Mesenchymal stemcells (MSCs) have shown a great potential for clinical applications in regenerative medicine. However, it remains challenging to follow the transplanted cell grafts in vivo. Nuclear magnetic resonance spectroscopy (NMR or MRS) is capable of determining and quantifying the cellular metabolites in tissue and organs non-invasively, therefore it is an attractive method for monitoring and evaluating the differentiation and functions of transplanted stem cells in vivo. In this study, metabolic changes of MSCs undergoing adipogenic differentiation to targeted fat cells were investigated in vitro, using solid-state high-resolution magic angle spinning 1H nuclear magnetic resonance spectroscopy. Quantification of metabolite concentrations before and after differentiation of MSCs showed decreased levels of intracellular metabolites, including choline, creatine, glutamate and myo-inositol, and a substantially increased level of fatty acids, when mesenchymal stem cells were differentiated preferentially to fat cells. Intracellular creatine, myo-inositol and choline reduced from 10.4 ± 0.72, 16.2 ± 1.2 and 8.22 ± 0.51 mm to 3.27 ± 0.34, 6.1 ± 0.46 and 3.11 ± 0.32 mm, respectively, while fatty acids increased from 32.6 ± 1.5 to 91.2 ± 3.2 mm after undergoing 3 weeks of differentiation. The increase of the fatty acid concentration measured by NMR is confirmed by the observation of 80% fat cells in differentiated cells by cell counting assay, suggesting resonances from fatty acids may be used as metabolite markers for monitoring MSC differentiation to fat cells in vivo, using the magnetic resonance spectroscopic technique readily available on MRI scanners.
One of the roadblocks to developing effective therapeutics for Huntington disease (HD) is the lack of animal models that develop progressive clinical traits comparable to those seen in patients. Here we report a longitudinal study that encompasses cognitive and motor assessment, and neuroimaging of a group of transgenic HD and control monkeys from infancy to adulthood. Along with progressive cognitive and motor impairment, neuroimaging revealed a progressive reduction in striatal volume. Magnetic resonance spectroscopy at 48 months of age revealed a decrease of N-acetylaspartate (NAA), further suggesting neuronal damage/loss in the striatum. Postmortem neuropathological analyses revealed significant neuronal loss in the striatum. Our results indicate that HD monkeys share similar disease patterns with HD patients, making them potentially suitable as a preclinical HD animal model.
by
Young-Seok Cho;
Gee Young Lee;
Hari Krishna Sajja;
Weiping Qian;
Zehong Cao;
Weiling He;
Prasanthi Karna;
Xiaoyuan Chen;
Hui Mao;
Andrew Wang;
Lily Yang
Molecular therapy using a small interfering RNA (siRNA) has shown promise in the development of novel therapeutics. Various formulations have been used for in vivo delivery of siRNAs. However, the stability of short double-stranded RNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients. In this study, multifunctional siRNA delivery nanoparticles are developed that combine imaging capability of nanoparticles with urokinase plasminogen activator receptor-targeted delivery of siRNA expressing DNA nanocassettes. This theranostic nanoparticle platform consists of a nanoparticle conjugated with targeting ligands and double-stranded DNA nanocassettes containing a U6 promoter and a shRNA gene for in vivo siRNA expression. Targeted delivery and gene silencing efficiency of firefly luciferase siRNA nanogenerators are demonstrated in tumor cells and in animal tumor models. Delivery of survivin siRNA expressing nanocassettes into tumor cells induces apoptotic cell death and sensitizes cells to chemotherapy drugs. The ability of expression of siRNAs from multiple nanocassettes conjugated to a single nanoparticle following receptor-mediated internalization should enhance the therapeutic effect of the siRNA-mediated cancer therapy.
Mesenchymal stemcells (MSCs) have shown a great potential for clinical applications in regenerative medicine. However, it remains challenging to follow the transplanted cell grafts in vivo. Nuclear magnetic resonance spectroscopy (NMR or MRS) is capable of determining and quantifying the cellular metabolites in tissue and organs non-invasively, therefore it is an attractive method for monitoring and evaluating the differentiation and functions of transplanted stem cells in vivo. In this study, metabolic changes of MSCs undergoing adipogenic differentiation to targeted fat cells were investigated in vitro, using solid-state high-resolution magic angle spinning 1H nuclear magnetic resonance spectroscopy. Quantification of metabolite concentrations before and after differentiation of MSCs showed decreased levels of intracellular metabolites, including choline, creatine, glutamate and myo-inositol, and a substantially increased level of fatty acids, when mesenchymal stem cells were differentiated preferentially to fat cells. Intracellular creatine, myo-inositol and choline reduced from 10.4 ± 0.72, 16.2 ± 1.2 and 8.22 ± 0.51 mm to 3.27 ± 0.34, 6.1 ± 0.46 and 3.11 ± 0.32 mm, respectively, while fatty acids increased from 32.6 ± 1.5 to 91.2 ± 3.2 mm after undergoing 3 weeks of differentiation. The increase of the fatty acid concentration measured by NMR is confirmed by the observation of 80% fat cells in differentiated cells by cell counting assay, suggesting resonances from fatty acids may be used as metabolite markers for monitoring MSC differentiation to fat cells in vivo, using the magnetic resonance spectroscopic technique readily available on MRI scanners.
by
Young-Seok Cho;
Gee Young Lee;
Hari Krishna Sajja;
Weiping Qian;
Zehong Cao;
Weiling He;
Prasanthi Karna;
Xiaoyuan Chen;
Hui Mao;
Andrew Wang;
Lily Yang
Molecular therapy using a small interfering RNA (siRNA) has shown promise in the development of novel therapeutics. Various formulations have been used for in vivo delivery of siRNAs. However, the stability of short double-stranded RNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients. In this study, multifunctional siRNA delivery nanoparticles are developed that combine imaging capability of nanoparticles with urokinase plasminogen activator receptor-targeted delivery of siRNA expressing DNA nanocassettes. This theranostic nanoparticle platform consists of a nanoparticle conjugated with targeting ligands and double-stranded DNA nanocassettes containing a U6 promoter and a shRNA gene for in vivo siRNA expression. Targeted delivery and gene silencing efficiency of firefly luciferase siRNA nanogenerators are demonstrated in tumor cells and in animal tumor models. Delivery of survivin siRNA expressing nanocassettes into tumor cells induces apoptotic cell death and sensitizes cells to chemotherapy drugs. The ability of expression of siRNAs from multiple nanocassettes conjugated to a single nanoparticle following receptor-mediated internalization should enhance the therapeutic effect of the siRNA-mediated cancer therapy.
While performing oxygen-related tumour treatments such as chemotherapy and photodynamic therapy, real-time monitoring hypoxia of tumour is of great value and significance. Here, we design a theranostic combination for light-activated ratiometric hypoxia imaging, hypoxia modulating and prodrug activation. This combination consisted of an oxygen-sensitive near-infrared-emitting ratiometric phosphorescence probe and a hypoxia-activated prodrug-loaded covalent organic framework. In this combination, the probe plays two roles, including quantitative monitoring of oxygen concentration by ratiometric imaging and consuming the oxygen of tumour under light excitation by photodynamic therapy. Meanwhile, the enhanced hypoxia microenvironment of tumour can raise the cytotoxicity of prodrug loaded in covalent organic framework, resulting in boosting antitumour therapeutic effects in vivo. This theranostic combination can precisely provide therapeutic regime and screen hypoxia-activated prodrugs based on real-time tumour hypoxia level, offering a strategy to develop hypoxia mediated tumour theranostics with hypoxia targeted prodrugs.
by
Anthony Chan;
Yan Xu;
Jie Jiang;
Tayeb Rahim;
Dongming Zhao;
Jannet Kocerha;
Tim Chi;
Sean Moran;
Heidi Engelhardt;
Katherine Larkin;
Adam Neumann;
Haiying Cheng;
Chunxia Li;
Katie Nelson;
Heather Banta;
Stuart M Zola;
Francois Villinger;
Jin Jing Yang;
Claudia M Testa;
Hui Mao;
Xiaodong Zhang;
Jocelyne Bachevalier
Background
A two-year longitudinal study composed of morphometric MRI measures and cognitive behavioral evaluation was performed on a transgenic Huntington’s disease (HD) monkey. rHD1, a transgenic HD monkey expressing exon 1 of the human gene encoding huntingtin (HTT) with 29 CAG repeats regulated by a human polyubiquitin C promoter was used together with four age-matched wild-type control monkeys. This is the first study on a primate model of human HD based on longitudinal clinical measurements.
Results
Changes in striatal and hippocampal volumes in rHD1 were observed with progressive impairment in motor functions and cognitive decline, including deficits in learning stimulus-reward associations, recognition memory and spatial memory. The results demonstrate a progressive cognitive decline and morphometric changes in the striatum and hippocampus in a transgenic HD monkey.
Conclusions
This is the first study on a primate model of human HD based on longitudinal clinical measurements. While this study is based a single HD monkey, an ongoing longitudinal study with additional HD monkeys will be important for the confirmation of our findings. A nonhuman primate model of HD could complement other animal models of HD to better understand the pathogenesis of HD and future development of diagnostics and therapeutics through longitudinal assessment.
by
Anthony Chan;
Yan Xu;
Jie Jiang;
Tayeb Rahim;
Dongming Zhao;
Jannet Kocerha;
Tim Chi;
Sean Moran;
Heidi Engelhardt;
Katherine Larkin;
Adam Neumann;
Haiying Cheng;
Chunxia Li;
Katie Nelson;
Heather Banta;
Stuart M Zola;
Francois Villinger;
Jin Jing Yang;
Claudia M Testa;
Hui Mao;
Xiaodong Zhang;
Jocelyne Bachevalier
Background
A two-year longitudinal study composed of morphometric MRI measures and cognitive behavioral evaluation was performed on a transgenic Huntington’s disease (HD) monkey. rHD1, a transgenic HD monkey expressing exon 1 of the human gene encoding huntingtin (HTT) with 29 CAG repeats regulated by a human polyubiquitin C promoter was used together with four age-matched wild-type control monkeys. This is the first study on a primate model of human HD based on longitudinal clinical measurements.
Results
Changes in striatal and hippocampal volumes in rHD1 were observed with progressive impairment in motor functions and cognitive decline, including deficits in learning stimulus-reward associations, recognition memory and spatial memory. The results demonstrate a progressive cognitive decline and morphometric changes in the striatum and hippocampus in a transgenic HD monkey.
Conclusions
This is the first study on a primate model of human HD based on longitudinal clinical measurements. While this study is based a single HD monkey, an ongoing longitudinal study with additional HD monkeys will be important for the confirmation of our findings. A nonhuman primate model of HD could complement other animal models of HD to better understand the pathogenesis of HD and future development of diagnostics and therapeutics through longitudinal assessment.