Publications by authors named "Yi-Ting Tsai"

183 Publications

Impaired cholesterol efflux in retinal pigment epithelium of individuals with juvenile macular degeneration.

Am J Hum Genet 2021 May 27;108(5):903-918. Epub 2021 Apr 27.

Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA; Department of Pathology & Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. Electronic address:

Macular degeneration (MD) is characterized by the progressive deterioration of the macula and represents one of the most prevalent causes of blindness worldwide. Abnormal intracellular accumulation of lipid droplets and pericellular deposits of lipid-rich material in the retinal pigment epithelium (RPE) called drusen are clinical hallmarks of different forms of MD including Doyne honeycomb retinal dystrophy (DHRD) and age-related MD (AMD). However, the appropriate molecular therapeutic target underlying these disorder phenotypes remains elusive. Here, we address this knowledge gap by comparing the proteomic profiles of induced pluripotent stem cell (iPSC)-derived RPEs (iRPE) from individuals with DHRD and their isogenic controls. Our analysis and follow-up studies elucidated the mechanism of lipid accumulation in DHRD iRPE cells. Specifically, we detected significant downregulation of carboxylesterase 1 (CES1), an enzyme that converts cholesteryl ester to free cholesterol, an indispensable process in cholesterol export. CES1 knockdown or overexpression of EFEMP1, a variant of EGF-containing fibulin extracellular matrix protein 1 that is associated with DHRD and attenuated cholesterol efflux and led to lipid droplet accumulation. In iRPE cells, we also found that EFEMP1 has a hyper-inhibitory effect on epidermal growth factor receptor (EGFR) signaling when compared to EFEMP1 and may suppress CES1 expression via the downregulation of transcription factor SP1. Taken together, these results highlight the homeostatic role of cholesterol efflux in iRPE cells and identify CES1 as a mediator of cholesterol efflux in MD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajhg.2021.04.006DOI Listing
May 2021

Rhodium-Catalyzed Aerobic Decomposition of 1,3-Diaryl-2-diazo-1,3-diketones: Mechanistic Investigation and Application to the Synthesis of Benzils.

J Org Chem 2021 Jan 2;86(1):813-828. Epub 2020 Dec 2.

Department of Chemistry, National Dong Hwa University, No. 1, Sec. 2, Da Hsueh Rd., Shoufeng, Hualien 97401, Taiwan, ROC.

The conversion of 1,3-diaryl-2-diazo-1,3-diketones to 1,2-daryl-1,2-diketones (benzils) is reported based on a rhodium(II)-catalyzed aerobic decomposition process. The reaction occurs at ambient temperatures and can be catalyzed by a few dirhodium carboxylates (5 mol %) under a balloon pressure of oxygen. Moreover, an oxygen atom from the O reagent is shown to be incorporated into the product, and this is accompanied by the extrusion of a carbonyl unit from the starting materials. Mechanistically, it is proposed that the decomposition may proceed the interaction of a ketene intermediate resulting from a Wolff rearrangement of the carbenoid, with a rhodium peroxide or peroxy radical species generated upon the activation of molecular oxygen. The proposed mechanism has been supported by the results from a set of controlled experiments. By using this newly developed strategy, a large array of benzil derivatives as well as 9,10-phenanthrenequinone were synthesized from the corresponding diazo substrates in varying yields. On the other hand, the method did not allow the generation of benzocyclobutene-1,2-dione from 2-diazo-1,3-indandione because of the difficulty of inducing the initial rearrangement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.joc.0c02366DOI Listing
January 2021

Real-World Infliximab Pharmacokinetic Study Informs an Electronic Health Record-Embedded Dashboard to Guide Precision Dosing in Children with Crohn's Disease.

Clin Pharmacol Ther 2020 Dec 22. Epub 2020 Dec 22.

Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.

Standard-of-care infliximab dosing regimens were developed prior to the routine use of therapeutic drug monitoring and identification of target concentrations. Not surprisingly, subtherapeutic infliximab concentrations in pediatric Crohn's disease (CD) are common. The primary aim was to conduct a real-world pharmacokinetic (PK) evaluation to discover blood biomarkers of rapid clearance, identify exposure targets, and a secondary aim to translate PK modeling to the clinic. In a multicenter observational study, 671 peak and trough infliximab concentrations from 78 patients with CD were analyzed with a drug-tolerant assay (Esoterix; LabCorp, Calabasas, CA). Individual area under the curve (AUC) estimates were generated as a measure of drug exposure over time. Population PK modeling (nonlinear mixed-effect modeling) identified serum albumin, antibody to infliximab, erythrocyte sedimentation rate (ESR), and neutrophil CD64 as biomarkers for drug clearance. Week 14 and week 52 biochemical remitters (fecal calprotectin < 250 µg/g) had higher infliximab exposure (AUC) throughout induction. The optimal infliximab AUC target during induction for week 14 biochemical remission was 79,348 µg*h/mL (area under the receiver operating characteristic curve (AUROC) 0.77, [0.63-0.90], 85.7% sensitive, and 64.3% specific) with those exceeding the AUC target more likely to achieve a surgery-free week 52 biochemical remission (OR 4.3, [1.2-14.6]). Pretreatment predictors for subtherapeutic week 14 AUC included neutrophil CD64 > 6 (OR 4.5, [1.4-17.8]), ESR > 30 mm/h (OR 3.8, [1.4-11]), age < 10 years old (OR 4.2, [1.2-20]), and weight < 30 kg (OR 6.6, [2.1-25]). We created a decision-support PK dashboard with an iterative process and embedded the modeling program within the electronic health record. Model-informed precision dosing guided by real-world PKs is now available at the bedside in real-time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cpt.2148DOI Listing
December 2020

Bringing rafts to life: Lessons learned from lipid organization across diverse biological membranes.

Chem Phys Lipids 2020 11 22;233:104984. Epub 2020 Oct 22.

Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States. Electronic address:

The ability of lipids to drive lateral organization is a remarkable feature of membranes and has been hypothesized to underlie the architecture of cells. Models for lipid rafts and related domains were originally based on the mammalian plasma membrane, but the nature of heterogeneity in this system is still not fully resolved. However, the concept of lipid-driven organization has been highly influential across biology, and has led to discoveries in organisms that feature a diversity of lipid chemistries and physiological needs. Here we review several emerging and instructive cases of membrane organization in non-mammalian systems. In bacteria, several types of membrane domains that act in metabolism and signaling have been elucidated. These widen our view of what constitutes a raft, but also introduce new questions about the relationship between organization and function. In yeast, observable membrane organization is found in both the plasma membrane and the vacuole. The latter serves as the best example of classic membrane phase partitioning in a living system to date, suggesting that internal organelles are important membranes to investigate across eukaryotes. Finally, we highlight plants as powerful model systems for complex membrane interactions in multicellular organisms. Plant membranes are organized by unique glycosphingolipids, supporting the importance of carbohydrate interactions in organizing lateral domains. These examples demonstrate that membrane organization is a potentially universal phenonenon in biology and argue for the continued broadening of lipid physical chemistry research into a wide range of systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemphyslip.2020.104984DOI Listing
November 2020

Ganoderma tsugae suppresses the proliferation of endometrial carcinoma cells via Akt signaling pathway.

Environ Toxicol 2021 Mar 12;36(3):320-327. Epub 2020 Oct 12.

Department of Biological Science and Technology, College of Life Sciences, China Medical University, Taichung, Taiwan.

Ganoderma is one of the common medicinal mushrooms in traditional Chinese medicine. Previous researches have unveiled the multifaceted biological activity of Ganoderma extract. Ganoderma tsugae has been investigated the potential on curing prostate, colon, lung, epidermoid, breast and ovarian cancers, but not including endometrial cancer. Endometrial cancer is a gynecological malignant tumor with serious drug resistance problem in clinical cancer treatment. This study aimed to demonstrate the first study of Ganoderma on treating endometrial cancer. The Ganoderma tsugae ethanol extract (GTEE) could suppress the proliferation of endometrial cancer cells HEC-1-A, KLE, and AN3 CA. GTEE also induced G1/S phase arrest and mitochondria-mediated apoptosis in endometrial cancer cells. Furthermore, the Akt signaling pathway could be suppressed by GTEE. Therefore, our results suggest for the first time that GTEE has the potential to be an adjuvant therapeutic agent in the treatment of endometrial cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/tox.23037DOI Listing
March 2021

The distribution of cultivable oral anaerobic microbiota identified by MALDI-TOF MS in healthy subjects and in patients with periodontal disease.

J Pharm Biomed Anal 2021 Jan 22;192:113647. Epub 2020 Sep 22.

Institute of Bioinformatics and Structural Biology and Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan. Electronic address:

In this study, we aimed to identify the cultivatable oral anaerobic bacterial distribution in oral cavity by MALDI-TOF Biotyper. The bacterial distribution of three groups, including subjects with/without periodontal disease, two clusters of age (60 years as the cutoff), and before/after treatment, were investigated in this study. There were 38 participants recruited in this study, involving 18 subjects with moderate to severe periodontal-infected patients and 20 healthy controls. Total number of 126 bacterial species were identified by MALDI-TOF MS. The relative abundance of Streptococcus gordonii and Streptococcus intermedius in periodontal patients is higher than healthy controls indicating potential biomarkers for periodontal disease. Participants with periodontal disease were subdivided in to two clusters of age (60 years as the cutoff), 11 and 7 participants were age <60 years and>60 years, respectively. Meanwhile, the incidence of Streptococcus pneumoniae and Streptococcus oralis infection were higher in the subjects above 60 years old than below. Moreover, the bacterial distribution between pre-treatment and post-treatment was similar indicating that basic treatment without the ability to redistribute the microbiota. In summary, the cultivable oral anaerobic bacteria were identified by MALDI-TOF MS and the bacterial distribution shifting was shown to be associated with the progress of periodontal disease to aging and basic treatment. This study provided information for diagnosis and treatment guidelines for oral healthcare.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpba.2020.113647DOI Listing
January 2021

TGF-β1 signaling protects retinal ganglion cells from oxidative stress via modulation of the HO-1/Nrf2 pathway.

Chem Biol Interact 2020 Nov 24;331:109249. Epub 2020 Sep 24.

Institute of Bioinformatics and Structural Biology, Department of Medical Sciences, National Tsing Hua University, Hsinchu, 300, Taiwan. Electronic address:

Oxidative stress provides a major contribution to the pathogenesis of glaucoma and may induce retinal ganglion cell (RGC) damage. Transforming growth factor β (TGF-β) has appeared as a neuroprotective protein in various indignities. However, the TGF-β mechanism of protective effects against oxidative stress damage in RGCs still undetermined. In our research, we investigated the regulatory mechanisms and potential effects of TGF-β1 & TGF-β2 in hydrogen peroxide (HO)-stimulated oxidative stress of RGCs in vitro. By a series of cell functional qualitative analysis, such as MTT cell viability assay, wound healing ability assay, apoptosis assay, intracellular ROS detection, immunoblot analysis, intracellular GSH content, and high-resolution respirometry, we illustrated the cell state in oxidative stress-induced injury. Results of protein expression showed that TGF-β1 & TGF-β2 was upregulated in RGCs after HO stimulation. Cell functional assays resulted that knockdown of TGF-β1 & TGF-β2 reduced survival rate whereas enhanced apoptosis and accumulation of reactive oxygen species (ROS). Especially TGF-β1 upregulation promoted the protein expression of aldehyde dehydrogenase 3A1 (ALDH3A1) and increased the activity of antioxidant and neuroprotection pathways. Additionally, TGF-β1 & TGF-β2 on antioxidant signaling was related to activation of heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor (Nrf2), which are stress-response proteins. ROS accumulation followed by the accumulation of hypoxia-inducible factor (HIF-1α) caused mitochondrial damage and led to neurodegeneration. In summary, our results demonstrated that TGF-β1 preserves RGCs from free radicals-mediated injury by upregulating the activation of Nrf2 expression and HO-1 signaling balance HIF-1α upregulation, implying a prospective role of TGF-β1 in retinal neuroprotection-related therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cbi.2020.109249DOI Listing
November 2020

Achieving Target Infliximab Drug Concentrations Improves Blood and Fecal Neutrophil Biomarkers in Crohn's Disease.

Inflamm Bowel Dis 2020 Sep 18. Epub 2020 Sep 18.

Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.

Background: The neutrophil fecal biomarkers, calprotectin (FCP) and lactoferrin (LCT), and peripheral blood neutrophil CD64 surface receptor (nCD64) are biomarkers for mucosal inflammation in inflammatory bowel disease (IBD). Although FCP has been evaluated as a biomarker for mucosal healing, cut points for LCT and nCD64 are less known. We aimed to identify the cut points for LCT and nCD64 that were associated with FCP remission, with a secondary aim to evaluate the relationship between biochemical outcomes and infliximab (IFX) trough concentrations.

Methods: We analyzed FCP, LCT, and nCD64 before and after IFX induction in a pediatric Crohn's disease (CD) cohort study. Week-14 FCP biomarker remission was defined as FCP <250 µg/g, with clinical response defined as a weighted Pediatric Crohn's Disease Activity Index <12.5 or Δ>17.5 improvement. Predictive outcomes were calculated by receiver operating characteristics (ROCs).

Results: Among 56 CD patients, ROC analysis identified an infusion 4 LCT <8.06 (area under the receiver operator characteristics [AUROC], 0.934, P < 0.001) and nCD64 <6.12 (AUROC, 0.76, P = 0.02) as the ideal cut points for week-14 FCP biomarker remission. End of induction IFX-trough of >9.4 µg/mL (AUROC, 0.799, P = 0.002) and >11.5 µg/mL (AUROC, 0.835, P = 0.003) were associated with a FCP <250 and FCP <100, respectively. We found patients achieving end of induction trough >5 µg/mL had a median FCP improvement (dose 1 to dose 4) of 90% compared with a median of 35% with levels <5 µg/mL (P = 0.024) with a similar median reduction in nCD64 (48% vs 20%, P = 0.031).

Conclusions: This study establishes cut points in neutrophil stool and blood biomarkers for both biochemical remission and therapeutic trough levels following induction therapy. Further studies that evaluate pharmacodynamic biomarker targets for endoscopic and histologic healing are warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ibd/izaa241DOI Listing
September 2020

The Role of Transforming Growth Factor-Beta in Retinal Ganglion Cells with Hyperglycemia and Oxidative Stress.

Int J Mol Sci 2020 Sep 4;21(18). Epub 2020 Sep 4.

Institute of Bioinformatics and Structural Biology & Department of Medical Sciences, National Tsing Hua University, Hsinchu 300, Taiwan.

A characteristic of diabetes mellitus is hyperglycemia, which is considered with an emphasis on the diabetic retinopathy of progressive neurodegenerative disease. Retinal ganglion cells (RGCs) are believed to be important cells affected in the pathogenesis of diabetic retinopathy. Transforming growth factor-beta (TGF-β) is a neuroprotective protein that helps to withstand various neuronal injuries. To investigate the potential roles and regulatory mechanisms of TGF-β in hyperglycemia-triggered damage of RGCs in vitro, we established RGCs in 5.5, 25, 50, and 100 mM D-glucose supplemented media and focused on the TGF-β-related oxidative stress pathway in combination with hydrogen peroxide (HO). Functional experiments showed that TGF-β1/2 protein expression was upregulated in RGCs with hyperglycemia. The knockdown of TGF-β enhanced the accumulation of reactive oxygen species (ROS), inhibited the cell proliferation rate, and reduced glutathione content in hyperglycemia. Furthermore, the results showed that the TGF-β-mediated enhancement of antioxidant signaling was correlated with the activation of stress response proteins and the antioxidant pathway, such as aldehyde dehydrogenase 3A1 (ALDH3A1), heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor (Nrf2), and hypoxia-inducible factor (HIF-1α). Summarizing, our results demonstrated that TGF-β keeps RGCs from hyperglycemia-triggered harm by promoting the activation of the antioxidant pathway, suggesting a potential anti-diabetic therapy for the treatment of diabetic retinopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21186482DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7554964PMC
September 2020

Targeting UDP-glucose dehydrogenase inhibits ovarian cancer growth and metastasis.

J Cell Mol Med 2020 10 7;24(20):11883-11902. Epub 2020 Sep 7.

Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.

More than 70% of patients with ovarian cancer are diagnosed in advanced stages. Therefore, it is urgent to identify a promising prognostic marker and understand the mechanism of ovarian cancer metastasis development. By using proteomics approaches, we found that UDP-glucose dehydrogenase (UGDH) was up-regulated in highly metastatic ovarian cancer TOV21G cells, characterized by high invasiveness (TOV21G ), in comparison to its parental control. Previous reports demonstrated that UGDH is involved in cell migration, but its specific role in cancer metastasis remains unclear. By performing immunohistochemical staining with tissue microarray, we found overexpression of UGDH in ovarian cancer tissue, but not in normal adjacent tissue. Silencing using RNA interference (RNAi) was utilized to knockdown UGDH, which resulted in a significant decrease in metastatic ability in transwell migration, transwell invasion and wound healing assays. The knockdown of UGDH caused cell cycle arrest in the G /G phase and induced a massive decrease of tumour formation rate in vivo. Our data showed that UGDH-depletion led to the down-regulation of epithelial-mesenchymal transition (EMT)-related markers as well as MMP2, and inactivation of the ERK/MAPK pathway. In conclusion, we found that the up-regulation of UGDH is related to ovarian cancer metastasis and the deficiency of UGDH leads to the decrease of cell migration, cell invasion, wound healing and cell proliferation ability. Our findings reveal that UGDH can serve as a prognostic marker and that the inhibition of UGDH is a promising strategy for ovarian cancer treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.15808DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578908PMC
October 2020

Characterization of intracellular buffering power in human induced pluripotent stem cells and the loss of pluripotency is delayed by acidic stimulation and increase of NHE1 activity.

J Cell Physiol 2021 Feb 25;236(2):1515-1528. Epub 2020 Aug 25.

Department of Surgery, Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.

The homeostasis of intracellular pH (pH ) affects many cellular functions. Our previous study has established a functional and molecular model of the active pH regulators in human induced pluripotent stem cells (hiPSCs). The aims of the present study were to further quantify passive pH buffering power (β) and to investigate the effects of extracellular pH and Na -H exchanger 1 (NHE1) activity on pluripotency in hiPSCs. pH was detected by microspectrofluorimetry with pH-sensitive dye-BCECF. Western blot, immunofluorescence staining, and flow cytometry were used to detect protein expression and pluripotency. Our study in hiPSCs showed that (a) the value of total (β ), intrinsic (β ), and CO -dependent ( ) buffering power all increased while pH increased; (b) during the spontaneous differentiation for 4 days, the β values of β and changed in a tendency of decrease, despite the absence of statistical significance; (c) an acidic cultured environment retained pluripotency and further upregulated expression and activity of NHE1 during spontaneous differentiation; (d) inhibition on NHE1 activity promoted the loss of pluripotency. In conclusion, we, for the first time, established a quantitative model of passive β during differentiation and demonstrated that maintenance of NHE1 at a higher level was of critical importance for pluripotency retention in hiPSCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcp.29959DOI Listing
February 2021

Diabetes Upregulates Oxidative Stress and Downregulates Cardiac Protection to Exacerbate Myocardial Ischemia/Reperfusion Injury in Rats.

Antioxidants (Basel) 2020 Jul 29;9(8). Epub 2020 Jul 29.

Department of Life Science, School of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan.

Diabetes exacerbates myocardial ischemia/reperfusion (IR) injury by incompletely understood mechanisms. We explored whether diabetes diminished BAG3/Bcl-2/Nrf-2/HO-1-mediated cardioprotection and overproduced oxidative stress contributing to exaggerated IR injury. Streptozotocin-induced diabetes enhanced hyperglycemia, cardiac NADPH oxidase p22/p67 expression, malondialdehyde amount and leukocyte infiltration, altered the mesenteric expression of 4-HNE, CaSR, p-eNOS and BAG3 and impaired microvascular reactivity to the vasoconstrictor/vasodilator by a wire myography. In response to myocardial IR, diabetes further depressed BAG3/Bcl-2/Nrf-2/HO-1 expression, increased cleaved-caspase 3/poly(ADP-ribose) polymerase (PARP)/TUNEL-mediated apoptosis and exacerbated IR-induced left ventricular dysfunction characterized by further depressed microcirculation, heart rate, left ventricular systolic pressure and peak rate of pressure increase/decrease (±dp/dt) and elevated left ventricular end-diastolic pressure (LVEDP) and Evans blue-2,3,5-triphenyltetrazolium chloride-stained infarct size in diabetic hearts. Our results implicated diabetes exacerbated IR-induced myocardial dysfunction through downregulated BAG3/Bcl-2/Nrf-2/HO-1 expression, increased p22/p67/caspase 3/PARP/apoptosis-mediated oxidative injury and impaired microvascular reactivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/antiox9080679DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465304PMC
July 2020

Progesterone receptor membrane component 1 is involved in oral cancer cell metastasis.

J Cell Mol Med 2020 09 16;24(17):9737-9751. Epub 2020 Jul 16.

Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.

Cancer metastasis is a common cause of failure in cancer therapy. However, over 60% of oral cancer patients present with advanced stage disease, and the five-year survival rates of these patients decrease from 72.6% to 20% as the stage becomes more advanced. In order to manage oral cancer, identification of metastasis biomarker and mechanism is critical. In this study, we use a pair of oral squamous cell carcinoma lines, OC3, and invasive OC3-I5 as a model system to examine invasive mechanism and to identify potential therapeutic targets. We used two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to examine the global protein expression changes between OC3 and invasive OC3-I5. A proteomic study reveals that invasive properties alter the expression of 101 proteins in OC3-I5 cells comparing to OC3 cells. Further studies have used RNA interference technique to monitor the influence of progesterone receptor membrane component 1 (PGRMC1) protein in invasion and evaluate their potency in regulating invasion and the mechanism it involved. The results demonstrated that expression of epithelial-mesenchymal transition (EMT) markers including Twist, p-Src, Snail1, SIP1, JAM-A, vimentin and vinculin was increased in OC3-I5 compared to OC3 cells, whereas E-cadherin expression was decreased in the OC3-I5 cells. Moreover, in mouse model, PGRMC1 is shown to affect not only migration and invasion but also metastasis in vivo. Taken together, the proteomic approach allows us to identify numerous proteins, including PGRMC1, involved in invasion mechanism. Our results provide useful diagnostic markers and therapeutic candidates for the treatment of oral cancer invasion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.15535DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7520311PMC
September 2020

Persistent cardiac arrest caused by profound hypokalaemia after large-dose insulin injection in a young man with type 1 diabetes mellitus: successful rescue with extracorporeal membrane oxygenation and subsequent ventricular assist device.

Cardiovasc J Afr 2020 Nov-Dec;31(6):339-342. Epub 2020 Jul 6.

Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Email:

A 28-year-old man who had a history of type 1 diabetes mellitus with poor medication compliance was referred to the emergency department of our institute with suspected diabetic ketoacidosis. The patient developed sudden cardiac arrest following continuous insulin administration. Laboratory data revealed severe hypokalaemia. Cardiopulmonary resuscitation was performed immediately for 63 minutes. Although his spontaneous circulation resumed, the haemodynamics remained unstable. Peripheral extracorporeal membrane oxygenation was therefore employed for mechanical circulatory support. Echocardiography under these conditions revealed generalised hypokinesia of the bilateral ventricles. The left ventricular ejection fraction was only 10-15%. The chest film revealed bilateral pulmonary congestion. The patient developed multiple organ dysfunction, including acute kidney injury, liver congestion and persistent pulmonary oedema, although the hypokalaemia resolved. A temporary bilateral ventricular assist device (Bi-VAD) was used for superior systemic perfusion and unloading of the bilateral ventricles after 16 hours of extracorporeal membrane oxygenation support. After the start of maintenance using the Bi-VAD, extracorporeal membrane oxygenation was discontinued and the inotropic agents were tapered down immediately. Subsequently, the haemodynamics stabilised. All the visceral organs were well perfused with Bi-VAD support. Subsequent echocardiography demonstrated recovery from the myocardial stunning, with the left ventricular ejection fraction returning to 50-60%. The Bi-VAD was gradually weaned and successfully removed 12 days after implantation. The patient had an uneventful recovery and was discharged without organ injury. Over one year of follow up in our out-patient clinic, adequate cardiac function and improved diabetes control were found.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5830/CVJA-2020-018DOI Listing
July 2020

Proteomic analysis of Antrodia Cinnamomea-induced ER stress in liver cancer cells.

J Pharm Biomed Anal 2020 Aug 16;187:113142. Epub 2020 Mar 16.

Department of Medical Research, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chia-Yi, Taiwan. Electronic address:

Antrodia Cinnamomea is a fungus species widely used as a herb medicine for hypertension, cancer and handover. Nevertheless, the biological roles of Antrodia Cinnamomea on the molecular mechanism of liver cancer are not entirely understood. To determine whether Antrodia Cinnamomea is able to be used for the treatment of liver cancer and its molecular mechanism, we examined the effect of Antrodia Cinnamomea on the differential proteomic patterns in liver cancer cell lines HepG2 and C3A as well as in Chang's liver cell, a normal liver cell, using quantitative proteomic approach. The proteomic analysis demonstrated that abundance of 82, 125 and 125 proteins was significantly altered in Chang's liver cells, C3A and HepG2, respectively. The experimental outcomes also demonstrated that Antrodia Cinnamomea-induced cytotoxicity in liver cancer cells mostly involved dysregulation of protein folding, cytoskeleton regulation, redox-regulation, glycolysis pathway as well as transcription regulation. Further analysis also revealed that Antrodia Cinnamomea promoted misfolding of intracellular proteins and dysregulate of cellular redox-balance resulting in ER-stress. To sum up our studies demonstrated that the proteomic strategy used in this study offered a tool to investigate the molecular mechanisms of Antrodia Cinnamomea-induced liver cancer cytotoxicity. The proteomic results might be further evaluated as prospective targets in liver cancer treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpba.2020.113142DOI Listing
August 2020

Proteomic Analysis of Metastasis-Specific Biomarkers in Pancreatic Cancer: Galectin-1 Plays an Important Metastatic Role in Pancreatic Cancer.

J Pharm Biomed Anal 2020 Jul 25;186:113300. Epub 2020 Apr 25.

Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan. Electronic address:

Cancer metastasis is the major cause of death in pancreatic cancer. We have established a pair of pancreatic ductal adenocarcinoma cell line, PANC1 and invasive PANC1-I5, as a model system toinvestigate the metastatic mechanism as well as potential therapeutic targets in pancreatic cancer. We used proteomic analysis based on two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to examine the global protein expression alterations between PANC1 and PANC1-I5. Proteomic study revealed that 88 proteins are differentially expressed between PANC1-I5 and PANC1 cells, and further functional evaluations through protein expression validation, gene knockout, migration and invasion analysis revealed that galectin-1 is one of the potential players in modulating pancreatic cancer metastasis. To conclude, we have identified numerous proteins might be associated with pancreatic cancer invasiveness in the pancreatic cancer model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpba.2020.113300DOI Listing
July 2020

Confers Obesity Resistance and Restores Intestinal Barrier Integrity in Leptin-deficient Obese Mice.

Nutrients 2020 Mar 10;12(3). Epub 2020 Mar 10.

Institute of Bioinformatics and Structural Biology and Department of Medical Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan.

Obesity is associated with metabolic disorders. Thus, obesity prevention and treatment are essential for health. (AC) is a multifunctional medicinal fungus used for the treatment of various diseases and for preventing diet-induced obesity. Leptin deficiency causes over-eating and spontaneous obesity. The concomitant metabolic symptoms are more severe than diet-induced obesity. Here, we used leptin-deficient () mice as an animal model for over-feeding to study the effect of AC on obesity. We fed C57BL/6 mice (WT, ) and mice with AC for four weeks before performing qRT-PCR and immunoblot analysis to elaborate AC-modulated mechanisms. Further, we used Caco-2 cells as a human intestinal epithelial barrier model to examine the effect of AC on intestinal permeability. Our results suggested that AC reduces lipid deposits of the liver and epididymal white adipose tissue (EWAT) by promoting lipid metabolism and inhibiting lipogenesis-associated genes and proteins in mice. Moreover, AC effectively repaired intestinal-barrier injury caused by leptin deficiency and enhanced intestinal barrier integrity in Caco-2 cells. Interestingly, AC significantly reduced body weight and EWAT with no compromise on food intake in mice. Thus, AC effectively reduced obesity caused by leptin-deficiency and can potentially be used as a nutraceutical for treating obesity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu12030726DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146579PMC
March 2020

Effects of Andrographolide on Intracellular pH Regulation, Cellular Migration, and Apoptosis in Human Cervical Cancer Cells †.

Cancers (Basel) 2020 Feb 7;12(2). Epub 2020 Feb 7.

Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan.

Cancer cells have been characterized with alkaline intracellular pH (pH) values (≥7.2) to enable cancer proliferation, migration, and progression. The aim of the present study was to explore the concentration-dependent effects of Andrographolide, an active diterpenoid compound of herb Andrographis paniculata, on Na/H exchanger isoform 1 (NHE1), cellular migration and apoptosis in human cervical cancer cells (HeLa). The pH was detected by microspectrofluorometry method, and intracellular acidification was induced by NHCl prepulse technique. Viability and protein expression were determined by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and Western blot, respectively. Human normal endocervical cells (End1), ectocervical cells (Ect1), and HeLa were bought commercially. The resting pH value of HeLa (≈7.47) was significantly higher than that of End1 and Ect1 (≈7.30), and shifted from alkaline to acidic following acid/base impacts. In HEPES (4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid | N-(2-Hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) -buffered superfusate, NHE1 and V-ATPase co-existed functionally for acid extrusion in HeLa, while only NHE1 existed functionally in End/Ect1. Andrographolide (3-1000 μM) concentration-dependently inhibited NHE1 activity. Cell-migration and expressions of NHE1, V-ATPase, PARP (poly-ADP-ribose-polymerase), pro-Caspase-3, and Bcl-2 were significantly reduced by pretreating with Andrographolide (≥100 μM) for 24-48 h in HeLa. Andrographolide inhibited cell viability of End1-cells/Ect1 and HeLa (≥100 and ≥30 μM, respectively). The present findings implicate the promising clinical applications of Andrographolide on cervical cancer treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers12020387DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7072207PMC
February 2020

Identification of hyperglycemia-associated microbiota alterations in saliva and gingival sulcus.

Arch Biochem Biophys 2020 03 23;682:108278. Epub 2020 Jan 23.

Institute of Bioinformatics and Structural Biology and Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan. Electronic address:

Oral microbes are a contributing factor to hyperglycemia by inducing an increase in insulin resistance resulting in uncontrolled blood glucose levels. However, the relationship between the distribution of oral flora and hyperglycemia is still controversial. Combining the power of MALDI-Biotyper with anaerobic bacterial culture, this study explores the correlation between anaerobic bacteria in the oral cavity and blood glucose levels. The results demonstrated that altered blood glucose levels contributed to a varied bacterial distribution in the oral cavity. Specifically, Veillonella spp. and Prevotella spp. were identified in a higher proportion in people with elevated blood glucose levels. Six bacterial species identified in this study (Prevotella melaninogenica, Campylobacter rectus, Streptococcus gordonii, Streptococcus mitis, Streptococcus salivarius, and Veillonella parvula) not only demonstrated a positive association with higher blood glucose levels, but also likely contribute to the development of the condition. The data demonstrated MALDI-TOF MS to be a simpler, faster, and more economical clinical identification tool that provides clarity and depth to the research on blood glucose and oral microbiota.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.abb.2020.108278DOI Listing
March 2020

Isoorientin Decreases Cell Migration via Decreasing Functional Activity and Molecular Expression of Proton-Linked Monocarboxylate Transporters in Human Lung Cancer Cells.

Am J Chin Med 2020 10;48(1):201-222. Epub 2020 Jan 10.

Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan.

Aggressive tumor cells mainly rely on glycolysis, and further release vast amounts of lactate and protons by monocarboxylate transporter (MCT), which causes a higher intracellular pH (pH) and acidic extracellular pH. Isoorientin, a principle flavonoid compound extracted from several plant species, shows various pharmacological activities. However, effects of isoorientin on anticancer and MCT await to explore in human lung cancer cells. Human lung cancer tissues were obtained from cancer patients undergoing surgery, while the human lung adenocarcinoma cells (A549) were bought commercially. Change of pH was detected by microspectrofluorometry method with a pH-sensitive fluorescent dye, BCECF. MTT and wound-healing assay were used to detect the cell viability and migration, respectively. Western blot techniques and immunocytochemistry staining were used to detect the protein expression. Our results indicated that the expression of MCTs1/4 and CD147 were upregulated significantly in human lung tissues. In experiments of A549 cells, under HEPES-buffer, the resting pH was 7.47, and isoorientin (1-300M) inhibited functional activity of MCT concentration-dependently (up to %). Pretreatment with isoorientin (3-100M) for 24h, MCT activity and cell migration were significantly inhibited (% and %, respectively), while the cell viability was not affected. Moreover, the expression of MCTs1/4, CD147, and matrix metalloproteinase (MMP) 2/9 were significantly down regulated. In summary, MCTs1/4 and CD147 are significantly upregulated in human lung adenocarcinoma tissues, and isoorientin inhibits cells-migration by inhibiting activity/expression of MCTs1/4 and MMPs2/9 in human lung cancer cells. These novel findings suggest that isoorientin could be a promising pharmacological agent for lung cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1142/S0192415X20500111DOI Listing
September 2020

Functional effects of urotensin-II on intracellular pH regulators in human radial artery smooth muscle cells.

Peptides 2020 04 23;126:170236. Epub 2019 Dec 23.

Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Electronic address:

The regulation of intracellular pH (pH) plays a vital role in various cellular functions. We previously demonstrated that three different acid extruders, the Na-H exchanger (NHE), Na-HCO co-transporter (NBC) and H-linked monocarboxylate transporter (MCT), functioned together in cultured human radial artery smooth muscle cells (HRASMCs). However, the functions of acid-loading transporters in HRASMCs remain poorly understood. Urotensin II (U-II), one of the most potent vasoconstrictors, is highly expressed in many cardiovascular diseases. The aim of this present study was to determine the concentration effect of U-II (3 pM∼100 nM) on the functional activity of pH regulators in HRASMCs. Cultured HRASMCs were derived from segments of human radial arteries obtained from patients undergoing bypass grafting. Changes in pH recovery due to intracellular acidification and alkalization induced by NHCl prepulse and Na-acetate prepulse, respectively, were detected by microspectrofluorimetry with the pH-sensitive fluorescent dye BCECF. Our present study showed that (a) U-II increased the activity of NHE in a concentration-dependent manner but did not change that of NBC or MCT or resting pH, (b) the Cl-OH exchanger (CHE) facilitated base extrusion, and (c) U-II induced a concentration-dependent increase in the activity of CHE. In conclusion, for the first time, our results highlight a concentration-dependent increase in the activity of NHE and CHE, but not NBC and MCT, induced by U-II in HRASMCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.peptides.2019.170236DOI Listing
April 2020

Chromium(III)-Doped Fluoride Phosphors with Broadband Infrared Emission for Light-Emitting Diodes.

Inorg Chem 2020 Jan 11;59(1):376-385. Epub 2019 Dec 11.

Department of Chemistry , National Taiwan University , Taipei 106 , Taiwan.

Two types of infrared fluoride phosphors, Cr-doped KAlF and KGaF, were developed in this research. The KAlF:Cr and KGaF:Cr fluoride phosphors were proven to be pure phase via X-ray diffraction refinement, which demonstrated that the procedure can be applied to large-scale production. Electron paramagnetic resonance measurements indicated that Cr ions in cubic with respect to noncubic are coupled better with KGaF than with KAlF. The main differences between these two phosphors, the site symmetry and pressure behavior of the spectra, were obtained in temperature- and pressure-dependent spectra. According to the calculation results, Cr in fluorine coordination at ambient pressure indicates an intermediate crystal field. For the phosphor-converted light-emitting diodes (LEDs) fabricated from these two phosphors, the spectral range is from 650 to 1000 nm, which resulted in a radiant flux of 7-8 mW with an input power of 1.05 W. The research reveals detailed luminous properties, which will lead to a new way of studying Cr-doped fluoride phosphors and their application in LEDs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.9b02630DOI Listing
January 2020

Elevated Pretreatment Plasma Oncostatin M Is Associated With Poor Biochemical Response to Infliximab.

Crohns Colitis 360 2019 Oct 19;1(3):otz026. Epub 2019 Aug 19.

Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.

Background: We hypothesized that elevations of plasma Oncostatin M (OSM) would be associated with infliximab nonresponse.

Methods: Plasma OSM was measured in Crohn disease patients pre-infliximab with biochemical response (>50% reduction in fecal calprotectin) as the primary outcome.

Results: The median OSM in biochemical responders was 86 (69-148) pg/mL compared with 166 (74-1766) pg/mL in nonresponders ( = 0.03). Plasma OSM > 143.5 pg/mL was 71% sensitive and 78% specific for biochemical nonresponse (area under the curve 0.71). Early biochemical nonremission was also associated with an elevated neutrophil CD64 expression (odds ratio 8.9, = 0.011).

Conclusions: Elevated preinfliximab plasma OSM and nCD64 surface expression were both associated with poor biochemical outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/crocol/otz026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6798793PMC
October 2019

Transplant Recipients Using Tacrolimus Had Higher Utilization of Healthcare Services Than Those Receiving Cyclosporine in Taiwan.

Front Pharmacol 2019 19;10:1074. Epub 2019 Sep 19.

Department of Pharmacy Practice, Tri-Service General Hospital, Taipei, Taiwan.

To date, population-based studies on the healthcare service utilization among stable heart, kidney, and liver transplant recipients with different calcineurin inhibitors are still scarce. Therefore, we used the Taiwan National Health Insurance Research Database to conduct a nationwide cross-sectional study to estimate the healthcare utilization of stable transplant recipients with tacrolimus or cyclosporine (n = 3,482). The sampled patients in this study comprised 377 heart, 1,693 kidney, and 1,412 liver transplant recipients between 1 January 2011 and 31 December 2011. Each subject was followed for a 1-year period to evaluate his/her healthcare service utilization. Outcome variables of the healthcare service utilization were stated as below: numbers of outpatient visits, outpatient costs, numbers of inpatient days, inpatients costs, and total costs of all healthcare services. As for all healthcare service utilization, stable transplant recipients on tacrolimus had significantly more outpatient visits (40.7 vs. 38.6), outpatient costs (US$10,383 vs. US$8,155), and total costs (US$12,516 vs. US$10,372) of all healthcare services than those on cyclosporine during the 1-year follow-up period. Additionally, further analysis showed that heart transplant recipients receiving tacrolimus incurred 1.7-fold higher inpatient costs compared to patients receiving cyclosporine. We concluded that transplant recipients using tacrolimus had significantly higher utilization of all healthcare services than those receiving cyclosporine as immunosuppressive therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2019.01074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6761300PMC
September 2019

CRISPR Base Editing in Induced Pluripotent Stem Cells.

Methods Mol Biol 2019 ;2045:337-346

Department of Ophthalmology, Columbia University, New York, NY, USA.

Induced pluripotent stem cells (iPSCs) have demonstrated tremendous potential in numerous disease modeling and regenerative medicine-based therapies. The development of innovative gene transduction and editing technologies has further augmented the potential of iPSCs. Cas9-cytidine deaminases, for example, have developed as an alternative strategy to integrate single-base mutations (C → T or G → A transitions) at specific genomic loci. In this chapter, we specifically describe CRISPR (clustered regularly interspaced short palindromic repeats) base editing in iPSCs for editing precise locations in the genome. This state-of-the-art approach enables highly efficient and accurate modifications in genes. Thus, this technique not only has the potential to have biotechnology and therapeutic applications but also the ability to reveal underlying mechanisms regarding pathologies caused by specific mutations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/7651_2019_243DOI Listing
June 2020

Development of Infliximab Target Concentrations During Induction in Pediatric Crohn Disease Patients.

J Pediatr Gastroenterol Nutr 2019 07;69(1):68-74

Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.

Objectives: Subtherapeutic drug concentrations contribute to both primary and secondary nonresponse to infliximab in children with Crohn disease (CD). The aim of this study was to evaluate treatment outcomes and infliximab concentrations at infusions 2 and 3 with an objective to establish infliximab targets during induction for primary responders.

Methods: Single-center, prospective cohort of anti- tumor necrosis factor-alpha naïve CD patients younger than 22 years starting infliximab. Clinical response was defined with the weighted pediatric CD activity index at the fourth infusion. Rates of biological response (>50% improvement in fecal calprotectin) and maintenance concentrations ≥5 μg/mL were secondary outcomes.

Results: We enrolled 72 patients with CD with 70 of 72 receiving infliximab monotherapy. Clinical response, biological response, and start of maintenance concentrations ≥5 μg/mL were achieved in 64%, 54%, and 22%, respectively. The median (interquartile range) infliximab concentrations at infusion 2 and 3 in clinical responders were 27.8 μg/mL (19.5-40) and 14 μg/mL (8.3-24) compared to 18.8 μg/mL (9.1-23, P < 0.001) and 7.8 μg/mL (4-13.2, P < 0.01) in nonresponders. Receiver operating characteristic analysis determined that an infliximab concentration ≥15.9 μg/mL at infusion 3 was associated with clinical response (area under the curve [AUC] 0.73), whereas an infusion 3 level ≥18 μg/mL was associated with a start of maintenance concentration >5 μg/mL (AUC 0.85). Independent predictors for infusion 3 levels <18 μg/mL included pretreatment prednisone, low body mass index, elevated erythrocyte sedimentation rate and C-reactive protein, hypoalbuminemia, and an infusion 2 infliximab level <29 μg/mL.

Conclusions: We found that infusion 2 (≥29 μg/mL) and infusion 3 (≥18 μg/mL) infliximab concentrations were strongly associated with improved early outcomes and higher first maintenance dose levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MPG.0000000000002304DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6607916PMC
July 2019

Stent Induced Veno-colic Fistula.

Eur J Vasc Endovasc Surg 2019 Jul 9;58(1):51. Epub 2019 May 9.

Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejvs.2019.03.030DOI Listing
July 2019

Mechanisms of neurodegeneration in a preclinical autosomal dominant retinitis pigmentosa knock-in model with a Rho mutation.

Cell Mol Life Sci 2019 Sep 11;76(18):3657-3665. Epub 2019 Apr 11.

Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, 10032, USA.

D190N, a missense mutation in rhodopsin, causes photoreceptor degeneration in patients with autosomal dominant retinitis pigmentosa (adRP). Two competing hypotheses have been developed to explain why D190N rod photoreceptors degenerate: (a) defective rhodopsin trafficking prevents proteins from correctly exiting the endoplasmic reticulum, leading to their accumulation, with deleterious effects or (b) elevated mutant rhodopsin expression and unabated signaling causes excitotoxicity. A knock-in D190N mouse model was engineered to delineate the mechanism of pathogenesis. Wild type (wt) and mutant rhodopsin appeared correctly localized in rod outer segments of D190N heterozygotes. Moreover, the rhodopsin glycosylation state in the mutants appeared similar to that in wt mice. Thus, it seems plausible that the injurious effect of the heterozygous mutation is not related to mistrafficking of the protein, but rather from constitutive rhodopsin activity and a greater propensity for chromophore isomerization even in the absence of light.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00018-019-03090-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7144803PMC
September 2019

B-type natriuretic peptide enhances fibrotic effects via matrix metalloproteinase-2 expression in the mouse atrium in vivo and in human atrial myofibroblasts in vitro.

Transl Res 2019 06 19;208:30-46. Epub 2019 Feb 19.

Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan; Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Department of Pharmacology & Graduate Institute of Pharmacology, National Defense Medical Center, Taipei, Taiwan. Electronic address:

B-type natriuretic peptide (BNP) was approved by the US Food and Drug Administration in 2001 for the treatment of heart failure. However, the effects of BNP in clinical applications are controversial and uncertain. Recently, study indicated that high BNP levels are associated with an increased risk of developing atrial fibrillation. In this study, we investigated the direct effects of BNP on TNF-α-induced atrial fibrosis mice, as well as its effects on human atrial myofibroblasts. We found that injecting TNF-α-induced mice with recombinant human BNP enhanced atrial fibrosis via matrix metalloproteinase-2 (MMP-2) expression and collagen accumulation. Furthermore, we found that BNP stimulated MMP-2 expression in human atrial myofibroblasts. Treatment of human atrial myofibroblasts with cycloheximide had no effect on this outcome; however, treatment of cells with MG132 enhanced BNP-induced MMP-2 expression, indicating that protein stability and inhibition of proteasome-mediated protein degradation pathways are potentially involved. Inhibition of SIRT1 significantly decreased BNP-induced MMP-2 expression. Additionally, confocal and coimmunoprecipitation data indicated that BNP-regulated MMP-2 expression are likely to be mediated through direct interaction with SIRT1, which is thought to deacetylate MMP-2 and to increase its protein stability in human atrial myofibroblasts. Finally, we confirmed that SIRT1 is expressed and cytoplasmically redistributed as well as colocalized with MMP-2 in mouse fibrotic atrial tissue. We suggest a possible fibrosis-promoting role of BNP in the atrium, although the antifibrotic properties of BNP in the ventricle have been reported in previous studies, and that the coordination between MMP-2 and SIRT1 in BNP-induced atrial myofibroblasts participates in atrial fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trsl.2019.02.007DOI Listing
June 2019