Cell Transplantation最新文献

Herein, we characterized the percentage of tacrolimus to the combined sirolimus and tacrolimus trough levels (tacrolimus %) observed during islet transplant-associated immune suppression therapy with post-transplant skin cancer. Although trough levels of tacrolimus and sirolimus were not different (P = 0.79, 0.73, respectively), high tacrolimus % resulted in a 1.32-fold increase in skin cancer odds when adjusting for age, sex, body mass index (BMI), and use of mycopheonlate mofetil (MMF; p = 0.039). Skin cancer patients were likely to have been older but not differ significantly (mean difference 12 years, P = 0.056), but age was significantly associated with a 1.22-fold increase in adjusted skin cancer odds (P = 0.046). BMI was inversely associated with skin cancer, with an adjusted odds ratio (OR) of 0.40 (P = 0.022). High tacrolimus % (>35) resulted in a 4.6-fold increase in skin cancer frequency, whereas sirolimus above 75% of the combined therapy led to a 5.2-fold increase in islet graft dysfunction (IGD) events/year. By calculating the maximum safe exposure (MSE) to tacrolimus % according to patient age and BMI, we found that cumulative months spent above MSE was predictive of skin cancer (1.20-fold increase, P = 0.003). Individuals exceeding the MSE for 1 year were 9.2 times more likely to develop skin cancer (P = 0.008). Results suggest that strategies targeting immunosuppression ratios based on age and BMI may minimize cancer risk while improving graft survival and function.

Tissue repair is an extremely crucial part of clinical treatment. During the course of disease treatment, surgery, chemotherapy, and radiotherapy cause tissue damage. On the other hand, Normal tissue from accidental or therapeutic exposure to high-dose radiation can cause severe tissue damage. There is an urgent need for developing medical countermeasures against radiation injury for tissue repair. Tissue repair involves the regeneration, proliferation, differentiation, and migration of tissue cells; imbalance of local tissue homeostasis, progressive chronic inflammation; decreased cell activity and stem cell function; and wound healing. Although many clinical treatments are currently available for tissue repair, they are expensive. The long recovery time and some unavoidable complications such as cell damage and the inflammatory reaction caused by radiotherapy have led to unsatisfactory results. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have similar tissue repair functions as MSCs. In tissue damage, EVs can be used as an alternative to stem cell therapy, thereby avoiding related complications such as immunological rejection. EVs play a major role in regulating tissue damage, anti-inflammation, pro-proliferation, and immune response, thus providing a diversified and efficient solution for the repair of disease- and radiotherapy-induced tissue damage. This article reviews the research progress of mesenchymal stem cell-derived EVs in promoting the repair of tissue including heart, lung, liver, intestine, skin, blood system, central nervous system, and tissue damage caused by radiotherapy, thereby aiming to offer new directions and ideas for the radiotherapy and regenerative applications.

The eye represents a highly specialized organ, with its main function being to convert light signals into electrical impulses. Any damage or disease of the eye induces a local inflammatory reaction that could be harmful for the specialized ocular cells. Therefore, the eye developed several immunoregulatory mechanisms which protect the ocular structures against deleterious immune reactions. This protection is ensured by the production of a variety of immunosuppressive molecules, which create the immune privilege of the eye. In addition, ocular cells are potent producers of numerous growth and trophic factors which support the survival and regeneration of diseased and damaged cells. If the immune privilege of the eye is interrupted and the regulatory mechanisms are not sufficiently effective, the eye disease can progress and result in worsening of vision or even blindness. In such cases, external immunotherapeutic interventions are needed. One perspective possibility of treatment is represented by mesenchymal stromal/stem cell (MSC) therapy. MSCs, which can be administered intraocularly or locally into diseased site, are potent producers of various immunoregulatory and regenerative molecules. The main advantages of MSC therapy include the safety of the treatment, the possibility to use autologous (patient's own) cells, and observations that the therapeutic properties of MSCs can be intentionally regulated by external factors during their preparation. In this review, we provide a survey of the immunoregulatory and regenerative mechanisms in the eye and describe the therapeutic potential of MSC application for corneal damages and retinal diseases.

Rheumatoid arthritis (RA) is a systemic, chronic inflammatory disease characterized by altered levels of inflammatory cytokines. One of the key cytokines involved in the pathogenesis of RA is tumor necrosis factor α (TNF-α), which plays a crucial role in the differentiation of T cells and B cells and serves as a primary trigger of inflammation and joint damage in RA. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have shown potential in alleviating the symptoms of RA. Previous in vitro studies indicate that TNF-α secreted by T cells can activate NF-κB in human MSCs, thereby triggering the immunoregulatory capacity of MSCs in a manner dependent on tumor necrosis factor receptor 1 (TNFR1). Inspired by these findings, we aimed to evaluate whether TNFR1 determine the therapeutic effects of hUC-MSCs on RA. First, we investigated whether TNFR1 is necessary for hUC-MSCs to inhibit TNF-α production of PBMCs, a source of elevated TNF-α in patients. Through coculture experiment, we confirmed that this inhibition was dependent on TNFR1. Subsequently, we administered hUC-MSCs or siTNFR1-MSCs to DBA/1J male mice with collagen-induced arthritis. The results indicated that hUC-MSCs significantly alleviated the pathological features of RA and suppressed the inflammatory cytokines IFN-γ, TNF-α, and IL-6 in peripheral blood, also in a manner dependent on TNFR1 either. Given the dramatic pathologic differences between hUC-MSCs and siTNFR1-MSCs treatments, we questioned whether production of growth factors and chemokines was significantly influenced by TNFR1. Consequently, we stimulated hUC-MSCs or siTNFR1-MSCs through IFN-γ, TNF-α, and IL-6, and profiled growth factors and chemokines in serum, which revealed significant changes of hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF), as well as chemokines CXCL9, CXCL10, IL-8, and RANTES. In summary, our findings suggest that TNFR1 may determine whether hUC-MSCs will gain abilities of anti-inflammation and tissue regeneration.

The trans-vessel wall device (TW-device) is a new endovascular tool for precise and safe delivery of various payloads (cells, viral, modified RNA, chemotherapy, growth factors) in oncology and regenerative medicine. The twofold aim of this study was to assess cell engraftment and tumor growth using the TW-device for endovascular transplantation and to evaluate its ability to directly access solid tumors. We used the VX2 model in the rabbit kidney to compare percutaneously implanted fresh VX2 cells with TW-device injections of cryopreserved VX2 cells. We demonstrated the feasibility of endovascular transplantation (n = 7) of tumor cells, achieving a 57.1% engraftment rate despite cryopreservation, comparable with 70% for percutaneous delivery of fresh cells (n = 10). Re-access using the TW-device was 100% successful (n = 11) with super-selective intratumoral contrast administration without complications. In conclusion, endovascular transplantation of VX2 cells using the TW-device resulted in proliferating cell grafts in the rabbit kidney establishing functional proof that cells indeed survive handling, preparation, and device passage. We also show the TW-device is able to access solid tumor parenchyma allowing precise intraparenchymal administration.This proof-of-concept study open up possibilities for repeated direct parenchymal injections via the endovascular route in any hard to reach organ.

Islet transplantation (IT) is a successful natural cell therapy. But the benefits are known mostly to individuals with severe type 1 diabetes who undergo IT and the health care professionals that work to make the therapy available, reproducible, and safe. Data linking IT to overall survival in T1D might alter this situation and frame the therapy in a more positive light. Recent analysis of mortality in several cohorts suggests that IT has possible survival benefits when used alone or in conjunction with renal transplantation. Multi-center prospective studies with long-term follow-up of individuals that receive stand-alone IT versus individuals who qualify for but do not undergo the procedure would seem reasonable to undertake to confirm an IT survival benefit.

Donor-specific antibodies (DSAs) are essential causes of graft rejection in haploidentical hematopoietic stem cell transplantation (haplo-HSCT). DSAs are unavoidable for some patients who have no alternative donor. Effective interventions to reduce DSAs are still needed, and the cost of the current therapies is relatively high. In this study, we retrospectively analyzed the data of 11 DSA-positive patients who received haplo-HSCT at our center and evaluated the therapeutic efficacy of the combination of intravenous immunoglobulin (IVIG), dexamethasone and high dose of transfused mononuclear cells (MNCs) for DSA desensitization. The kinetics of DSAs at different times and the engraftment and transplantation outcomes were also observed. We found that all patients had successful donor-cell engraftment and that no patient developed poor graft function. The median engraftment times of neutrophils and platelets were 14 days (range, 11-24 days) and 13 days (range, 11-123 days), respectively. The DSA levels of all patients became negative or dropped under 2000 within 22 days after HSCT. A total of 36.4% of patients developed grade II-IV acute graft-versus-host disease (aGVHD), and 9.1% of patients died of severe gastrointestinal aGVHD. Of the 7 surviving patients, four were diagnosed with chronic GVHD. After a median follow-up of 28.9 months (2.0-52.1 months), four patients died: of relapse (two), aGVHD (one), and multiple-organ failure (one). The 2-year OS, DFS, and NRM were 63.6%, 45.4%, and 18.2%, respectively. Combination therapy with IVIG, dexamethasone, and a high dose of MNCs transfusion, a simple and efficient procedure, was safe and effective for DSA desensitization and peripheral blood stem cell (PBSC) engraftment.

Pediatric organ transplant recipients have a higher risk for wait list mortality due to the scarcity of size matched organs. Neonatal organ donation could potentially ameliorate the discrepancy but is currently not implemented in Sweden. This study aims to evaluate the potential of neonatal organ donation in central Sweden using a standardized protocol with organ specific criteria. Data on 2,061 neonates who deceased in central Sweden from 2006 to 2016 were collected; 308 neonates met criteria for possible donation. Medical records of all possible donors were reviewed, identifying 85 potential donors. Main cause of death was hypoxic ischemic encephalopathy 47% (n = 40). Median weight was 2,355 (IQR: 1,953) g, with 31% receiving inotropic support. Median creatinine of 72 (IQR: 67) µmol/l, urine production 3 (IQR: 2.2) ml/kg/h, ALT 0.51 (IQR: 1.5) µkat/l, and AST 1.7 (IQR: 3.1) µkat/l. Criteria for kidney donation was met in 39 potential neonatal, 29 for liver and 18 for heart, corresponding to a potential increase of 1.9, 1.4, and 0.9 donors PMP per year, respectively. In total, 16 neonates had a catastrophic neurological injury in combination with lack of brainstem reflexes, indicating plausibility of donation after brain death. Expanding organ donation into the neonatal period in Sweden could lead to an increase in organs available for transplant.

Mesenchymal stem cells (MSCs) are pluripotent stem cells with self-renewal. They play a critical role in cell therapy due to their powerful immunomodulatory and regenerative effects. Recent studies suggest that one of the key therapeutic mechanisms of MSCs seems to derive from their paracrine product, called extracellular vesicles (EVs). The EVs contain much DNA, messenger RNA (mRNA), microRNA, and protein components, which can exert intracellular communication to target cells. In clinical applications, the MSC-EVs have been widely used in tissue repair and immune disorder diseases. However, there are serval issues need to be considered such as how to accomplish the large-scale production of EVs and how to verify the exact mechanism of EVs. In this review, we summarize the current progress of MSC-EVs and discuss the challenges and future of MSC-EVs.