Increased apoptosis in cryopreserved autologous hematopoietic progenitor cells collected by apheresis and delayed neutrophil recovery after transplantation: a nested case-control study

Potential of natural products in inflammation: biological activities, structure-activity relationships, and mechanistic targets

A balance between the development and suppression of inflammation can always be found in the body. When this balance is disturbed, a strong inflammatory response can damage the body. It sometimes is necessary to use drugs with a significant anti-inflammatory effect, such as nonsteroidal anti-inflammatory drugs and steroid hormones, to control inflammation in the body. However, the existing anti-inflammatory drugs have many adverse effects, which can be deadly in severe cases, making research into new safer and more effective anti-inflammatory drugs necessary. Currently, numerous types of natural products with anti-inflammatory activity and distinct structural features are available, and these natural products have great potential for the development of novel anti-inflammatory drugs. This review summarizes 260 natural products and their derivatives with anti-inflammatory activities in the last two decades, classified by their active ingredients, and focuses on their structure-activity relationships in anti-inflammation to lay the foundation for subsequent new drug development. We also elucidate the mechanisms and pathways of natural products that exert anti-inflammatory effects via network pharmacology predictions, providing direction for identifying subsequent targets of anti-inflammatory natural products.

Loss of CD34+ Cells and Effect of the Number of Viable Cryopreserved CD34+ Cells in the Infused Blood Grafts on Hematologic Recovery, Progression-Free Survival and Overall Survival in NHL Patients After Autologous Stem Cell Transplantation

PATIENTS

This post-hoc study aimed to find out factors affecting graft viable CD34+ cell loss during processing and cryopreservation in 129 non-Hodgkin lymphoma (NHL) patients receiving autologous stem cell transplantation (auto-SCT) and the impact of a low (< 2.0 × 106/kg, group A) and a decent number (≥ 2 × 106/kg, group B) of viable CD34+ cells infused on the hematologic recovery, progression-free survival (PFS) and overall survival (OS) after auto-SCT.

RESULTS

The median loss of viable CD34+ cells during cryopreservation was higher in group A (47% vs. 19%, p < .001). A higher yield of CD34+ cells at the first apheresis in group B (p = .002) was linked with greater loss of viable graft CD34+ cells after cryopreservation. Filgrastim (FIL) use for mobilization seemed to associate with higher viable CD34+ cell loss compared to pegfilgrastim (PEG) or lipegfilgrastim (LIPEG) in both groups (in group A FIL 66 vs. PEG 35%, p = .006; in group B FIL 37 vs. PEG 15 vs. LIPEG 13%, p < .001). Hematologic recovery after auto-SCT was faster in group B. Neither viable CD34+ cell loss during storage nor viable CD34+ cell number < 2.0 × 106/kg infused affected on PFS or OS.

CONCLUSIONS

G-CSF type used in mobilization and mobilization capacity were found to correlate with viable CD34+ cell loss during processing and storage. Most importantly, low infused viable CD34+ cell count did not seem to impact on PFS or OS.

Effects of cell concentration, time of fresh storage, and cryopreservation on peripheral blood stem cells: PBSC fresh storage and cryopreservation

INTRODUCTION

Peripheral blood stem cells are widely used in autologous or allogeneic transplantation. The quality of the product directly impacts clinical outcomes, and the cell quality and/or functionality may be influenced by the storage conditions as time, temperature, total nucleated cells (TNC) concentration and cryopreservation requirement.

OBJECTIVE

To verify the effects of time, cell concentration, and cryopreservation/thawing in the viability and functionality of stem cells for transplantation.

METHODS

We evaluated TNC, CD45⁺ viable cells, CD34⁺ viable cells, and cell viability and functionality of 11 samples. Measurements were performed immediately and 24 h, 48 h, 72 h, and 96 h after sample collection at high and low TNC concentrations. The same parameters were also evaluated after cryopreservation and thawing of the samples.

RESULT

Duration of storage and TNC concentration exhibited a negative effect on cell quality (CD45⁺ viable cells, CD34⁺ viable cells and functionality). Moreover, the association of these parameters increased the negative effect on graft quality. Cryopreservation and thawing also negatively affected the collected sample regarding viable CD34⁺ cells (recovery 66.2 %), viable CD45⁺ cells (recovery 56.8 %), and 7-AAD viability. No significant losses in viable CD45⁺/CD34⁺ cells and functionality were observed in the first 24 h in both TNC conditions.

CONCLUSION

These results emphasize the importance to consider carefully the storage conditions until transplantation, measuring TNC/μL until 24 h after collection (diluting the product when TNC > 300 × 10³/μL) and infusing fresh graft as soon as possible.

Long-Term Cryopreservation Does Not Affect Quality of Peripheral Blood Stem Cell Grafts: A Comparative Study of Native, Short-Term and Long-Term Cryopreserved Haematopoietic Stem Cells

Cryopreserved haematopoietic progenitor cells are used to restore autologous haematopoiesis after high dose chemotherapy. Although the cells are routinely stored for a long period, concerns remain about the maximum storage time and the possible negative effect of storage on their potency. We evaluated the effect of cryopreservation on the quality of peripheral stem cell grafts stored for a short (3 months) and a long (10 years) period and we compared it to native products.The viability of CD34+ cells remained unaffected during storage, the apoptotic cells were represented up to 10% and did not differ between groups. The clonogenic activity measured by ATP production has decreased with the length of storage (ATP/cell 1.28 nM in native vs. 0.63 in long term stored products, P < 0.05). Only borderline changes without statistical significance were detected when examining mitochondrial and aldehyde dehydrogenase metabolic activity and intracellular pH, showing their good preservation during cell storage. Our experience demonstrates that cryostorage has no major negative effect on stem cell quality and potency, and therefore autologous stem cells can be stored safely for an extended period of at least 10 years. On the other hand, long term storage for 10 years and longer may lead to mild reduction of clonogenic capacity. When a sufficient dose of stem cells is infused, these changes will not have a clinical impact. However, in products stored beyond 10 years, especially when a low number of CD34+ cells is available, the quality of stem cell graft should be verified before infusion using the appropriate potency assays.

Inhibition of ice recrystallization during cryopreservation of cord blood grafts improves platelet engraftment

BACKGROUND

Platelet engraftment following cord blood (CB) transplantation remains a significant hurdle to this day. The uncontrolled growth of ice, a process referred to as ice recrystallization, is one of several mechanisms that lead to cell loss and decreased potency during freezing and thawing. We hypothesized that reducing cell damage induced by ice recrystallization in CB units (CBUs) would reduce losses of stem and progenitor cells and therefore improve engraftment. We previously demonstrated that the ice recrystallization inhibitor (IRI) N-(2-fluorophenyl)-D-gluconamide (IRI 2) increases the postthaw recovery of CB progenitors. Herein, we set out to ascertain whether IRI 2 can enhance platelet and bone marrow engraftment activity of hematopoietic stem cells (HSCs) in cryopreserved CBUs using a serial transplantation model.

STUDY DESIGN AND METHODS

CBUs were processed following standard volume/red blood cell reduction procedure and portions frozen with dimethyl sulfoxide (DMSO) supplemented or not with IRI 2. Thawed CB samples were serially transplanted into immunodeficient mice.

RESULTS

Our results show that supplementation of DMSO with IRI 2 had several beneficial effects. Specifically, higher levels of human platelets were observed in the peripheral blood (p < 0.05; n = 4) upon transplant of CBUs preserved with the IRIs. In addition, human BM chimerism and the number of human CFU progenitors in the bone marrow were superior in IRI 2 recipients compared to DMSO recipients. Moreover, IRI 2 had no negative impact on the multilineage differentiation and self-renewal activities of HSCs.

DISCUSSION

Taken together, these results demonstrate that supplementation of a hematopoietic graft with IRI can improve the postthaw engraftment activities of HSCs.

Cryopreservation and thawing of hematopoietic stem cell CD34-induced apoptosis through caspase pathway activation: Key role of granulocytes

INTRODUCTION

Cell damage inescapably occurs during both the freezing and the thawing graft processes for autologous hematopoietic stem cell (HSC) transplantation. To estimate HSC injury, a quality control is performed including: (i) CD34⁺ quantification; (ii) percentage of CD34⁺ viability and (iii) evaluation of HSC functional ability to form colony forming unit-granulocyte macrophage (CFU-GM). Apoptosis involves complex pathways such as caspase enzymes. Here, we assess the extent of apoptosis that is caspase-dependent before and after cryoconservation of CD34⁺, using a Fluorescent Labeled Inhibitor of CAspases (FLICA).

METHODS

Caspase pathway activation status was evaluated in 46 patients (multiple myeloma [n = 24], lymphoma [n = 22]), by flow cytometry, using a 7-aminoactinomycin-D (7AAD)/FLICA staining test, in CD34⁺, CD3⁺, CD14⁺ and CD56⁺ cells. Viable 7AAD^-/FLICA⁺ cells were then correlated with various parameters.

RESULTS

We showed a significant caspase pathway activation, with 23% CD34⁺/7AAD^-/FLICA⁺ cells after thawing, compared with the 2% described in fresh CD34⁺ cells (P < 0.0001). Moreover, caspase pathway was significantly activated in thawing CD3⁺, CD56⁺ and CD14⁺ cells. We also report a significant correlation between the rate of CD34⁺/7AAD^-/FLICA⁺ cells and post-thawing granulocytes count (P = 0.042) and their potential to be differentiated into CFU-GM (P = 0.004).

DISCUSSION

Our results show substantial cell death, induced by the increase of caspase pathway activation, secondary to the thawing process, and across all study cell types. This observation may affect the immune response quality during recipient aplasia, without detecting a clinical impact. Moreover, caspase pathway activation through CD3⁺ and CD56⁺ subpopulations could modify the therapeutic result of donor lymphocytes infusion (DLI).

Cryopreservation of adult unrelated donor products in hematopoietic cell transplantation: the OneMatch experience and systematic review of the literature

BACKGROUND

The frequency of cryopreserving blood stem or progenitor products from unrelated donors is not known and the underlying reasons are poorly documented. Greater insight is needed to develop policies on cryopreservation that balance donor safety with patient needs.

STUDY DESIGN AND METHODS

Cryopreservation requests between January 1, 2014, and May 31, 2016, at the OneMatch Stem Cell and Marrow Network at Canadian Blood Services were reviewed and a systematic review of the literature was performed.

RESULTS

Thirty products of 719 (4.2%) unrelated donor collections facilitated by OneMatch were cryopreserved. Patient-related reasons were most common and included the need to delay transplant for continued antimicrobial treatment (six patients), patient too deconditioned to proceed with scheduled transplant (five patients), and/or need for more treatment for relapsed disease (three patients). Donor-related issues leading to cryopreservation requests were less common (five cases), mainly due to lack of donor availability after attempting to reschedule. Cryopreservation of a product that was never infused occurred infrequently (two cases, 7%). In our systematic review of the literature, 993 cases were identified in 32 published reports. Both patient-related and donor-related reasons were cited but not specifically reported, precluding quantitative insight regarding the relative frequency of causes. The impact of cryopreservation on hematopoietic engraftment appears negligible when compared to controls in a subset of studies; however, reporting of outcomes was inconsistent.

CONCLUSION

Future studies with standard outcome measures are needed to clarify the impact of cryopreservation on engraftment and other transplant outcomes. International guidelines that consider the ethical framework surrounding requests for donor product cryopreservation are needed.

Small-Molecule Ice Recrystallization Inhibitors Improve the Post-Thaw Function of Hematopoietic Stem and Progenitor Cells

The success of hematopoietic stem cell transplantation depends in part on the number and the quality of cells transplanted. Cryoinjuries during freezing and thawing reduce the ability of hematopoietic stem and progenitor cells (HSPCs) to proliferate and differentiate after thawing. Up to 20% of the patients undergoing umbilical cord blood (UCB) transplant experience delayed or failed engraftment, likely because of the inadequate hematopoietic potency of the unit. Therefore, the optimization of cryopreservation protocols, with an emphasis on the preservation of HSPCs, is an important issue. Current protocols typically utilize a 10% dimethyl sulfoxide cryoprotectant solution. This solution ensures 70-80% post-thaw cell viability by diluting intracellular solutes and maintaining the cell volume during cryopreservation. However, this solution fails to fully protect HSPCs, resulting in the loss of potency. Therefore, a new class of cryoprotectants (N-aryl-d-aldonamides) was designed and assessed for the ability to inhibit ice recrystallization and to protect HSPCs against cryoinjury. Several highly active ice recrystallization inhibitors were discovered. When used as additives to the conventional cryoprotectant solution, these nontoxic small molecules improved the preservation of functionally divergent hematopoietic progenitors in the colony-forming unit and long-term culture-initiating cell assays. By contrast, structurally similar compounds that did not inhibit ice recrystallization failed to improve the post-thaw recovery of myeloid progenitors. Together, these results demonstrate that the supplementation of cryopreservation solution with compounds capable of controlling ice recrystallization increases the post-thaw function and potency of HSPCs in UCB. This increase may translate into reduced risk of engraftment failure and allow for greater use of cryopreserved cord blood units.

Small molecule ice recrystallization inhibitors mitigate red blood cell lysis during freezing, transient warming and thawing

During cryopreservation, ice recrystallization is a major cause of cellular damage. Conventional cryoprotectants such as dimethyl sulfoxide (DMSO) and glycerol function by a number of different mechanisms but do not mitigate or control ice recrystallization at concentrations utilized in cryopreservation procedures. In North America, cryopreservation of human red blood cells (RBCs) utilizes high concentrations of glycerol. RBC units frozen under these conditions must be subjected to a time-consuming deglycerolization process after thawing in order to remove the glycerol to <1% prior to transfusion thus limiting the use of frozen RBC units in emergency situations. We have identified several low molecular mass ice recrystallization inhibitors (IRIs) that are effective cryoprotectants for human RBCs, resulting in 70–80% intact RBCs using only 15% glycerol and slow freezing rates. These compounds are capable of reducing the average ice crystal size of extracellular ice relative to a 15% glycerol control validating the positive correlation between a reduction in ice crystal size and increased post-thaw recovery of RBCs. The most potent IRI from this study is also capable of protecting frozen RBCs against the large temperature fluctuations associated with transient warming.

Mesenchymal stromal cells from patients with acute myeloid leukemia have altered capacity to expand differentiated hematopoietic progenitors

The bone marrow microenvironment may be permissive to the emergence and progression of acute myeloid leukemia (AML). Studying interactions between the microenvironment and leukemia cells should provide new insight for therapeutic advances. Mesenchymal stromal cells (MSCs) are central to the maintenance of the hematopoietic niche. Here we compared the functions and gene expression patterns of MSCs derived from bone marrow aspirates of healthy donors and patients with AML. MSCs expanded from AML patients had heterogeneous morphology and displayed a wide range of proliferation capacity compared to MSCs from healthy controls. The ability of AML-MSCs to support the expansion of committed hematopoietic progenitors from umbilical cord blood-derived CD34+ cells may be impaired while the expression of genes associated with maintaining hematopoietic quiescence appeared to be increased in AML-MSCs compared to healthy donors. These results highlight important potential differences in the biologic profile of MSCs from AML patients compared to healthy donors that may contribute to the emergence or progression of leukemia.

A new system for quality control in hematopoietic progenitor cell units before reinfusion in autologous transplant

BACKGROUND

In our Center, the cell viability, the integrity of the bag, and the clonogenic assay were evaluated before the reinfusion of hematopoietic progenitor cells-apheresis (HPC-A). This quality control (QC) should be made 14 days before the reinfusion to the patient to have the result of the functional test on the proliferative capacity of hematopoietic progenitors.

STUDY DESIGN AND METHODS

This study was designed to assess the potential of an automatic cell counting system (NucleoCounter NC-3000, ChemoMetec) in our clinical routine as a support of the clonogenic assay and the cytofluorimetric analysis for the QC of the cryopreserved HPC-A. The cell viability was evaluated by flow cytometry using the modified International Society of Hematotherapy and Graft Engineering protocol. The proliferative potential was assessed by specific clonogenic tests using a commercial medium. Furthermore, we evaluated the cellular functionality with NucleoCounter NC-3000, by using two protocols: "vitality assay" and "mitochondrial potential assay."

RESULTS

The evaluation of the total nucleated cells in preapoptosis measured by 5,5,6,6-tetrachloro-1,1,3,3-tetraethylbenzimidazol-carbocyanine iodide (JC-1) assay showed a negative correlation (r=-0.43) with the total number of colonies (colony-forming unit [CFU]-granulocyte-macrophage progenitors plus burst-forming unit-erythroid progenitors plus CFU-granulocyte, erythroid, macrophage, megakaryocyte progenitors) obtained after seeding of 50 × 10(6) /L viable total nucleated cells. We observed a significant difference (p<0.0001) comparing the median number of colonies (166.70; SD, ± 136.36) obtained with a value of JC-1 less than 30% to the number of colonies (61.75; SD, ± 59.76) obtained with a value of JC-1 more than 30%.

CONCLUSION

The evaluation of cell functionality by the use of the NucleoCounter NC-3000 is in agreement with results from clonogenic assay and can be considered an effective alternative in the routine laboratory.

Quantifying loss of CD34+ cells collected by apheresis after processing for freezing and post-thaw

INTRODUCTION

CD34(+) cells collected for autologous bone marrow transplantation (BMT) are usually quantified in the apheresis product after collection, but the necessity to repeat these measures post-thaw is controversial.

METHODS

We examined the loss of CD34(+) cells after collection, preparation for freezing and post-thaw in apheresis products collected for BMT.

RESULTS

Median number of CD34(+) cells collected per unit was 1.61×10(6)/kg, viability: 97-100%. This number decreased to 1.38×10(6)/kg, viability: 96-100% before freezing and was 1.17×10(6)/kg post-thaw. Viability decreased to 86-98%. The relative loss of viable PBHPC showed an inverse correlation with the ratio "CD34(+) cells/total nucleated cells" (r=-0.45; p=<0.0005). This relative loss was largest in patients with Hodgkin's lymphoma.

CONCLUSION

Cryopreservation and thawing of PBHPCs in leukapheresis products provokes a small but significant stem cell loss. So, quantification of viable CD34(+) cells post-thaw is important, especially in poorly mobilizing patients. Besides, the ratio "CD34(+) cells/total nucleated cells" after leukapheresis is an important parameter for prediction of neutrophil recovery after BMT.