Establishing delivery route-dependent safety and efficacy of living biodrug mesenchymal stem cells in heart failure patients

BACKGROUND Mesenchymal stem cells(MSCs)as living biopharmaceuticals with unique properties,i.e.,stemness,viability,phenotypes,paracrine activity,etc.,need to be administered such that they reach the target site,maintaining these properties unchanged and are retained at the injury site to participate in the repair process.Route of delivery(RoD)remains one of the critical determinants of safety and efficacy.This study elucidates the safety and effectiveness of different RoDs of MSC treatment in heart failure(HF)based on phase II randomized clinical trials(RCTs).We hypothesize that the RoD modulates the safety and efficacy of MSCbased therapy and determines the outcome of the intervention.AIM To investigate the effect of RoD of MSCs on safety and efficacy in HF patients.METHODS RCTs were retrieved from six databases.Safety endpoints included mortality and serious adverse events(SAEs),while efficacy outcomes encompassed changes in left ventricular ejection fraction(LVEF),6-minute walk distance(6MWD),and pro-B-type natriuretic peptide(pro-BNP).Subgroup analyses on RoD were performed for all study endpoints.RESULTS Twelve RCTs were included.Overall,MSC therapy demonstrated a significant decrease in mortality[relative risk(RR):0.55,95%confidence interval(95%CI):0.33-0.92,P=0.02]compared to control,while SAE outcomes showed no significant difference(RR:0.84,95%CI:0.66-1.05,P=0.11).RoD subgroup analysis revealed a significant difference in SAE among the transendocardial(TESI)injection subgroup(RR=0.71,95%CI:0.54-0.95,P=0.04).The pooled weighted mean difference(WMD)demonstrated an overall significant improvement of LVEF by 2.44%(WMD:2.44%,95%CI:0.80-4.29,P value≤0.001),with only intracoronary(IC)subgroup showing significant improvement(WMD:7.26%,95%CI:5.61-8.92,P≤0.001).Furthermore,the IC delivery route significantly improved 6MWD by 115 m(WMD=114.99 m,95%CI:91.48-138.50),respectively.In biochemical efficacy outcomes,only the IC subgroup showed a significant reduction in pro-BNP by-860.64 pg/mL(WMD:-860.64 pg/Ml,95%CI:-944.02 to-777.26,P=0.001).CONCLUSION Our study concluded that all delivery methods of MSC-based therapy are safe.Despite the overall benefits in efficacy,the TESI and IC routes provided better outcomes than other methods.Larger-scale trials are warranted before implementing MSC-based therapy in routine clinical practice.

Living biodrugs and how tissue source influences mesenchymal stem cell therapeutics for heart failure

In this editorial we comment on the article by Safwan M et al.We especially fo-cused on the cardiac function restoration by the use of mesenchymal stem cells(MSCs)therapy for heart failure(HF),which has emerged as a new treatment approach as“Living Biodrugs”.HF remains a significant clinical challenge due to the heart’s inability to pump blood effectively,despite advancements in medical and device-based therapies.MSCs have emerged as a promising therapeutic approach,offering benefits beyond traditional treatments through their ability to modulate inflammation,reduce fibrosis,and promote endogenous tissue rege-neration.MSCs can be derived from various tissues,including bone marrow and umbilical cord.Umbilical cord-derived MSCs exhibit superior expansion ca-pabilities,making them an attractive option for HF therapy.Conversely,bone marrow-derived MSCs have been extensively studied for their potential to im-prove cardiac function but face challenges related to cell retention and delivery.Future research is focusing on optimizing MSC sources,enhancing differentiation and immune modulation,and improving delivery methods to overcome current limitations.

Mechanism of adipose-derived mesenchymal stem cell exosomes in the treatment of heart failure

BACKGROUND Heart failure(HF)is a global health problem characterized by impaired heart function.Cardiac remodeling and cell death contribute to the development of HF.Although treatments such as digoxin and angiotensin receptor blocker drugs have been used,their effectiveness in reducing mortality is uncertain.Researchers are exploring the use of adipose-derived mesenchymal stem cell(ADMSC)exosomes(Exos)as a potential therapy for HF.These vesicles,secreted by cells,may aid in tissue repair and regulation of inflammation and immune responses.However,further investigation is needed to understand the specific role of these vesicles in HF treatment.AIM To investigate the mechanism of extracellular vesicles produced by ADMSC s in the treatment of HF.METHODS Exogenous surface markers of ADMSCs were found,and ADMSCs were cultured.RESULTS The identification of surface markers showed that the surface markers CD44 and CD29 of adipose-derived stem cells(ADSCs)were well expressed,while the surface markers CD45 and CD34 of ADSCs were negative,so the cultured cells were considered ADSCs.Western blotting detected the Exo surface marker protein,which expressed CD63 protein but did not express calnexin protein,indicating that ADSC-derived Exos were successfully extracted.CONCLUSION The secretion of MSCs from adipose tissue can increase ATP levels,block cardiomyocyte apoptosis,and enhance the heart function of animals susceptible to HF.The inhibition of Bax,caspase-3 and p53 protein expression may be related to this process.

Peripheral blood stem cells transplantation in patients with heart failure after myocardial infarction:their efficiency and safety

Objective To compare the efficiency and safety of intracoronary transplantation of peripheral blood stem cells (PBSC) between elderly and younger patients with heart failure after myocardial infarction (MI). Methods Twenty-five patients with heart failure after MI were divided into aged group(≥60 years,n=13) and non-aged group(<60years,n=12)to receive intracoronary PBSC transplantation (PBSCT) following bone marrow cells mobilized by granulocyte colony-stimulating factor(G-CSF). Clinical data including coronary lesion characteristic, left ventricular shape,infarct region area and cardiac function, as well as adverse side effects between the two groups were compared. Left ventricular function was evaluated before and 6 months after the treatment by single photon emission computed tomography(SPECT). Results At 6 months, the left ventricular ejection fraction (LVEF) and 6 minute walk test (6MWT) distance increased, while the left ventricular diastolic diameter (LVDd) decreased significantly in both groups. There were no significant difference between the two groups in absolute change in the cardiac function parameters. Conclusions The present study demonstrated that autologous intracoronary PBSCT might be safe and feasible for both old and younger patients with heart failure after MI and left ventricular function is significantly improved.(J Geriatr Cardiol 2007;4:233-237.)

Intraportal mesenchymal stem cell transplantation prevents acute liver failure through promoting cell proliferation and inhibiting apoptosis

BACKGROUND： Transplantation of mesenchymal stem cells （MSCs） has been regarded as a potential treatment for acute liver failure （ALF）, but the optimal route was unknown. The present study aimed to explore the most effective MSCs transplantation route in a swine ALF model. METHODS： The swine ALF model induced by intravenous injection of D-Gal was treated by the transplantation of swine MSCs through four routes including intraportal injection （InP group）, hepatic intra-arterial injection （AH group）, peripheral intravenous injection （PV group） and intrahepatic injection （IH group）. The living conditions and survival time were recorded. Blood samples before and after MSCs trans- plantation were collected for the analysis of hepatic function. The histology of liver injury was interpreted and scored in terminal samples. Hepatic apoptosis was detected by TUNEL assay. Apoptosis and proliferation related protein expressions including cleaved caspase-3, survivin, AKT, phospho-AKT （Ser473）, ERK and phospho-ERK （Tyr204） were analyzed by Western blotting. RESULTS： The average survival time of each group was 10.7± 1.6 days （InP）, 6.0±0.9 days （AH）, 4.7±1.4 days （PV）, 4.3± 0.8 days （IH）, respectively, when compared with the average survival time of 3.8±0.8 days in the D-Gal group. The survival rates between the InP group and D-Gal group revealed a statistically significant difference （P〈0.01）. Pathological and biochemical analysis showed that liver damage was the worst in the D-Gal group, while less injury in the InP group. Histopathological scores revealed a significant decrease in the InP group （3.17±1.04, P〈0.01） and AH group （8.17±0.76, P〈0.05） as compared with that in the D-Gal group （11.50±1.32）. The apoptosis rate in the InP group （25.0%±3.4%, P〈0.01） and AH group （40.5%±1.0% , P〈0.05） was lower than that in the D-Gal group （70.6%±8.5%）. The expression of active caspase-3 was inhibited, while the expression of survivin, AKT, phospho- AKT （Ser473）, ERK and phospho-ERK （Tyr204） was elevated in the InP group. CONCLUSIONS： Intraportal injection was superior to other pathways for MSC transplantation. Intraportal MSC trans- plantation could improve liver function, inhibit apoptosis and prolong the survival time of swine with ALE The transplanted MSCs may participate in liver regeneration via promoting cell proliferation and suppressing apoptosis during the initial stage of ALE

Effects of xenogeneic adipose-derived stem cell transplantation on acute-on-chronic liver failure

BACKGROUND:Adipose-derived stem cells(ADSCs) are particularly attractive in future clinical applications of stem cell-based therapy for acute-on-chronic liver failure(ACLF) This study was undertaken to evaluate the therapeutic potential of ADSCs on ACLF.METHODS:ADSCs isolated from porcine fat tissue were expanded and labeled with BrdU.Rabbit models of ACLF were created by administration of D-Gal following CCl 4-induced cirrhosis.One day after administration of D-Gal,rabbits of the ACLF/ADSCs group(n=15) were received ADSCs transplantation,while those in the ACLF/saline group(n=15) were treated with the same volume of saline.Biochemical parameters and histomorphological scoring were evaluated;the distribution and characteristics of transplanted ADSCs as well as the pathology of the liver were examined.RESULTS:ADSCs transplantation improved the survival rate and the liver function of rabbits with ACLF.Biochemical parameters of the ACLF/ADSCs group were improved compared with those of the ACLF/saline group,and histomorphological scoring of the ACLF/ADSCs group was significantly lower than that of the ACLF/saline group.ADSCs were identified in the periportal region of the liver after cell transplantation.CONCLUSION:Xenogenic ADSCs have therapeutic efficacy in the ACLF rabbit model.

Cardiac autonomic nerve fiber regeneration in chronic heart failure Do Akt gene-transduced mesenchymal stem cells promote repair?

BACKGROUND： Transplantation of Akt-over-expressing mesenchymal stem ceils （Akt-MSCs） has been shown to repair infarcted myocardium and improve cardiac function. However, little is known about the therapeutic effects of Akt-MSCs on cardiac autonomic neuropathy in chronic heart failure （CHF）. OBJECTIVE： The present study used adriamycin-induced CHF rat models to observe the effect of Akt-MSCs on cardiac autonomic nervous regeneration and the factors mediating this effect. DESIGN, TIME AND SETTING： A randomized, controlled animal experiment was performed at the Central Laboratory of Basic Medical College, China Medical University, between September 2008 and April 2009. MATERIALS： Rabbit anti-choline acetyltransferase （CHAT）, growth associated protein-43 （GAP-43） synaptophysin （SYN） polyclonal antibodies and the secondary antibody （goat anti-rabbit IgG） were purchased from Boster, China. Cat-A-Kit assay system was provided by Amersham, USA. METHODS： （1） Adult rat MSCs were isolated and cultured for the preparation of Akt-MSCs. （2） Forty male Wistar rats were intramyocardially administered adriamycin at 2 mg/kg over 3 days for a total of five times and once a week for additional five times thereafter to establish CHF models. At 2 weeks after final adriamycin treatment, 34 successful CHF rat models were randomized to three groups： Akt-MSCs （n = 11）, simple MSCs （s-MSCs, n =11）, and control （n = 12）. Each group was intravenously administered Akt-MSCs （2x106 cells in 100 IJL PBS）, s-MSCs （2×10^6 cells in 100 μL PBS） or equal volume of phosphate buffered saline, once a day for a total of three times. MAIN OUTCOME MEASURES： At 4 weeks after final adriamycin treatment, myocardial norepinephrine （NE） content was detected using a Cat-A-Kit assay system. Myocardial CHAT, SYN and GAP-43 were performed by immunohistochemistry and Western blot analysis. Prior to, 2 and 4 weeks after adriamycin treatment, echocardiographic examination was performed and left ventricular ejection fraction （LVEF） was determined. RESULTS： Myocardial NE content, as well as SYN-positive and GAP-43-positive nerve fiber density and expression, and LVEF, was the greatest in the Akt-MSCs group, followed by the s-MSCs group, and lastly the control group （P 〈 0.05 or P 〈 0.01）. ChAT expression was similar between Akt-MSCs and s-MSCs groups, but it was higher compared with the control group （P 〈 0.05）. NE contents were negatively correlated to LVEF （r = -0.64, P = 0.015）. CONCLUSION： Transplantation of MSCs, in particular Akt-MSCs, promotes cardiac nervous regeneration in failing heart, which might be mediated by GAP-43.

Intrahepatic transplantation of hepatic oval cells for fulminant hepatic failure in rats

AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GFP） or 5, 6- carboxyfluorescein diacetate succinmidyl ester （CFDASE）. Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA- SE labeled HOC （5 × 10^6 cells each rat） were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin （ALB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and total bilirubin （TBil） levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.RESULTS： The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 （9/15 vs 6/15） and 72 h （9/15 vs 4/15） after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum AIb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.CONCLUSION： CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.

Protecting the delivery of heart failure: Regenerative Medicine/Stem Cell Therapeutics:Potential protections afforded by the Department of Health and Human Services and Health Resources Service Administration’s Bureau of Special Programs

Advances in stem cell science and potential clinical applications have brought clinical medicine closer to the actualization of Regenerative Medicine—an extension of transplantation of organs and cells and implantation of bioprosthetics and biodevices. The goal of such therapeutics will be intervention prior to onset of severe individual disability, enhance organ function and enhance patient performance status without incurring the economic impacts of standard organ transplantation. Regenerative Medicine is already demonstrating proof of principle or efficacy in restora- tion of myocardial contractility, joint mobility and function, immune competence, pulmonary function, immunologic self- tolerance, motor function and normal hemoglobin production with the next targets—diabetes mellitus (type I and type II), neurologic injury, hepatic dysfunction preparing to enter trials. Expenditures on health care needs of an aging U.S. citizenry approximate 20-25% ($3 trillion) of U.S. GDP currently and may to grow to 40% of U.S. GDP by 2025. As the potential of Regenerative Medicine is clinically realized, the societal impact and economic benefits will be disproportionately magnified in the economies of industrialized nations. The experi- ence of the Department of Health and Human Services (HHS), United Network for Organ Sharing (UNOS), the National Bone Marrow Donor Registry (NBMDR), and the National Vaccine Injury Compensation Programs (NVICP) can help ensure that as Regenerative Medicine strives to achieve clinical benefits while avoiding decimation of therapeutic options by product liability and medical malpractice concerns—concerns that crippled the U.S. vaccine manufacturing industry until the creation of the NVICP. The first 50 years of organ/cell/tissue transplantation demonstrates that clinical reality of allogeneic and autologous transplantation can antedate complete understanding of the basic science underlying successful transplantation. Product liability and medical malpractice liability have not impeded the development and growth of organ/cell/tissue transplanta- tion despite increased risks of infection, malignancy and cardiovascular disease in transplant recipients. Currently, human transplantation is only performed using FDA/CBER-approved, non-embryonic stem cells from peripheral blood, bone marrow or umbilical cord blood. Federal legislation passed in 2005 (HR2520 and S1317: The Bone Marrow and Cord Blood Cell Transplantation Program) authorizes the Secretary of Health and Human Services acting through the Director of HRSA to ensure uniform stem cell units distribution and outcomes monitoring via the federally-designated C.W. Bill Young Cell Transplant Program. Historically in the U.S., human biological therapies (vaccines, organ transplant and stem cell transplant) have re- quired federal protections to ensure continued distribution, fair access and avoidance of inhibitory product liability via protections afforded under the “stewardship” of the Secretary of Health and Human Services. The National Childhood Vaccine Injury Act of 1986 established the NVICP to equitably and expeditiously compensate individuals, or families of individuals, who have been declared injured by vaccines, thereby stabilizing a once imperiled vaccine supply by substan-tially reducing the threat of liability for vaccine companies, physicians, and other health care professionals who administer vaccines. Vaccines were the first biologics administered to U.S. citizens en masse and presage stem cell therapeutics (which may similarly be administered to millions) will similarly necessitate that a Stem Cell Injury Compensation Program (SCICP) will also need to be in place to demonstrate an intention to do good, an understanding that industry may do well, but that the health care consumer has a right of protection—all recognized from the outset. The Federal Tort Claims Act (FTCA) addresses liability claims via the Executive, Judicial and Legislative branches of Government, providing an um- brella of liability protection to other participants in the stem cell unit “chain of custody” under the FTCA—similar to the protection from product liability seen in organ and stem cell transplantation for the past 40-50 years. Efficacious development of regenerative medicine capabilities will mandate controlled access must first be provided for individuals with life-threatening diseases without therapeutic options or unable to benefit from or receive proven therapeutic options (ALS, cardiomyopathy and deemed not a candidate for heart transplantation, IDDM with hypoglyce- mic unawareness and no allogeneic source of traditional islet cell replacement available via HRSA) and mandates the prompt adoption of business and legal principles to ensure that the fate of the vaccine manufacturing industry does not become the fate of the stem cell therapeutics industry. If legal and regulatory concerns consume an increasing percentage of health care dollars that could be focused upon innovation, the Regenerative Medicine model will have not realized its full potential. The Diabetes Transplantation/Regenerative Medicine Model is the first organ to cell transplant model outside of oncology to demonstrate the regenerative medicine paradigm. Since all human tissues can be already recapitulated by human stem cells and key patent holders already exist, outlet or distribution of “more-than-minimally-manipulated stem cell units” as an IND approved under FDA/CBER guidelines can be accomplished via the current HHS/HRSA/Dept of Trans- plant methodology. As cardiovascular stem cell researchers develop human therapeutics utilizing more-than-minimally- manipulated stem cell products, they could be afforded protections from product liability historically enjoyed by the transplant community. Extending the Diabetes Transplant/Regenerative Medicine Model to the more than 5 million Americans with chronic heart failure, cell-based therapies to regenerate myocardial contractility could fill an existing void and be delivered in conjunction with and consistent with existing distribution of organs and tissues via HRSA/Department of Transplantation.

Respiratory failure in the hematopoietic stem cell transplant recipient

The number of patients receiving hematopoietic stem cell transplantation(HSCT) is rapidly rising worldwide. Despite substantial improvements in peri-transplant care, pulmonary complications resulting in respiratory failure remain a major contributor to morbidity and mortality in the post-transplant period, and represent a major barrier to the overall success of HSCT. Infectious complications include pneumonia due to bacteria, viruses, and fungi, and most commonly occur during neutropenia in the early post-transplant period. Non-infectious complications include idiopathic pneumonia syndrome, periengraftment respiratory distress syndrome, diffuse alveolar hemorrhage, pulmonary veno-occlusive disease, delayed pulmonary toxicity syndrome, cryptogenic organizing pneumonia, bronchiolitis obliterans syndrome, and post-transplant lymphoproliferative disorder. These complications have distinct clinical features and risk factors, occur at differing times following transplant, and contribute to morbidity and mortality.

Stem cell therapy for heart failure:Medical breakthrough,or dead end?

Heart failure continues to be one of the leading causes of morbidity and mortality worldwide.Myocardial infarction is the primary causative agent of chronic heart failure resulting in cardiomyocyte necrosis and the subsequent formation of fibrotic scar tissue.Current pharmacological and non-pharmacological therapies focus on managing symptoms of heart failure yet remain unable to reverse the underlying pathology.Heart transplantation usually cannot be relied on,as there is a major discrepancy between the availability of donors and recipients.As a result,heart failure carries a poor prognosis and high mortality rate.As the heart lacks significant endogenous regeneration potential,novel therapeutic approaches have incorporated the use of stem cells as a vehicle to treat heart failure as they possess the ability to self-renew and differentiate into multiple cell lineages and tissues.This review will discuss past,present,and future clinical trials,factors that influence stem cell therapy outcomes as well as ethical and safety considerations.Preclinical and clinical studies have shown a wide spectrum of outcomes when applying stem cells to improve cardiac function.This may reflect the infancy of clinical trials and the limited knowledge on the optimal cell type,dosing,route of administration,patient parameters and other important variables that contribute to successful stem cell therapy.Nonetheless,the field of stem cell therapeutics continues to advance at an unprecedented pace.We remain cautiously optimistic that stem cells will play a role in heart failure management in years to come.

Dynamic tracking of stem cells in an acute liver failure model

AIM： To investigate a dual labeling technique, which would enable real-time monitoring of transplanted em- bryonic stem cell （ESC） kinetics, as well as long-term tracking. METHODS： Liver damage was induced in C57/BL6 male mice （n = 40） by acetaminophen （APAP） 300 mg/kg administered intraperitoneally. Green fluores- cence protein （GFP） positive C57/BL6 mouse ESCs were stained with the near-infrared fluorescent lipophilic tracer 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbo- cyanine iodide （DiR） immediately before transplantationinto the spleen. Each of the animals in the cell therapy group （n = 20） received 5 x 106 ESCs 4 h following treatment with APAP. The control group （n = 20） re- ceived the vehicle only. The distribution and dynamics of the cells were monitored in real-time with the IVIS lumina-2 at 30 rain post transplantation, then at 3, 12, 24, 48 and 72 h, and after one and 2 wk. Immunohisto- chemical examination of liver tissue was used to identify expression of GFP and albumin. Plasma alanine amino- transferase （ALT） was measured as an indication of liver damage.RESULTS： DiR-stained ESCs were easily tracked with the IVIS using the indocyanine green filter due to its high background passband with minimal background autofluorescence. The transplanted cells were confined inside the spleen at 30 min post-transplantation, gradu- ally moved into the splenic vein, and were detectable in parts of the liver at the 3 h time-point. Within 24 h of transplantation, homing of almost 90% of cells was confirmed in the liver. On day three, however, the DiR signal started to fade out, and ex vivo IVIS imaging of different organs allowed signal detection at time-points when the signal could not be detected by in vivo imag- ing, and confirmed that the highest photon emission was in the liver （P 〈 0.0001）. At 2 wk, the DiRsignal was no longer detectable in vivo; however, immuno- histochemistry analysis of constitutively-expressed GFP was used to provide an insight into the distribution of the cells. GFP ＋ve cells were detected in tissue sections resembling hepatocytes and were dispersed throughout the hepatic parenchyma, with the presence of a larger number of GFP ＋ve cells incorporated within the sinu- soidal endothelial lining. Very faint albumin expression was detected in the transplanted GFP ＋re cells at 72 h; however at 2 wk, few cells that were positive for GFP were also strongly positive for albumin. There was a significant improvement in serum levels of ALT, albumin and bilirubin in both groups at 2 wk when compared with the 72 h time-point. In the cell therapy group, serum ALT was significantly （P = 0.016） lower and al- bumin （P = 0.009） was significantly higher when com- pared with the control group at the 2 wk time-point;however there was no difference in mortality between the two groups. CONCLUSION： Dual labeling is an easy to use and cheap method for longitudinal monitoring of distribu- tion, survival and engraftment of transplanted cells, and could be used for cell therapy models.

MRI of magnetically labeled mesenchymal stem cells in hepatic failure model

AIM:To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.METHODS:Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mes-enteric vein into rabbits (n=16) with carbon tetrachloride-induced hepatic failure.Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1,3,and 7 d after transplantation.Signal intensity (SI) changes on T2weighted MRI were measured,and correlation between MR findings and histomorphologic findings was also investigated.RESULTS:SI on T2-weighted MRI decreased significantly in the liver 2 h after injection of human MSCs and returned gradually to the levels found before injection in 7 d.Changes in SI in the liver at 2 h,1,3,and 7 d were 41.87% ± 9.63%,10.42% ± 4.3%,5.12% ± 1.9%,3.75% ± 1.2%,respectively (P < 0.001).Histologic analyses confirmed the presence of MSCs in the liver,localized mainly in the sinusoids in early period (2 h and 1 d) and concentrated to the border zone in late period (3 and 7 d).The number of iron-positive cells in the liver at 2 h and on 1,3 and 7 d after transplantation was 29.2 ± 4.8,10.1 ± 3.7,6.7 ± 2.2,and 5.8 ± 2.1,respectively (P=0.013).CONCLUSION:Intravascularly injected SPIO-labeled MSCs in an experimental rabbit model of hepatic failure can be detected and followed with MRI.

Effect evaluation of interleukin-1 receptor antagonist nanoparticles for mesenchymal stem cell transplantation

AIM: To study the efficacy of marrow mesenchymal stem cells (MSCs) transplantation combined with interleukin-1 receptor antagonist (IL-1Ra) for acute liver failure (ALF). METHODS: Chinese experimental miniature swine were randomly divided into four groups (n = 7), and all animals were given D-galactosamine (D-gal) to induce ALF. Group A animals were then injected with 40 mL saline via the portal vein 24 h after D-gal induction;Group B animals were injected with 2 mg/kg IL-1Ra via the ear vein 18 h, 2 d and 4 d after D-gal induction; Group C received approximately 1 × 108 green fluorescence protein (GFP)-labeled MSCs (GFP-MSCs) suspended in 40 mL normal saline via the portal vein 24 h after D-gal induction; Group D animals were injected with 2 mg/kg IL-1Ra via the ear vein 18 h after D-gal induction, MSCs transplantation was then carried out at 24 h after D-gal induction, and finally 2 mg/kg IL-1Ra was injected via the ear vein 1 d and 3 d after surgery as before. Liver function, serum inflammatory parameters and pathological changes were measured and the fate of MSCs was determined.RESULTS: The optimal efficiency of transfection (97%) was achieved at an multiplicity of infection of 80, as observed by fluorescence microscopy and flow cytometry (FCM). Over 90% of GFP-MSCs were identified as CD44+ CD90+ CD45-MSCs by FCM, which indicated that most GFP-MSCs retained MSCs characteristics. Biochemical assays, the levels of serum inflammatory parameters and histological results in Group D all showed a significant improvement in liver injury compared with the other groups (P < 0.05). The number of GFP-MSCs in Group D was also greater than that in Group B, and the long-term cell proliferation rate was also better in Group D than in the other groups.CONCLUSION: MSCs transplantation is useful in ALF, IL-1Ra plays an important role in alleviating the inflammatory condition, and combination therapy with MSCs transplantation and IL-1Ra is a promising treatment for ALF.

Therapeutic potential of menstrual blood stem cells in treating acute liver failure

BACKGROUND Acute liver failure(ALF)is a significant and complex hepatic insult that may rapidly progress to life-threatening conditions.Recently,menstrual blood stem cells(MenSCs)have been identified as a group of easily accessible mesenchymal stem cells with the advantages of non-invasive acquisition,low immunogenicity,a greater capacity of self-renewal and multi-lineage differentiation,making them promising candidates for stem cell-based therapy to revolutionize the treatment strategies for liver failure.AIM To investigate the therapeutic potential of MenSCs for treating ALF in pigs and to dynamically trace the biodistribution of transplanted cells.METHODS MenSCs were labeled in vitro with PKH26,a lipophilic fluorescent dye.The treatment group received immediate transplantation of PKH26-labelled MenSCs(2.5×106/kg)via the portal vein after D-galactosamine injection,and the control group underwent sham operation.The survival time,liver function,and hepatic pathological changes were compared between the two groups.Three major organs(liver,lungs and spleen)were extracted from animals and imaged directly with the In vivo Imaging System(IVIS)at the predetermined time points.The regions of interest were drawn to quantify the cell uptake in different organs.RESULTS The labelling procedure did not affect the morphology,viability or multipotential differentiation of MenSCs.Biochemical analysis showed that the levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),total bilirubin(TBIL)and prothrombin time(PT)measured at selected time points 24 h after transplantation were significantly decreased in the treatment group(P<0.05).The survival time of ALF animals was prolonged in the treatment group compared with the control group(75.75±5.11 h vs 53.75±2.37 h,log rank,P<0.001).The liver pathological tissue in the MenSC treatment group showed obviously increased numbers of remaining hepatocytes and a comparatively slight necrotic degree and area.In addition,the IVIS imaging revealed that PKH26-positive MenSCs were clearly retained in the liver initially and then diffused through the systemic circulation.Interestingly,the signal intensity in the liver increased obviously at 36 h,which corresponded to the biochemical result that liver function deteriorated most rapidly at 24-36 h.CONCLUSION Our study demonstrates the therapeutic efficacy and homing ability of transplanted MenSCs in a large animal model of ALF and suggests that MenSC transplantation could be a promising strategy for treating ALF.

Mesenchymal stem cells from the human umbilical cord ameliorate fulminant hepatic failure and increase survival in mice

BACKGROUND：Cell therapy has been promising for various diseases.We investigated whether transplantation of human umbilical cord mesenchymal stem cells（h UCMSCs）has any therapeutic effects on D-galactosamine/lipopolysaccharide（Gal N/LPS）-induced fulminant hepatic failure in mice.METHODS：h UCMSCs isolated from human umbilical cord were cultured and transplanted via the tail vein into severe combined immune deficiency mice with Gal N/LPS-induced fulminant hepatic failure.After transplantation,the localization and differentiation of h UCMSCs in the injured livers were investigated by immunohistochemical and genetic analy- ses. The recovery of the injured livers was evaluated histologi- cally. The survival rate of experimental animals was analyzed by the Kaplan-Meier method and log-rank test. RESULTS： hUCMSCs expressed high levels of CD29, CD73, CD13, CD105 and CD90, but did not express CD31, CD79b, CD133, CD34, and CD45. Cultured hUCMSCs displayed adip- ogenic and osteogenic differentiation potential. Hematoxylin and eosin staining revealed that transplantation of hUCMSCs reduced hepatic necrosis and promoted liver regeneration. Transplantation of hUCMSCs prolonged the survival rate of mice with fulminant hepatic failure. Polymerase chain reaction for human alu sequences showed the presence of human cells in mouse livers. Positive staining for human albumin, human alpha-fetoprotein and human cytokeratin 18 suggested the for- mation of hUCMSCs-derived hepatocyte-like cells in vivo.CONCLUSIONS： hUCMSC was a potential candidate for stem cell based therapies. After transplantation, hUCMSCs partially repaired hepatic damage induced by GalN/LPS in mice. hUC- MSCs engrafted into the injured liver and differentiated into hepatocyte-like cells.

Moving forward on the pathway of cell-based therapies in ischemic heart disease and heart failure-time for new recommendations?

Although substantial advances have been made in treating ischemic heart disease and subsequent heart failure, the overall morbidity and mortality from these conditions remain high. Stem cell-based therapy has emerged as a promising approach for prompting cardiac rejuvenation. Various cell types have been tested in the clinical arena, proving consistent safety results. As for efficiency outcomes, contradictory findings have been reported, partly due to inconsistency in study protocols but also due to poor survival, engraftment and differentiation of transplanted cells in the hostile milieu of the ischemic host tissue. Studies have varied in terms of route of delivery, type and dose of implanted stem cells, patient selection and randomization, and assessment of therapeutic effect. Founded on the main achievements and challenges within almost 20 years of research, a number of official documents have been published by leading experts in the field. Core recommendations have focused on developing and optimizing effective strategies to enrich cell retention and their regenerative potential. Issued consensus and position papers have stemmed from an unmet need to provide a harmonized framework for future research, resulting in improved therapeutic application of cell-based therapies for cardiac regeneration and repair.

Combined mesenchymal stem cell transplantation and interleukin-1 receptor antagonism after partial hepatectomy

AIM: To study the therapeutic effects of mesenchymal stem cells (MSCs) and an interleukin-1 receptor antagonist (IL-1Ra) in acute liver failure.METHODS: Chinese experimental miniature swine (15 &#x000b1; 3 kg, 5-8 mo) were obtained from the Laboratory Animal Centre of the Affiliated Drum Tower Hospital of Nanjing University Medical School. Acute liver failure was induced via 85% hepatectomy, and animals were treated by MSC transplantation combined with IL-1Ra injection. Blood samples were collected for hepatic function analysis, and the living conditions and survival time were recorded. Liver injury was histologically analyzed. Hepatic cell regeneration and apoptosis were studied by Ki67 immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. The levels of protein kinase B and nuclear factor-&#x003ba;B expression were analyzed by Western blotting.RESULTS: MSCs were infected with a lentivirus for expression of green fluorescent protein (GFP) for subsequent identification; 97.3% of the MSCs were positive for GFP as assessed by flow cytometry. Additional flow cytometric analysis of cell surface marker expression demonstrated that &#x0003e; 90% of GFP-expressing MSCs were also positive for CD29, CD44, and CD90, indicating that most of these cells expressed typical markers of MSCs, and the population of MSCs was almost pure. Transplantation of MSCs in combination with 2 mg/kg IL-1Ra therapy significantly improved survival time compared to the acute liver failure model group (35.3 &#x000b1; 6.7 d vs 17.3 &#x000b1; 5.5 d, P &#x0003c; 0.05). Combined therapy also promoted improvement in serum inflammatory cytokines and biochemical conditions. The observed hepatic histopathologic score was significantly lower in the group with combined therapy than in the model group (3.50 &#x000b1; 0.87 vs 8.17 &#x000b1; 1.26, P &#x0003c; 0.01). In addition, liver cell apoptosis in the combined therapy group was significantly inhibited (18.1 &#x000b1; 2.1% vs 70.8 &#x000b1; 3.7%, P &#x0003c; 0.01), and hepatic cell regeneration increased. A significant increase in protein kinase B expression and decrease in nuclear factor-&#x003ba;B expression were observed (P &#x0003c; 0.01), which supports their important roles in liver regeneration.CONCLUSION: MSCs and IL-1Ra had a synergistic effect in liver regeneration via regulation of inflammation and apoptotic signaling.

Advances and perspectives on cellular therapy in acquired bone marrow failure diseases

Acquired bone marrow failure diseases(ABMFD) are a class of hematopoietic stem cell diseases with a commonality of non-inherited disruption of hematopoiesis that results in pancytopenia. ABMFDs also are a group of heterogeneous diseases with different etiologies and treatment options. The three most common ABMFDs are aplastic anemia, myelodysplastic syndrome, and paroxysmal nocturnal hemoglobinuria. Stem cell transplantation is the only treatment that can cure these diseases. However, due to high therapy-related mortality, stem cell transplantation has rarely been used as a first line treatment in treating ABMFD. With the advance of personalized medicine and precision medicine, various novel cellular therapy strategies are in trial to increase the efficiency and efficacy of ABMFD treatment. This article aims to review current available stem cell transplantation protocols and promising cellular therapy research in treating ABMFD.

Targeted migration of mesenchymal stem cells modified with CXCR4 to acute failing liver improves liver regeneration

AIM: To improve the colonization rate of transplanted mesenchymal stem cells (MSCs) in the liver and effect of MSC transplantation for acute liver failure (ALF).