Human adipose tissue- and umbilical cord-derived stem cells: which is a better alternative to treat spinal cord injury?

Therapeutic potential of adipose derived stromal cells for major skin inflammatory diseases

Inflammatory skin diseases like psoriasis and atopic dermatitis are chronic inflammatory skin conditions continuously under investigation due to increased prevalence and lack of cure. Moreover, long-term treatments available are often associated with adverse effects and drug resistance. Consequently, there is a clear unmet need for new therapeutic approaches. One promising and cutting-edge treatment option is the use of adipose-derived mesenchymal stromal cells (AD-MSCs) due to its immunomodulatory and anti-inflammatory properties. Therefore, this mini review aims to highlight why adipose-derived mesenchymal stromal cells are a potential new treatment for these diseases by summarizing the pre-clinical and clinical studies investigated up to date and addressing current limitations and unresolved clinical questions from a dermatological and immunomodulatory point of view.

Therapeutic effect of umbilical cord blood cells on spinal cord injury

Spinal cord injury (SCI) is a nervous system disease characterized by sensory and motor dysfunction, axonal apoptosis, decreased vascular density, and inflammation. At present, surgical treatment, drug treatment, and cell therapy can be used. Surgical treatment can improve motor and independent function scores, and drug treatment can promote the recovery of neurons in the spinal cord, but only improve symptoms. Complete recovery of SCI has not yet been achieved. However, the differentiation of stem cells brings hope for the treatment of SCI. Umbilical cord blood cells (UCBs) are ethically readily available and can repair neuronal damage. However, it is still unclear how they can improve symptoms and repair nerve severity. In this paper, the role of UCBs in the treatment of SCI is described in detail from different aspects such as behavior, morphology, and molecular expression changes, so as to provide new ideas and theoretical directions for future research.

Clinical Trials Targeting Secondary Damage after Traumatic Spinal Cord Injury

Spinal cord injury (SCI) often causes loss of sensory and motor function resulting in a significant reduction in quality of life for patients. Currently, no therapies are available that can repair spinal cord tissue. After the primary SCI, an acute inflammatory response induces further tissue damage in a process known as secondary injury. Targeting secondary injury to prevent additional tissue damage during the acute and subacute phases of SCI represents a promising strategy to improve patient outcomes. Here, we review clinical trials of neuroprotective therapeutics expected to mitigate secondary injury, focusing primarily on those in the last decade. The strategies discussed are broadly categorized as acute-phase procedural/surgical interventions, systemically delivered pharmacological agents, and cell-based therapies. In addition, we summarize the potential for combinatorial therapies and considerations.

The optimal transplantation strategy of umbilical cord mesenchymal stem cells in spinal cord injury: a systematic review and network meta-analysis based on animal studies

Objective

Umbilical cord mesenchymal stem cells (UCMSCs) have great potential in the treatment of spinal cord injury. However, the specific therapeutic effect and optimal transplantation strategy are still unclear. Therefore, exploring the optimal treatment strategy of UCMSCs in animal studies by systematic review can provide reference for the development of animal studies and clinical research in the future.

Methods

Databases of PubMed, Ovid-Embase, Web of Science, CNKI, WanFang, VIP, and CBM were searched for the literature in February 11, 2022. Two independent reviewers performed the literature search, identification, screening, quality assessment, and data extraction.

Results and Discussion

A total of 40 animal studies were included for combined analysis. In different subgroups, the results of traditional meta-analysis and network meta-analysis were consistent, that is, the therapeutic effect of high-dose (≥ 1 × 10⁶) transplantation of UCMSCs was significantly better than that of low dose (< 1 × 10⁶), the therapeutic effect of local transplantation of UCMSCs was significantly better than that of intravenous transplantation, and the therapeutic effect of subacute transplantation of UCMSCs was significantly better than that of acute and chronic transplantation. However, in view of the inherent risk of bias and limited internal and external validity of the current animal studies, more high-quality, direct comparison studies are needed to further explore the optimal transplantation strategy for UCMSCs in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03103-8.

Human Adipose-Derived Stem Cells Combined with Nano-Hydrogel Promote Functional Recovery after Spinal Cord Injury in Rats

Simple Summary

Nerve regeneration and functional recovery after spinal cord injury (SCI) are worldwide problems. Scientists have achieved encouraging results in the repair of spinal cord injuries using natural or synthetic materials. In this paper, we report that nano-hydrogel combined with human adipose-derived stem cells regulate the inflammatory microenvironment, protect neurons and axons, and promote motor function recovery. In addition, three proteins related to neuronal and axonal growth were screened by Liquid chromatography-mass spectrometry. These results provide evidence for clinical treatment of spinal cord injury.

Abstract

The treatment of spinal cord injury aims to reconstruct the fiber connection and restore the interrupted neural pathways. Adipose mesenchymal stem cells (ADSCs) can promote the recovery of motor functions in spinal cord injury. However, poor survival of ADSCs and leakage outside of the injury site after local transplantation reduce the number of cells, which seriously attenuates the cumulative effect. We performed heterotopic transplantation on rats with severe spinal cord injury using human ADSCs loaded within self-assembly hydrogel RADA16-RGD (R: arginine; A: alanine; D: aspartic acid; G: glycine). Our results indicate that the combined transplantation of human ADSCs with RADA16-RGD improved the survival of ADSCs at the injured site. The inflammatory reaction was inhibited, with improved survival of the neurons and increased residual area of nerve fibers and myelin protein. The functional behaviors were promoted, as determined by the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale score and electrophysiological measurements. ADSCs can promote the repair of spinal cord injury. This study provides new ideas for the treatment of spinal cord injury.

Dose optimization of intrathecal administration of human umbilical cord mesenchymal stem cells for the treatment of subacute incomplete spinal cord injury

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate for spinal cord injury (SCI) repair owing to their advantages of low immunogenicity and easy accessibility over other MSC sources. However, modest clinical efficacy hampered the progression of these cells to clinical translation. This discrepancy may be due to many variables, such as cell source, timing of implantation, route of administration, and relevant efficacious cell dose, which are critical factors that affect the efficacy of treatment of patients with SCI. Previously, we have evaluated the safety and efficacy of 4 × 10⁶ hUC-MSCs/kg in the treatment of subacute SCI by intrathecal implantation in rat models. To search for a more accurate dose range for clinical translation, we compared the effects of three different doses of hUC-MSCs – low (0.25 × 10⁶ cells/kg), medium (1 × 10⁶ cells/kg) and high (4 × 10⁶ cells/kg) – on subacute SCI repair through an elaborate combination of behavioral analyses, anatomical analyses, magnetic resonance imaging-diffusion tensor imaging (MRI-DTI), biotinylated dextran amine (BDA) tracing, electrophysiology, and quantification of mRNA levels of ion channels and neurotransmitter receptors. Our study demonstrated that the medium dose, but not the low dose, is as efficient as the high dose in producing the desired therapeutic outcomes. Furthermore, partial restoration of the γ-aminobutyric acid type A (GABA_A) receptor expression by the effective doses indicates that GABA_A receptors are possible candidates for therapeutic targeting of dormant relay pathways in injured spinal cord. Overall, this study revealed that intrathecal implantation of 1 × 10⁶ hUC-MSCs/kg is an alternative approach for treating subacute SCI.

OUP accepted manuscript

Traumatic injury of the central nervous system (CNS) is a worldwide health problem affecting millions of people. Trauma of the CNS, that is, traumatic brain injury (TBI) and spinal cord injury (SCI), lead to massive and progressive cell loss and axonal degeneration, usually with very limited regeneration. At present, there are no treatments to protect injured CNS tissue or to replace the lost tissue. Stem cells are a cell type that by definition can self-renew and give rise to multiple cell lineages. In recent years, therapies using stem and progenitor cells have shown promising effects in experimental CNS trauma, particularly in the acute-subacute stage, but also in chronic injuries. However, the therapeutic mechanisms by which transplanted cells achieve the structural and/or functional improvements are often not clear. Stem cell therapies for CNS trauma can be categorized into 2 main concepts, transplantation of exogenous neural stem cells and neural progenitor cells and recruitment of endogenous stem and progenitor cells. In this review, focusing on the advances during the last decade, we will discuss the major cell therapies, the pros and cons of these 2 concepts for TBI and SCI, and the treatment strategies we believe will be successful.

Comparison of mesenchymal stromal cells from peritoneal dialysis effluent with those from umbilical cords: characteristics and therapeutic effects on chronic peritoneal dialysis in uremic rats

Background

A long-term of peritoneal dialysis (PD) using a hypertonic PD solution (PDS) leads to patient’s peritoneal membrane (PM) injury, resulting in ultrafiltration failure (UFF) and PD drop-out. Our previous study shows that PD effluent-derived mesenchymal stromal cells (pMSCs) prevent the PM injury in normal rats after repeated exposure of the peritoneal cavity to a PDS. This study was designed to compare the cytoprotection between pMSCs and umbilical cord-derived MSCs (UC-MSCs) in the treatment of both PM and kidney injury in uremic rats with chronic PD.

Methods

5/6 nephrectomized (5/6Nx) Sprague Dawley rats were intraperitoneally (IP) injected Dianeal (4.25% dextrose, 10 mL/rat/day) and were treated with pMSCs or umbilical cord (UC)-MSCs (approximately 2 × 10⁶/rat/week, IP). Ultrafiltration was determined by IP injection of 30 mL of Dianeal (4.25% dextrose) with 1.5-h dewell time, and kidney failure by serum creatinine (SCr) and blood urea nitrogen (BUN). The structure of the PM and kidneys was assessed using histology. Gene expression was examined using quantitative reverse transcription PCR, and protein levels using flow cytometric and Western blot analyses.

Results

We showed a slight difference in the morphology between pMSCs and UC-MSCs in plastic dishes, and significantly higher expression levels of stemness-related genes (NANOG, OCT4, SOX2, CCNA2, RAD21, and EXO1) and MSCs surface markers (CD29, CD44, CD90 and CD105) in UC-MSCs than those in pMSCs, but no difference in the differentiation to chondrocytes, osteocytes or adipocytes. pMSC treatment was more effective than UC-MSCs in the protection of the MP and remnant kidneys in 5/6Nx rats from PDS-induced injury, which was associated with higher resistance of pMSCs than UC-MSCs to uremic toxins in culture, and more reduction of peritoneal mesothelial cell death by the secretome from pMSCs than from UC-MSCs in response to PDS exposure. The secretome from both pMSCs and UC-MSCs similarly inactivated NOS2 in activated THP1 cells.

Conclusions

As compared to UC-MSCs, pMSCs may more potently prevent PDS-induced PM and remnant kidney injury in this uremic rat model of chronic PD, suggesting that autotransplantation of ex vivo-expanded pMSCs may become a promising therapy for UFF and deterioration of remnant kidney function in PD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02473-9.

hucMSCs transplantation promotes locomotor function recovery, reduces apoptosis and inhibits demyelination after SCI in rats

AIMS

Spinal cord injury (SCI) can cause a variety of cells apoptosis, neurodegeneration, and eventually permanent paralysis. This study aimed to examine whether transplanting human umbilical cord mesenchymal stem cells (hucMSCs) can promote locomotor function recovery, reduce apoptosis and inhibit demyelination in SCI models.

MAIN METHODS

Rats were allocated into Sham group (spinal cord exposure only), SCI + PBS group (spinal cord impact plus phosphate-buffered saline (PBS) injections), SCI + hucMSCs group (spinal cord impact plus hucMSCs injections) groups. Behavioral tests, Basso-Beattie-Bresnahan locomotion scores (BBB scores), were carried out at 0, 3, 7, 14, 21, 28 days after SCI surgery. Hematoxylin-eosin staining observed spinal cord morphology. Nissl staining detected the number of nissl bodies. Myelin basic protein (MBP) and oligodendrocyte (CNPase) were examed by immunohistochemical staining. The apoptosis of oligodendrocyte and neurons were detected by immunofluorescence.

RESULTS

The 28-day behavioral test showed that the BBB score of rats in the SCI + hucMSCs group increased significantly, comparing to the SCI + PBS group. The numbers of nissl bodies and myelin sheath in the damaged area of SCI + hucMSCs group were also significantly increased compared to the SCI + PBS group. HucMSCs transplanting decreased the expression of protein level of Caspase-3 and Bax and increased the Bcl-2, MBP and CNPase, rescued the apoptosis of neurons and the oligodendrocyte.

CONCLUSION

These results showed that hucMSCs can improve motor function, tissue repairing and reducing apoptosis in SCI rats.

hiPSC-derived NSCs effectively promote the functional recovery of acute spinal cord injury in mice

Background

Spinal cord injury (SCI) is a common disease that results in motor and sensory disorders and even lifelong paralysis. The transplantation of stem cells, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), or subsequently generated stem/progenitor cells, is predicted to be a promising treatment for SCI. In this study, we aimed to investigate effect of human iPSC-derived neural stem cells (hiPSC-NSCs) and umbilical cord-derived MSCs (huMSCs) in a mouse model of acute SCI.

Methods

Acute SCI mice model were established and were randomly treated as phosphate-buffered saline (PBS) (control group), repaired with 1 × 10⁵ hiPSC-NSCs (NSC group), and 1 × 10⁵ huMSCs (MSC group), respectively, in a total of 54 mice (n = 18 each). Hind limb motor function was evaluated in open-field tests using the Basso Mouse Scale (BMS) at days post-operation (dpo) 1, 3, 5, and 7 after spinal cord injury, and weekly thereafter. Spinal cord and serum samples were harvested at dpo 7, 14, and 21. Haematoxylin-eosin (H&E) staining and Masson staining were used to evaluate the morphological changes and fibrosis area. The differentiation of the transplanted cells in vivo was evaluated with immunohistochemical staining.

Results

The hiPSC-NSC-treated group presented a significantly smaller glial fibrillary acidic protein (GFAP) positive area than MSC-treated mice at all time points. Additionally, MSC-transplanted mice had a similar GFAP+ area to mice receiving PBS. At dpo 14, the immunostained hiPSC-NSCs were positive for SRY-related high-mobility-group (HMG)-box protein-2 (SOX2). Furthermore, the transplanted hiPSC-NSCs differentiated into GFAP-positive astrocytes and beta-III tubulin-positive neurons, whereas the transplanted huMSCs differentiated into GFAP-positive astrocytes. In addition, hiPSC-NSC transplantation reduced fibrosis formation and the inflammation level. Compared with the control or huMSC transplanted group, the group with transplantation of hiPSC-NSCs exhibited significantly improved behaviours, particularly limb coordination.

Conclusions

HiPSC-NSCs promote functional recovery in mice with acute SCI by replacing missing neurons and attenuating fibrosis, glial scar formation, and inflammation.

Graphical abstract

Knockdown of long non-coding RNA LEF1-AS1 attenuates apoptosis and inflammatory injury of microglia cells following spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is associated with health burden both at personal and societal levels. Recent assessments on the role of lncRNAs in SCI regulation have matured. Therefore, to comprehensively explore the function of lncRNA LEF1-AS1 in SCI, there is an urgent need to understand its occurrence and development.

METHODS

Using in vitro experiments, we used lipopolysaccharide (LPS) to treat and establish the SCI model primarily on microglial cells. Gain- and loss of function assays of LEF1-AS1 and miR-222-5p were conducted. Cell viability and apoptosis of microglial cells were assessed via CCK8 assay and flow cytometry, respectively. Adult Sprague-Dawley (SD) rats were randomly divided into four groups: Control, SCI, sh-NC, and sh-LEF-AS1 groups. ELISA test was used to determine the expression of TNF-α and IL-6, whereas the protein level of apoptotic-related markers (Bcl-2, Bax, and cleaved caspase-3) was assessed using Western blot technique.

RESULTS

We revealed that LncRNA LEF1-AS1 was distinctly upregulated, whereas miR-222-5p was significantly downregulated in LPS-treated SCI and microglial cells. However, LEF1-AS1 knockdown enhanced cell viability, inhibited apoptosis, as well as inflammation of LPS-mediated microglial cells. On the contrary, miR-222-5p upregulation decreased cell viability, promoted apoptosis, and inflammation of microglial cells. Mechanistically, LEF1-AS1 served as a competitive endogenous RNA (ceRNA) by sponging miR-222-5p, targeting RAMP3. RAMP3 overexpression attenuated LEF1-AS1-mediated protective effects on LPS-mediated microglial cells from apoptosis and inflammation.

CONCLUSION

In summary, these findings ascertain that knockdown of LEF1-AS1 impedes SCI progression via the miR-222-5p/RAMP3 axis.

Progress in clinical trials of cell transplantation for the treatment of spinal cord injury: how many questions remain unanswered?

Spinal cord injury can lead to severe motor, sensory and autonomic nervous dysfunctions. However, there is currently no effective treatment for spinal cord injury. Neural stem cells and progenitor cells, bone marrow mesenchymal stem cells, olfactory ensheathing cells, umbilical cord blood stem cells, adipose stem cells, hematopoietic stem cells, oligodendrocyte precursor cells, macrophages and Schwann cells have been studied as potential treatments for spinal cord injury. These treatments were mainly performed in animals. However, subtle changes in sensory function, nerve root movement and pain cannot be fully investigated with animal studies. Although these cell types have shown excellent safety and effectiveness in various animal models, sufficient evidence of efficacy for clinical translation is still lacking. Cell transplantation should be combined with tissue engineering scaffolds, local drug delivery systems, postoperative adjuvant therapy and physical rehabilitation training as part of a comprehensive treatment plan to provide the possibility for patients with SCI to return to normal life. This review summarizes and analyzes the clinical trials of cell transplantation therapy in spinal cord injury, with the aim of providing a rational foundation for the development of clinical treatments for spinal cord injury.