Bone marrow-derived stem cells in liver repair: 10 years down the line

Chemically-induced cancers do not originate from bone marrow-derived cells

BACKGROUND

The identification and characterization of cancer stem cells (CSCs) is imperative to understanding the mechanism of cancer pathogenesis. Growing evidence suggests that CSCs play critical roles in the development and progression of cancer. However, controversy exists as to whether CSCs arise from bone marrow-derived cells (BMDCs).

METHODOLOGY AND PRINCIPAL FINDINGS

In the present study, n-nitrosodiethylamine (DEN) was used to induce tumor formation in female mice that received bone marrow from male mice. Tumor formation was induced in 20/26 mice, including 12 liver tumors, 6 lung tumors, 1 bladder tumor and 1 nasopharyngeal tumor. Through comparison of fluorescence in situ hybridization (FISH) results in corresponding areas from serial tumor sections stained with H&E, we determined that BMDCs were recruited to both tumor tissue and normal surrounding tissue at a very low frequency (0.2-1% in tumors and 0-0.3% in normal tissues). However, approximately 3-70% of cells in the tissues surrounding the tumor were BMDCs, and the percentage of BMDCs was highly associated with the inflammatory status of the tissue. In the present study, no evidence was found to support the existence of fusion cells formed form BMDCs and tissue-specific stem cells.

CONCLUSIONS

In summary, our data suggest that although BMDCs may contribute to tumor progression, they are unlike to contribute to tumor initiation.

Are autologous bone marrow stem cell transplantation and transcatheter arterial embolization the best choices for patients with hepatocellular carcinoma and hepatic dysfunction? Report of a case

The purpose of this work was to evaluate the effects of autologous bone marrow stem cell transplantation (AMSCT) and transarterial embolization (TAE) in patients with hepatocellular carcinoma (HCC) and hepatic dysfunction. A 58-year-old male with HCC and hepatic function of Child's class C was treated with 8 ml of a lipiodol emulsion by injection into the artery feeding of his tumor, and >10(8) bone marrow stem cells were isolated from 400 ml bone marrow and then injected into the right hepatic artery. The patient's laboratory examinations revealed a progressive decrease in total bilirubin (from 264.8 to 77.9 μmol/L) and direct bilirubin (from 222.0 to 59.7 μmol/L) after 1 month, and a repeat CT showed that most of the tumor was filled with lipiodol. The combined treatment using AMSCT and TAE is a good choice of treatment for HCC patients who are unable to tolerate TACE due to hepatic dysfunction.

Treatment of newborn G6pc(-/-) mice with bone marrow-derived myelomonocytes induces liver repair

BACKGROUND & AIMS

Several studies have shown that bone marrow-derived committed myelomonocytic cells can repopulate diseased livers by fusing with host hepatocytes and can restore normal liver function. These data suggest that myelomonocyte transplantation could be a promising approach for targeted and well-tolerated cell therapy aimed at liver regeneration. We sought to determine whether bone marrow-derived myelomonocytic cells could be effective for liver reconstitution in newborn mice knock-out for glucose-6-phosphatase-α.

METHODS

Bone marrow-derived myelomonocytic cells obtained from adult wild type mice were transplanted in newborn knock-out mice. Tissues of control and treated mice were frozen for histochemical analysis, or paraffin-embedded and stained with hematoxylin and eosin for histological examination or analyzed by immunohistochemistry or fluorescent in situ hybridization.

RESULTS

Histological sections of livers of treated knock-out mice revealed areas of regenerating tissue consisting of hepatocytes of normal appearance and partial recovery of normal architecture as early as 1 week after myelomonocytic cells transplant. FISH analysis with X and Y chromosome paints indicated fusion between infused cells and host hepatocytes. Glucose-6-phosphatase activity was detected in treated mice with improved profiles of liver functional parameters.

CONCLUSIONS

Our data indicate that bone marrow-derived myelomonocytic cell transplant may represent an effective way to achieve liver reconstitution of highly degenerated livers in newborn animals.

Diabetic impairment of C-kit bone marrow stem cells involves the disorders of inflammatory factors, cell adhesion and extracellular matrix molecules

Bone marrow stem cells from diabetes mellitus patients exhibit functional impairment, but the relative molecular mechanisms responsible for this impairment are poorly understood. We investigated the mechanisms responsible for diabetes-related functional impairment of bone marrow stem cells by extensively screening the expression levels of inflammatory factors, cell cycle regulating molecules, extracellular matrix molecules and adhesion molecules. Bone marrow cells were collected from type 2 diabetic (db/db) and healthy control (db/m+) mice, and c-kit⁺ stem cells were purified (purity>85%) for experiments. Compared with the healthy control mice, diabetic mice had significantly fewer c-kit⁺ stem cells, and these cells had a lower potency of endothelial differentiation; however, the production of the angiogenic growth factor VEGF did not differ between groups. A pathway-focused array showed that the c-kit⁺ stem cells from diabetic mice had up-regulated expression levels of many inflammatory factors, including Tlr4, Cxcl9, Il9, Tgfb1, Il4, and Tnfsf5, but no obvious change in the expression levels of cell cycle molecules. Interestingly, diabetes-related alterations of the extracellular matrix and adhesion molecules were varied; Pecam, Mmp10, Lamc1, Itgb7, Mmp9, and Timp4 were up-regulated, but Col11a1, Fn1, Admts2, and Itgav were down-regulated. Some of these changes were also confirmed at the protein level by flow cytometry analysis. In conclusion, c-kit⁺ bone marrow stem cells from diabetic mice exhibited an extensive enhancement of inflammatory factors and disorders of the extracellular matrix and adhesion molecules. Further intervention studies are required to determine the precise role of each molecule in the diabetes-related functional impairment of c-kit⁺ bone marrow stem cells.

Therapeutic potential of adipose tissue-derived stem cells for liver failure according to the transplantation routes

Purpose

Even though adipose tissue-derived stem cells (ADSCs) have been spotlighted as a possible alternative for liver transplantation in an experimental setting, the mechanism by which ADSCs improve liver dysfunction remains poorly characterized. The objective of this study was to evaluate the therapeutic ability of undifferentiated ADSCs, and find a few clues on how ADSCs alleviate liver damage by comparing the transplantation routes.

Methods

In vitro generated human ADSCs were checked for surface markers and stage-specific genes for characterization. Afterwards, they were transplanted into C57BL/6 mice with CCl4-induced liver injury. The transplantations were made via tail vein, portal vein, and direct liver parenchymal injection. At 1 and 3 post-transplantation days, serum biochemical parameters and/or liver specimens were evaluated.

Results

We have shown here that ADSCs have the characteristics of mesenchymal stem cells, and belong to endodermal and/or early hepatic differentiation stage. After transplantation into the mice with acute liver failure, markers of liver injury, such as alanineaminotransferase, aspartateaminotransferase, as well as ammonia, decreased. Of these transplantation routes, transplantation via tail vein rendered the most prominent reduction in the biochemical parameters.

Conclusion

Undifferentiated ADSCs have the ability to improve hepatic function in mice with acute liver injury. Moreover, our transplantation route study supports the theory that ADSCs in systemic circulation can exert endocrine or paracrine effects to ameliorate the injured liver.

Therapeutic application of stem cells in gastroenterology: An up-date

Adult stem cells represent the self-renewing progenitors of numerous body tissues, and they are currently classified according to their origin and differentiation ability. In recent years, the research on stem cells has expanded enormously and holds therapeutic promises for many patients suffering from currently disabling diseases. This paper focuses on the possible use of stem cells in the two main clinical settings in gastroenterology, i.e., hepatic and intestinal diseases, which have a strong impact on public health worldwide. Despite encouraging results obtained in both regenerative medicine and immune-mediated conditions, further studies are needed to fully understand the biology of stem cells and carefully assess their putative oncogenic properties. Moreover, the research on stem cells arouses fervent ethical, social and political debate. The Italian Society of Gastroenterology sponsored a workshop on stem cells held in Verona during the XVI Congress of the Federation of Italian Societies of Digestive Diseases (March 6-9, 2010). Here, we report on the issues discussed, including liver and intestinal diseases that may benefit from stem cell therapy, the biology of hepatic and intestinal tissue repair, and stem cell usage in clinical trials.

Autologous bone marrow mesenchymal stem cell transplantation in liver failure patients caused by hepatitis B: short-term and long-term outcomes

Our study aimed to investigate the short-term efficacy and long-term prognosis of liver failure patients caused by hepatitis B after a single transplantation with autologous marrow mesenchymal stem cells (MMSCs). A total of 527 inpatients with liver failure caused by hepatitis B were recruited and received the same medical treatments, among whom 53 patients underwent a single transplantation with autologous MMSCs. A total of 105 patients matched for age, sex, and biochemical indexes, including alanine aminotransferase (ALT), albumin, total bilirubin (TBIL), prothrombin time (PT), and Model for End-Stage Liver Disease (MELD), comprised the control group. A total of 120 mL of bone marrow was obtained from each patient and then diluted and separated. Then, the MMSC suspension was slowly transfused into the liver through the proper hepatic artery. The success rate of transplantation was 100%, without serious side effects or complications. Levels of ALB, TBIL, and PT and MELD score of patients in the transplantation group were markedly improved from 2-3 weeks after transplantation, compared with those in the control group. At 192 weeks of follow-up, there were no dramatic differences in incidence of hepatocellular carcinoma (HCC) or mortality between the two groups. Additionally, there were no significant differences in the incidence of HCC or mortality between patients with and without cirrhosis in the transplantation group.

CONCLUSION

Autologous MMSC transplantation is safe for liver failure patients caused by chronic hepatitis B. Short-term efficacy was favorable, but long-term outcomes were not markedly improved. In respect to several parameters, this method is preferable for patients with liver cirrhosis and may have potential for reducing their incidence of HCC and mortality.

Efficacy of autologous bone marrow stem cell transplantation via the hepatic artery in combination with octreotide in the management of refractory ascites in patients with hepatic cirrhosis

AIM: To evaluate the efficacy of transplantation of autologous bone marrow stem cells via the hepatic artery in combination with octreotide in the treatment of refractory ascites in patients with cirrhosis.

METHODS: Thirty-three cirrhotic patients with refractory ascites were randomly divided into two groups: treatment group (n = 14) and control group (n = 19). The treatment group underwent conventional therapy, transplantation of autologous bone marrow stem cells via the hepatic artery, and treatment with octreotide, while the control group underwent conventional therapy and treatment with octreotide. The abdominal circumference, appetite, urine volume, the status of edema of the lower extremities and ascites, serum urea nitrogen, creatinine, albumin, and health status score were compared between before and after treatment and between the two groups.

RESULTS: No obvious complications occurred in all patients. One week after treatment, the total response rate showed no significant difference between the treatment and control groups (78.57% vs 78.95%, P > 0.05). However, the total response rate at week 4 was significantly higher in the treatment group than in the control group (92.86% vs 63.16%, P < 0.05). After four weeks of treatment, the improvements in abdominal circumference and urine volume were more significant in the treatment group than in the control group (both P < 0.05), and albumin was increased from 19.79 g/L ± 4.02 g/L to 27.34 g/L ± 4.00 g/L (P < 0.05). The healthy status, as assessed according to the Karnofsky Performance Status (KPS) scale, was better in the treatment group than in the control group (P < 0.05).

CONCLUSION: Transplantation of autologous bone marrow stem cells via the hepatic artery in combination with octreotide has good short-term efficacy and safety in the management of refractory ascites in patients with cirrhosis.

Differential bone marrow hematopoietic stem cells mobilization in hepatectomized patients

BACKGROUND

The involvement of bone marrow hematopoietic stem cells (BMHSC) mobilization during liver regeneration from hepatectomized patients is under debate. The main aim of this study was to investigate the role of BMHSC mobilization after hepatic resection in 33 patients with liver disease.

METHODS AND RESULTS

Mobilization of CD34(+) BMHSC after 72 h of surgery was found in peripheral blood of some, but not all, of the hepatectomized patients. These CD34(+) cells co-expressed other stem cells markers. The patients without BMHSC mobilization showed high levels of circulating and liver tissue BMHSC (CD34(+) cells) previous to surgery. Therefore, two types of patients: "mobilizers" and "non-mobilizers" were distinguished based on the values of CD34(+) cells before and after surgery. Changes in cytokines involved in the hepatic regeneration (HGF and TGF-β), and in BMHSC mobilization process (SCF, SDF-1, IL-12, or MMP-2), were detected in both groups. In addition, a higher activation previous to surgery of the SDF-1/CXCR4 axis in liver tissue was observed in non mobilizers patients compared to mobilizer patients.

CONCLUSION

BMHSC mobilization seems to be associated with variations in the levels of cytokines and proteolytic enzymes involved in hepatic regeneration and bone marrow matrix degradation. Hepatectomy may be an insufficient stimulus for BMSHC mobilization. The pre-hepatectomy higher levels CD34(+) cells in peripheral blood and liver, associated to the activation of hepatic SDF-1/CXCR4 axis, suggest a BMHSC mobilization process previous to surgery in non mobilizer patients.

Bone marrow mesenchymal cells: how do they contribute to tissue repair and are they really stem cells?

Adult stem cells typically generate the cell types of the tissue in which they reside, and thus the range of their differentiation is considered limited. Bone marrow mesenchymal stem cells (MSCs) are different from other somatic stem cells in that they differentiate not only into the same mesodermal-lineage such as bone, cartilage, and adipocytes but also into other lineages of ectodermal and endodermal cells. Thus, MSCs are a unique type of adult stem cells. In addition, MSCs home to damaged sites, differentiate into cells specific to the tissue and contribute to tissue repair. Therefore, application of MSCs in the treatment of various diseases, including liver dysfunction, myocardial infarction, and central nervous system repair, has been initiated. Because MSCs are generally harvested as adherent cells from bone marrow aspirates, however, they comprise heterogeneous cell populations and their wide-ranging differentiation ability and repair functions are not yet clear. Recent evidence suggests that a very small subpopulation of cells that assume a repair function with the ability to differentiate into trilineage cells resides among human MSCs and effective utilization of such cells is expected to improve the repair effect of MSCs. This review summarizes recent advances in the clarification of MSC properties and discusses future perspectives.

Use of stem cells for liver diseases-current scenario

End-stage liver disease and liver failure are major health problems worldwide leading to high mortality and morbidity and high healthcare costs. Currently, orthotropic liver transplantation is the only effective treatment available to the patients of end-stage liver disease. However, a serious shortage of liver donors, high cost, and risk of organ rejection are the major obstacles to liver transplantation. Because of the ability of stem cells for differentiation into any tissue type, they have huge potential in therapy of various end-stage or degenerative diseases and traumatic injuries. Stem cell therapy has the potential to provide a valuable adjunct and alternative to liver transplantation and has immense potential in the management of end stage liver disease and liver failure. Stem cell therapy can be mediated by either a direct contribution to the functional hepatocyte population with embryonic, induced pluripotent, or adult stem cells or by promotion of endogenous regenerative processes with bone marrow-derived stem cells. Initial translational studies have been encouraging and have suggested improved liver function in advanced chronic liver disease and enhanced liver regeneration after portal vein embolization and partial hepatic resection. Stem cells infusion in cirrhotic patients has improved liver parameters and could form a viable bridge to transplantation. The present review summarizes basic of stem cell biology relevant to clinicians and an update on recent advances on the management of liver diseases using stem cells.

Bone marrow mesenchymal stem cells as a treatment for acute liver failure

Bone marrow mesenchymal stem cells (BM-MSCs) are a kind of multipotent stem cells that have the capacity to undergo self-renewal and multi-lineage differentiation. In an appropriate microenvironment, BM-MSCs can differentiate into bone, cartilage, fat, nerve, liver or other cells. Based on this characteristic, BM-MSCs might be used as new seed cells for orthotopic liver transplantation and bioartificial liver support system. This paper reviews the recent advances in research on the use of BM-MSCs as a treatment for acute liver failure.

Histochemistry and cell biology: the annual review 2010

This review summarizes recent advances in histochemistry and cell biology which complement and extend our knowledge regarding various aspects of protein functions, cell and tissue biology, employing appropriate in vivo model systems in conjunction with established and novel approaches. In this context several non-expected results and discoveries were obtained which paved the way of research into new directions. Once the reader embarks on reading this review, it quickly becomes quite obvious that the studies contribute not only to a better understanding of fundamental biological processes but also provide use-oriented aspects that can be derived therefrom.

Global transcriptome analysis of human bone marrow stromal cells (BMSC) reveals proliferative, mobile and interactive cells that produce abundant extracellular matrix proteins, some of which may affect BMSC potency

BACKGROUND AIMS

Bone marrow stromal cells (BMSC) are being used for immune modulatory, anti-inflammatory and tissue engineering applications, but the properties responsible for these effects are not completely understood. Human BMSC were characterized to identify factors that might be responsible for their clinical effects and biomarkers for assessing their quality.

METHODS

Early passage BMSC prepared from marrow aspirates of seven healthy subjects were compared with three human embryonic stem cell (hESC) samples, CD34(+) cells from three healthy subjects and three fibroblast cell lines. The cells were analyzed with oligonucleotide expression microarrays with more than 35 000 probes.

RESULTS

BMSC gene expression signatures of BMSC differed from those of hematopoietic stem cells (HSC), hESC and fibroblasts. Genes upregulated in BMSC were involved with cell movement, cell-to-cell signaling and interaction and proliferation. The upregulated genes most probably belonged to pathways for integrin signaling, integrin-linked kinase (ILK) signaling, NF-E2-related factor-2 (NFR2)-mediated oxidative stress response, regulation of actin-based motility by Rho, actin cytoskeletal signaling, caveolar-mediated endocytosis, clathrin-mediated endocytosis and Wingless-type MMTV integration site (Wnt/β catenin signaling. Among the most highly upregulated genes were structural extracellular matrix (ECM) proteins (α5 and β5 integrin chains, fibronectin and collagen type IIIα1 and Vα1) and functional EMC proteins [connective tissue growth factor (CTGF), transforming growth factor beta-induced protein (TGFBI) and A disintegrin and metalloproteinase (ADAM12)].

CONCLUSIONS

Global analysis of human BMSC suggests that they are mobile, metabolically active, proliferative and interactive cells that make use of integrins and integrin signaling. They produce abundant ECM proteins that may contribute to their clinical immune modulatory and anti-inflammatory effects.

Decreased collagen types I and IV, laminin, CK-19 and α-SMA expression after bone marrow cell transplantation in rats with liver fibrosis

Bone marrow cells have frequently been tested in animal models of liver fibrosis to assess their role in hepatic regeneration. The mononuclear fraction of bone marrow cells is of particular interest, as many studies show that these cells may be beneficial to treat hepatic fibrosis. In this study, we used the bile duct ligation model to induce hepatic fibrosis in an irreversible manner, and rats were treated with bone marrow mononuclear (BMMN) cells after fibrosis was established. Analysis of collagen types I and IV, laminin and α-SMA showed a decreased expression of these proteins in fibrotic livers after 7 days of BMMN cell injection. Moreover, cytokeratin-19 analysis showed a reduction in bile ducts in the BMMN cell-treated group. These results were accompanied by ameliorated levels of hepatic enzymes GPT (Glutamic-pyruvic transaminase), GOT (glutamic-oxaloacetic transaminase) and alkaline phosphatase (AP). Therefore, we showed that BMMN cells decrease hepatic fibrosis by significantly reducing myofibroblast numbers and through reduction of the collagen and laminin-rich extracellular matrix of fibrotic septa and hepatic sinusoids.

Stem cell-based therapies for liver diseases: state of the art and new perspectives

Millions of patients worldwide suffer from end-stage liver pathologies, whose only curative therapy is liver transplantation (OLT). Given the donor organ shortage, alternatives to OLT have been evaluated, including cell therapies. Hepatocyte transplantation has been attempted to cure metabolic liver disorders and end-stage liver diseases. The evaluation of its efficacy is complicated by the shortage of human hepatocytes and their difficult expansion and cryopreservation. Recent advances in cell biology have led to the concept of "regenerative medicine", based on the therapeutic potential of stem cells (SCs). Different types of SCs are theoretically eligible for liver cell replacement. These include embryonic and fetal SCs, induced pluripotent cells, annex SCs, endogenous liver SCs, and extrahepatic adult SCs. Aim of this paper is to critically analyze the possible sources of SCs suitable for liver repopulation and the results of the clinical trials that have been published until now.

Treatment of different types of cirrhosis by autologous bone marrow stem cell transplantation via the hepatic artery: an analysis of 12 cases

AIM: To evaluate the efficacy and feasibility of autologous bone marrow stem cell transplantation via the hepatic artery in the treatment of different types and degrees of cirrhosis.

METHODS: Twelve patients with different types and degrees of decompensated cirrhosis, including 8 with hepatitis B-associated cirrhosis, 2 with alcoholic cirrhosis, and 2 with cryptogenic cirrhosis, were investigated retrospectively. Of all the patients, 4 had Child-Pugh grade B cirrhosis and 8 had grade C disease. At 2, 4 and 8 weeks after transplantation, the changes in symptoms (acratia, anorexia and abdominal distension), liver function and coagulation function were observed to analyze the efficacy and feasibility of autologous bone marrow stem cell transplantation via the hepatic artery in the treatment of cirrhosis.

RESULTS: Successful transplantation was achieved in all the 12 patients without obvious complications. The levels of plasma ALT and AST decreased after transplantation. TBIL decreased from 47.68 μmol/L ± 19.8 μmol/L at pretreatment to 36.45 μmol/L ± 20.78 μmol/L at 4 wk post-transplantation. Albumin increased from 18.79 g/L ± 7.02 g/L at pretreatment to 25.67 g/L ± 5.33 g/L at 2 wk. Although PT and PTA showed obvious improvement at 2 wk (P < 0.05), no significant improvement was noted at 4 and 8 wk (both P > 0.05). The total effective rate was 83.33% and 83.33% at 2 and 4 wk, respectively, but decreased to 66.67% at 8 wk. The improvement of TBIL and ALB in patients with alcoholic and cryptogenic cirrhosis at 2 and 4 wk was better than that in patients with hepatitis B-associated cirrhosis. The effective rate in patients with Child-Pugh B disease at 8 wk was significantly higher than that in patients with Child-Pugh C disease (100% vs 50%, P < 0.05).

CONCLUSION: Autologous bone marrow stem cell transplantation via the hepatic artery can improve hepatic cirrhosis, especially in patients with alcoholic or cryptogenic cirrhosis and those with a mild degree of cirrhosis.

The fatty acid constitution and ordering state of membranes in dominant temperature-sensitive lethal mutation and wild-type Drosophila melanogaster larvae

The ordering state and changes in fatty acid composition of microsomal (MS) and mitochondrial (MC) membranes of two dominant temperature-sensitive (DTS) lethal mutations and the wild-type Oregon-R strain larvae of Drosophila melanogaster have been studied at 18 and 29 degrees C and after temperature-shift experiments. The membranes of wild-type larvae have a stable ordering state, with "S" values between 0.6 (18 degrees C) and 0.5 (29 degrees C) in both membranes which remained unchanged in shift experiments, although the ratios of saturated/unsaturated fatty acids were changed as expected. The strongly DTS mutation 1(2) 10DTS forms very rigid membranes at the restrictive temperature (29 degrees C) which cannot be normalized after shift down, while shift up or development at the permissive temperature results in normal ordering state. This mutant is less able to adjust MS and MC fatty acid composition in response to the growth temperature than the wild type. The less temperature-sensitive 1(2)2DTS allele occupies an intermediate state between Oregon-R and 1(2)10DTS in both respects. We assume and the genetical data suggest that the DTS mutant gene product is in competition with the wild-type product, resulting in a membrane structure which is not able to accommodate to the restrictive temperature.