Larry Loo - Academia.edu (original) (raw)

Papers by Larry Loo

Research paper thumbnail of BCL-xL/BCL2L1 is a critical anti-apoptotic protein that promotes the survival of differentiating pancreatic cells from human pluripotent stem cells

Cell Death and Disease, May 18, 2020

Research paper thumbnail of Insight into muscle stem cell regeneration and mechanobiology

Stem Cell Research & Therapy, May 12, 2023

Research paper thumbnail of FGFR-mediated ERK1/2 signaling contributes to mesendoderm and definitive endoderm formation in vitro

Research paper thumbnail of Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm

Research paper thumbnail of An Integrative Glycomic Approach for Quantitative Meat Species Profiling

Foods

It is estimated that food fraud, where meat from different species is deceitfully labelled or con... more It is estimated that food fraud, where meat from different species is deceitfully labelled or contaminated, has cost the global food industry around USD 6.2 to USD 40 billion annually. To overcome this problem, novel and robust quantitative methods are needed to accurately characterise and profile meat samples. In this study, we use a glycomic approach for the profiling of meat from different species. This involves an O-glycan analysis using LC-MS qTOF, and an N-glycan analysis using a high-resolution non-targeted ultra-performance liquid chromatography-fluorescence-mass spectrometry (UPLC-FLR-MS) on chicken, pork, and beef meat samples. Our integrated glycomic approach reveals the distinct glycan profile of chicken, pork, and beef samples; glycosylation attributes such as fucosylation, sialylation, galactosylation, high mannose, α-galactose, Neu5Gc, and Neu5Ac are significantly different between meat from different species. The multi-attribute data consisting of the abundance of ea...

Research paper thumbnail of Elucidating the role of SCD1 in B cell development and function

Research paper thumbnail of Decompartmentalisation as a simple color manipulation of plant-based marbling meat alternatives

Research paper thumbnail of Dynamics of BCL-2 family of proteins in early pancreatic progenitors and β-cells

Research paper thumbnail of Defective insulin receptor signaling in hPSCs skews pluripotency and negatively perturbs neural differentiation

Journal of Biological Chemistry

Research paper thumbnail of BCL-xL/BCL2L1 is a critical anti-apoptotic protein that promotes the survival of differentiating pancreatic cells from human pluripotent stem cells

Cell Death & Disease

The differentiation of human pluripotent stem cells into pancreatic cells involves cellular proli... more The differentiation of human pluripotent stem cells into pancreatic cells involves cellular proliferation and apoptosis during cell fate transitions. However, their implications for establishing cellular identity are unclear. Here, we profiled the expression of BCL-2 family of proteins during pancreatic specification and observed an upregulation of BCL-xL, downregulation of BAK and corresponding downregulation of cleaved CASP3 representative of apoptosis. Experimental inhibition of BCL-xL reciprocally increased apoptosis and resulted in a decreased gene expression of pancreatic markers despite a compensatory increase in anti-apoptotic protein BCL-2. RNA-Seq analyses then revealed a downregulation of multiple metabolic genes upon inhibition of BCL-xL. Follow-up bioenergetics assays revealed broad downregulation of both glycolysis and oxidative phosphorylation when BCL-xL was inhibited. Early perturbation of BCL-xL during pancreatic specification also had subsequent detrimental effect...

Research paper thumbnail of Dynamic proteome profiling of human pluripotent stem cell-derived pancreatic progenitors

STEM CELLS

A comprehensive characterization of the molecular processes controlling cell fate decisions is es... more A comprehensive characterization of the molecular processes controlling cell fate decisions is essential to derive stable progenitors and terminally differentiated cells that are functional from human pluripotent stem cells (hPSCs). Here, we report the use of quantitative proteomics to describe early proteome adaptations during hPSC differentiation toward pancreatic progenitors. We report that the use of unbiased quantitative proteomics allows the simultaneous profiling of numerous proteins at multiple time points, and is a valuable tool to guide the discovery of signaling events and molecular signatures underlying cellular differentiation. We also monitored the activity level of pathways whose roles are pivotal in the early pancreas differentiation, including the Hippo signaling pathway. The quantitative proteomics data set provides insights into the dynamics of the global proteome during the transition of hPSCs from a pluripotent state toward pancreatic differentiation.

Research paper thumbnail of 326-LB: BCL-xL/BCL2L1 Is a Critical Anti-Apoptotic Protein that Suppresses BAK to Promote Pancreatic Specification from Human Pluripotent Stem Cells

Diabetes

The differentiation of human pluripotent stem cells (hPSCs) into desired cell types such as the p... more The differentiation of human pluripotent stem cells (hPSCs) into desired cell types such as the pancreatic cells involve cellular proliferation and apoptosis during cell fate transitions. Although different rates of cell growth and death are typically observed during differentiation, its implications for pancreatic tissue formation in humans remain unclear. Here, we profiled the expression of BCL-2 family of proteins during pancreatic specification from hPSCs and observed an upregulation of BCL- XL, downregulation of BAK and corresponding downregulation of cleaved CASP3 representative of apoptosis. The inhibition or downregulation of BCL-xL reciprocally increased apoptosis and resulted in a decreased gene expression of pancreatic markers despite a compensatory increase in companion anti-apoptotic protein BCL2. RNA-Seq analyses revealed a downregulation of multiple metabolic genes upon inhibition of BCL-xL function. Bioenergetics assays then revealed a broad downregulation of both glycolysis and oxidative phosphorylation when BCL-xL function was inhibited. In conclusion, we have identified anti-apoptotic protein BCL-xL to be necessary for suppressing the expression of pro-apoptotic protein BAK to facilitate proper pancreas formation in human cells. This is the first report that links a member of the BCL-2 family with pancreatic specification. Therefore, modulation of these two BCL-2 family of proteins can potentially increase the survival and robustness of pancreatic progenitors that ultimately defines human pancreatic beta cell mass and function. Disclosure L. Loo: None. A. Teo: None. S. Ghosh: None. A. Soetedjo: None. L. Nguyen: None. V.G. Krishnan: None. S. Hoon: None. Funding Agency for Science, Technology and Research; Institute of Molecular and Cell Biology

Research paper thumbnail of Cover Image, Volume 20, Issue 1

Diabetes, Obesity and Metabolism

Research paper thumbnail of The molecular functions of hepatocyte nuclear factors - In and beyond the liver

Journal of hepatology, 2018

The hepatocyte nuclear factors (HNFs) namely HNF1α/β, FOXA1/2/3, HNF4α/γ and ONECUT1/2 are expres... more The hepatocyte nuclear factors (HNFs) namely HNF1α/β, FOXA1/2/3, HNF4α/γ and ONECUT1/2 are expressed in a variety of tissues and organs, including the liver, pancreas and kidney. The spatial and temporal manner of HNF expression regulates embryonic development and subsequently the development of multiple tissues during adulthood. Though the HNFs were initially identified individually based on their roles in the liver, numerous studies have now revealed that the HNFs cross-regulate one another and exhibit synergistic relationships in the regulation of tissue development and function. The complex HNF transcriptional regulatory networks have largely been elucidated in rodent models, but less so in human biological systems. Several heterozygous mutations in these HNFs were found to cause diseases in humans but not in rodents, suggesting clear species-specific differences in mutational mechanisms that remain to be uncovered. In this review, we compare and contrast the expression patterns...

Research paper thumbnail of An arduous journey from human pluripotent stem cells to functional pancreatic β cells

Diabetes, Obesity and Metabolism

Type 1 and type 2 diabetes are caused by a destruction and decrease in the number of functional i... more Type 1 and type 2 diabetes are caused by a destruction and decrease in the number of functional insulin-producing β cells, respectively; therefore, the generation of functional β cells from human embryonic stem cells and human induced pluripotent stem cells, collectively known as human pluripotent stem cells (hPSCs), for potential cell replacement therapy and disease modelling is an intensely investigated area. Recent scientific breakthroughs enabled derivation of large quantities of human pancreatic β-like cells in vitro, although with varied glucose-stimulated insulin secretion kinetics. In the present review, we comprehensively summarize, compare and critically analyze the intricacies of these developing technologies, including differentiation platforms, robustness of protocols, and methodologies used to characterize hPSC-derived β-like cells. We also discuss experimental issues that need to be resolved before these β-like cells can be used clinically.

Research paper thumbnail of BCL-xL/BCL2L1 is a critical anti-apoptotic protein that promotes the survival of differentiating pancreatic cells from human pluripotent stem cells

Cell Death and Disease, May 18, 2020

Research paper thumbnail of Insight into muscle stem cell regeneration and mechanobiology

Stem Cell Research & Therapy, May 12, 2023

Research paper thumbnail of FGFR-mediated ERK1/2 signaling contributes to mesendoderm and definitive endoderm formation in vitro

Research paper thumbnail of Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm

Research paper thumbnail of An Integrative Glycomic Approach for Quantitative Meat Species Profiling

Foods

It is estimated that food fraud, where meat from different species is deceitfully labelled or con... more It is estimated that food fraud, where meat from different species is deceitfully labelled or contaminated, has cost the global food industry around USD 6.2 to USD 40 billion annually. To overcome this problem, novel and robust quantitative methods are needed to accurately characterise and profile meat samples. In this study, we use a glycomic approach for the profiling of meat from different species. This involves an O-glycan analysis using LC-MS qTOF, and an N-glycan analysis using a high-resolution non-targeted ultra-performance liquid chromatography-fluorescence-mass spectrometry (UPLC-FLR-MS) on chicken, pork, and beef meat samples. Our integrated glycomic approach reveals the distinct glycan profile of chicken, pork, and beef samples; glycosylation attributes such as fucosylation, sialylation, galactosylation, high mannose, α-galactose, Neu5Gc, and Neu5Ac are significantly different between meat from different species. The multi-attribute data consisting of the abundance of ea...

Research paper thumbnail of Elucidating the role of SCD1 in B cell development and function

Research paper thumbnail of Decompartmentalisation as a simple color manipulation of plant-based marbling meat alternatives

Research paper thumbnail of Dynamics of BCL-2 family of proteins in early pancreatic progenitors and β-cells

Research paper thumbnail of Defective insulin receptor signaling in hPSCs skews pluripotency and negatively perturbs neural differentiation

Journal of Biological Chemistry

Research paper thumbnail of BCL-xL/BCL2L1 is a critical anti-apoptotic protein that promotes the survival of differentiating pancreatic cells from human pluripotent stem cells

Cell Death & Disease

The differentiation of human pluripotent stem cells into pancreatic cells involves cellular proli... more The differentiation of human pluripotent stem cells into pancreatic cells involves cellular proliferation and apoptosis during cell fate transitions. However, their implications for establishing cellular identity are unclear. Here, we profiled the expression of BCL-2 family of proteins during pancreatic specification and observed an upregulation of BCL-xL, downregulation of BAK and corresponding downregulation of cleaved CASP3 representative of apoptosis. Experimental inhibition of BCL-xL reciprocally increased apoptosis and resulted in a decreased gene expression of pancreatic markers despite a compensatory increase in anti-apoptotic protein BCL-2. RNA-Seq analyses then revealed a downregulation of multiple metabolic genes upon inhibition of BCL-xL. Follow-up bioenergetics assays revealed broad downregulation of both glycolysis and oxidative phosphorylation when BCL-xL was inhibited. Early perturbation of BCL-xL during pancreatic specification also had subsequent detrimental effect...

Research paper thumbnail of Dynamic proteome profiling of human pluripotent stem cell-derived pancreatic progenitors

STEM CELLS

A comprehensive characterization of the molecular processes controlling cell fate decisions is es... more A comprehensive characterization of the molecular processes controlling cell fate decisions is essential to derive stable progenitors and terminally differentiated cells that are functional from human pluripotent stem cells (hPSCs). Here, we report the use of quantitative proteomics to describe early proteome adaptations during hPSC differentiation toward pancreatic progenitors. We report that the use of unbiased quantitative proteomics allows the simultaneous profiling of numerous proteins at multiple time points, and is a valuable tool to guide the discovery of signaling events and molecular signatures underlying cellular differentiation. We also monitored the activity level of pathways whose roles are pivotal in the early pancreas differentiation, including the Hippo signaling pathway. The quantitative proteomics data set provides insights into the dynamics of the global proteome during the transition of hPSCs from a pluripotent state toward pancreatic differentiation.

Research paper thumbnail of 326-LB: BCL-xL/BCL2L1 Is a Critical Anti-Apoptotic Protein that Suppresses BAK to Promote Pancreatic Specification from Human Pluripotent Stem Cells

Diabetes

The differentiation of human pluripotent stem cells (hPSCs) into desired cell types such as the p... more The differentiation of human pluripotent stem cells (hPSCs) into desired cell types such as the pancreatic cells involve cellular proliferation and apoptosis during cell fate transitions. Although different rates of cell growth and death are typically observed during differentiation, its implications for pancreatic tissue formation in humans remain unclear. Here, we profiled the expression of BCL-2 family of proteins during pancreatic specification from hPSCs and observed an upregulation of BCL- XL, downregulation of BAK and corresponding downregulation of cleaved CASP3 representative of apoptosis. The inhibition or downregulation of BCL-xL reciprocally increased apoptosis and resulted in a decreased gene expression of pancreatic markers despite a compensatory increase in companion anti-apoptotic protein BCL2. RNA-Seq analyses revealed a downregulation of multiple metabolic genes upon inhibition of BCL-xL function. Bioenergetics assays then revealed a broad downregulation of both glycolysis and oxidative phosphorylation when BCL-xL function was inhibited. In conclusion, we have identified anti-apoptotic protein BCL-xL to be necessary for suppressing the expression of pro-apoptotic protein BAK to facilitate proper pancreas formation in human cells. This is the first report that links a member of the BCL-2 family with pancreatic specification. Therefore, modulation of these two BCL-2 family of proteins can potentially increase the survival and robustness of pancreatic progenitors that ultimately defines human pancreatic beta cell mass and function. Disclosure L. Loo: None. A. Teo: None. S. Ghosh: None. A. Soetedjo: None. L. Nguyen: None. V.G. Krishnan: None. S. Hoon: None. Funding Agency for Science, Technology and Research; Institute of Molecular and Cell Biology

Research paper thumbnail of Cover Image, Volume 20, Issue 1

Diabetes, Obesity and Metabolism

Research paper thumbnail of The molecular functions of hepatocyte nuclear factors - In and beyond the liver

Journal of hepatology, 2018

The hepatocyte nuclear factors (HNFs) namely HNF1α/β, FOXA1/2/3, HNF4α/γ and ONECUT1/2 are expres... more The hepatocyte nuclear factors (HNFs) namely HNF1α/β, FOXA1/2/3, HNF4α/γ and ONECUT1/2 are expressed in a variety of tissues and organs, including the liver, pancreas and kidney. The spatial and temporal manner of HNF expression regulates embryonic development and subsequently the development of multiple tissues during adulthood. Though the HNFs were initially identified individually based on their roles in the liver, numerous studies have now revealed that the HNFs cross-regulate one another and exhibit synergistic relationships in the regulation of tissue development and function. The complex HNF transcriptional regulatory networks have largely been elucidated in rodent models, but less so in human biological systems. Several heterozygous mutations in these HNFs were found to cause diseases in humans but not in rodents, suggesting clear species-specific differences in mutational mechanisms that remain to be uncovered. In this review, we compare and contrast the expression patterns...

Research paper thumbnail of An arduous journey from human pluripotent stem cells to functional pancreatic β cells

Diabetes, Obesity and Metabolism

Type 1 and type 2 diabetes are caused by a destruction and decrease in the number of functional i... more Type 1 and type 2 diabetes are caused by a destruction and decrease in the number of functional insulin-producing β cells, respectively; therefore, the generation of functional β cells from human embryonic stem cells and human induced pluripotent stem cells, collectively known as human pluripotent stem cells (hPSCs), for potential cell replacement therapy and disease modelling is an intensely investigated area. Recent scientific breakthroughs enabled derivation of large quantities of human pancreatic β-like cells in vitro, although with varied glucose-stimulated insulin secretion kinetics. In the present review, we comprehensively summarize, compare and critically analyze the intricacies of these developing technologies, including differentiation platforms, robustness of protocols, and methodologies used to characterize hPSC-derived β-like cells. We also discuss experimental issues that need to be resolved before these β-like cells can be used clinically.