Giandomenico Amico

Efficient human fetal liver cell isolation protocol based on vascular perfusion for liver cell–based therapy and case report on cell transplantation

Although hepatic cell transplantation (CT) holds the promise of bridging patients with end‐stage chronic liver failure to whole liver transplantation, suitable cell populations are under debate. In addition to hepatic cells, mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) are being considered as alternative cell sources for initial clinical cell work. Fetal liver (FL) tissue contains potential progenitors for all these cell lineages. Based on the collagenase incubation of tissue fragments, traditional isolation techniques yield only a fraction of the number of available cells. We report a 5‐step method in which a portal vein in situ perfusion technique is used for tissue from the late second trimester. This method results in the high viabilities known for adult liver vascular perfusion, addresses the low cell yields of conventional digestion methods, and reduces the exposure of the tissue to collagenase 4‐fold. We used donated tissue from gestational weeks 18 to 22, which yielded 1.8 ± 0.7 × 109 cells with an average viability of 78%. Because HSC transplantation and MSC transplantation are of interest for the treatment of hepatic failure, we phenotypically confirmed that in addition to hepatic progenitors, the resulting cell preparation contained cells expressing typical MSC and HSC markers. The percentage of FL cells expressing proliferation markers was 45 times greater than the percentage of adult hepatocytes expressing these markers and was comparable to the percentage of immortalized HepG2 liver hepatocellular carcinoma cells; this indicated the strong proliferative capacity of fetal cells. We report a case of human FL CT with the described liver cell population for clinical end‐stage chronic liver failure. The patients Model for End‐Stage Liver Disease (MELD) score improved from 15 to 10 within the first 18 months of observation. In conclusion, this human FL cell isolation protocol may be of interest for further clinical translation work on the development of liver cell–based therapies. Liver Transpl 18:226–237, 2012.

Elevated blood Hsp60, its structural similarities and cross-reactivity with thyroid molecules, and its presence on the plasma membrane of oncocytes point to the chaperonin as an immunopathogenic factor in Hashimoto's thyroiditis

The role Hsp60 might play in various inflammatory and autoimmune diseases is under investigation, but little information exists pertaining to Hashimoto’s thyroiditis (HT). With the aim to fill this gap, in the present work, we directed our attention to Hsp60 participation in HT pathogenesis. We found Hsp60 levels increased in the blood of HT patients compared to controls. The chaperonin was immunolocalized in thyroid tissue specimens from patients with HT, both in thyrocytes and oncocytes (Hurthle cells) with higher levels compared to controls (goiter). In oncocytes, we found Hsp60 not only in the cytoplasm but also on the plasma membrane, as shown by double immunofluorescence performed on fine needle aspiration cytology. By bioinformatics, we found regions in the Hsp60 molecule with remarkable structural similarity with the thyroglobulin (TG) and thyroid peroxidase (TPO) molecules, which supports the notion that autoantibodies against TG and TPO are likely to recognize Hsp60 on the plasma membrane of oncocytes. This was also supported by data obtained by ELISA, showing that anti-TG and anti-TPO antibodies cross-react with human recombinant Hsp60. Antibody-antigen (Hsp60) reaction on the cell surface could very well mediate thyroid cell damage and destruction, perpetuating inflammation. Experiments with recombinant Hsp60 did not show stimulation of cytokine production by peripheral blood mononuclear cells from HT patients. All together, these results led us to hypothesize that Hsp60 may be an active player in HT pathogenesis via an antibody-mediated immune mechanism.

Phases I-II Matched Case-Control Study of Human Fetal Liver Cell Transplantation for Treatment of Chronic Liver Disease:

Fetal hepatocytes have a high regenerative capacity. The aim of the study was to assess treatment safety and clinical efficacy of human fetal liver cell transplantation through splenic artery infusion. Patients with endstage chronic liver disease on the waiting list for liver transplantation were enrolled. A retrospectively selected contemporary matched-pair group served as control. Nonsorted raw fetal liver cell preparations were isolated from therapeutically aborted fetuses. The end points of the study were safety and improvement of the Model for End-Stage Liver Disease (MELD) and Child-Pugh scores. Nine patients received a total of 13 intrasplenic infusions and were compared with 16 patients on standard therapy. There were no side effects related to the infusion procedure. At the end of follow-up, the MELD score (mean ± SD) in the treatment group remained stable from baseline (16.0 ± 2.9) to the last observation (15.7 ± 3.8), while it increased in the control group from 15.3 ± 2.5 to 19 ± 5.7 (p = 0.0437). The Child-Pugh score (mean ± SD) dropped from 10.1 ± 1.5 to 9.1 ± 1.4 in the treatment group and increased from 10.0 ± 1.2 to 11.1 ± 1.6 in the control group (p = 0.0076). All treated patients with history of recurrent portosystemic encephalopathy (PSE) had no further episodes during 1-year follow-up. No improvement was observed in the control group patients with PSE at study inclusion. Treatment was considered a failure in six of the nine patients (three deaths not liver related, one liver transplant, two MELD score increases) compared with 14 of the 16 patients in the control group (six deaths, five of which were caused by liver failure, four liver transplants, and four MELD score increases). Intrasplenic fetal liver cell infusion is a safe and well-tolerated procedure in patients with end-stage chronic liver disease. A positive effect on clinical scores and on encephalopathy emerged from this preliminary study.

Characterization of Liver-Specific Functions of Human Fetal Hepatocytes in Culture.

This study was designed to assess liver-specific functions of human fetal liver cells proposed as a potential source for hepatocyte transplantation. Fetal liver cells were isolated from livers of different gestational ages (16-22 weeks), and the functions of cell preparations were evaluated by establishing primary cultures. We observed that 20- to 22-week-gestation fetal liver cell cultures contained a predominance of cells with hepatocytic traits that did not divide in vitro but were functionally competent. Fetal hepatocytes performed liver-specific functions at levels comparable to those of their adult counterpart. Moreover, exposure to dexamethasone in combination with oncostatin M promptly induced further maturation of the cells through the acquisition of additional functions (i.e., ability to store glycogen and uptake of indocyanine green). In some cases, particularly in cultures obtained from fetuses of earlier gestational ages (16-18 weeks gestation), cells with mature hepatocytic traits proved to be sporadic, and the primary cultures were mainly populated by clusters of proliferating cells. Consequently, the values of liver-specific functions detected in these cultures were low. We observed that a low cell density culture system rapidly prompted loss of the mature hepatocytic phenotype with downregulations of all the liver-specific functions. We found that human fetal liver cells can be cryopreserved without significant loss of viability and function and evaluated up to 1 year in storage in liquid nitrogen. They might, therefore, be suitable for cell banking and allow for the transplantation of large numbers of cells, thus improving clinical outcomes. Overall, our results indicate that fetal hepatocytes could be used as a cell source for hepatocyte transplantation. Fetal liver cells have been used so far to treat end-stage liver disease. Additional studies are needed to include these cells in cell-based therapies aimed to treat liver failure and inborn errors of metabolism.

Isolation and Characterization of Multipotent Cells from Human Fetal Dermis

We report that cells from human fetal dermis, termed here multipotent fetal dermal cells, can be isolated with high efficiency by using a nonenzymatic, cell outgrowth method. The resulting cell population was consistent with the definition of mesenchymal stromal cells by the International Society for Cellular Therapy. As multipotent fetal dermal cells proliferate extensively, with no loss of multilineage differentiation potential up to passage 25, they may be an ideal source for cell therapy to repair damaged tissues and organs. Multipotent fetal dermal cells were not recognized as targets by T lymphocytes in vitro, thus supporting their feasibility for allogenic transplantation. Moreover, the expansion protocol did not affect the normal phenotype and karyotype of cells. When compared with adult dermal cells, fetal cells displayed several advantages, including a greater cellular yield after isolation, the ability to proliferate longer, and the retention of differentiation potential. Interestingly, multipotent fetal dermal cells expressed the pluripotency marker SSEA4 (90.56 ± 3.15% fetal vs. 10.5 ± 8.5% adult) and coexpressed mesenchymal and epithelial markers (>80% CD90+/CK18+ cells), coexpression lacking in the adult counterparts isolated under the same conditions. Multipotent fetal dermal cells were able to form capillary structures, as well as differentiate into a simple epithelium in vitro, indicating skin regeneration capabilities.

2-Cinnamamido, 2-(3-phenylpropiolamido), and 2-(3-phenylpropanamido)benzamides: synthesis, antiproliferative activity, and mechanism of action

Several new benzamides 4a-q were synthesized by stirring in pyridine the acid chlorides 3a-q with the appropriate anthranilamide derivatives 2a-g. Some of the synthesized compounds were evaluated for their in vitro antiproliferative activity against a panel of 5 human cell lines (K562 human chronic myelogenous leukemia cells, MCF-7 breast cancer cells, HTC-116 and HT26 colon cancer cells and NCI H460 non-small cell lung cancer cells).

Unbiased and quantitative proteomics reveals highly increased angiogenesis induction by the secretome of mesenchymal stromal cells isolated from fetal rather than adult skin

Scarless wound healing and functional regeneration are typical processes of the fetus, gradually lost during postnatal life, and maximally attributed to fetal skin tissue and induced by fetal skin fibroblasts. The latter have been successfully applied to postnatal wounds, with clear advantages compared with autologous dermis grafts or adult fibroblast applications. Our goal was to functionally identify and uncover key factors and mechanisms through the analysis of secretomes, the principal players in all cell therapies based on mesenchymal stromal cells (MSCs). Cell secretomes also putatively mediate skin regenerative effects achieved in clinical applications of fetal skin fibroblasts. An innovative and unbiased approach of comparative and quantitative proteomics of cell conditioned media enabled us to gain knowledge of key molecules and processes from a translational perspective. Using banks of fetal and adult skin fibroblasts that we previously characterized as being MSCs, we discovered secretome changes by identification and comparative quantification, distinguishing secretome signatures of fetal skin MSCs putatively relevant for therapeutic microenvironment modulation. The uncovered proteins can trigger, directly and by modulation of extracellular matrix, angiogenesis, thus highlighting its key role towards scarless wound healing. The angiogenic trigger was functionally validated and corroborated in vitro, with fetal skin MSC secretomes stabilizing and inducing the formation of capillary‐like networks by endothelial cells and fetal liver MSCs, respectively. Our approach and our results may aid in the development of cell‐based and cell‐free products for skin regeneration in acute or chronic injury, and also for wound healing in the regeneration of other tissues. Copyright

Wharton’s jelly mesenchymal stromal cells immunomodulatory molecules: their journey from umbilical cord to differentiated cells

Wharton’s jelly mesenchymal stromal cells (WJ-MSCs) have a unique ability to cross lineage borders. Their immunomodulatory and anti-inflammatory features, further render these cells promising for regenerative medicine applications. Few data are present in literature on the expression of immunomodulatory molecules in umbilical cord (UC) tissue and their maintenance in paired cultured WJ-MSCs, an important aspect in cellular therapy applications. In addition, few data exist on the maintenance of expression of immunomodulatory molecules in mature cell types differentiated from MSCs. Therefore we investigated, in vivo (in UC at full term) and in vitro (in either undifferentiated or differentiated WJ-MSCs), the expression of different markers and their maintenance alongside cell culture, ex vivo expansion and differentiation. IHC, ICC, RT-PCR and flow cytometry were used to detect expression of markers in both paired UC sections and WJ-MSCs. Differentiation was performed towards the standard mesenchymal lineages as well as hepatocyte-like cells. Paired ICC and IHC analyses showed that for most of the analyzed molecules the expression at the protein level is maintained in both UC tissue and WJ-MSCs. Structural molecules were expressed in both WJ and umbilical epithelium (UE), as well as in WJ-MSCs. We showed for the first time that UE and WJ were positive for both HLA-ABC and HLA-E, while HLA-DR was not detectable. The same data were confirmed on WJ-MSCs. Both B7-1 and B7-2 were absent in UC and WJ-MSCs, while we showed for the first time that B7-H3 was highly expressed in both WJ and WJMSCs. Differentiation experiments showed that immunomodulatory molecules were expressed upon application of complex differentiation protocols, in parallel to the acquisition of mature markers or functions. Some important conclusions may be drawn from the current experiments: i) WJMSCs mostly maintain the expression of molecules just present in their “niche”, under standard culture conditions; ii) the parallel expression of immunomodulatory molecules sheds new light on the ability of WJ-MSCs to modulate host immune responses; iii) the in vivo expression of molecules such as HLA-E and B7-H3 opens new questions on the role of WJ during pregnancy; iv) the expression of these molecules in differentiated cells provides key features for in vivo applications, in particular for hepatocyte-like cells.

Wharton’s jelly mesenchymal stem cells differentiation into hepatocyte-like cells: functional characterization and expression of immunomodulatory molecules

Mesenchymal stem cells derived from Wharton’s jelly (WJ-MSCs) recently emerged as promising tools for cellular therapy due to their ability to differentiate into diverse cell types and their immunomodulatory features. Little is known on the expression of immunomodulatory molecules in mature cells differentiated from WJ-MSCs, therefore we aimed to characterize the extent of maintenance of the naive traits of these cells also in a highly specialized differentiated counterpart. WJ-MSCs were differentiated into hepatocyte-like cells (HLCs) with a four weeks protocol. RT-PCR, flow cytometry, IHC and ICC were performed to assess expression of key markers in both undifferentiated and differentiated cells. Hepatocyte specific assays such as PAS staining, CYP3A4 induction and activity, G6Pase activity, were performed to demonstrate the acquisition of traits of the mature hepatocyte phenotype. WJ-MSCs were successfully differentiated into HLCs using a multi-step protocol. These cells were able to store glycogen, incorporate specific live cells stains, perform enzymatic reactions and metabolic activities which are usually featured by mature hepatocytes. In addition, WJ-MSCs did express several immune-related molecules, for which an immunomodulatory role has been demonstrated both in vitro and in vivo. We demonstrated for the first time that key molecules as HLA-E and B7-H3 are expressed also by HLCs derived from WJ-MSCs. Our data showed for the first time that HLCs mostly maintain the expression of immune-modulating molecules, together with new markers and functional features of mature cells. In multiple pathologic conditions the intrinsic immunomodulatory ability of differentiated cells may help survive the interaction with the host immune system, even in the absence of a specific immunosuppressive therapy. This, together with the acquisition of key mature hepatocyte functions, may render WJ-MSCs promising in cell therapy applications for liver diseases.

Isolation and phenotypical characterization of mesenchymal stem cells from the Wharton's jelly of pre-term human umbilical cord

Extraembryonic tissues such as umbilical cord are considered a promising source of stem cells, potentially useful in therapy. Pre-term umbilical cords may be also a useful source of mesenchymal populations, given also that pre-term birth infants may develop diseases during childhood which may be reverted by a cell therapy approach. Pre-term cords can be also made available from therapeutic abortions, providing a further cell source to obtain high numbers of WJ-MSCs. Little is known about the phenotype and differentiative potential of these cells. Preterm UC were obtained following therapeutic abortions after mothers’ informed consent and processed within 12 hours from tissue collection. Characterization of cells was performed at P2 and P5, by both flow cytometry (FC) and ICC, to detect of classical MSC markers, immunomodulatory molecules, tissue-specific markers. The isolation protocol allowed to successfully derive WJ-MSCs which showed the typical morphology, and were routinely passaged up to passage 10. Multi-color flow cytometric analyses showed that isolated cells were positive for classical MSCs markers (CD29, CD44, CD73, CD90, CD105) and. negative (or weakly positive) for typical hematopoietic and endothelial markers (CD45, CD34, CD14, CD68, CD39 and CD31). In addition, we demonstrated the expression of tissue specific markers, both endodermal (CK18, CK19, alpha-fetoprotein and albumin) and neuro-ectodermal (nestin). This may indicate the potential of preterm WJ-MSC to undergo multiple differentiation pathways, as demonstrated for cells isolated from term UC. Preterm WJ-MSCs showed MHC class I expression (but not class II), suggesting hypoimmunogenic properties for these cells. Moreover, B7H3 expression should favor immune tolerance by the host following cellular transplantation. ICC allowed confirming part of the FC data and was used to assess the expression of further antigens. Present data demonstrate that preterm WJ-MSCs can be isolated and expanded, with high reproducibility. these cells do express classical MSC markers and immunomodulatory molecules, independently from the underlying pathology which led to abortion.