Comparison of viability and antioxidant capacity between canine adipose-derived mesenchymal stem cells and heme oxygenase-1-overexpressed cells after freeze-thawing

Regulation of the Nrf2/HO-1 axis by mesenchymal stem cells-derived extracellular vesicles: implications for disease treatment

This comprehensive review inspects the therapeutic potential of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) across multiple organ systems. Examining their impact on the integumentary, respiratory, cardiovascular, urinary, and skeletal systems, the study highlights the versatility of MSC-EVs in addressing diverse medical conditions. Key pathways, such as Nrf2/HO-1, consistently emerge as central mediators of their antioxidative and anti-inflammatory effects. From expediting diabetic wound healing to mitigating oxidative stress-induced skin injuries, alleviating acute lung injuries, and even offering solutions for conditions like myocardial infarction and renal ischemia-reperfusion injury, MSC-EVs demonstrate promising therapeutic efficacy. Their adaptability to different administration routes and identifying specific factors opens avenues for innovative regenerative strategies. This review positions MSC-EVs as promising candidates for future clinical applications, providing a comprehensive overview of their potential impact on regenerative medicine.

3D culture of mesenchymal stem cells from the yolk sac to generate intestinal organoid

Organoids are in vitro models that originated from the three-dimensional culture of stem cells with the ability to reproduce part of the in vivo structural and functional specificities of body organs. Intestinal organoids have great relevance in cell therapy, as they provide more accurate information about tissue composition and architecture in relation to two-dimensional culture, in addition to serving as a study model for host interaction and drug testing. The yolk sac (YS) is a promising source of mesenchymal stem cells (MSCs), which are multipotent stem cells with self-renewal ability and potential to differentiated into mesenchymal lineages. Besides this, the YS is responsible for the formation of intestinal epithelium during embryonic development. Thus, the aim of this study was to verify if the three-dimensional in vitro culture of stem cells derived from the canine YS is capable of developing intestinal organoids. MSCs from the canine YS and gut cells were isolated and characterized, then three-dimensionally cultured in Matrigel. In both cells lineages, spherical organoids were observed and after 10 days the gut cells formed crypt-like buds and villus-like structures. Despite having the same induction of differentiation process and having the expression of intestinal markers, the MSC from the YS morphology was not in the form of crypt budding. The hypothesis is that these cells could generate structures equivalent to the intestinal organoids of the colon that other studies showed formed only spherical structures. The culture of MSC from the YS, as well as the establishment of protocols for 3D cultivation of this tissue, is relevant, as it will serve as a tool in various applications in basic and scientific biology.

Canine peripheral blood mononuclear cell-derived B lymphocytes pretreated with lipopolysaccharide enhance the immunomodulatory effect through macrophage polarization

BACKGROUND

Preconditioning with lipopolysaccharide (LPS) is used to improve the secretion of anti-inflammatory agents in B cells. However, there are only a few studies on canine B cells.

OBJECTIVE

This study aimed to evaluate the immune regulatory capacity of canine peripheral blood mononuclear cell-derived B cells pretreated with LPS.

METHODS

Canine B cells were isolated from canine peripheral blood mononuclear cells, which were obtained from three healthy canine donors. The B cells were preconditioned with LPS, and then cell viability and the expression of the regulatory B cell marker were assessed. Finally, RNA extraction and immunofluorescence analysis were performed.

RESULTS

LPS primed B cells expressed the interleukin (IL)-10 surface marker and immunoregulatory gene expression, such as IL-10, programmed death-ligand 1, and transforming growth factor beta. Macrophages in the inflammatory condition cocultured with primed B cells were found to have significantly down-regulated pro-inflammatory cytokine, such as tumor necrosis factor-α, and up-regulated anti-inflammatory cytokines such as IL-10. Additionally, it was revealed that co-culture with primed B cells re-polarized M1 macrophages to M2 macrophages.

CONCLUSIONS

This study revealed that LPS-primed B cells have an anti-inflammatory effect and can re-polarize macrophages, suggesting the possibility of using LPS-primed B cells as a therapeutic agent for its anti-inflammatory effects and immune modulation.

Cryopreservation of heat-shocked canine adipose-derived mesenchymal stromal cells with 10% dimethyl sulfoxide and 40% serum results in better viability, proliferation, anti-oxidation, and in-vitro differentiation

Cryopreserved canine adipose-derived mesenchymal stromal cells (Ad-MSCs) can be used instantly in dogs for clinical uses. However, cryopreservation results in a reduction of the cellular viability, proliferation, and anti-oxidation of post-thawed Ad-MSCs. Therefore, there is a need for in-vitro procedure to improve post-thawed Ad-MSCs' viability, proliferation, anti-oxidation, and differentiation capacity. In this study, fresh-Ad-MSCs were activated with heat shock, hypoxia (5% O₂), or hypoxia (5% O₂) + heat shock treatments. The results showed that compared to the other treatments, heat shock significantly improved the proliferation rate, anti-oxidation, heat shock proteins and growth factors expressions of canine-fresh-Ad-MSCs. Consequently, fresh-Ad-MSCs were heat-shocked and then cryopreserved with different combinations of dimethyl sulfoxide (Me₂SO) and fetal bovine serum (FBS) to determine the combination that could effectively preserve the cellular viability, proliferation, anti-oxidation and differentiation capacity of Ad-MSCs after cryopreservation. We found that C-HST-Ad-MSCs cryopreserved with 10% Me₂SO + 40% FBS presented significantly (p < 0.05) improved cellular viability, proliferation rate, anti-oxidant capacity, and differentiation potential as compared to C-HST-Ad-MSCs cryopreserved with 1% Me₂SO + 10% FBS or 1% Me₂SO alone or control. We concluded, heat shock treatment is much better to enhance the characteristics of fresh-Ad-MSCs than other treatments, moreover, C-HST-Ad-MSCs in 10% Me₂SO + 40% FBS showed better results compared to other cryopreserved groups. However, future work is required to optimize the expression of heat shock proteins, which would further improve the characteristics of fresh- and cryopreserved-HST-Ad-MSCs and reduce the dependency on Me₂SO and FBS.

Therapeutic Effects of Intravenous Injection of Fresh and Frozen Thawed HO-1-Overexpressed Ad-MSCs in Dogs with Acute Spinal Cord Injury

Owing to the antioxidant and anti-inflammatory functions of hemeoxygenase-1 (HO-1), HO-1-expressing canine adipose-derived mesenchymal stem cells (Ad-MSCs) could be efficacious in treating spinal cord injury (SCI). Further, frozen thawed HO-1 Ad-MSCs could be instantly available as an emergency treatment for SCI. We compared the effects of intravenous treatment with freshly cultured HO-1 Ad-MSCs (HO-1 MSCs), only green fluorescent protein-expressing Ad-MSCs (GFP MSCs), and frozen thawed HO-1 Ad-MSCs (FT-HO-1 MSCs) in dogs with acute SCI. For four weeks, dogs were evaluated for improvement in hind limb locomotion using a canine Basso Beattie Bresnahan (cBBB) score. Upon completion of the study, injured spinal cord segments were harvested and used for western blot and histopathological analyses. All cell types had migrated to the injured spinal cord segment. The group that received HO-1 MSCs showed significant improvement in the cBBB score within four weeks. This group also showed significantly higher expression of NF-M and reduced astrogliosis. There was reduced expression of proinflammatory cytokines (IL6, TNF-α, and IL-1β) and increased expression of anti-inflammatory markers (IL-10, HO-1) in the HO-1 MSC group. Histopathological assessment revealed decreased fibrosis at the epicenter of the lesion and increased myelination in the HO-1 MSC group. Together, these data suggest that HO-1 MSCs could improve hind limb function by increasing the anti-inflammatory reaction, leading to neural sparing. Further, we found similar results between GFP MSCs and FT-HO-1 MSCs, which suggest that FT-HO-1 MSCs could be used as an emergency treatment for SCI.

Improved Healing after the Co-Transplantation of HO-1 and BDNF Overexpressed Mesenchymal Stem Cells in the Subacute Spinal Cord Injury of Dogs

Abundant expression of proinflammatory cytokines after a spinal cord injury (SCI) creates an inhibitory microenvironment for neuroregeneration. The mesenchymal stem cells help to mitigate the inflammation and improve neural growth and survival. For this purpose, we potentiated the function of adipose-derived mesenchymal stem cells (Ad-MSCs) by transfecting them with brain-derived neurotrophic factor (BDNF) and heme oxygenase-1 (HO-1), through a lentivirus, to produce BDNF overexpressed Ad-MSCs (BDNF-MSCs), and HO-1 overexpressed Ad-MSCs (HO-1-MSCs). Sixteen SCI beagle dogs were randomly assigned into four treatment groups. We injected both HO-1 and BDNF-overexpressed MSCs as a combination group, to selectively control inflammation and induce neuroregeneration in SCI dogs, and compared this with BDNF-MSCs, HO-1-MSCs, and GFP-MSCs injected dogs. The groups were compared in terms of improvement in canine Basso, Beattie, and Bresnahan (cBBB) score during 8 weeks of experimentation. After 8 weeks, spinal cords were harvested and subjected to western blot analysis, immunofluorescent staining, and hematoxylin and eosin (H&E) staining. The combination group showed a significant improvement in hindlimb functions, with a higher BBB score, and a robust increase in neuroregeneration, depicted by a higher expression of Tuj-1, NF-M, and GAP-43 due to a decreased expression of the inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and an increased expression of interleukin-10 (IL-10) (P ≤ 0.05). H&E staining showed more reduced intraparenchymal fibrosis in the combination group than in other groups (P ≤ 0.05). It was thus suggested that the cotransplantation of HO-1 and BDNF-MSCs is more effective in promoting the healing of SCI. HO-1-MSCs reduce inflammation, which favors BDNF-induced neuroregeneration in SCI of dogs.

Effect of canine mesenchymal stromal cells overexpressing heme oxygenase-1 in spinal cord injury

Heme oxygenase-1 (HO-1) is a stress-responsive enzyme that modulates the immune response and oxidative stress associated with spinal cord injury (SCI). This study aimed to investigate neuronal regeneration via transplantation of mesenchymal stromal cells (MSCs) overexpressing HO-1. Canine MSCs overexpressing HO-1 were generated by using a lentivirus packaging protocol. Eight beagle dogs with experimentally-induced SCI were divided into GFP-labeled MSC (MSC-GFP) and HO-1-overexpressing MSC (MSC-HO-1) groups. MSCs (1 × 10⁷ cells) were transplanted at 1 week after SCI. Spinal cords were harvested 8 weeks after transplantation, after which histopathological, immunofluorescence, and western blot analyses were performed. The MSC-HO-1 group showed significantly improved functional recovery at 7 weeks after transplantation. Histopathological results showed fibrotic changes and microglial cell infiltration were significantly decreased in the MSC-HO-1 group. Immunohistochemical (IHC) results showed significantly increased expression levels of HO-1 and neuronal markers in the MSC-HO-1 group. Western blot results showed significantly decreased expression of tumor necrosis factor-alpha, interleukin-6, cycloogygenase 2, phosphorylated-signal transducer and activator of transcription 3, and galactosylceramidase in the MSC-HO-1 group, while expression levels of glial fibrillary acidic protein, β3-tubulin, neurofilament medium, and neuronal nuclear antigen were similar to those observed in IHC results. Our results demonstrate that functional recovery after SCI can be promoted to a greater extent by transplantation of HO-1-overexpressing MSCs than by normal MSCs.

Different Bone Healing Effects of Undifferentiated and Osteogenic Differentiated Mesenchymal Stromal Cell Sheets in Canine Radial Fracture Model

Cell sheets technology is being available for fracture healing. This study was performed to clarify bone healing mechanism of undifferentiated (UCS) and osteogenic (OCS) differentiated mesenchymal stromal cell (MSC) sheets in the fracture model of dogs. UCS and OCS were harvested at 10 days of culture. Transverse fractures at the radius of six beagle dogs were assigned into three groups (n = 4 in each group) i.e. UCS, OCS and control. The fractures were fixed with a 2.7 mm locking plate and six screws. Cell sheets were wrapped around the fracture site. Bones were harvested 8 weeks after operation, then scanned by micro-computed tomography (micro-CT) and analyzed histopathologically. The micro-CT revealed different aspects of bone regeneration among the groups. The percentages of external callus volume out of total bone volume in control, UCS, and OCS groups were 42.1, 13.0 and 4.9% (p < 0.05) respectively. However, the percentages of limbs having connectivity of gaps were 25, 12.5 and 75% respectively. In histopathological assessments, OCS group showed well organized and mature woven bone with peripheral cartilage at the fracture site, whereas control group showed cartilage formation without bone maturation or ossification at the fracture site. Meanwhile, fracture site was only filled with fibrous connective tissue without endochondral ossification and bone formation in UCS group. It was suggested that the MSC sheets reduced the quantity of external callus, and OCS induced the primary bone healing.