Yulia Shandalov | Technion - Israel Institute of Technology (original) (raw)
Papers by Yulia Shandalov
Proceedings of the National Academy of Sciences, 2011
Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of ti... more Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of tissue, requiring surgical reconstruction by means of autologous muscle flaps. The scant availability of quality vascularized flaps and donor site morbidity often limit their use. Engineered vascularized grafts provide an alternative for this need. This work describes a first-time analysis, of the degree of in vitro vascularization and tissue organization, required to enhance the pace and efficacy of vascularized muscle graft integration in vivo. While one-day in vitro was sufficient for graft integration, a three-week culturing period, yielding semiorganized vessel structures and muscle fibers, significantly improved grafting efficacy. Implanted vessel networks were gradually replaced by host vessels, coupled with enhanced perfusion and capillary density. Upregulation of key graft angiogenic factors suggest its active role in promoting the angiogenic response. Transition from satellite cells to mature fibers was indicated by increased gene expression, increased capillary to fiber ratio, and similar morphology to normal muscle. We suggest a "relay" approach in which extended in vitro incubation, enabling the formation of a more structured vascular bed, allows for graft-host angiogenic collaboration that promotes anastomosis and vascular integration. The enhanced angiogenic response supports enhanced muscle regeneration, maturation, and integration.
Methods (San Diego, Calif.), Jan 2, 2015
Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved us... more Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved using autologous flaps. However, their use is limited due to their inadequate availability and due to post-operative donor site scarification. This work presents a step-by-step technique for fabrication of a vascularized muscle flap, to be applied in full-thickness abdominal wall defect reconstruction. Poly l-lactic acid/poly lactic-co-glycolic acid scaffolds, prepared using a salt leaching technique, were used as the supporting matrix in vitro for simultaneously seeded endothelial cells, fibroblasts and myoblasts. The cell-embedded graft was then implanted around femoral artery and vein vessels, which provided a central blood supply. Vascularization and perfusion were achieved by capillary sprouting from the main host vessel into the graft. A thick and vascularized tissue was formed within one week, and was then transferred as an autologous flap together with its main vessels, to a full-t...
Cellular oncology : the official journal of the International Society for Cellular Oncology, 2008
We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires... more We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway. With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm. The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inh...
Proceedings of the National Academy of Sciences, 2014
Large soft tissue defects involve significant tissue loss, requiring surgical reconstruction. Aut... more Large soft tissue defects involve significant tissue loss, requiring surgical reconstruction. Autologous flaps are occasionally scant, demand prolonged transfer surgery, and induce donor site morbidity. The present work set out to fabricate an engineered muscle flap bearing its own functional vascular pedicle for repair of a large soft tissue defect in mice. Full-thickness abdominal wall defect was reconstructed using this engineered vascular muscle flap. A 3D engineered tissue constructed of a porous, biodegradable polymer scaffold embedded with endothelial cells, fibroblasts, and/or myoblasts was cultured in vitro and then implanted around the femoral artery and veins before being transferred, as an axial flap, with its vascular pedicle to reconstruct a full-thickness abdominal wall defect in the same mouse. Within 1 wk of implantation, scaffolds showed extensive functional vascular density and perfusion and anastomosis with host vessels. At 1 wk posttransfer, the engineered muscle flaps were highly vascularized, were well-integrated within the surrounding tissue, and featured sufficient mechanical strength to support the abdominal viscera. Thus, the described engineered muscle flap, equipped with an autologous vascular pedicle, constitutes an effective tool for reconstruction of large defects, thereby circumventing the need for both harvesting autologous flaps and postoperative scarification.
Proceedings of the National Academy of Sciences, 2011
Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of ti... more Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of tissue, requiring surgical reconstruction by means of autologous muscle flaps. The scant availability of quality vascularized flaps and donor site morbidity often limit their use. Engineered vascularized grafts provide an alternative for this need. This work describes a first-time analysis, of the degree of in vitro vascularization and tissue organization, required to enhance the pace and efficacy of vascularized muscle graft integration in vivo. While one-day in vitro was sufficient for graft integration, a three-week culturing period, yielding semiorganized vessel structures and muscle fibers, significantly improved grafting efficacy. Implanted vessel networks were gradually replaced by host vessels, coupled with enhanced perfusion and capillary density. Upregulation of key graft angiogenic factors suggest its active role in promoting the angiogenic response. Transition from satellite cells to mature fibers was indicated by increased gene expression, increased capillary to fiber ratio, and similar morphology to normal muscle. We suggest a "relay" approach in which extended in vitro incubation, enabling the formation of a more structured vascular bed, allows for graft-host angiogenic collaboration that promotes anastomosis and vascular integration. The enhanced angiogenic response supports enhanced muscle regeneration, maturation, and integration.
Pharmacogenetics and Genomics, 2008
The involvement of the 18-kDa translocator protein (TSPO), formerly known as the peripheral-type ... more The involvement of the 18-kDa translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor, in apoptosis regulation of HT29 colorectal cancer cells was studied in-vitro. In-vivo TSPO involvement in tumor growth of HT29 cells xenografted into SCID mice was studied. Knockdown of TSPO expression in the human HT29 cell line was established by stable transfection with vectors containing the TSPO gene in the antisense direction. Successful TSPO knockdown was characterized by reduction of 20% in TSPO RNA levels, 50% in protein expression of the TSPO, and 50% in binding with the TSPO ligand, [3H]PK 11195. Subsequently, in-vitro cell viability and proliferation assays were applied. In addition, transient transfecton with short interfering RNA (siRNA) directed against human TSPO was studied in this way. Furthermore, we also grafted HT29 cells subcutaneously into the right thighs of SCID mice to examine the effects of the putative TSPO agonist, FGIN-1-27, on tumor growth in-vivo. In-vitro TSPO knockdown established by stable transfection of TSPO antisense gene resulted in HT29 clones displaying significantly lower levels of cell death as determined with trypan blue (50% less), lower apoptotic rates (28% less), and higher proliferation rates (48% more one week after seeding and 27% more two weeks after seeding). Transient transfection with anti-human TSPO siRNA resulted in similar viability and antiapoptotic effects. In-vivo, the proapoptotic TSPO ligand, FGIN-1-27 significantly reduced the growth rate of grafted tumors (40% less), in comparison with vehicle-treated mice. TSPO knockdown by genetic manipulation transforms the human HT29 cancer line to a more malignant type in-vitro. In-vivo pharmacological treatment with the putative TSPO agonist FGIN-1-27 reduces tumor growth of the HT29 cell line. These data suggest that TSPO involvement in apoptosis provides a target for anticancer treatment.
Journal of Bioenergetics and Biomembranes, 2008
The voltage dependent anion channel (VDAC), located in the outer mitochondrial membrane, function... more The voltage dependent anion channel (VDAC), located in the outer mitochondrial membrane, functions as a major channel allowing passage of small molecules and ions between the mitochondrial inter-membrane space and cytoplasm. Together with the adenine nucleotide translocator (ANT), which is located in the inner mitochondrial membrane, the VDAC is considered to form the core of a mitochondrial multiprotein complex, named the mitochondrial permeability transition pore (MPTP). Both VDAC and ANT appear to take part in activation of the mitochondrial apoptosis pathway. Other proteins also appear to be associated with the MPTP, for example, the 18 kDa mitochondrial Translocator Protein (TSPO), Bcl-2, hexokinase, cyclophylin D, and others. Interactions between VDAC and TSPO are considered to play a role in apoptotic cell death. As a consequence, due to its apoptotic functions, the TSPO has become a target for drug development directed to find treatments for neurodegenerative diseases and cancer. In this context, TSPO appears to be involved in the generation of reactive oxygen species (ROS). This generation of ROS may provide a link between activation of TSPO and of VDAC, to induce activation of the mitochondrial apoptosis pathway. ROS are known to be able to release cytochrome c from cardiolipins located at the inner mitochondrial membrane. In addition, ROS appear to be able to activate VDAC and allow VDAC mediated release of cytochrome c into the cytosol. Release of cytochrome c from the mitochondria forms the initiating step for activation of the mitochondrial apoptosis pathway.
Apoptosis, 2010
Erucylphosphohomocholine (ErPC3, Erufosine TM ) was reported previously to induce apoptosis in ot... more Erucylphosphohomocholine (ErPC3, Erufosine TM ) was reported previously to induce apoptosis in otherwise highly apoptosis-resistant malignant glioma cell lines while sparing their non-tumorigenic counterparts. We also previously found that the mitochondrial 18 kDa Translocator Protein (TSPO) is required for apoptosis induction by ErPC3. These previous studies also suggested involvement of reactive oxygen species (ROS). In the present study we further investigated the potential involvement of ROS generation, the participation of the mitochondrial respiration chain, and the role of the mitochondrial F O F 1 -ATP(synth)ase in the pro-apoptotic effects of ErPC3 on U87MG and U118MG human glioblastoma cell lines. For this purpose, cells were treated with the ROS chelator butylated hydroxyanisole (BHA), the mitochondrial respiration chain inhibitors rotenone, antimycin A, myxothiazol, and the uncoupler CCCP. Also oligomycin and piceatannol were studied as inhibitors of the F O and F 1 subunits of the mitochondrial F O F 1 -ATP(synth)ase, respectively. BHA was able to attenuate apoptosis induction by ErPC3, including mitochondrial ROS generation as determined with cardiolipin oxidation, as well as collapse of the mitochondrial membrane potential (Dw m ). Similarly, we found that oligomycin attenuated apoptosis and collapse of the Dw m , normally induced by ErPC3, including the accompanying reductions in cellular ATP levels. Other inhibitors of the mitochondrial respiration chain, as well as piceatannol, did not show such effects. Consequently, our findings strongly point to a role for the F O subunit of the mitochondrial F O F 1 -ATP(synth)ase in ErPC3-induced apoptosis and dissipation of Dw m as well as ROS generation by ErPC3 and TSPO.
Proceedings of the National Academy of Sciences, 2011
Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of ti... more Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of tissue, requiring surgical reconstruction by means of autologous muscle flaps. The scant availability of quality vascularized flaps and donor site morbidity often limit their use. Engineered vascularized grafts provide an alternative for this need. This work describes a first-time analysis, of the degree of in vitro vascularization and tissue organization, required to enhance the pace and efficacy of vascularized muscle graft integration in vivo. While one-day in vitro was sufficient for graft integration, a three-week culturing period, yielding semiorganized vessel structures and muscle fibers, significantly improved grafting efficacy. Implanted vessel networks were gradually replaced by host vessels, coupled with enhanced perfusion and capillary density. Upregulation of key graft angiogenic factors suggest its active role in promoting the angiogenic response. Transition from satellite cells to mature fibers was indicated by increased gene expression, increased capillary to fiber ratio, and similar morphology to normal muscle. We suggest a "relay" approach in which extended in vitro incubation, enabling the formation of a more structured vascular bed, allows for graft-host angiogenic collaboration that promotes anastomosis and vascular integration. The enhanced angiogenic response supports enhanced muscle regeneration, maturation, and integration.
Methods (San Diego, Calif.), Jan 2, 2015
Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved us... more Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved using autologous flaps. However, their use is limited due to their inadequate availability and due to post-operative donor site scarification. This work presents a step-by-step technique for fabrication of a vascularized muscle flap, to be applied in full-thickness abdominal wall defect reconstruction. Poly l-lactic acid/poly lactic-co-glycolic acid scaffolds, prepared using a salt leaching technique, were used as the supporting matrix in vitro for simultaneously seeded endothelial cells, fibroblasts and myoblasts. The cell-embedded graft was then implanted around femoral artery and vein vessels, which provided a central blood supply. Vascularization and perfusion were achieved by capillary sprouting from the main host vessel into the graft. A thick and vascularized tissue was formed within one week, and was then transferred as an autologous flap together with its main vessels, to a full-t...
Cellular oncology : the official journal of the International Society for Cellular Oncology, 2008
We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires... more We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway. With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm. The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inh...
Proceedings of the National Academy of Sciences, 2014
Large soft tissue defects involve significant tissue loss, requiring surgical reconstruction. Aut... more Large soft tissue defects involve significant tissue loss, requiring surgical reconstruction. Autologous flaps are occasionally scant, demand prolonged transfer surgery, and induce donor site morbidity. The present work set out to fabricate an engineered muscle flap bearing its own functional vascular pedicle for repair of a large soft tissue defect in mice. Full-thickness abdominal wall defect was reconstructed using this engineered vascular muscle flap. A 3D engineered tissue constructed of a porous, biodegradable polymer scaffold embedded with endothelial cells, fibroblasts, and/or myoblasts was cultured in vitro and then implanted around the femoral artery and veins before being transferred, as an axial flap, with its vascular pedicle to reconstruct a full-thickness abdominal wall defect in the same mouse. Within 1 wk of implantation, scaffolds showed extensive functional vascular density and perfusion and anastomosis with host vessels. At 1 wk posttransfer, the engineered muscle flaps were highly vascularized, were well-integrated within the surrounding tissue, and featured sufficient mechanical strength to support the abdominal viscera. Thus, the described engineered muscle flap, equipped with an autologous vascular pedicle, constitutes an effective tool for reconstruction of large defects, thereby circumventing the need for both harvesting autologous flaps and postoperative scarification.
Proceedings of the National Academy of Sciences, 2011
Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of ti... more Severe traumatic events such as burns, and cancer therapy, often involve a significant loss of tissue, requiring surgical reconstruction by means of autologous muscle flaps. The scant availability of quality vascularized flaps and donor site morbidity often limit their use. Engineered vascularized grafts provide an alternative for this need. This work describes a first-time analysis, of the degree of in vitro vascularization and tissue organization, required to enhance the pace and efficacy of vascularized muscle graft integration in vivo. While one-day in vitro was sufficient for graft integration, a three-week culturing period, yielding semiorganized vessel structures and muscle fibers, significantly improved grafting efficacy. Implanted vessel networks were gradually replaced by host vessels, coupled with enhanced perfusion and capillary density. Upregulation of key graft angiogenic factors suggest its active role in promoting the angiogenic response. Transition from satellite cells to mature fibers was indicated by increased gene expression, increased capillary to fiber ratio, and similar morphology to normal muscle. We suggest a "relay" approach in which extended in vitro incubation, enabling the formation of a more structured vascular bed, allows for graft-host angiogenic collaboration that promotes anastomosis and vascular integration. The enhanced angiogenic response supports enhanced muscle regeneration, maturation, and integration.
Pharmacogenetics and Genomics, 2008
The involvement of the 18-kDa translocator protein (TSPO), formerly known as the peripheral-type ... more The involvement of the 18-kDa translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor, in apoptosis regulation of HT29 colorectal cancer cells was studied in-vitro. In-vivo TSPO involvement in tumor growth of HT29 cells xenografted into SCID mice was studied. Knockdown of TSPO expression in the human HT29 cell line was established by stable transfection with vectors containing the TSPO gene in the antisense direction. Successful TSPO knockdown was characterized by reduction of 20% in TSPO RNA levels, 50% in protein expression of the TSPO, and 50% in binding with the TSPO ligand, [3H]PK 11195. Subsequently, in-vitro cell viability and proliferation assays were applied. In addition, transient transfecton with short interfering RNA (siRNA) directed against human TSPO was studied in this way. Furthermore, we also grafted HT29 cells subcutaneously into the right thighs of SCID mice to examine the effects of the putative TSPO agonist, FGIN-1-27, on tumor growth in-vivo. In-vitro TSPO knockdown established by stable transfection of TSPO antisense gene resulted in HT29 clones displaying significantly lower levels of cell death as determined with trypan blue (50% less), lower apoptotic rates (28% less), and higher proliferation rates (48% more one week after seeding and 27% more two weeks after seeding). Transient transfection with anti-human TSPO siRNA resulted in similar viability and antiapoptotic effects. In-vivo, the proapoptotic TSPO ligand, FGIN-1-27 significantly reduced the growth rate of grafted tumors (40% less), in comparison with vehicle-treated mice. TSPO knockdown by genetic manipulation transforms the human HT29 cancer line to a more malignant type in-vitro. In-vivo pharmacological treatment with the putative TSPO agonist FGIN-1-27 reduces tumor growth of the HT29 cell line. These data suggest that TSPO involvement in apoptosis provides a target for anticancer treatment.
Journal of Bioenergetics and Biomembranes, 2008
The voltage dependent anion channel (VDAC), located in the outer mitochondrial membrane, function... more The voltage dependent anion channel (VDAC), located in the outer mitochondrial membrane, functions as a major channel allowing passage of small molecules and ions between the mitochondrial inter-membrane space and cytoplasm. Together with the adenine nucleotide translocator (ANT), which is located in the inner mitochondrial membrane, the VDAC is considered to form the core of a mitochondrial multiprotein complex, named the mitochondrial permeability transition pore (MPTP). Both VDAC and ANT appear to take part in activation of the mitochondrial apoptosis pathway. Other proteins also appear to be associated with the MPTP, for example, the 18 kDa mitochondrial Translocator Protein (TSPO), Bcl-2, hexokinase, cyclophylin D, and others. Interactions between VDAC and TSPO are considered to play a role in apoptotic cell death. As a consequence, due to its apoptotic functions, the TSPO has become a target for drug development directed to find treatments for neurodegenerative diseases and cancer. In this context, TSPO appears to be involved in the generation of reactive oxygen species (ROS). This generation of ROS may provide a link between activation of TSPO and of VDAC, to induce activation of the mitochondrial apoptosis pathway. ROS are known to be able to release cytochrome c from cardiolipins located at the inner mitochondrial membrane. In addition, ROS appear to be able to activate VDAC and allow VDAC mediated release of cytochrome c into the cytosol. Release of cytochrome c from the mitochondria forms the initiating step for activation of the mitochondrial apoptosis pathway.
Apoptosis, 2010
Erucylphosphohomocholine (ErPC3, Erufosine TM ) was reported previously to induce apoptosis in ot... more Erucylphosphohomocholine (ErPC3, Erufosine TM ) was reported previously to induce apoptosis in otherwise highly apoptosis-resistant malignant glioma cell lines while sparing their non-tumorigenic counterparts. We also previously found that the mitochondrial 18 kDa Translocator Protein (TSPO) is required for apoptosis induction by ErPC3. These previous studies also suggested involvement of reactive oxygen species (ROS). In the present study we further investigated the potential involvement of ROS generation, the participation of the mitochondrial respiration chain, and the role of the mitochondrial F O F 1 -ATP(synth)ase in the pro-apoptotic effects of ErPC3 on U87MG and U118MG human glioblastoma cell lines. For this purpose, cells were treated with the ROS chelator butylated hydroxyanisole (BHA), the mitochondrial respiration chain inhibitors rotenone, antimycin A, myxothiazol, and the uncoupler CCCP. Also oligomycin and piceatannol were studied as inhibitors of the F O and F 1 subunits of the mitochondrial F O F 1 -ATP(synth)ase, respectively. BHA was able to attenuate apoptosis induction by ErPC3, including mitochondrial ROS generation as determined with cardiolipin oxidation, as well as collapse of the mitochondrial membrane potential (Dw m ). Similarly, we found that oligomycin attenuated apoptosis and collapse of the Dw m , normally induced by ErPC3, including the accompanying reductions in cellular ATP levels. Other inhibitors of the mitochondrial respiration chain, as well as piceatannol, did not show such effects. Consequently, our findings strongly point to a role for the F O subunit of the mitochondrial F O F 1 -ATP(synth)ase in ErPC3-induced apoptosis and dissipation of Dw m as well as ROS generation by ErPC3 and TSPO.