Adipose-derived cellular and cell-derived regenerative therapies in dermatology and aesthetic rejuvenation

Cellular and cell-derived components of adipose-derived tissue for the purposes of dermatologic and aesthetic rejuvenation applications have become increasingly studied and integrated into clinical practice. These components include micro-fragmented fat (nanofat), the stromal vascular fraction (SVF), adipose-derived mesenchymal stem cells (ASC), and extracellular vesicles (EVs), which have all shown capability to repair, regenerate, and rejuvenate surrounding tissue. Various aesthetic applications including hair growth, scar reduction, skin ischemia-reperfusion recovery, and facial rejuvenation are reviewed. In particular, results from preclinical and clinical studies are discussed, with a focus on clarification of nomenclature.

Effect of Comedications and Endotoxins on Mesenchymal Stem Cell Secretomes, Migratory and Immunomodulatory Capacity

Mesenchymal stem cells (MSCs) are becoming an increasingly popular therapeutic option among patients with a broad range of ailments to modulate immunity and induce regeneration. The majority of patients receiving these MSC therapies are on concurrent medication or have ongoing infection. In the present study, we examined the effect of immunosuppressive drugs and lipopolysaccharides (LPS)/endotoxins on the secretory profile, migration towards site of injury, and suppression of lymphocyte proliferation of bone marrow-derived MSCs (BMSCs). Generally, LPS coculture augmented the secretory capacity of BMSCs while exposure to immunosuppressive drugs resulted primarily in no change or attenuated secretion, with some cases of increased secretion, dependent on the cytokine assayed. Among the immunosuppressants evaluated, Hydrocortisone had the most widespread inhibitory effect, while LPS from E. coli O111:B4 had the most potent stimulatory effect. In addition, we also showed that Hydrocortisone or LPS from E. coli O111:B4 affected the migratory and immunosuppressive capacity of BMSCs. Following simulation with Hydrocortisone, BMSC migration was attenuated, and immunosuppressive capacity against T cell proliferation was enhanced, however, the opposite effects were seen with LPS from E. coli O111:B4. Our data suggests that the clinical outcomes of MSC-based therapy are affected by the use of immunosuppressive medication or the presence of endotoxemia in patients.

Impact of good and poor mobilizers on hematopoietic progenitor cell collection efficiency and product quality

BACKGROUND

Mobilization regimen choice is a significant contributing factor for successful hematopoietic progenitor cell (HPC) collection by leukocytapheresis and reaching the target CD34+ cell dose. How mobilization regimen affects collection efficiency and the quality of products collected using the Spectra Optia apheresis instrument is not fully known.

METHODS

We evaluated the impact of granulocyte-colony stimulating factor (GCSF) and GCSF/plerixafor mobilization regimens on CE and product composition. We studied 373 leukocytapheresis HPC collections for 147 autologous transplants from January 1, 2010 to December 31, 2014. Patients were categorized in two groups; good mobilizers, mobilized with GCSF only (GM) and poor mobilizers, mobilized with GCSF and Plerixafor (PM).

RESULTS

Overall, compared with PM group, total nucleated cell (TNC) yield was significantly lower in GM group (P = <.001). In contrast, median percent mononuclear cell (MNC) collected from GM (86.5%) was significantly higher than products collected from PM group (79.5%; P < .001). Compared with GM group, CD34+ cell CE was about 10% lower in PM group (P < .008). In addition, daily CD34+ cell/Kg yield was significantly higher in GM (2.08 × 10/Kg) compared with PM group (1.64 x 10/Kg, P = .019). Overall, the median number of collections per patient was two for GM and three for PM (P = .004).

CONCLUSION

Products collected from PM group contained higher TNC content relative to GM group but had lower MNC enrichment, CD34+ cell CE and daily CD34+ cell yield per Kg.

Characterization and cost-benefit analysis of automated bioreactor-expanded mesenchymal stem cells for clinical applications

BACKGROUND

Expanding quantities of mesenchymal stem cells (MSCs) sufficient to treat large numbers of patients in cellular therapy and regenerative medicine clinical trials is an ongoing challenge for cell manufacturing facilities.

STUDY DESIGN AND METHODS

We evaluated options for scaling up large quantities of bone marrow-derived MSCs (BM-MSCs) using methods that can be performed in compliance with Good Manufacturing Practices (GMP). We expanded BM-MSCs from fresh marrow aspirate in αMEM supplemented with 5% human platelet lysate using both an automated cell expansion system (Quantum, Terumo BCT) and a manual flask-based method using multilayer flasks. We compared MSCs expanded using both methods and assessed their differentiation to adipogenic and osteogenic tissue, capacity to suppress T-cell proliferation, cytokines, and growth factor secretion profile and cost-effectiveness of manufacturing enough BM-MSCs to administer a single dose of 100 × 10⁶ cells per subject in a clinical trial of 100 subjects.

RESULTS

We have established that large quantities of clinical-grade BM-MSCs manufactured with an automated hollow-fiber bioreactor were phenotypically (CD73, CD90, CD105) and functionally (adipogenic and osteogenic differentiation and cytokine and growth factor secretion) similar to manually expanded BM-MSCs. In addition, MSC manufacturing costs significantly less and required less time and effort when using the Quantum automated cell expansion system over the manual multilayer flasks method.

CONCLUSION

MSCs manufactured by an automated bioreactor are physically and functionally equivalent to the MSCs manufactured by the manual flask method and have met the standards required for clinical application.

A Prospective, Single-Blind, Placebo-Controlled Trial of Bone Marrow Aspirate Concentrate for Knee Osteoarthritis

BACKGROUND

Bone marrow aspirate concentrate (BMAC) is increasingly used as a regenerative therapy for musculoskeletal pathological conditions despite limited evidence-based support.

HYPOTHESIS

BMAC will prove feasible, safe, and efficacious for the treatment of pain due to mild to moderate degenerative joint disease of the knee.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

In this prospective, single-blind, placebo-controlled trial, 25 patients with bilateral knee pain from bilateral osteoarthritis were randomized to receive BMAC into one knee and saline placebo into the other. Fifty-two milliliters of bone marrow was aspirated from the iliac crests and concentrated in an automated centrifuge. The resulting BMAC was combined with platelet-poor plasma for an injection into the arthritic knee and was compared with a saline injection into the contralateral knee, thereby utilizing each patient as his or her own control. Safety outcomes, pain relief, and function as measured by Osteoarthritis Research Society International (OARSI) measures and the visual analog scale (VAS) score were tracked initially at 1 week, 3 months, and 6 months after the procedure.

RESULTS

There were no serious adverse events from the BMAC procedure. OARSI Intermittent and Constant Osteoarthritis Pain and VAS pain scores in both knees decreased significantly from baseline at 1 week, 3 months, and 6 months ( P ≤ .019 for all). Pain relief, although dramatic, did not differ significantly between treated knees ( P > .09 for all).

CONCLUSION

Early results show that BMAC is safe to use and is a reliable and viable cellular product. Study patients experienced a similar relief of pain in both BMAC- and saline-treated arthritic knees. Further study is required to determine the mechanisms of action, duration of efficacy, optimal frequency of treatments, and regenerative potential. Registration: ClinicalTrials.gov record 12-004459.

Genetic modification of H2AX renders mesenchymal stromal cell-derived dopamine neurons more resistant to DNA damage and subsequent apoptosis

BACKGROUND AIMS

Aberrant production of reactive oxygen species (ROS) and its impact on the integrity of genomic DNA have been considered one of the major risk factors for the loss of dopaminergic neurons in Parkinson's disease (PD). Stem cell transplantation as a strategy to replenish new functional neurons has great potential for PD treatment. However, limited survival of stem cells post-transplantation has always been an obstacle ascribed to the existence of neurotoxic environment in PD patients.

METHODS

To improve the survival of transplanted stem cells for PD treatment, we explored a new strategy based on the function of the H2AX gene (H2A histone family, member X) in determination of DNA repair and cell apoptosis. We introduced a mutant form Y142F of H2AX into dopamine (DA) neuron-like cells differentiated from bone marrow-derived mesenchymal stromal cells (BMSCs).

RESULTS

Expression of H2AX(Y142F) renders DA neuron-like cells more resistant to DNA damage and subsequent cell death induced by ultraviolet irradiation and 1-methyl-4-phenylpyridinium (MPP+) treatment.

DISCUSSION

This is a meaningful attempt to improve the sustainability of BMSC-derived dopamine neurons under a brain neurotoxic environment. Further studies are needed to evaluate the implications of our findings in stem cell therapy for PD and related diseases.

Dual roles of autologous CD8+ T cells in hematopoietic progenitor cell mobilization and engraftment

BACKGROUND

Poor marrow cellularity alone cannot explain poor hematopoietic progenitor cell (HPC) mobilization. This study assessed the role of CD8+ T cells in HPC cell mobilization and engraftment.

STUDY DESIGN AND METHODS

Mobilization and engraftment were assessed in 192 autologous HPC donors. CD34+, CD4+, and CD8+ T-cell contents in apheresis products were evaluated. Using a chemotaxis assay, we assessed the effect of purified autologous CD8+ T cells from low and high mobilizers on HPC migration from high to low stromal cell-derived factor (SDF-1α) concentration gradients. We also assessed CD8+ T-cell content association with days to neutrophil engraftment.

RESULTS

The median number of CD34+ cells/kg was 4.7 × 10(6) . Patients were categorized according to their total CD34+ cell collection quartile distribution into low, moderate, and high mobilizers. We found that HPC products from low mobilizers contained more CD8+ T cells than HPC products from moderate and high mobilizers. Chemotaxis assays showed depletion of CD8+ T cells enhances HPC mobilization independent of SDF-1α concentration. Neutrophil engraftment analysis showed that the higher the CD8+ T-cell content per unit CD34+ cell, the faster the rate of engraftment.

CONCLUSION

Our findings suggest CD8+ T cells inhibit HPC mobilization and facilitate homing and engraftment.

Association of surgeon with surgical site infection after liver transplantation

Surgical site infection (SSI) after liver transplantation has been associated with increased risk of allograft loss and death. Identification of modifiable risk factors for these infections is imperative. To our knowledge, intraoperative practices associated with transplant surgeons have not been assessed as a risk factor. A retrospective cohort study of risk factors for SSI after 1036 first liver transplantations completed by seven surgeons at a single center between 2003 and 2008 was undertaken. Cox proportional hazards models were used to evaluate the association between surgeons and SSIs. SSIs were identified in 166 of 1036 patients (16%). Single variable analysis showed strong evidence of an association between surgeon and SSI (p = 0.0007); the estimated cumulative incidence of SSI ranged from 7% to 24%. This result was consistent in multivariable analysis adjusting for potentially confounding variables (p = 0.002). The occurrence of organ-space or deep SSI varied significantly among surgeons in both single variable analysis (p = 0.005) and multivariable analysis (p = 0.006). These findings provide evidence that differences in the surgical practices of individual surgeons are associated with risk for SSI after liver transplantation. Identification of specific surgical practices associated with risk of SSI is warranted.

Hematopoietic stem cells from poor and good mobilizers are qualitatively equivalent

BACKGROUND

Marrow damage from chemo- and radiation therapies has been suggested to affect quality and quantity of hematopoietic stem cell (HSC) products. We tested the hypothesis that CD34+ cells (HSCs) from low mobilizers are qualitatively inferior to HSCs from high mobilizers.

STUDY DESIGN AND METHODS

HSC quality was defined by proportion of primitive HSC subsets (CD34+CD38-, CD34+HLA-DR-, and CD34+ in G0 stage of cell cycle), the proportion of HSCs that express CXCR4 and CD26 homing proteins, and days to neutrophil and platelet (PLT) engraftments after transplant. HSC content and CD34 subsets analyses were performed using flow cytometry following the ISHAGE protocol. We evaluated the HSC quantity and quality of 139 autologous filgrastim-mobilized HSC products. Patients were categorized into low, moderate, and high mobilizers if their total HSC collection was less than 3 × 10(6), 3 × 10(6) or more and less than 5 × 10(6), and 5 × 10(6)/kg or more, respectively.

RESULTS

The median number of primitive CD34 subsets increases with increasing HSC numbers and this association was significant (p = 0.001). However, when the ratios of the primitive CD34 subsets to total HSC counts were compared among the mobilization groups, the ratios were not significantly different. Coexpression of neither CD26 nor CXCR4 with CD34 antigen correlated with HSC mobilization. Evaluation of days to neutrophil engraftment among the mobilization groups did not show a significant difference (p = 0.1). However, days to PLT engraftment among the mobilization groups was significantly different (p = 0.05).

CONCLUSION

The quality of HSCs from low mobilizers was comparable to HSCs from high mobilizers.

Efficacy and cost-benefit analysis of risk-adaptive use of plerixafor for autologous hematopoietic progenitor cell mobilization

BACKGROUND

Plerixafor (P) reduces mobilization failure rates but it is very expensive. For better utilization of P, we employed a risk-adaptive strategy of using it only in patients who are at high risk of mobilization failure, defined by peripheral blood (PB) CD34+ cell count of fewer than 10×10(6)/L after 4 days of filgrastim (F) alone.

STUDY DESIGN AND METHODS

Herein, we present the results of efficacy and cost-benefit analysis of this risk-adaptive approach for hematopoietic progenitor cell (HPC) collection. All patients received daily F for 4 days, and P was added for those "at-risk" patients from Day 4 with apheresis commencing the following morning. F and P were continued daily for up to a maximum of 4 days or until more than 5×10(6) CD34+ cells/kg were collected. Forty-two transplant-eligible patients underwent HPC mobilization.

RESULTS

Eighteen patients mobilized with F alone and 24 patients required P with F. Two patients failed adequate HPC mobilization after F+P. Addition of P increased the PB CD34+ count by 6.8-fold with a mean yield of 4.9×10(6) CD34+ cells/kg. Decision-analysis model estimated cost-effectiveness for this risk-adaptive approach of using P with savings of $19,300/patient. Engraftment after HPC infusion was similar among the patients regardless of mobilization regimens.

CONCLUSION

These results suggest that addition of P to F based on a risk-adaptive strategy significantly reduces the frequency of mobilization failures and is also cost-effective.

Evaluation of mobilized peripheral blood CD34(+) cells from patients with severe coronary artery disease as a source of endothelial progenitor cells

BACKGROUND AIMS

The distinction between hematopoietic stem cells (HSC) and endothelial progenitor cells (EPC) is poorly defined. Co-expression of CD34 antigen with vascular endothelial growth factor (VEGF) receptor (VEGFR2) is currently used to define EPC ( 1 ).

METHODS

We evaluated the phenotypic and genomic characteristics of peripheral blood-derived CD34(+) cells in 22 granulocyte-colony-stimulating factor (G-CSF)-mobilized patients with severe coronary artery disease and assessed the influence of cell selection and storage on CD34(+) cell characteristics.

RESULTS

The median CD34(+) cell contents in the products before and after enrichment with the Isolex 300i Magnetic Cell Selection System were 0.2% and 82.5%, respectively. Cell-cycle analysis showed that 80% of CD34(+) cells were in G0 stage; 70% of the isolated CD34(+) cells co-expressed CD133, a marker for more immature progenitors. However, less than 5% of the isolated CD34(+) cells co-expressed the notch receptor Jagged-1 (CD339) and only 2% of the isolated CD34(+) population were positive for VEGFR2 (CD309). Molecular assessment of the isolated CD34(+) cells demonstrated extremely low expression of VEGFR2 and endothelial nitric oxide synthase (eNOS) and high expression of VEGF-A. Overnight storage at 4 degrees C did not significantly affect CD34(+) cell counts and viability. Storage in liquid nitrogen for 7 weeks did not affect the percentage of CD34(+) cells but was associated with a 26% drop in cell viability.

CONCLUSIONS

We have demonstrated that the majority of isolated CD34(+) cells consist of immature and quiescent cells that lack prototypic markers of EPC. High VEGF-A gene expression might be one of the mechanisms for CD34(+) cell-induced angiogenesis.

Clinical impact of blood storage lesions

Recent reports suggest that transfusion of old red blood cell (RBC) units (>2 weeks) was associated with increased risks of postoperative complications and higher mortality rate caught public attention (Yap et al., Ann Thorac Surg 2008; 86:554-559 and Koch et al., 2008; 358:1229-1239). This rekindled the decades old discussion regarding the impact of RBC aging and storage lesions in patient care. The objectives of this review are to provide readers with an overview of the process of banking RBC that may have an impact on its quality, the reported clinical impact of storage lesions, the consequences of transfusing new RBC units only to the nation's blood supply and potential solutions that may improve the feasibility of blood banks to issue new blood units only.

Massive gliosis induced by interleukin-6 suppresses Abeta deposition in vivo: evidence against inflammation as a driving force for amyloid deposition

Proinflammatory stimuli, after amyloid beta (Abeta) deposition, have been hypothesized to create a self-reinforcing positive feedback loop that increases amyloidogenic processing of the Abeta precursor protein (APP), promoting further Abeta accumulation and neuroinflammation in Alzheimer's disease (AD). Interleukin-6 (IL-6), a proinflammatory cytokine, has been shown to be increased in AD patients implying a pathological interaction. To assess the effects of IL-6 on Abeta deposition and APP processing in vivo, we overexpressed murine IL-6 (mIL-6) in the brains of APP transgenic TgCRND8 and TG2576 mice. mIL-6 expression resulted in extensive gliosis and concurrently attenuated Abeta deposition in TgCRND8 mouse brains. This was accompanied by up-regulation of glial phagocytic markers in vivo and resulted in enhanced microglia-mediated phagocytosis of Abeta aggregates in vitro. Further, mIL-6-induced neuroinflammation had no effect on APP processing in TgCRND8 and had no effect on APP processing or steady-state levels of Abeta in young Tg2576 mice. These results indicate that mIL-6-mediated reactive gliosis may be beneficial early in the disease process by potentially enhancing Abeta plaque clearance rather than mediating a neurotoxic feedback loop that exacerbates amyloid pathology. This is the first study that methodically dissects the contribution of mIL-6 with regard to its potential role in modulating Abeta deposition in vivo.

Multiple myeloma patients receiving large volume leukapheresis efficiently yield enough CD34+ cells to allow double transplants

Current protocols for myeloma patients require more than one autologous transplant. We performed a retrospective study to determine the cost-effectiveness of large volume leukapheresis (LVL) compared with standard volume leukapheresis (SVL) collection when two transplants are required. We evaluated 87 patients who underwent a cumulative total of 260 LVL and SVL collections. The median product volume per collection was 356 ml for LVL, and this was significantly higher than the median product volume per collection for SVL (median 149.5 ml, P < 0.001). The median total CD34+ cell yield/kg was 6.4 x 10(6) for LVL and 5.2 x 10(6) for SVL. This difference was statistically significant (P = 0.005). Because the target CD34+ cell dose for a single transplant was 3 x 10(6)/kg at our institution, overall the LVL yields enough CD34+ cells that could allow for two transplants. Therefore, more patients in the LVL group were able to undergo a potential second transplant. Because of the reserved cells for a second transplant, LVL patients received significantly less CD34+ cell/kg per transplant than the patients in SVL group (P = <0.001). As a result, LVL group had statistically significant but clinically insignificant delay in neutrophil (P = <0.001) and platelet (P = 0.02) engraftments. Additionally, using LVL instead of SVL to collect >or=6 x 10(6)/kg CD34+ cells may potentially save $7,497 per patient. We therefore conclude that LVL is the method of choice for collection of multiple myeloma patients when two transplants are anticipated.

Platelet count is a sensitive predictor of autologous peripheral blood progenitor cell collection yield in previously treated plasma cell disease patients

BACKGROUND

It is often a clinical dilemma to determine when to collect autologous peripheral blood progenitor cells (PBPCs) in patients who received prior chemotherapy. It is also challenging to predict if the collected cells will be enough for one or two transplants.

STUDY DESIGN AND METHODS

A total of 103 PBPC donors were followed to evaluate factors that predict poor autologous PBPC collection. The donors were categorized into three groups: plasma cell disorders (PCDs), lymphomas, and normal allogeneic donors.

RESULTS

Our evaluation showed that platelet (PLT) count before growth factor administration significantly correlated with total CD34+ cell yield (Spearman r = 0.38, p < 0.001). Further analysis showed this correlation was only significant in plasma cell disease patients who received prior chemotherapy (Spearman r = 0.5, p = 0.008). Baseline PLT counts did not correlate with PBPC collection yield in untreated PCD, lymphoma, and normal allogeneic donors. In addition, daily PLT count during PBPC harvest correlated with CD34+ cell yield for that day (Spearman r = 0.41, p < 0.001). With a multiple linear regression model (adjusted R(2) = 0.31, AIC = 63.1), it has been determined that the baseline PLT count significantly correlates with total CD34+ cell yield in treated PCD patients.

CONCLUSION

Baseline PLT count is a sensitive indicator of autologous PBPC mobilization in PCD patients who received prior chemotherapy. This finding may be considered before growth factor administration to determine the optimal period to mobilize treated PCD patients and to predict if enough cells can be collected for one or two transplants.

CD34(+) CD38(-) and CD34(+) HLA-DR(-) cells in BM stem cell grafts correlate with short-term engraftment but have no influence on long-term hematopoietic reconstitution after autologous transplantation

BACKGROUND

Prior studies have demonstrated that relatively immature hematopoietic stem cells, including CD34(+) CD38(-) and CD34(+) HLA-DR(-) subsets, correlate with short-term hematopoietic reconstruction (SHR) after transplantation. The aim of this study was to investigate whether these immature CD34(+) subsets also correlate with long-term hematopoietic reconstitution (LHR) in recipients of ABMT.

METHODS

We examined stem cell grafts from 58 patients with B-cell lymphoma or CLL who underwent ABMT after myeloablative conditioning. We determined whether total mononuclear cell dose (MNC), colony-forming unit-granulocyte-monocyte (CFU-GM), CD34(+) cell dose and CD34(+) cell subsets (CD34(+) CD38(-) and CD34(+) HLA-DR(-) were associated with SHR and/or LHR. Time to neutrophil engraftment (TNE) and time to platelet engraftment (TPE) were used to measure SHR, while platelet counts at day 100 and 1 year post-ABMT were used as indicators for LHR.

RESULTS AND DISCUSSION

CD34(+) cell dose and CD34(+) cell subsets were significantly associated with SHR. However, at day 100 and 1 year post-transplant only total CD34(+) cell dose was associated with LHR. The association of total CD34(+) cell dose with LHR persisted after adjusting for age, sex and disease. None of the CD34(+) cell subsets analyzed showed evidence of significant association with LHR.

A novel source of viable peripheral blood mononuclear cells from leukoreduction system chambers

BACKGROUND

Buffy coats are becoming less available as a source of research-grade peripheral blood mononuclear cells (PBMNCs). Therefore, alternative sources of these cells were investigated.

STUDY DESIGN AND METHODS

PBMNCs isolated from the cells retained in leukoreduction system chambers (LRSCs) and those eluted from white blood cell filters were compared. From LRSCs (1.88 +/- 0.40) x 10(9) PBMNCs (n = 13) versus (0.43 +/- 0.15) x 10(9) PBMNCs were isolated from leukofilter eluates (LFEs, n = 8; p < 0.0001).

RESULTS

Cells from LRSCs and LFEs produced similar numbers of burst-forming unit-erythroid, colony-forming unit (CFU)-granulocyte-macrophage, and CFU-granulocyte-erythrocyte-monocyte-macrophage-megakaryocyte colonies. The percentages of cells positive for CD3, CD4, CD8, CD14, CD19, and CD56 in the PBMNCs isolated from LRSCs and LFEs were indistinguishable. Cells isolated from LRSCs expressed higher levels of CD69 and CD25 in reaction to staphylococcal enterotoxin B than the cells isolated from LFEs. The source of cells affected neither the yield and purity of immunomagnetically isolated CD3+ cells, CD14+ cells, and CD56+ cells nor the function of T cells, natural killer cells, and in vitro matured dendritic cells (DCs). DC yield from LRSC-derived CD14+ cells, however, was higher.

CONCLUSION

LRSCs are a novel source of fully functional PBMNCs that can replace the more traditional sources of research-grade cellular products.