Low-Dose Decitabine Assists Human Umbilical Cord-Derived Mesenchymal Stem Cells in Protecting β Cells via the Modulation of the Macrophage Phenotype in Type 2 Diabetic Mice

The phenotype and related gene expressions of macrophages in adipose tissue of T2D mice following MSCs infusion

BACKGROUND

Infusion of mesenchymal stem cells (MSCs) induces polarization of M2 macrophages in adipose tissue of type 2 diabetes (T2D) mice. Studies have shown that M2 macrophages were divided into four sub-phenotypes (M2a, M2b, M2c and M2d) with different functions, and manuscripts have also confirmed that macrophages co-cultured with MSCs were not matched with known four phenotype macrophages. Therefore, our study explored the phenotype and related gene expressions of macrophages in the adipose tissue of T2D mice with/without MSCs infusion.

METHODS

We induced a T2D mouse model by using high-fat diets and streptozotocin (STZ) injection. The mice were divided into three groups: the control group, the T2D group, and the MSCs group. MSCs were systemically injected once a week for 6 weeks. The phenotype of macrophages in adipose tissue was detected via flow cytometric analysis. We also investigated the gene expression of macrophages in different groups via SMART-RNA-sequencing and quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR).

RESULTS

The present study found that the macrophages of adipose tissue in the MSCs group were polarized to the M2 phenotype mixed with four sub-phenotypes. Besides, M2a and M2c held a dominant position, while M2b and M2d (tumor-associated macrophages, TAMs) exhibited a decreasing trend after infusion of MSCs. Moreover, the MSCs group did not appear to express higher levels of tumor-associated, inflammation-associated, or fibrosis-associated genes in comparison to the T2D group.

CONCLUSION

The present results unveiled that the macrophage phenotype was inclined to be present in a hybridity state of four M2 sub-phenotypes and the genes related to tumor-promoting, pro-inflammation and pro-fibrosis were not increased after MSCs injection.

Human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications: applications and research advances

Diabetes mellitus and its complications pose a major threat to global health and affect the quality of life and life expectancy of patients. Currently, the application of traditional therapeutic drugs for diabetes mellitus has great limitations and can only temporarily control blood glucose but not fundamentally cure it. Mesenchymal stem cells, as pluripotent stromal cells, have multidirectional differentiation potential, high self-renewal, immune regulation, and low immunogenicity, which provide a new idea and possible development direction for diabetes mellitus treatment. Regenerative medicine with mesenchymal stem cells treatment as the core treatment will become another treatment option for diabetes mellitus after traditional treatment. Recently, human umbilical cord mesenchymal stem cells have been widely used in basic and clinical research on diabetes mellitus and its complications because of their abundance, low ethical controversy, low risk of infection, and high proliferation and differentiation ability. This paper reviews the therapeutic role and mechanism of human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications and highlights the challenges faced by the clinical application of human umbilical cord mesenchymal stem cells to provide a more theoretical basis for the application of human umbilical cord mesenchymal stem cells in diabetes mellitus patients.

Combination of sodium butyrate and decitabine promotes transgene expression in CHO cells via apoptosis inhibition

Chinese hamster ovary (CHO) cells are currently the most widely used host cells for production of recombinant therapeutic proteins (RTPs). Small-molecule additives related to cell cycle apoptosis and autophagy regulation have been used to promote RTP production. By combining two small-molecule additives, positive synergistic effects on transgene expression were observed in CHO cells. In the present study, six small-molecule additives were used, including hydrocinnamic acid (HCA), sodium butyrate (NaB), lithium acetate (LiAc), sodium succinate dibasic hexahydrate (SDH), decitabine (DAC), and sodium propionate (SP). Experiments to test the effects of their pairwise combinations on two different recombinant CHO cell lines (rCHO) were designed using Design-Expert 12.0. Different effects of various pairs of small molecules on apoptosis- and autophagy-related protein expression were observed in the rCHOs. The results showed that compared to the control culture, NaB alone increased the volumetric yield and specific productivity (Qp) by 166% and 143%, respectively. The volumetric yield and Qp of NaB combined with DAC (Cg1)-treated cells increased by 178% and 212%, respectively. Cg1 selectively blocked the cells in the G0/G1 cell cycle stage. The relative expression levels of B-cell lymphoma 2 (Bcl-2), Beclin 1, and microtubule-associated protein light chain 3 (LC3B) in Cg1-treated CHO cells were significantly increased, while relative levels of cleaved caspase-3 expression were significantly decreased. In conclusion, Cg1 had the most obvious effect on RTP production and Qp in CHO cells, suggesting the Cg1 combination of small molecules may be used to improve the expression of recombinant protein in CHO cells.

Recent advancement on development of drug-induced macrophage polarization in control of human diseases

Macrophages, an important part of human immune system, possess a high plasticity and heterogeneity (macrophage polarization) as classically activated macrophages (M1) and alternatively activated macrophages (M2), which exert pro-inflammatory/anti-tumor and anti-inflammatory/pro-tumor effects, respectively. Thus, drug development in induction of macrophage polarization could be used to treat different human diseases. This review summarizes the recent advancement on modulation of macrophage polarization and its related molecular mechanisms induced by a number of agents. Research on the anti-inflammatory drugs to regulate the macrophage polarization accounts for a large proportion in the field and types of diseases investigated could include atherosclerosis, enteritis, nephritis, and the nervous system and skeletal diseases, while study of the anti-tumor agents to modify macrophage polarization is a novel area of research. Future study of the molecular mechanisms by which the different agents regulate the macrophage polarization could lead to an effective control of various human diseases, including inflammation and cancers.

Human umbilical cord mesenchymal stem cells in type 2 diabetes mellitus: the emerging therapeutic approach

The umbilical cord has been proved to be an easy-access, reliable, and useful source of mesenchymal stem cells (MSC) for clinical applications due to its primitive, immunomodulatory, non-immunogenic, secretory and paracrine, migratory, proliferative, and multipotent properties. This set of characteristics has recently attracted great research interest in the fields of nanotechnology and regenerative medicine and cellular therapy. Accumulating evidence supports a pronounced therapeutic potential of MSC in many different pathologies, from hematology to immunology, wound-healing, tissue regeneration, and oncology. Diabetes mellitus, branded the epidemic of the century, is considered a chronic metabolic disorder, representing a major burden for health system sustainability and an important public health challenge to modern societies. The available treatments for type 2 diabetes mellitus (T2DM) still rely mainly on combinations of oral antidiabetic agents with lifestyle and nutritional adjustments. Despite the continuous development of novel and better hypoglycemic drugs, their efficacy is limited in the installment and progression of silent T2DM complications. T2DM comorbidities and mortality rates still make it a serious, common, costly, and long-term manageable disease. Recently, experimental models, preclinical observations, and clinical studies have provided some insights and preliminary promising results using umbilical cord MSCs to treat and manage diabetes. This review focuses on the latest research and applications of human-derived umbilical cord MSC in the treatment and management of T2DM, exploring and systematizing the key effects of both umbilical cord MSC and its factor-rich secretome accordingly with the major complications associated to T2DM.

Mesenchymal Stem Cell-Based Therapy for Diabetes Mellitus: Enhancement Strategies and Future Perspectives

Diabetes mellitus (DM), a chronic disorder of carbohydrate metabolism, is characterized by the unbridled hyperglycemia resulted from the impaired ability of the body to either produce or respond to insulin. As a cell-based regenerative therapy, mesenchymal stem cells (MSCs) hold immense potency for curing DM duo to their easy isolation, multi-differentiation potential, and immunomodulatory property. However, despite the promising efficacy in pre-clinical animal models, naive MSC administration fails to exhibit clinically satisfactory therapeutic outcomes, which varies greatly among individuals with DM. Recently, numbers of innovative strategies have been applied to improve MSC-based therapy. Preconditioning, genetic modification, combination therapy and exosome application are representative strategies to maximize the therapeutic benefits of MSCs. Therefore, in this review, we summarize recent advancements in mechanistic studies of MSCs-based treatment for DM, and mainly focus on the novel approaches aiming to improve the anti-diabetic potentials of naive MSCs. Additionally, the potential directions of MSCs-based therapy for DM are also proposed at a glance.