Migration of Adipose-derived Mesenchymal Stem Cells Stably Expressing Chondroitinase ABC In vitro

Chondroitinase as a therapeutic enzyme: Prospects and challenges

The chondroitinases (Chase) are bacterial lyases that specifically digest chondroitin sulfate and/or dermatan sulfate glycosaminoglycans via a β-elimination reaction and generate unsaturated disaccharides. In recent decades, these enzymes have attracted the attention of many researchers due to their potential applications in various aspects of medicine from the treatment of spinal cord injury to use as an analytical tool. In spite of this diverse spectrum, the application of Chase is faced with several limitations and challenges such as thermal instability and lack of a suitable delivery system. In the current review, we address potential therapeutic applications of Chase with emphasis on the challenges ahead. Then, we summarize the latest achievements to overcome the problems by considering the studies carried out in the field of enzyme engineering, drug delivery, and combination-based therapy.

Exosomes secreted by hypoxia-preconditioned adipose-derived mesenchymal stem cells reduce neuronal apoptosis in rats with spinal cord injury

Neuronal death is the main cause of nerve function impairment after spinal cord injury (SCI). Exosome-based therapy has become a novel strategy for tissue injury repair. We designed a method to treat SCI using exosomes secreted by adipose tissue-derived stromal cells (ADSCs) under hypoxic conditions. We established a neuronal oxygen-glucose deprivation and reperfusion (OGD/R) model in vitro to simulate the hypoxic environment after SCI. We observed that exosomes derived from hypoxia-conditioned ADSCs (Hypo-exos) significantly reduced neuronal apoptosis after OGD. By establishing a rat SCI model, we found that Hypo-exos can significantly reduce the formation of cavities in the injured area and improve the functional recovery of the hind limbs of rats after injury. To explore the molecular mechanism, we conducted miRNA sequencing analysis of exosomes. Through RT-PCR, dual luciferase reporter assays and signaling pathway chip analysis, we determined that miR-499a-5p regulates the JNK3/c-jun-apoptotic signaling pathway by targeting JNK3. Furthermore, we verified the expression of the key proteins in the JNK3/c-jun-apoptotic signaling pathway by immunofluorescence and western blotting. These results support the hypothesis that Hypo-exos can reduce neuronal apoptosis after SCI and may provide new methods to treat SCI.

Advanced approaches to regenerate spinal cord injury: The development of cell and tissue engineering therapy and combinational treatments

Spinal cord injury (SCI) is a central nervous system (CNS) devastate event that is commonly caused by traumatic or non-traumatic events. The reinnervation of spinal cord axons is hampered through a myriad of devices counting on the damaged myelin, inflammation, glial scar, and defective inhibitory molecules. Unfortunately, an effective treatment to completely repair SCI and improve functional recovery has not been found. In this regard, strategies such as using cells, biomaterials, biomolecules, and drugs have been reported to be effective for SCI recovery. Furthermore, recent advances in combinatorial treatments, which address various aspects of SCI pathophysiology, provide optimistic outcomes for spinal cord regeneration. According to the global importance of SCI, the goal of this article review is to provide an overview of the pathophysiology of SCI, with an emphasis on the latest modes of intervention and current advanced approaches for the treatment of SCI, in conjunction with an assessment of combinatorial approaches in preclinical and clinical trials. So, this article can give scientists and clinicians' clues to help them better understand how to construct preclinical and clinical studies that could lead to a breakthrough in spinal cord regeneration.

PTEN-silencing combined with ChABC-overexpression in adipose-derived stem cells promotes functional recovery of spinal cord injury in rats

The efficiency of cell therapy after spinal cord injury (SCI) depend on the survival of transplanted cells. However, sterile microenvironment and glial scar hyperplasia extremely reduce their numbers. Our previous study found overexpression of ChABC gene is positively correlated to migration ability. Expression of PTEN gene is closely associated with proliferation. However, whether manipulation of PTEN and ChABC on adipose-derived mesenchymal stem cells (ADSCs) promote motor recovery is unknown. This study aimed to promote hindlimb function recovery in SCI rats by enhancing proliferation and migration ability of ADSCs, transiently silencing expression of PTEN following overexpression of ChABC (double-gene modified ADSCs, DG-ADSCs). After PTEN silencing, we observed strong proliferation and accelerated G1-S transition in DG-ADSCs using CCK8 assay and flow cytometry. In addition, we demonstrated that migration numbers of DG-ADSCs were higher than control group using Transwell assay. The protein and mRNA levels of MAP2 and βⅢ-tubulin in DG-ADSCs were increased compared with ADSCs. These results were further confirmed in SCI rats. Increased survival cells and reduction of glial scars were quantitatively analyzed in DG-ADSCs groups, which is definitely correlated to function recovery. Recovery of motor function was observed in DG-ADSCs treatment rats using BBB score, which emphasized that improved viability of transplanted cells and reduction of glial scars were an effective strategy for enhancing recovery of neurological function after SCI.

Novel Assay Analyzing Tropism between Adipose-Derived Stem Cells and Breast Cancer Cells Reveals a Low Oncogenic Response

Introduction

In the surgical world of breast cancer reconstruction, fat grafting is commonly viewed as an oncogenic risk. Scientific studies add confusion, given the stark lack of clinical evidence suggesting pro-oncogenic links. Typically, classic migration assays (e.g., Boyden chamber) between adipose-derived stem cells and breast cancer cells define this cell relationship as pro-oncogenic.

Objective

We sought to develop a new migration model which better explains existing clinical data.

Methods

Silicon chambers were used to seed isolated populations of cells simultaneously in culture dish. Once cells had adhered, chambers were removed and cells were allowed to follow natural trophic cues. Multiple permutations of MDA-MB-231, MCF-7, HS-27, and ASCs were engineered. Cells were stained with MitoTracker for fluorescent visualization. A human cytokine array (RayBiotech) was performed on the media of migrating assays. Cellular tropism and blot intensity were quantitatively measured in Image J.

Results

An in vitro model was successfully constructed where ASCs reproducibly and freely migrated. Cytokine arrays reveal higher levels of IL-6 and CCL2 in the media of Boyden chambers containing ASCs and MDA-MB-231, compared to the novel assay, comprised of the same cell numbers, types, and incubation times.

Conclusion

These data collectively show for the first time the attraction of ASCs to malignant breast cancer cells; a phenomenon which many ASC studies infer. The cytokine profile of the novel system described is less oncogenic than the commonly described Boyden chamber. These data integrate better into the clinical data, which fail to link cancer recurrence with fat grafting.

Human intracerebroventricular (ICV) injection of autologous, non-engineered, adipose-derived stromal vascular fraction (ADSVF) for neurodegenerative disorders: results of a 3-year phase 1 study of 113 injections in 31 patients

We have chosen to test the safety of human intracerebroventricular (ICV) brain injections of autologous non-genetically-modified adipose-derived stromal vascular fraction (ADSVF). In this IRB-approved trial, 24 patients received ICV ADSVF via an implanted reservoir between 5/22/14 and 5/22/17. Seven others were injected via their ventriculo-peritoneal shunts. Ten patients had Alzheimer's disease (AD), 6 had amyotrophic lateral sclerosis (ALS), 6 had progressive multiple sclerosis (MS-P), 6 had Parkinson's "Plus" (PD+), 1 had spinal cord injury, 1 had traumatic brain injury, and 1 had stroke. Median age was 74 (range 41-83). Injections were planned every 2-3 months. Thirty-one patients had 113 injections. Patients received SVF injection volumes of 3.5-20 cc (median:4 cc) containing 4.05 × 10⁵ to 6.2 × 10⁷ cells/cc, which contained an average of 8% hematopoietic and 7.5% adipose stem cells. Follow-up ranged from 0 to 36 months (median: 9.2 months). MRIs post injection(s) were unchanged, except for one AD patient whose hippocampal volume increased from < 5th percentile to 48th percentile (NeuroQuant^® volumetric MRI). Of the 10 AD patients, 8 were stable or improved in tests of cognition. Two showed improvement in P-tau and ß-amyloid levels. Of the 6 MS-P patients all are stable or improved. Four of 6 ALS patients died of disease progression. Twelve of 111 injections (11%) led to 1-4 days of transient meningismus, and mild temperature elevation, which resolved with acetaminophen and/or dexamethasone. Two (1.8% of injections) required hospitalization for these symptoms. One patient (0.9% of injections) had his reservoir removed and later replaced for presumed infection. In this Phase 1 safety trial, ADSVF was safely injected into the human brain ventricular system in patients with no other treatment options. Secondary endpoints of clinical improvement or stability were particularly promising in the AD and MS-P groups. These results will be submitted for a Phase 2 FDA-approved trial.

Andrographolide Promotes Neural Differentiation of Rat Adipose Tissue-Derived Stromal Cells through Wnt/β-Catenin Signaling Pathway

Adipose tissue-derived stromal cells (ADSCs) are a high-yield source of pluripotent stem cells for use in cell-based therapies. We explored the effect of andrographolide (ANDRO, one of the ingredients of the medicinal herb extract) on the neural differentiation of rat ADSCs and associated molecular mechanisms. We observed that rat ADSCs were small and spindle-shaped and expressed multiple stem cell markers including nestin. They were multipotent as evidenced by adipogenic, osteogenic, chondrogenic, and neural differentiation under appropriate conditions. The proportion of cells exhibiting neural-like morphology was higher, and neurites developed faster in the ANDRO group than in the control group in the same neural differentiation medium. Expression levels of the neural lineage markers MAP2, tau, GFAP, and β-tubulin III were higher in the ANDRO group. ANDRO induced a concentration-dependent increase in Wnt/β-catenin signaling as evidenced by the enhanced expression of nuclear β-catenin and the inhibited form of GSK-3β (pSer9). Thus, this study shows for the first time how by enhancing the neural differentiation of ADSCs we expect that ANDRO pretreatment may increase the efficacy of adult stem cell transplantation in nervous system diseases, but more exploration is needed.