Publications by authors named "Changning Wang"

58 Publications

Novel Positron Emission Tomography Radiotracers for Imaging Mitochondrial Complex I.

ACS Chem Neurosci 2021 Nov 23. Epub 2021 Nov 23.

Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia 23298, United States.

Mitochondrial dysfunction has been indicated in neurodegenerative and other disorders. The mitochondrial complex I (MC-I) of the electron transport chain (ETC) on the inner membrane is the electron entry point of the ETC and is essential for the production of reactive oxygen species. Based on a recently identified β-keto-amide type MC-I modulator from our laboratory, an F-labeled positron emission tomography (PET) tracer, , was prepared. PET/CT imaging studies demonstrated that exhibited rapid brain uptake without significant wash out during the 60 min scanning time. In addition, the binding of was higher in the regions of the brain stem, cerebellum, and midbrain. The uptake of can be significantly blocked by its parent compound. Collectively, the results strongly suggest successful development of MC-I PET tracers from this chemical scaffold that can be used in future mitochondrial dysfunction studies of the central nervous system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acschemneuro.1c00297DOI Listing
November 2021

Visualization of Receptor-Interacting Protein Kinase 1 (RIPK1) by Brain Imaging with Positron Emission Tomography.

J Med Chem 2021 10 15;64(20):15420-15428. Epub 2021 Oct 15.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States.

We report the development of the first positron emission tomography (PET) radiotracer, [F]CNY-07, based on a highly specific and potent RIPK1 inhibitor, Nec-1s, for RIPK1/necroptosis brain imaging in rodents. [F]CNY-07 was synthesized through copper-mediated F-radiolabeling from an aryl boronic ester precursor and studied PET imaging in rodents. PET imaging results showed that [F]CNY-07 can penetrate the blood-brain barrier with a maximum percent injected dose per unit volume of 3 at 10 min postinjection in the brain . Self-blocking studies of [F]CNY-07 by pretreating with unlabeled molecules in rodents showed reduced radioactivity in animal brains (30% radioactivity decreased), indicating the binding specificity of our radiotracer. Our studies demonstrate that [F]CNY-07 has provided a useful PET radioligand enabling brain RIPK1 imaging, which could be a valuable research tool in studying RIPK1-related neurological disorders in animals and potentially humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.1c01477DOI Listing
October 2021

Design, Synthesis, and Evaluation of Thienodiazepine Derivatives as Positron Emission Tomography Imaging Probes for Bromodomain and Extra-Terminal Domain Family Proteins.

J Med Chem 2021 Oct 22;64(19):14745-14756. Epub 2021 Sep 22.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States.

To better understand the role of bromodomain and extra-terminal domain (BET) proteins in epigenetic mechanisms, we developed a series of thienodiazepine-based derivatives and identified two compounds, and , as potent BET inhibitors. Further pharmacokinetic studies and analysis of metabolic stability of revealed excellent brain penetration and reasonable metabolic stability. Compounds and were radiolabeled with fluorine-18 in two steps and utilized in positron emission tomography (PET) imaging studies in mice. Preliminary PET imaging results demonstrated that [F] and [F] have good brain uptake (with maximum SUV = 1.7 and 2, respectively) and binding specificity in mice brains. These results show that [F] is a potential PET radiotracer that could be applied to imaging BET proteins in the brain. Further optimization and improvement of the metabolic stability of [F] are still needed in order to create optimal PET imaging probes of BET family members.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.1c01323DOI Listing
October 2021

Synthesis and Characterization of a Positron Emission Tomography Imaging Probe Selectively Targeting the Second Bromodomain of Bromodomain Protein BRD4.

Bioconjug Chem 2021 08 17;32(8):1711-1718. Epub 2021 Jun 17.

Two tandem bromodomains (BD1 and BD2) of bromodomain and extraterminal domain (BET) family proteins have shown distinct roles in mediating gene transcription and expression. Inhibitors that interact with a specific bromodomain may contribute to a specific therapeutic potential with fewer side effects. However, little is known about this disease-related target. Positron emission tomography (PET) imaging could allow us to achieve in-depth knowledge of the BD2 bromodomain. Herein we describe the radiosynthesis and evaluation of [C] as a BRD4 BD2 bromodomain PET imaging radioligand. Our preliminary PET imaging results in rodents demonstrated that [C] had suitable biodistribution in peripheral organs and tissues. Further blocking studies indicated that [C] had good binding specificity toward the BD2 bromodomain. This study may pave the way for the development of a PET radioligand specifically targeting BD1/2 bromodomains as well as for the biological mechanism investigation of BD1/2 bromodomains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.bioconjchem.1c00245DOI Listing
August 2021

Molecular imaging of NAD -dependent deacetylase SIRT1 in the brain.

Alzheimers Dement 2021 Apr 15. Epub 2021 Apr 15.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.

Introduction: Aging is an inevitable physiological process and the biggest risk factor of Alzheimer's disease (AD). Developing an imaging tracer to visualize aging-related changes in the brain may provide a useful biomarker in elucidating neuroanatomical mechanisms of AD.

Methods: We developed and characterized a new tracer that can be used to visualize SIRT1 in brains related to aging and AD by positron emission tomography imaging.

Results: The SIRT1 tracer displayed desirable brain uptake and selectivity, as well as stable metabolism and proper kinetics and distribution in rodent and nonhuman primate brains. This new tracer was further validated by visualizing SIRT1 in brains of AD transgenic mice, compared to nontransgenic animals.

Discussion: Our SIRT1 tracer not only enables, for the first time, the demonstration of SIRT1 in animal brains, but also allows visualization and recapitulation of AD-related SIRT1 neuropathological changes in animal brains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/alz.12344DOI Listing
April 2021

Synthesis of Mitochondria-Anchored Nitroimidazoles with a Versatile NIR Fluorophore for Hypoxic Tumor-Targeting Imaging and Chemoradiotherapy.

J Med Chem 2021 03 10;64(6):3381-3391. Epub 2021 Mar 10.

State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University (Army Medical University), 30 Gaotanyan Street, Shapingba District, Chongqing 400038, People's Republic of China.

Nitroimidazoles are one of the most common radiosensitizers investigated to combat hypoxia-induced resistance to cancer radiotherapy. However, due to poor selectivity distinguishing cancer cells from normal cells, effective doses of radiosensitization are much closer to the doses of toxicity induced by nitroimidazoles, limiting their clinical application. In this work, a tumor-targeting near-infrared (NIR) cyanine dye (IR-808) was utilized as a targeting ligand and an NIR fluorophore tracer to chemically conjugate with different structures of hypoxia-affinic nitroimidazoles. One of the NIR fluorophore-conjugated nitroimidazoles (808-NM2) was identified to preferentially accumulate in hypoxic tumor cells, sensitively outline the tumor contour, and effectively inhibit tumor growth synergistically by chemotherapy and radiotherapy. More importantly, nitroimidazoles were successfully taken into cancer cell mitochondria via 808-NM2 conjugate to exert the synergistic effect of chemoradiotherapy. Regarding the important roles of mitochondria on cancer cell survival and metastasis under hypoxia, 808-NM2 may be hopeful to fight against hypoxic tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.0c02250DOI Listing
March 2021

Discovery of a Positron Emission Tomography Radiotracer Selectively Targeting the BD1 Bromodomains of BET Proteins.

ACS Med Chem Lett 2021 Feb 8;12(2):282-287. Epub 2021 Jan 8.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States.

In this paper, we report the design, synthesis, and biological evaluation of the first selective bromodomain and extra-terminal domain (BET) BD1 bromodomains of the PET radiotracer [F]PB006. The standard compound PB006 showed high affinity and good selectivity toward BRD4 BD1 ( = 100 nM and 29-fold selectively for BD1 over BD2) in an binding assay. PET imaging experiments in rodents were performed to evaluate the bioactivity of [F]PB006 . A biodistribution study of [F]PB006 in mice revealed high radiotracer uptake in peripheral tissues, such as liver and kidney, and moderate radiotracer uptake in the brain. Further blocking studies demonstrated the significant radioactivity decreasing (20-30% reduction compared with baseline) by pretreating unlabeled PB006 and JQ1, suggesting the high binding selectivity and specificity of [F]PB006. Our study indicated that [F]PB006 is a potent PET probe selectively targeting BET BD1, and further structural optimization of the radiotracer is still required to improve brain uptake to support neuroepigenetic imaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsmedchemlett.0c00650DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883468PMC
February 2021

Discovery of carbon-11 labeled sulfonamide derivative: A PET tracer for imaging brain NLRP3 inflammasome.

Bioorg Med Chem Lett 2021 02 6;34:127777. Epub 2021 Jan 6.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States. Electronic address:

We report herein the discovery of a positron emission tomography (PET) tracer for the (NOD)-like receptor protein 3 (NLRP3). Our recent medicinal chemistry campaign on developing sulfonamide-based NLRP3 inhibitors led to an analog, 1, with a methoxy substituent amenable to labeling with carbon-11. PET/CT imaging studies indicated that [C]1 exhibited rapid blood-brain barrier (BBB) penetration and moderate brain uptake, as well as blockable uptake in the brain. [C]1, thus suggesting the potential to serve as a useful tool for imaging NLRP3 inflammasome in living brains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bmcl.2021.127777DOI Listing
February 2021

Integrated contact lens sensor system based on multifunctional ultrathin MoS transistors.

Matter 2021 Mar 30;4(3):969-985. Epub 2020 Dec 30.

Advanced Technology Institute, University of Surrey, Guildford, Surrey GU2 7XH, UK.

Smart contact lenses attract extensive interests due to their capability of directly monitoring physiological and ambient information. However, previous demonstrations usually lacked efficient sensor modalities, facile fabrication process, mechanical stability, or biocompatibility. Here, we demonstrate a flexible approach for fabrication of multifunctional smart contact lenses with an ultrathin MoS transistors-based serpentine mesh sensor system. The integrated sensor systems contain a photodetector for receiving optical information, a glucose sensor for monitoring glucose level directly from tear fluid, and a temperature sensor for diagnosing potential corneal disease. Unlike traditional sensors and circuit chips sandwiched in the lens substrate, this serpentine mesh sensor system can be directly mounted onto the lenses and maintain direct contact with tears, delivering high detection sensitivity, while being mechanically robust and not interfering with either blinking or vision. Furthermore, the cytotoxicity tests reveal good biocompatibility, thus holding promise as next-generation soft electronics for healthcare and medical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.matt.2020.12.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7773002PMC
March 2021

Synthesis and Characterization of Carbon-11 Labeled Iloperidone for Imaging of α-Adrenoceptor in Brain.

Front Mol Biosci 2020 24;7:586327. Epub 2020 Sep 24.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States.

α-Adrenoceptor is implicated in numerous neuronal diseases. The development of new modulators targeting this receptor as well as the investigation of the role of α-adrenoceptor in healthy and disease conditions, however, is hindered by the lack of specific positron emission tomography (PET) radiotracers. Iloperidone shows a high binding affinity to α-adrenoceptor and moderate selectivity over other brain receptors. We report herein the synthesis and characterization of carbon-11 labeled iloperidone for imaging of α-adrenoceptor in brain. The radiolabeling of [C]iloperidone was carried out conveniently in one step by treating precursor with [C]CHI in DMF in the presence of KCO. Then, [C]iloperidone was purified by semi-preparative HPLC, and characterized in C57BL/6 mice using PET/CT scanning. The desired product [C]iloperidone was obtained in an average decay corrected radiochemical of 12% ( = 3) and over 99% radiochemical purity. The average molar radioactivity was 357 GBq/μmol with total synthetic time of 35-40 min. PET/CT scanning in C57BL/6 mice showed favorable pharmacokinetic properties and high brain exposure of [C]iloperidone. Blocking experiments by pretreatment with the unlabeled iloperidone showed the significant blocking effects with about 25% reduction in brain uptake. These results suggested that [C]iloperidone can serve as a lead compound for the further development of specific radiotracers for PET imaging of α-adrenoceptor in brain clinically.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmolb.2020.586327DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7542234PMC
September 2020

Alpha-Synuclein in Alcohol Use Disorder, Connections with Parkinson's Disease and Potential Therapeutic Role of 5' Untranslated Region-Directed Small Molecules.

Biomolecules 2020 10 21;10(10). Epub 2020 Oct 21.

Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.

Alpha-synuclein (α-Syn) is a 140-amino acid (aa) protein encoded by the Synuclein alpha SNCA gene. It is the synaptic protein associated with Parkinson's disease (PD) and is the most highly expressed protein in the Lewy bodies associated with PD and other alpha synucleopathies, including Lewy body dementia (LBD) and multiple system atrophy (MSA). Iron deposits are present in the core of Lewy bodies, and there are reports suggesting that divalent metal ions including Cu and Fe enhance the aggregation of α-Syn. Differential expression of α-Syn is associated with alcohol use disorder (AUD), and specific genetic variants contribute to the risk for alcoholism, including alcohol craving. Spliced variants of α-Syn, leading to the expression of several shorter forms which are more prone to aggregation, are associated with both PD and AUD, and common transcript variants may be able to predict at-risk populations for some movement disorders or subtypes of PD, including secondary Parkinsonism. Both PD and AUD are associated with liver and brain iron dyshomeostasis. Research over the past decade has shown that α-Syn has iron import functions with an ability to oxidize the Fe form of iron to Fe to facilitate its entry into cells. Our prior research has identified an iron-responsive element (IRE) in the 5' untranslated region (5'UTR) of α-Syn mRNA, and we have used the α-Syn 5'UTR to screen for small molecules that modulate its expression in the H4 neuronal cell line. These screens have led us to identify several interesting small molecules capable of both decreasing and increasing α-Syn expression and that may have the potential, together with the recently described mesenchymal stem cell therapies, to normalize α-Syn expression in different regions of the alcoholic and PD brain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom10101465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7589448PMC
October 2020

Molecular imaging of Alzheimer's disease-related gamma-secretase in mice and nonhuman primates.

J Exp Med 2020 12;217(12)

Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA.

The pathogenesis of Alzheimer's disease (AD) is primarily driven by brain accumulation of the amyloid-β-42 (Aβ42) peptide generated from the amyloid-β precursor protein (APP) via cleavages by β- and γ-secretase. γ-Secretase is a prime drug target for AD; however, its brain regional expression and distribution remain largely unknown. Here, we are aimed at developing molecular imaging tools for visualizing γ-secretase. We used our recently developed γ-secretase modulators (GSMs) and synthesized our GSM-based imaging agent, [11C]SGSM-15606. We subsequently performed molecular imaging in rodents, including AD transgenic animals, and macaques, which revealed that our probe displayed good brain uptake and selectivity, stable metabolism, and appropriate kinetics and distribution for imaging γ-secretase in the brain. Interestingly, rodents and macaques shared certain brain areas with high γ-secretase expression, suggesting a functional conservation of γ-secretase. Collectively, we have provided the first molecular brain imaging of γ-secretase, which may not only accelerate our drug discovery for AD but also advance our understanding of AD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20182266DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7553790PMC
December 2020

Development of a Novel Positron Emission Tomography (PET) Radiotracer Targeting Bromodomain and Extra-Terminal Domain (BET) Family Proteins.

Front Mol Biosci 2020 12;7:198. Epub 2020 Aug 12.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.

Bromodomain and extra-terminal domain (BET) family proteins have become a hot research area because of their close relationship with a variety of human diseases. The non-invasive imaging technique, such as positron emission tomography (PET), provides a powerful tool to visualize and quantify the BET family proteins that accelerating the investigation of this domain. Herein, we describe the development of a promising PET probe, , specifically targeting BET family proteins based on the potent BET inhibitor CF53. was successfully radio-synthesized with good yield and high purity after the optimization of radiolabeling conditions. The bio-activities evaluation of was performed using PET imaging in rodents. The results demonstrated that has favorable uptake in peripheral organs and moderate uptake in the brain. Further blocking studies indicated the high binding specificity and selectivity for BET proteins of this probe. Our findings suggest that is a promising BET PET probe for BET proteins as well as epigenetic imaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmolb.2020.00198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7434981PMC
August 2020

Gut Microbiota Influences Neuropathic Pain Through Modulating Proinflammatory and Anti-inflammatory T Cells.

Anesth Analg 2021 04;132(4):1146-1155

From the Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts.

Background: Gut microbiota, a consortium of diverse microorganisms residing in the gastrointestinal tract, has emerged as a key player in neuroinflammatory responses, supporting the functional relevance of the "gut-brain axis." Chronic-constriction injury of the sciatic nerve (CCI) is a commonly used animal model of neuropathic pain with a major input from T cell-mediated immune responses. In this article, we sought to examine whether gut microbiota influences CCI neuropathic pain, and, if so, whether T-cell immune responses are implicated.

Methods: We used a mixture of wide-spectrum oral antibiotics to perturbate gut microbiota in mice and then performed CCI in these animals. Nociceptive behaviors, including mechanical allodynia and thermal hyperalgesia, were examined before and after CCI. Additionally, we characterized the spinal cord infiltrating T cells by examining interferon (IFN)-γ, interleukin (IL)-17, and Foxp3. Using a Foxp3-GFP-DTR "knock-in" mouse model that allows punctual depletion of regulatory T cells, we interrogated the role of these cells in mediating the effects of gut microbiota in the context of CCI neuropathic pain.

Results: We found that oral antibiotics induced gut microbiota changes and attenuated the development of CCI neuropathic pain, as demonstrated by dampened mechanical allodynia and thermal hyperalgesia. Percentages of IFN-γ-producing Th1 cells and Foxp3+ regulatory T cells were significantly different between animals that received oral antibiotics (Th1 mean = 1.0, 95% confidence interval [CI], 0.9-1.2; Foxp3 mean = 8.1, 95% CI, 6.8-9.3) and those that received regular water (Th1 mean = 8.4, 95% CI, 7.8-9.0, P < .01 oral antibiotics versus water, Cohen's d = 18.8; Foxp 3 mean = 2.8, 95% CI, 2.2-3.3, P < .01 oral antibiotics versus water, Cohen's d = 6.2). These T cells characterized a skewing from a proinflammatory to an anti-inflammatory immune profile induced by gut microbiota changes. Moreover, we depleted Foxp3+ regulatory T cells and found that their depletion reversed the protection of neuropathic pain mediated by gut microbiota changes, along with a dramatic increase of IFN-γ-producing Th1 cell infiltration in the spinal cord (before depletion mean = 2.8%, 95% CI, 2.2-3.5; after depletion mean = 9.1%, 95% CI, 7.2-11.0, p < .01 before versus after, Cohen's d = 5.0).

Conclusions: Gut microbiota plays a critical role in CCI neuropathic pain. This role is mediated, in part, through modulating proinflammatory and anti-inflammatory T cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1213/ANE.0000000000005155DOI Listing
April 2021

In vivo human brain expression of histone deacetylases in bipolar disorder.

Transl Psychiatry 2020 07 8;10(1):224. Epub 2020 Jul 8.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.

The etiology of bipolar disorder (BD) is unknown and the neurobiological underpinnings are not fully understood. Both genetic and environmental factors contribute to the risk of BD, which may be linked through epigenetic mechanisms, including those regulated by histone deacetylase (HDAC) enzymes. This study measures in vivo HDAC expression in individuals with BD for the first time using the HDAC-specific radiotracer [C]Martinostat. Eleven participants with BD and 11 age- and sex-matched control participants (CON) completed a simultaneous magnetic resonance - positron emission tomography (MR-PET) scan with [C]Martinostat. Lower [C]Martinostat uptake was found in the right amygdala of BD compared to CON. We assessed uptake in the dorsolateral prefrontal cortex (DLPFC) to compare previous findings of lower uptake in the DLPFC in schizophrenia and found no group differences in BD. Exploratory whole-brain voxelwise analysis showed lower [C]Martinostat uptake in the bilateral thalamus, orbitofrontal cortex, right hippocampus, and right amygdala in BD compared to CON. Furthermore, regional [C]Martinostat uptake was associated with emotion regulation in BD in fronto-limbic areas, which aligns with findings from previous structural, functional, and molecular neuroimaging studies in BD. Regional [C]Martinostat uptake was associated with attention in BD in fronto-parietal and temporal regions. These findings indicate a potential role of HDACs in BD pathophysiology. In particular, HDAC expression levels may modulate attention and emotion regulation, which represent two core clinical features of BD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41398-020-00911-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7343804PMC
July 2020

Imaging assisted evaluation of antitumor efficacy of a new histone deacetylase inhibitor in the castration-resistant prostate cancer.

Eur J Nucl Med Mol Imaging 2021 01 26;48(1):53-66. Epub 2020 Jun 26.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.

Purpose: Castration-resistant prostate cancer (CRPC) is the most common cause of death in men. The effectiveness of HDAC inhibitors has been demonstrated by preclinical models, but not in clinical studies, probably due to the ineffectively accumulation of HDACI in prostate cancer cells. The purpose of this work was to evaluate effects of a novel HDACI (CN133) on CRPC xenograft model and 22Rv1 cells, and develops methods, PET/CT imaging, to detect the therapeutic effects of CN133 on this cancer.

Methods: We designed and performed study to compare the effects of CN133 with SAHA on the 22Rv1 xenograft model and 22Rv1 cells. Using PET/CT imaging with [C] Martinostat and [F] FDG, we imaged mice bearing 22Rv1 xenografts before and after 21-day treatment with placebo and CN133 (1 mg/kg), and uptake on pre-treatment and post-treatment imaging was measured. The anti-tumor mechanisms of CN133 were investigated by qPCR, western blot, and ChIP-qPCR.

Results: Our data showed that the CN133 treatment led to a 50% reduction of tumor volume compared to the placebo that was more efficacious than SAHA treatment in this preclinical model. [C] Martinostat PET imaging could identify early lesions of prostate cancer and can also be used to monitor the therapeutic effect of CN133 in CRPC. Using pharmacological approaches, we demonstrated that effects of CN133 showed almost 100-fold efficacy than SAHA treatment in the experiment of cell proliferation, invasion, and migration. The anti-tumor mechanisms of CN133 were due to the inhibition of AR signaling pathway activity by decreased HDAC 2 and 3 protein expressions.

Conclusion: Taken together, these studies provide not only a novel epigenetic approach for prostate cancer therapy but also offering a potential tool, [C] Martinostat PET/CT imaging, to detect the early phase of prostate cancer and monitor therapeutic effect of CN133. These results will likely lead to human trials in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00259-020-04896-7DOI Listing
January 2021

Radiosynthesis and in vivo evaluation of a new positron emission tomography radiotracer targeting bromodomain and extra-terminal domain (BET) family proteins.

Nucl Med Biol 2020 May - Jun;84-85:96-101. Epub 2020 Apr 9.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. Electronic address:

Introduction: Bromodomain and extra-terminal domain (BET) family proteins play a vital role in the epigenetic regulation process by interacting with acetylated lysine (Ac-K) residues in histones. BET inhibitors have become promising candidates to treat various diseases through the inhibition of the interaction between BET bromodomains and Ac-K of histone tails. With a molecular imaging probe, noninvasive imaging such as positron emission tomography (PET) can visualize the distribution and roles of BET family proteins in vivo and enlighten our understanding of BET protein function in both healthy and diseased tissue.

Methods: We radiolabeled the potent BET inhibitor INCB054329 by N-methylation to make [C]PB003 as a BET PET radiotracer. The bioactivity evaluation of unlabeled PB003 in vitro was performed to confirm its binding affinity for BRDs, then the PET/CT imaging in rodents was performed to evaluate the bioactivity of [C]PB003 in vivo.

Results: In our in vitro evaluation, PB003 showed a high BET binding affinity for BRDs (K = 2 nM, 1.2 nM, and 1.2 nM for BRD2, BRD3, and BRD4, respectively). In vivo PET/CT imaging demonstrated that [C]PB003 has favorable uptake with appropriate kinetics and distributions in main peripheral organs. Besides, the blockade of [C]PB003 binding was found in our blocking study which indicated the specificity of [C]PB003. However, the BBB penetration and brain uptake of [C]PB003 was limited, with only a maximum 0.2% injected dose/g at ~2 min post-injection.

Conclusion: The imaging results in rodents in vivo demonstrate that [C]PB003 binds to BET with high selectivity and specificity and has favorable uptake in peripheral organs. However, the low brain uptake of [C]PB003 limits the visualization of brain regions indicating the efforts are still needed to discover the new BET imaging probes for brain visualization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nucmedbio.2020.04.003DOI Listing
July 2021

Design, synthesis and biological evaluation of novel O-carbamoyl ferulamide derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

Eur J Med Chem 2020 May 24;194:112265. Epub 2020 Mar 24.

Institute of Traditional Chinese Medicine Pharmacology and Toxicology, Sichuan Academy of Chinese Medicine Sciences, Chengdu, 610041, China. Electronic address:

A novel series of O-carbamoyl ferulamide derivatives were designed by multitarget-directed ligands (MTDLs) strategy, the derivatives were synthesized and evaluated to treat Alzheimer's disease (AD). In vitro biological evaluation demonstrated that compound 4f was the best pseudo-irreversible hBChE (human butyrylcholinesterase) inhibitor with an IC value of 0.97 μM 4f was a potent selective MAO-B (monoamine oxidase-B) inhibitor (IC = 5.3 μM), and could inhibit (58.2%) and disaggregate (43.3%) self-mediated Aβ aggregation. 4f also could reduce the levels of pathological tau and APP clearance, and displayed a wide safe range hepatotoxicity on LO2 cells. The in vivo studies revealed that 4f exhibited fascinating dyskinesia recovery rate and response efficiency on AlCl-mediated zebrafish, and demonstrated significant protective effect on vascular injury caused by Aβ. PET-CT imaging demonstrated that [C]4f exhibited high BBB penetration (especially could reach to hippocampus and striatum of brain) and had a fast brain uptake after intravenous bolus injection. Furthermore, compound 4f could improve scopolamine-induced cognitive impairment. Further, the metabolism in vitro of 4f was also investigated, and presented 3 metabolites in rat liver microsome metabolism, 4 metabolites in human liver microsome, and 4 metabolites in rat intestinal flora, providing previous data for the preclinical study. Therefore, these results implied that compound 4f was an advanced multi-function agent and deserved further preclinical study against mild-to-serve Alzheimer's disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2020.112265DOI Listing
May 2020

A New Positron Emission Tomography Probe for Orexin Receptors Neuroimaging.

Molecules 2020 Feb 25;25(5). Epub 2020 Feb 25.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.

The orexin receptor (OX) is critically involved in motivation and sleep-wake regulation and holds promising therapeutic potential in various mood disorders. To further investigate the role of orexin receptors (OXRs) in the living human brain and to evaluate the treatment potential of orexin-targeting therapeutics, we herein report a novel PET probe ([C]CW24) for OXRs in the brain. CW24 has moderate binding affinity for OXRs (IC = 0.253 μM and 1.406 μM for OXR and OXR, respectively) and shows good selectivity to OXRs over 40 other central nervous system (CNS) targets. [C]CW24 has high brain uptake in rodents and nonhuman primates, suitable metabolic stability, and appropriate distribution and pharmacokinetics for brain positron emission tomography (PET) imaging. [C]CW24 warrants further evaluation as a PET imaging probe of OXRs in the brain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules25051018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7179119PMC
February 2020

Novel radioligands for imaging sigma-1 receptor in brain using positron emission tomography (PET).

Acta Pharm Sin B 2019 Nov 11;9(6):1204-1215. Epub 2019 Jul 11.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.

The sigma-1 receptor ( R) is a unique intracellular protein. R plays a major role in various pathological conditions in the central nervous system (CNS), implicated in several neuropsychiatric disorders. Imaging of R in the brain using positron emission tomography (PET) could serve as a noninvasively tool for enhancing the understanding of the disease's pathophysiology. Moreover, R PET tracers can be used for target validation and quantification in diagnosis. Herein, we describe the radiosynthesis, PET/CT imaging of novel R C-labeled radioligands based on 6-hydroxypyridazinone, [C]HCC0923 and [C]HCC0929. Two radioligands have high affinities to R, with good selectivity. In mice PET/CT imaging, both radioligands showed appropriate kinetics and distributions. Additionally, the specific interactions of two radioligands were reduced by compounds and (self-blocking). Of the two, [C]HCC0929 was further investigated in positive ligands blocking studies, using classic R agonist SA 4503 and R antagonist PD 144418. Both R ligands could extensively decreased the uptake of [C]HCC0929 in mice brain. Besides, the biodistribution of major brain regions and organs of mice were determined . These studies demonstrated that two radioligands, especially [C]HCC0929, possessed ideal imaging properties and might be valuable tools for non-invasive quantification of R in brain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.apsb.2019.07.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6900558PMC
November 2019

Peroxisome proliferator activated receptor γ promotes mineralization and differentiation in cementoblasts via inhibiting Wnt/β-catenin signaling pathway.

J Cell Biochem 2019 Nov 11. Epub 2019 Nov 11.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Hubei, China.

Peroxisome proliferator activated receptor γ (PPARγ) is a member of the nuclear receptor family of transcription factors, which involved in inflammation regulating and bone remodeling. Rare studies explored the effects of PPARγ on mineralization and differentiation in cementoblasts. To explore the potential approaches to repair the damaged periodontal tissues especially for cementum, the present study aims to investigate the effects and the regulating mechanism of PPARγ on mineralization and differentiation in cementoblasts. Murine cementoblast cell lines (OCCM-30) were cultured in basic medium for 24 hours/48 hours or in mineralization medium for 3/7/10 days, respectively at addition of dimethyl sulphoxide, rosiglitazone (PPARγ agonist), GW9662 (PPARγ antagonist), lithium chloride (LiCl), tumor necrosis factor-α (TNF-α), or respective combination. Expression of mineralization genes alkaline phosphatase (ALP), runt related transcription factors 2 (RUNX2), and osteocalcin (OCN) were detected by quantitative real-time polymerase chain reaction or/and Western blot. ALP staining and alizarin red staining were used to evaluate the mineralization in OCCM-30 cells. The change of β-catenin expression and translocation in cytoplasm/nucleus was analyzed by Western blot and immunofluorescence. The results showed that PPARγ agonist rosiglitazone improved the expression of ALP, RUNX2, and OCN, deepened ALP staining, increased mineralized nodules formation, and decreased β-catenin expression in the nucleus. LiCl, an activator of the Wnt signaling pathway, inhibited the expression of mineralization genes and reversed the upregulated expression of mineralization genes resulted from rosiglitazone. Under inflammatory microenvironment, rosiglitazone not only suppressed the expression of interleukin-1β caused by TNF-α, but improved the expression of mineralization genes in OCCM-30 cells. In conclusion, PPARγ could promote mineralization and differentiation in cementoblasts via inhibiting the Wnt/β-catenin signaling pathway, which would shed new light on the treatment of periodontitis and periodontal tissue regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcb.29509DOI Listing
November 2019

Synthesis of C-labeled DNA polymerase-β inhibitor 5-methoxyflavone and PET/CT imaging thereof.

Nucl Med Biol 2019 Nov - Dec;78-79:17-22. Epub 2019 Oct 23.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, United States. Electronic address:

Introduction: "Cell-cycle hypothesis" is emerging in recent years to suggest that aberrant cell cycle re-entry of differentiated neurons leads to a remarkable genetic disequilibrium which is likely to be the primary cause of neuronal apoptosis. DNA polymerase-β is involved in neuronal DNA replication during cell cycle re-entry, thus constituting a promising target for Alzheimer's disease treatment. Recently, 5-methoxyflavone was identified as a candidate molecule endowed with good biological activity and selectivity on the DNA pol-β in multiple in vitro AD models. In vivo assays, especially the brain uptake of 5-methoxyflavone, is need to be evaluated for further development for AD treatment. We report herein the synthesis of C-labeled 5-methoxyflavone, and the evaluation of in vivo properties of 5-[C]methoxyflavone in rodents.

Methods: The strategy for synthesis of 5-[C]methoxyflavone was developed by treating precursor 5-hydroxyflavone with [C]CHI and KOH in anhydrous DMF. 5-[C]Methoxyflavone was purified, then evaluated in mice by using PET/CT imaging.

Results: The 5-[C]methoxyflavone was synthesized conveniently in an average decay corrected yield of 22% (n = 3) with a radiochemical purity >99%. The average molar radioactivity of 5-[C]methoxyflavone was 383 GBq/μmol. The average concentration was 0.107 μg/mL. PET/CT imaging in mice showed 5-[C]methoxyflavone rapidly passed through the blood-brain barrier with 8.36 ± 0.61%ID/g at 2 min post injection, and the radioactivity accumulation in brain was still noticeable with 2.48 ± 0.59%ID/g at 28 min post injection. The clearance rate was 3.37 (brain/brain ratio). The blood and muscle uptakes were low. The lung displayed high initial uptake and subsequent rapid clearance, while the liver and kidney displayed a relatively slow clearance. Real-time imaging showed that 5-[C]methoxyflavone accumulated immediately in the heart, then transferred to the liver and intestine, and was not observed in lower digestive tract.

Conclusions: 5-[C]Methoxyflavone was synthesized conveniently in one step. The results of PET/CT imaging in C57BL/6 mice suggested 5-[C]methoxyflavone possesses appropriate pharmacokinetic properties and favorable brain uptake, thus being proved to be suitable for further development for AD treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nucmedbio.2019.10.005DOI Listing
July 2020

Positron emission tomography probes targeting bromodomain and extra-terminal (BET) domains to enable in vivo neuroepigenetic imaging.

Chem Commun (Camb) 2019 Oct;55(86):12932-12935

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.

Here, we report the development of novel PET radiotracer ([11C]CW22) of BET proteins. In vivo imaging results in rodents and nonhuman primates (NHP) demonstrate that [11C]CW22 has excellent brain uptake, good specificity, good selectivity, suitable metabolism, appropriate kinetics and distribution in the brain. Our studies demonstrated that [11C]CW22 exhibits ideal properties as a PET imaging probe of BET proteins for further validation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9cc06734eDOI Listing
October 2019

Neuroepigenetic signatures of age and sex in the living human brain.

Nat Commun 2019 07 3;10(1):2945. Epub 2019 Jul 3.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.

Age- and sex-related alterations in gene transcription have been demonstrated, however the underlying mechanisms are unresolved. Neuroepigenetic pathways regulate gene transcription in the brain. Here, we measure in vivo expression of the epigenetic enzymes, histone deacetylases (HDACs), across healthy human aging and between sexes using [C]Martinostat positron emission tomography (PET) neuroimaging (n = 41). Relative HDAC expression increases with age in cerebral white matter, and correlates with age-associated disruptions in white matter microstructure. A post mortem study confirmed that HDAC1 and HDAC2 paralogs are elevated in white matter tissue from elderly donors. There are also sex-specific in vivo HDAC expression differences in brain regions associated with emotion and memory, including the amygdala and hippocampus. Hippocampus and white matter HDAC expression negatively correlates with emotion regulation skills (n = 23). Age and sex are associated with HDAC expression in vivo, which could drive age- and sex-related transcriptional changes and impact human behavior.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-019-11031-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6610136PMC
July 2019

Paper-Cut Flexible Multifunctional Electronics Using MoS Nanosheet.

Nanomaterials (Basel) 2019 Jun 26;9(7). Epub 2019 Jun 26.

School of Engineering and Applied Science, The George Washington University, Washington, DC 20052, USA.

Art and science represent human creativity and rational thinking, respectively. When the two seemingly opposite fields are intertwined, there is always a life-changing spark. In particular, the integration of ancient traditional Chinese art into the latest electronic devices is always been an unexcavated topic. Fabricating two-dimensional material with a tensile strain less than 3% with an ultimate global stretch has been an important problem that plagues the current flexible electronics field. The current research is limited to material in small scale, and it is always necessary to develop and extend large-sized flexible electronic systems. Here, inspired by the traditional Chinese paper-cut structure, we present a highly deformable multifunctional electronic system based on the MoS nanosheet. In this work, we first demonstrate how the traditional paper-cut structure can open the view of flexible electronics. In order to obtain a large area of MoS with excellent performance, we use a metal-assisted exfoliation method to transfer MoS, followed by fabricating a field effect transistor to characterize its excellent electrical properties. Two photodetectors and a temperature sensor are produced with good performance. The mechanical simulation proves that the structure has more advantages in stretchability than other typical paper-cut structures. From the experimental and mechanical point of view, it is proved that the device can work stably under high deformation. We finally show that the device has broad application prospects in highly deformed organs, tissues, and joints. These findings set a good example of traditional Chinese culture to guide innovation in the field of electronic devices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nano9070922DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6669538PMC
June 2019

Reduced ribosomal RNA expression and unchanged ribosomal DNA promoter methylation in oral squamous cell carcinoma.

Mol Genet Genomic Med 2019 07 6;7(7):e00783. Epub 2019 Jun 6.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.

Background: Ribosomal RNA (rRNA) consists of four non-coding RNAs, the 28S, 5.8S, 18S, and 5S rRNA. Abnormal expression of rRNA has been found in multiple tumors, and the methylation of rDNA promoter may affect rRNA expression as an epigenetic regulatory mechanism. Oral squamous cell carcinoma (OSCC) is a kind of aggressive tumors which occurs in multiple sites in oral cavity. rRNA expression and the methylation of rDNA promoter in modulating rRNA expression in OSCC maintain unclear. This study aims to investigate the rRNA expression, the methylation status within rDNA promoter, and the underlying mechanism of methylation in regulating rRNA expression in OSCC.

Methods: Twelve primary OSCC and matched normal tissue samples were collected from patients with OSCC. Quantitative real-time PCR was used to evaluate the rRNA level. HpaII/MspI digestion and bisulfite sequencing were used to investigate the methylation status of rDNA promoter.

Results: Ribosomal RNA levels were suppressed in OSCC as compared with matched normal tissues. HpaII/MspI digestion and bisulfite sequencing showed no significant differences for the methylation of rDNA promoter between the tumor and matched normal tissues.

Conclusion: The methylation in rDNA promoter could not explain for the suppressed rRNA expression in OSCC tissues.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mgg3.783DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6625366PMC
July 2019

PET neuroimaging reveals histone deacetylase dysregulation in schizophrenia.

J Clin Invest 2019 01 10;129(1):364-372. Epub 2018 Dec 10.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.

Background: Patients with schizophrenia (SCZ) experience chronic cognitive deficits. Histone deacetylases (HDACs) are enzymes that regulate cognitive circuitry; however, the role of HDACs in cognitive disorders, including SCZ, remains unknown in humans. We previously determined that HDAC2 mRNA levels were lower in dorsolateral prefrontal cortex (DLPFC) tissue from donors with SCZ compared with controls. Here we investigated the relationship between in vivo HDAC expression and cognitive impairment in patients with SCZ and matched healthy controls using [11C]Martinostat positron emission tomography (PET).

Methods: In a case-control study, relative [11C]Martinostat uptake was compared between 14 patients with SCZ or schizoaffective disorder (SCZ/SAD) and 17 controls using hypothesis-driven region-of-interest analysis and unbiased whole brain voxel-wise approaches. Clinical measures, including the MATRICS consensus cognitive battery, were administered.

Results: Relative HDAC expression was lower in the DLPFC of patients with SCZ/SAD compared with controls, and HDAC expression positively correlated with cognitive performance scores across groups. Patients with SCZ/SAD also showed lower relative HDAC expression in the dorsomedial prefrontal cortex and orbitofrontal gyrus, and higher relative HDAC expression in the cerebral white matter, pons, and cerebellum compared with controls.

Conclusions: These findings provide in vivo evidence of HDAC dysregulation in patients with SCZ and suggest that altered HDAC expression may impact cognitive function in humans.

Funding: National Institute of Mental Health (NIMH), Brain and Behavior Foundation, Massachusetts General Hospital (MGH), Athinoula A. Martinos Center for Biomedical Imaging, National Institute of Biomedical Imaging and Bioengineering (NIBIB), NIH Shared Instrumentation Grant Program.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI123743DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307962PMC
January 2019

Discrepancies in Kappa Opioid Agonist Binding Revealed through PET Imaging.

ACS Chem Neurosci 2019 01 17;10(1):384-395. Epub 2018 Oct 17.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology , Massachusetts General Hospital, Harvard Medical School , Charlestown , Massachusetts 02129 , United States.

Kappa opioid receptor (KOR) modulation has been pursued in many conceptual frameworks for the treatment of human pain, depression, and anxiety. As such, several imaging tools have been developed to characterize the density of KORs in the human brain and its occupancy by exogenous drug-like compounds. While exploring the pharmacology of KOR tool compounds using positron emission tomography (PET), we observed discrepancies in the apparent competition binding as measured by changes in binding potential (BP, binding potential with respect to non-displaceable uptake). This prompted us to systematically look at the relationships between baseline BP maps for three common KOR PET radioligands, the antagonists [C]LY2795050 and [C]LY2459989, and the agonist [C]GR103545. We then measured changes in BP using kappa antagonists (naloxone, naltrexone, LY2795050, JDTic, nor-BNI), and found BP was affected similarly between [C]GR103545 and [C]LY2459989. Longitudinal PET studies with nor-BNI and JDTic were also examined, and we observed a persistent decrease in [C]GR103545 BP up to 25 days after drug administration for both nor-BNI and JDTic. Kappa agonists were also administered, and butorphan and GR89696 (racemic GR103545) impacted binding to comparable levels between the two radiotracers. Of greatest significance, kappa agonists salvinorin A and U-50488 caused dramatic reductions in [C]GR103545 BP but did not change [C]LY2459989 binding. This discrepancy was further examined in dose-response studies with each radiotracer as well as in vitro binding experiments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acschemneuro.8b00293DOI Listing
January 2019

Fam83h mutation inhibits the mineralization in ameloblasts by activating Wnt/β-catenin signaling pathway.

Biochem Biophys Res Commun 2018 06 3;501(1):206-211. Epub 2018 May 3.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, Hubei, 430079, PR China. Electronic address:

FAM83H was identified as the major causative gene for autosomal dominant hypocalcified amelogenesis imperfect (ADHCAI). The pathogenic mechanism of FAM83H in ADHCAI remains elusive. The present study aims to investigate the effect of Fam83h mutation on the mineralization of mouse ameloblast cell line LS8 and to explore the possible pathogenesis of ADHCAI. Lentivirus package was performed for the plasmids with mouse Fam83h mutant cDNA (c.1186C > T, M3) and empty vector (Control) and transfected into LS8, which were divided into M3-FLAG and Control groups. Immunoprecipitation, western-blot and immunofluorescence were performed to detect the expression and subcellular localization of Fam83 h, CK1α and β-catenin. ALP activity, ALP staining, expression of the mineralization factors were detected in two groups during mineralization induction. Expression of the mineralization factors was also detected in M3-FLAG and LS8 exposing to pyrvinium pamoate. Compared with the Control, the Fam83h mutation altered the expression and localization of Fam83 h, CK1α and β-catenin in LS8, inhibited the mineralization and down-regulated the expression of mineralization factors in M3-FLAG. Pyrvinium pamoate, an inhibitor of the Wnt/β-catenin signaling pathway, up-regulated expression of mineralization factors in LS8 and rescued the inhibited mineralization in M3-FLAG. The results indicated that the Fam83h mutation could inhibit the mineralization in ameloblasts by activating Wnt/β-catenin signaling pathway.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2018.04.216DOI Listing
June 2018

Peroxisome proliferator-activated receptor γ plays dual roles on experimental periodontitis in rats.

J Clin Periodontol 2018 05 20;45(5):514-523. Epub 2018 Apr 20.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei, China.

Aim: To investigate the effects of peroxisome proliferator-activated receptor γ (PPARγ) on inflammation control and bone remodelling in experimental periodontitis in rats.

Materials And Methods: Experimental periodontitis was induced in rats by thread ligation around cervixes of mandibular first molars. PPARγ agonist, antagonist and vehicle were intraperitoneally administrated, respectively, into rats. Ninety-six male SD rats were randomly divided into control, ligation + vehicle, ligation + agonist and ligation + antagonist groups. After 1, 4 and 8 weeks, alveolar bone loss was assessed by Micro-CT and HE staining. Inflammation and bone metabolism factors were evaluated by ELISA and immunohistochemical examination. Osteoclasts were quantified by tartrate-resistant acid phosphatase (TRAP) staining.

Results: Alveolar bone loss was significantly reduced after 1 week, while significantly increased after 8 weeks in agonist group, but antagonist group showed the opposite trend. Agonist decreased some inflammatory cytokines expression after 1 and 4 weeks, downregulated OPG, RUNX2, BMP-2 and upregulated RANKL after 8 weeks, but antagonist brought the opposite effect. PPARγ agonist significantly reduced osteoclast counting after 1 week, while increased it after 8 weeks.

Conclusions: During periodontitis progression, PPARγ could inhibit inflammation, prevent bone resorption within a short time, while the long-term PPARγ activation would lead to increased bone resorption, and PPARγ repression by antagonist would enhance alveolar bone formation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcpe.12891DOI Listing
May 2018
-->