinical studies, one for spinal cord injury and one for hind limb ischemia. Proteomic analysis of expanded UCB cells in these studies showed that the cells were neuroprotective, anti-inflammatory and angiogenic. These findings are also supported by in vitro studies where expanded UCB CD34+ cells showed increased gene expression of neurotrophic and angiogenic factors compared to unexpanded CD34+ cells. Preclinical evidence demonstrates that unexpanded CD34+ cells are a promising therapy for neurological conditions where they have been shown to improve multiple indices of injury in rodent models of stroke, Parkinson's disease and neonatal hypoxic ischemic brain injury. This review will highlight the current application of expanded UCB derived HSCs in transplant medicine, and also explore the potential use of expanded HSCs as a therapy for neurological conditions. It is proposed that expanded UCB derived CD34+ cells are an appropriate cellular therapy for a range of neurological conditions in children and adults.

Impact of donor NKG2D and MICA gene polymorphism on clinical outcomes of adult and paediatric allogeneic cord blood transplantation for malignant diseases

OBJECTIVES

NKG2D is an activating receptor expressed by natural killer (NK) and CD8+ T cells and activation intensity varies by NKG2D expression level or nature of its ligand. An NKG2D gene polymorphism determines high (HNK1) or low (LNK1) expression. MICA is the most polymorphic NKG2D ligand and stronger effector cell activation associates with methionine rather than valine at residue 129. We investigated correlation between cord blood (CB) NKG2D and MICA genotypes and haematopoietic stem cell (HSC) transplant outcome.

METHODS

We retrospectively studied 267 CB HSC recipients (178 adult and 87 paediatric) who underwent transplant for malignant disease between 2007 and 2018, analysing CB graft DNA for NKG2D and MICA polymorphisms using Sanger sequencing. Multivariate analysis was used to correlate these results with transplant outcomes.

RESULTS

In adult patients, LNK1 homozygous CB significantly improved 60-day neutrophil engraftment (hazard ratio (HR) 0.6; 95% confidence interval (CI) 0.4-0.9; p = .003). In paediatrics, HNK1 homozygous CB improved 60-day engraftment (HR 0.4; 95% CI 0.2-0.7; p = .003), as did MICA-129 methionine+ CB grafts (HR 1.7 95% CI 1.1-2.6; p = .02).

CONCLUSION

CB NKG2D and MICA genotypes potentially improve CB HSC engraftment. However, results contrast between adult and paediatric recipients and may reflect transplant procedure disparities between cohorts.