Dafna Benayahu - Academia.edu (original) (raw)
Papers by Dafna Benayahu
Adipose tissue dysfunction is central to insulin resistance, and the emergence of type 2 diabetes... more Adipose tissue dysfunction is central to insulin resistance, and the emergence of type 2 diabetes (T2D) is associated with elevated levels of carbonyl metabolites from glucose metabolism. In this study, using methylglyoxal (MGO) and glycolaldehyde (GAD) carbonyl metabolites, induced protein glycation leading to misfolding and β-sheet formation and generation of advanced glycation end products (AGEs). The formed AGEs compromise adipocytes activity.Microscopic and spectroscopic assays were used to examine the impact of MGO and GAD on lipid droplet - associated proteins. The results provide information about how glycation leads to the appearance of amyloidogenic proteins formation that hinders metabolism and autophagy in adipocytes. We measured the beneficial effects of metformin, an anti-diabetic drug, on misfolded protein as assessed by thioflavin (ThT) spectroscopy and improved autophagy. In vitro findings were complemented by in vivo analysis of white adipose tissue (WAT), where li...
The Journal of Steroid Biochemistry and Molecular Biology, May 1, 2012
PubMed, 2022
Recent advances in the field of stem cell research now enable their utilisation for biotechnology... more Recent advances in the field of stem cell research now enable their utilisation for biotechnology applications in regenerative medicine and food tech. The first use of stem cells as biomedical devices employed a combination of cells and scaffold to restore, improve, or replace damaged tissues and to grow new viable tissue for replacement organs. This approach has also been adopted to replace meat production in the food industry. Mesenchymal stem cells are the source material used to induce cells to differentiate into the desired lineage. These technologies require mass propagation and rely on supplying the regulatory factors that direct differentiation. Mesenchymal stem cells can differentiate into fibroblastic and skeletal cells; fibroblastic/chondrogenic/osteogenic/myogenic and adipogenic lineages. Each differentiation fate requires specific key molecular regulators and appropriate activation conditions. Stem cell commitment determination involves a concerted effort of coordinated activation and silencing of lineage-specific genes. Transcription factors which bind gene promoters and chromatin-remodelling proteins are key players in the control process of lineage commitment and differentiation from embryogenesis through adulthood. Consequently, a major research challenge is to characterise such molecular pathways that coordinate lineage-specific differentiation and function. Revealing the mechanisms of action and the main factors will provide the knowledge necessary to control activation and regulation to achieve a specific lineage. Growing cells on a scaffold is a support system that mimics natural tissue and transduces the appropriate signals of the tissue niche for appropriate cellular function. The outcome of such research will deepen the understanding of cell differentiation to promote and advance the biotech, allowing the cell expansion required for their usage in therapy or the development of food tech.
Calcified Tissue International, Oct 1, 1996
RSC Adv., 2014
Dopamine detection from PC12 cell populations and monitoring of yeast redox metabolism demonstrat... more Dopamine detection from PC12 cell populations and monitoring of yeast redox metabolism demonstrate the multifunctionality of the compact microfluidic cell culture and electrochemical analysis platform with in-built fluid handling and detection unit.
International Journal of Molecular Sciences, Dec 3, 2022
Journal of Cellular Physiology, Aug 20, 2022
Lipid droplets (LDs) are important cellular organelles due to their ability to accumulate and sto... more Lipid droplets (LDs) are important cellular organelles due to their ability to accumulate and store lipids. LD dynamics are associated with various cellular and metabolic processes. Accurate monitoring of LD's size and shape is of prime importance as it indicates the metabolic status of the cells. Unintrusive continuous quantification techniques have a clear advantage in analyzing LDs as they measure and monitor the cells' metabolic function and droplets over time. Here, we present a novel machine‐learning‐based method for LDs analysis by segmentation of phase‐contrast images of differentiated adipocytes (in vitro) and adipose tissue (in vivo). We developed a new workflow based on the ImageJ waikato environment for knowledge analysis segmentation plugin, which provides an accurate, label‐free, live single‐cell, and organelle quantification of LD‐related parameters. By applying the new method on differentiating 3T3‐L1 cells, the size of LDs was analyzed over time in differentiated adipocytes and their correlation with other morphological parameters. Moreover, we analyzed the LDs dynamics during catabolic changes such as lipolysis and lipophagy and demonstrated its ability to identify different cellular subpopulations based on their structural, numerical, and spatial variability. This analysis was also implemented on unstained ex vivo adipose tissues to measure adipocyte size, an important readout of the tissue's metabolism. The presented approach can be applied in different LD‐related metabolic conditions to provide a better understanding of LD biogenesis and function in vivo and in vitro while serving as a new platform that enables rapid and accurate screening of data sets.
International Journal of Molecular Sciences, Jan 23, 2023
ACS Biomaterials Science & Engineering, Jun 18, 2021
Structural alterations in proteins have a significant impact on their function and body physiolog... more Structural alterations in proteins have a significant impact on their function and body physiology. Glycation via nonenzymatic forms of cross-linking leads to proteins' conformational changes, the macromolecule being recognized as a stable fibrillary structure, oligomerization, and becoming advanced glycation end products (AGEs). Protein that undergoes glycation-related modifications, namely, β-sheet enriched structural changes, are recognized as amyloid. In the current study, we characterized a single protein modified in vitro under physiological conditions to represent a protein glycation model. The glycation altered the helical conformation of serum albumin (SA) and promoted the formation of a β-sheet enriched with amyloid fibrils detected at multidimensional levels. The nanoscale resolution by spectroscopy in the presence of thioflavin-T (ThT) and 8-anilinonaphthalene-1-sulfonic acid (8-ANS) showed binding of the fibrils formed in the presence of glucose (GLU) and the carbonyl metabolites methylglyoxal (MGO) and glycolaldehyde (GAD). In the presence of MGO and GAD, the SA becomes insoluble aggregates, demonstrated by TEM microscopy and dynamic light scattering (DLS). The protein oligomerization was visualized when separated via SDS gel electrophoresis and mass photometry (MP) assays. Following the glycation, eventually, the material polymerized and became stiffer. The level of stiffness was analyzed by a rheometer that revealed a quick alteration under MGO and GAD. This is the first study to combine multiple spectroscopy assays, imaging, and rheology measurements of SA and to demonstrate a resolution on a nanoscale structural toward better resolution of the conformational changes of glycated SA, oligomerization, and protein aggregations under physiological conditions.
International Journal of Molecular Sciences
Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM... more Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM). The visceral adipose tissue (VAT) is dynamically altered in response to nutritional regimens that lead to local cues affecting the cells and ECM. The adipocytes are in conjunction with the surrounding ECM that maintains the tissue’s niche, provides a scaffold for cells and modulates their signaling. In this study, we provide a better understanding of the crosstalk between nutritional regimens and the ECM’s stiffness. Histological analyses showed that the adipocytes in mice fed a high-fat diet (HFD) were increased in size, while the ECM was also altered with changes in mass and composition. HFD-fed mice exhibited a decrease in elastin and an increase in collagenous proteins. Rheometer measurements revealed a stiffer ECM in whole tissue (nECM) and decellularized (deECM) in HFD-fed animals. These alterations in the ECM regulate cellular activity and influence their metabolic function. HF...
Plasma membrane proteins are extremely important in cell signaling and cellular functions. Protei... more Plasma membrane proteins are extremely important in cell signaling and cellular functions. Protein expression and localization alter in response to various signals in a way that is dependent on cell type and niche. Compartmental quantification of the expression of particular proteins is a very useful means of understanding their role in cellular processes. Immunofluorescence staining is frequently used to investigate the distribution of proteins of interest. Here, we present an imaging method for quantifying the membrane to cytoplasm ratio (MCR) of proteins analyzed at single-cell resolution. This technique provides a robust quantification of membrane proteins and contributes new insights into membrane expression dynamics. We have developed a protocol that uses immunostaining to assess protein expression according to the fluorescent cellular distribution and to compute the MCR. The method was applied to measure the MCR of glucose transporter 4 (GLUT4) in response to insulin in 3T3-L...
The Journal of Experimental Biology, 2017
Journal of Molecular Biology, Sep 1, 2005
ABSTRACT The present study describes a newly identified protein named CReMM (chromatin-related me... more ABSTRACT The present study describes a newly identified protein named CReMM (chromatin-related mesenchymal modulator). The protein was studied by bioinformatic means and classified as a member of the third subfamily of chromodomain helicase DNA-binding proteins (CHD). In silico translation defined CReMM as a multiple domains protein including two chromodomains, SNF2/ATPase, helicase C domain and an A/T-DNA-binding domain (DBD). Predicted extensive post-translation phosphorylation on serine and tyrosine residues was demonstrated by Western blot in the presence and in the absence of phosphatase inhibitors using specific antibodies. Immunoprecipitated CReMM disclosed a DNA-dependent ATPase activity quantified by colorimetric assay. Electrophoresis mobility-shift assay (EMSA) validated that CReMM binds to A/T-rich DNA. CReMM is expressed in mesenchymal progenitors, as shown in vitro and in vivo. CReMM protein structural motifs and proven biochemical activities highlight its role in chromatin remodeling. Further delineation of the function of this protein will provide information about its dynamics in transcriptional regulation of mesenchymal cells.
Humana Press eBooks, 2008
Laser capture microdissection (LCM) method allows selection of individual or clustered cells from... more Laser capture microdissection (LCM) method allows selection of individual or clustered cells from intact tissues. This technology enables one to pick cells from tissues that are difficult to study individually, sort the anatomical complexity of these tissues, and make the cells available for molecular analyses. Following the cells' extraction, the nucleic acids and proteins can be isolated and used for multiple applications that provide an opportunity to uncover the molecular control of cellular fate in the natural microenvironment. Utilization of LCM for the molecular analysis of cells from skeletal tissues will enable one to study differential patterns of gene expression in the native intact skeletal tissue with reliable interpretation of function for known genes as well as to discover novel genes. Variability between samples may be caused either by differences in the tissue samples (different areas isolated from the same section) or some variances in sample handling. LCM is a multi-task technology that combines histology, microscopy work, and dedicated molecular biology. The LCM application will provide results that will pave the way toward high throughput profiling of tissue-specific gene expression using Gene Chip arrays. Detailed description of in vivo molecular pathways will make it possible to elaborate on control systems to apply for the repair of genetic or metabolic diseases of skeletal tissues.
Journal of Cellular Physiology, 2005
We describe a novel human gene, named SEL‐OB/SVEP1, expressed by skeletal tissues in vivo and by ... more We describe a novel human gene, named SEL‐OB/SVEP1, expressed by skeletal tissues in vivo and by cultured osteogenic cells. The mRNA expression was analyzed on frozen tissues retrieved by laser‐capture microscope dissection (LCM) and was detected in osteogenic tissues (periosteum and bone) but not in cartilage or skeletal muscle. The SEL‐OB/SVEP1 cDNA of 11,139 bp was in silico translated into a 3574AA protein with expected molecular weight of 370 kDa. The protein is composed of multiple domains including complement control protein (CCP) modules with selectin superfamily signature; sushi and other domains, such as vWA, EGF, PTX, and HYR. Stromal osteogenic cells were analyzed for the protein expression using anti‐SEL‐OB/SVEP1 for immuno‐precipitation and Western blot application confirm the presence of high molecular weight protein. Immuno‐histochemistry and fluorescence‐activated cell sorting (FACS) were applied to detect SEL‐OB/SVEP1 on the surface of stromal cells. ELISA quantified the dependence of protein expression on cell density. Bioinformatic analysis of SEL‐OB/SVEP1 revealed domains compositions recognized in cell surface molecules and suggested its role in cell adhesion. Analysis of mesechymal osteogenic cells' adhesion in presence of anti‐SEL‐OB/SVEP1 antibody demonstrated its interference with initial adhesion stages. In summary, present study describes novel SEL‐OB/SVEP1 protein with a unique composition of functional domains, restricted pattern of expression in skeletal cells and demonstrated involvement in attachment of mesenchymal cells. The unusual composition of functional domains puts SEL‐OB/SVEP1 in the discrete new group of membrane proteins involved in cell adhesion processes. All together makes SEL‐OB/SVEP1 an attractive marker for studying the role of stromal osteogenic cells and their interactions within the bone marrow microenvironment creating a network that regulates the skeletal homeostasis. J. Cell. Physiol. 206: 420–427, 2006. © 2005 Wiley‐Liss, Inc.
The task of detecting and tracking of mitosis is important in many biomedical areas such as cance... more The task of detecting and tracking of mitosis is important in many biomedical areas such as cancer and stem cell research. This task becomes complex when done in a high-density cell array, largely due to an extremely imbalanced data, with a very small number of proliferating cells in each image. Using the fact that before proliferating, cells seems to get rounder and brighter, our group extracted bright blobs in each image and considered the patch around each blob as a candidate for mitosis. These candidates were labeled and divided into training, validation and test sets, and used for training of a Convolutional Neural Network (CNN). In the current work, in order to overcome the small number of mitosis samples in the training set, we generated synthetic patches of mitosis using Generative Adversarial Networks (GANs). Trying to predict the labels of the test set candidates using a CNN trained by both real and the synthetically generated images showed an increase in both sensitivity and specificity, in comparison to a CNN trained only on real examples.
Studies in mechanobiology, tissue engineering and biomaterials, 2015
Mechanical behavior and properties of adipose tissue -- Mathematical models of adipose tissue dyn... more Mechanical behavior and properties of adipose tissue -- Mathematical models of adipose tissue dynamics -- Mechanical stretching and signaling pathways in adipogenesis- Role of mechanical stimulations in directing mesenchymal stem cell adipogenesis -- The vicious cycle of estrogen consumption and obesity: The role of mechanotransduction -- Extracellular matrix remodeling and mechanical stresses as modulators of adipose tissue metabolism and inflammation -- The Impact of Obesity and Weight Loss on Gait in Adults -- Excessive Weight Bearing Compromises Foot Structure and Function across the Lifespan -- Obesity, Osteoarthritis and Aging: The Biomechanical Links -- Impaired neutrophil mechanoregulation by fluid flow: A potential contributing factor for microvascular dysfunction in obesity -- Mechanotransduction and the myogenic response in diabetes -- Role of adipose cells in tumor microenvironment.
Journal of Cellular Physiology, 2006
Adipose tissue dysfunction is central to insulin resistance, and the emergence of type 2 diabetes... more Adipose tissue dysfunction is central to insulin resistance, and the emergence of type 2 diabetes (T2D) is associated with elevated levels of carbonyl metabolites from glucose metabolism. In this study, using methylglyoxal (MGO) and glycolaldehyde (GAD) carbonyl metabolites, induced protein glycation leading to misfolding and β-sheet formation and generation of advanced glycation end products (AGEs). The formed AGEs compromise adipocytes activity.Microscopic and spectroscopic assays were used to examine the impact of MGO and GAD on lipid droplet - associated proteins. The results provide information about how glycation leads to the appearance of amyloidogenic proteins formation that hinders metabolism and autophagy in adipocytes. We measured the beneficial effects of metformin, an anti-diabetic drug, on misfolded protein as assessed by thioflavin (ThT) spectroscopy and improved autophagy. In vitro findings were complemented by in vivo analysis of white adipose tissue (WAT), where li...
The Journal of Steroid Biochemistry and Molecular Biology, May 1, 2012
PubMed, 2022
Recent advances in the field of stem cell research now enable their utilisation for biotechnology... more Recent advances in the field of stem cell research now enable their utilisation for biotechnology applications in regenerative medicine and food tech. The first use of stem cells as biomedical devices employed a combination of cells and scaffold to restore, improve, or replace damaged tissues and to grow new viable tissue for replacement organs. This approach has also been adopted to replace meat production in the food industry. Mesenchymal stem cells are the source material used to induce cells to differentiate into the desired lineage. These technologies require mass propagation and rely on supplying the regulatory factors that direct differentiation. Mesenchymal stem cells can differentiate into fibroblastic and skeletal cells; fibroblastic/chondrogenic/osteogenic/myogenic and adipogenic lineages. Each differentiation fate requires specific key molecular regulators and appropriate activation conditions. Stem cell commitment determination involves a concerted effort of coordinated activation and silencing of lineage-specific genes. Transcription factors which bind gene promoters and chromatin-remodelling proteins are key players in the control process of lineage commitment and differentiation from embryogenesis through adulthood. Consequently, a major research challenge is to characterise such molecular pathways that coordinate lineage-specific differentiation and function. Revealing the mechanisms of action and the main factors will provide the knowledge necessary to control activation and regulation to achieve a specific lineage. Growing cells on a scaffold is a support system that mimics natural tissue and transduces the appropriate signals of the tissue niche for appropriate cellular function. The outcome of such research will deepen the understanding of cell differentiation to promote and advance the biotech, allowing the cell expansion required for their usage in therapy or the development of food tech.
Calcified Tissue International, Oct 1, 1996
RSC Adv., 2014
Dopamine detection from PC12 cell populations and monitoring of yeast redox metabolism demonstrat... more Dopamine detection from PC12 cell populations and monitoring of yeast redox metabolism demonstrate the multifunctionality of the compact microfluidic cell culture and electrochemical analysis platform with in-built fluid handling and detection unit.
International Journal of Molecular Sciences, Dec 3, 2022
Journal of Cellular Physiology, Aug 20, 2022
Lipid droplets (LDs) are important cellular organelles due to their ability to accumulate and sto... more Lipid droplets (LDs) are important cellular organelles due to their ability to accumulate and store lipids. LD dynamics are associated with various cellular and metabolic processes. Accurate monitoring of LD's size and shape is of prime importance as it indicates the metabolic status of the cells. Unintrusive continuous quantification techniques have a clear advantage in analyzing LDs as they measure and monitor the cells' metabolic function and droplets over time. Here, we present a novel machine‐learning‐based method for LDs analysis by segmentation of phase‐contrast images of differentiated adipocytes (in vitro) and adipose tissue (in vivo). We developed a new workflow based on the ImageJ waikato environment for knowledge analysis segmentation plugin, which provides an accurate, label‐free, live single‐cell, and organelle quantification of LD‐related parameters. By applying the new method on differentiating 3T3‐L1 cells, the size of LDs was analyzed over time in differentiated adipocytes and their correlation with other morphological parameters. Moreover, we analyzed the LDs dynamics during catabolic changes such as lipolysis and lipophagy and demonstrated its ability to identify different cellular subpopulations based on their structural, numerical, and spatial variability. This analysis was also implemented on unstained ex vivo adipose tissues to measure adipocyte size, an important readout of the tissue's metabolism. The presented approach can be applied in different LD‐related metabolic conditions to provide a better understanding of LD biogenesis and function in vivo and in vitro while serving as a new platform that enables rapid and accurate screening of data sets.
International Journal of Molecular Sciences, Jan 23, 2023
ACS Biomaterials Science & Engineering, Jun 18, 2021
Structural alterations in proteins have a significant impact on their function and body physiolog... more Structural alterations in proteins have a significant impact on their function and body physiology. Glycation via nonenzymatic forms of cross-linking leads to proteins' conformational changes, the macromolecule being recognized as a stable fibrillary structure, oligomerization, and becoming advanced glycation end products (AGEs). Protein that undergoes glycation-related modifications, namely, β-sheet enriched structural changes, are recognized as amyloid. In the current study, we characterized a single protein modified in vitro under physiological conditions to represent a protein glycation model. The glycation altered the helical conformation of serum albumin (SA) and promoted the formation of a β-sheet enriched with amyloid fibrils detected at multidimensional levels. The nanoscale resolution by spectroscopy in the presence of thioflavin-T (ThT) and 8-anilinonaphthalene-1-sulfonic acid (8-ANS) showed binding of the fibrils formed in the presence of glucose (GLU) and the carbonyl metabolites methylglyoxal (MGO) and glycolaldehyde (GAD). In the presence of MGO and GAD, the SA becomes insoluble aggregates, demonstrated by TEM microscopy and dynamic light scattering (DLS). The protein oligomerization was visualized when separated via SDS gel electrophoresis and mass photometry (MP) assays. Following the glycation, eventually, the material polymerized and became stiffer. The level of stiffness was analyzed by a rheometer that revealed a quick alteration under MGO and GAD. This is the first study to combine multiple spectroscopy assays, imaging, and rheology measurements of SA and to demonstrate a resolution on a nanoscale structural toward better resolution of the conformational changes of glycated SA, oligomerization, and protein aggregations under physiological conditions.
International Journal of Molecular Sciences
Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM... more Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM). The visceral adipose tissue (VAT) is dynamically altered in response to nutritional regimens that lead to local cues affecting the cells and ECM. The adipocytes are in conjunction with the surrounding ECM that maintains the tissue’s niche, provides a scaffold for cells and modulates their signaling. In this study, we provide a better understanding of the crosstalk between nutritional regimens and the ECM’s stiffness. Histological analyses showed that the adipocytes in mice fed a high-fat diet (HFD) were increased in size, while the ECM was also altered with changes in mass and composition. HFD-fed mice exhibited a decrease in elastin and an increase in collagenous proteins. Rheometer measurements revealed a stiffer ECM in whole tissue (nECM) and decellularized (deECM) in HFD-fed animals. These alterations in the ECM regulate cellular activity and influence their metabolic function. HF...
Plasma membrane proteins are extremely important in cell signaling and cellular functions. Protei... more Plasma membrane proteins are extremely important in cell signaling and cellular functions. Protein expression and localization alter in response to various signals in a way that is dependent on cell type and niche. Compartmental quantification of the expression of particular proteins is a very useful means of understanding their role in cellular processes. Immunofluorescence staining is frequently used to investigate the distribution of proteins of interest. Here, we present an imaging method for quantifying the membrane to cytoplasm ratio (MCR) of proteins analyzed at single-cell resolution. This technique provides a robust quantification of membrane proteins and contributes new insights into membrane expression dynamics. We have developed a protocol that uses immunostaining to assess protein expression according to the fluorescent cellular distribution and to compute the MCR. The method was applied to measure the MCR of glucose transporter 4 (GLUT4) in response to insulin in 3T3-L...
The Journal of Experimental Biology, 2017
Journal of Molecular Biology, Sep 1, 2005
ABSTRACT The present study describes a newly identified protein named CReMM (chromatin-related me... more ABSTRACT The present study describes a newly identified protein named CReMM (chromatin-related mesenchymal modulator). The protein was studied by bioinformatic means and classified as a member of the third subfamily of chromodomain helicase DNA-binding proteins (CHD). In silico translation defined CReMM as a multiple domains protein including two chromodomains, SNF2/ATPase, helicase C domain and an A/T-DNA-binding domain (DBD). Predicted extensive post-translation phosphorylation on serine and tyrosine residues was demonstrated by Western blot in the presence and in the absence of phosphatase inhibitors using specific antibodies. Immunoprecipitated CReMM disclosed a DNA-dependent ATPase activity quantified by colorimetric assay. Electrophoresis mobility-shift assay (EMSA) validated that CReMM binds to A/T-rich DNA. CReMM is expressed in mesenchymal progenitors, as shown in vitro and in vivo. CReMM protein structural motifs and proven biochemical activities highlight its role in chromatin remodeling. Further delineation of the function of this protein will provide information about its dynamics in transcriptional regulation of mesenchymal cells.
Humana Press eBooks, 2008
Laser capture microdissection (LCM) method allows selection of individual or clustered cells from... more Laser capture microdissection (LCM) method allows selection of individual or clustered cells from intact tissues. This technology enables one to pick cells from tissues that are difficult to study individually, sort the anatomical complexity of these tissues, and make the cells available for molecular analyses. Following the cells' extraction, the nucleic acids and proteins can be isolated and used for multiple applications that provide an opportunity to uncover the molecular control of cellular fate in the natural microenvironment. Utilization of LCM for the molecular analysis of cells from skeletal tissues will enable one to study differential patterns of gene expression in the native intact skeletal tissue with reliable interpretation of function for known genes as well as to discover novel genes. Variability between samples may be caused either by differences in the tissue samples (different areas isolated from the same section) or some variances in sample handling. LCM is a multi-task technology that combines histology, microscopy work, and dedicated molecular biology. The LCM application will provide results that will pave the way toward high throughput profiling of tissue-specific gene expression using Gene Chip arrays. Detailed description of in vivo molecular pathways will make it possible to elaborate on control systems to apply for the repair of genetic or metabolic diseases of skeletal tissues.
Journal of Cellular Physiology, 2005
We describe a novel human gene, named SEL‐OB/SVEP1, expressed by skeletal tissues in vivo and by ... more We describe a novel human gene, named SEL‐OB/SVEP1, expressed by skeletal tissues in vivo and by cultured osteogenic cells. The mRNA expression was analyzed on frozen tissues retrieved by laser‐capture microscope dissection (LCM) and was detected in osteogenic tissues (periosteum and bone) but not in cartilage or skeletal muscle. The SEL‐OB/SVEP1 cDNA of 11,139 bp was in silico translated into a 3574AA protein with expected molecular weight of 370 kDa. The protein is composed of multiple domains including complement control protein (CCP) modules with selectin superfamily signature; sushi and other domains, such as vWA, EGF, PTX, and HYR. Stromal osteogenic cells were analyzed for the protein expression using anti‐SEL‐OB/SVEP1 for immuno‐precipitation and Western blot application confirm the presence of high molecular weight protein. Immuno‐histochemistry and fluorescence‐activated cell sorting (FACS) were applied to detect SEL‐OB/SVEP1 on the surface of stromal cells. ELISA quantified the dependence of protein expression on cell density. Bioinformatic analysis of SEL‐OB/SVEP1 revealed domains compositions recognized in cell surface molecules and suggested its role in cell adhesion. Analysis of mesechymal osteogenic cells' adhesion in presence of anti‐SEL‐OB/SVEP1 antibody demonstrated its interference with initial adhesion stages. In summary, present study describes novel SEL‐OB/SVEP1 protein with a unique composition of functional domains, restricted pattern of expression in skeletal cells and demonstrated involvement in attachment of mesenchymal cells. The unusual composition of functional domains puts SEL‐OB/SVEP1 in the discrete new group of membrane proteins involved in cell adhesion processes. All together makes SEL‐OB/SVEP1 an attractive marker for studying the role of stromal osteogenic cells and their interactions within the bone marrow microenvironment creating a network that regulates the skeletal homeostasis. J. Cell. Physiol. 206: 420–427, 2006. © 2005 Wiley‐Liss, Inc.
The task of detecting and tracking of mitosis is important in many biomedical areas such as cance... more The task of detecting and tracking of mitosis is important in many biomedical areas such as cancer and stem cell research. This task becomes complex when done in a high-density cell array, largely due to an extremely imbalanced data, with a very small number of proliferating cells in each image. Using the fact that before proliferating, cells seems to get rounder and brighter, our group extracted bright blobs in each image and considered the patch around each blob as a candidate for mitosis. These candidates were labeled and divided into training, validation and test sets, and used for training of a Convolutional Neural Network (CNN). In the current work, in order to overcome the small number of mitosis samples in the training set, we generated synthetic patches of mitosis using Generative Adversarial Networks (GANs). Trying to predict the labels of the test set candidates using a CNN trained by both real and the synthetically generated images showed an increase in both sensitivity and specificity, in comparison to a CNN trained only on real examples.
Studies in mechanobiology, tissue engineering and biomaterials, 2015
Mechanical behavior and properties of adipose tissue -- Mathematical models of adipose tissue dyn... more Mechanical behavior and properties of adipose tissue -- Mathematical models of adipose tissue dynamics -- Mechanical stretching and signaling pathways in adipogenesis- Role of mechanical stimulations in directing mesenchymal stem cell adipogenesis -- The vicious cycle of estrogen consumption and obesity: The role of mechanotransduction -- Extracellular matrix remodeling and mechanical stresses as modulators of adipose tissue metabolism and inflammation -- The Impact of Obesity and Weight Loss on Gait in Adults -- Excessive Weight Bearing Compromises Foot Structure and Function across the Lifespan -- Obesity, Osteoarthritis and Aging: The Biomechanical Links -- Impaired neutrophil mechanoregulation by fluid flow: A potential contributing factor for microvascular dysfunction in obesity -- Mechanotransduction and the myogenic response in diabetes -- Role of adipose cells in tumor microenvironment.
Journal of Cellular Physiology, 2006