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Lu X, Cummings C, Osuala UA, Yennawar NH, Namitz KEW, Hellner B, Besada-Lombana PB, Peterson RD, Clark AJ. Characterization of recombinant human lactoferrin expressed in Komagataella phaffii. Analyst 2024; 149:3636-3650. [PMID: 38814097 PMCID: PMC11215759 DOI: 10.1039/d4an00333k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
This work presents a thorough characterization of Helaina recombinant human lactoferrin (rhLF, Effera™) expressed in a yeast system at an industrial scale for the first time. Proteomic analysis confirmed that its amino acid sequence is identical to that of native human LF. N-linked glycans were detected at three known glycosylation sites, namely, Asparagines-156, -497, and -642 and they were predominantly oligomannose structures having five to nine mannoses. Helaina rhLF's protein secondary structure was nearly identical to that of human milk lactoferrin (hmLF), as revealed by microfluidic modulation spectroscopy. Results of small-angle X-ray scattering (SAXS) and analytical ultracentrifugation analyses confirmed that, like hmLF, Helaina rhLF displayed well-folded globular structures in solution. Reconstructed solvent envelopes of Helaina rhLF, obtained through the SAXS analysis, demonstrated a remarkable fit with the reported crystalline structure of iron-bound native hmLF. Differential scanning calorimetry investigations into the thermal stability of Helaina rhLF revealed two distinct denaturation temperatures at 68.7 ± 0.9 °C and 91.9 ± 0.5 °C, consistently mirroring denaturation temperatures observed for apo- and holo-hmLF. Overall, Helaina rhLF differed from hmLF in the N-glycans they possessed; nevertheless, the characterization results affirmed that Helaina rhLF was of high purity and exhibited globular structures closely akin to that of hmLF.
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Affiliation(s)
- Xiaoning Lu
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
| | - Chad Cummings
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
| | - Udodili A Osuala
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
| | - Neela H Yennawar
- X-ray Crystallography Core Facility, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kevin E W Namitz
- X-ray Crystallography Core Facility, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Brittney Hellner
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
| | | | - Ross D Peterson
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
| | - Anthony J Clark
- Helaina Inc., 345 Park Avenue South, 5th Floor, New York, NY 10010, USA.
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Jaye S, Sandau US, McFarland TJ, Woltjer RL, Saugstad JA. A clathrin mediated endocytosis scaffolding protein, Intersectin 1, changes in an isoform, brain region, and sex specific manner in Alzheimer's disease. Front Neurosci 2024; 18:1426180. [PMID: 38915309 PMCID: PMC11195150 DOI: 10.3389/fnins.2024.1426180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 05/28/2024] [Indexed: 06/26/2024] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia and is characterized by the accumulation of amyloid-beta (Aβ) plaques and neurofibrillary Tau tangles in the brain. We previously identified a set of candidate AD microRNAs (miRNAs) in human cerebrospinal fluid (CSF) and used a target prediction pipeline to identify mRNAs and pathways that could potentially be regulated by the miRNAs. Of these pathways, clathrin mediated endocytosis (CME) was selected for further investigation. CME is altered in multiple brain cell types in AD and is implicated in early cellular phenotypes such as enlarged early endosomes and pathogenic processing of Aβ. However, a comprehensive evaluation of major CME hub proteins in humans with AD across multiple brain regions is lacking. Thus, we used immunoblots to evaluate human post-mortem AD and control (CTL) frontal cortex (FC; AD n = 22, CTL n = 23) and hippocampus (HP; AD n = 34, CTL n = 22) for changes in Intersectin 1 (ITSN1), Phosphatidylinositol Binding Clathrin Assembly Protein gene (PICALM), Clathrin Light Chain (CLT), FCH and Mu Domain Containing Endocytic Adaptor 1 (FCHO1), Adaptor Related Protein Complex 2 (AP2) Subunit Alpha 1 (AP2A1), and Dynamin 2 (DNM2). Of these, we found that in AD, ITSN1-long (ITSN1-L) was decreased in the FC of males and HP of females, while ITSN1-short was increased in the HP of both males and females. We further evaluated ITSN1-L levels in cortex (CTX) and HP of the 5xFAD mouse model of Aβ pathology at different timepoints during aging and disease progression by immunoblot (n = 5-8 per group). At 3 months, female 5xFAD exhibited an increase of ITSN1-L in CTX but a decrease at 6 and 9 months. Additionally, immunofluorescent staining of 5xFAD primary HP neurons showed an increase of ITSN1-L in matured 5xFAD neurons at 21 and 28 days in vitro. Together, our studies show that in AD, isoforms of ITSN1 change in a brain region-and sex-dependent manner. Further, changes in ITSN1-L are transient with levels increasing during early Aβ accumulation and decreasing during later progression. These findings suggest that ITSN1 expression, and consequently CME activity, may change depending on the stage of disease progression.
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Affiliation(s)
- Sierra Jaye
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Ursula S. Sandau
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Trevor J. McFarland
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Randy L. Woltjer
- Division of Neuropathology, Department of Pathology, Oregon Health and Science University, Portland, OR, United States
| | - Julie A. Saugstad
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
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Afzal S, Dürrast N, Hassan I, Soleimanpour E, Tsai PL, Dieterich DC, Fendt M. Probing cognitive flexibility in Shank2-deficient mice: Effects of D-cycloserine and NMDAR signaling hub dynamics. Prog Neuropsychopharmacol Biol Psychiatry 2024; 134:111051. [PMID: 38849086 DOI: 10.1016/j.pnpbp.2024.111051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/31/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
Neurodevelopmental disorders such as autism spectrum disorder (ASD) have a heterogeneous etiology but are largely associated with genetic factors. Robust evidence from recent human genetic studies has linked mutations in the Shank2 gene to idiopathic ASD. Modeling these Shank2 mutations in animal models recapitulates behavioral changes, e.g. impaired social interaction and repetitive behavior of ASD patients. Shank2-deficient mice exhibit NMDA receptor (NMDAR) hypofunction and associated behavioral deficits. Of note, NMDARs are strongly implicated in cognitive flexibility. Their hypofunction, e.g. observed in schizophrenia, or their pharmacological inhibition leads to impaired cognitive flexibility. However, the association between Shank2 mutations and cognitive flexibility is poorly understood. Using Shank2-deficient mice, we explored the role of Shank2 in cognitive flexibility measured by the attentional set shifting task (ASST) and whether ASST performance in Shank2-deficient mice can be modulated by treatment with the partial NMDAR agonist D-cycloserine (DCS). Furthermore, we investigated the effects of Shank2 deficiency, ASST training, and DCS treatment on the expression level of NMDAR signaling hub components in the orbitofrontal cortex (OFC), including NMDAR subunits (GluN2A, GluN2B, GluN2C), phosphoglycerate dehydrogenase and serine racemase. Surprisingly, Shank2 deficiency did not affect ASST performance or alter the expression of the investigated NMDAR signaling hub components. Importantly, however, DCS significantly improved ASST performance, demonstrating that positive NMDAR modulation facilitates cognitive flexibility. Furthermore, DCS increased the expression of GluN2A in the OFC, but not that of other NMDAR signaling hub components. Our findings highlight the potential of DCS as a pharmacological intervention to improve cognitive flexibility impairments downstream of NMDAR modulation and substantiate the key role of NMDAR in cognitive flexibility.
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Affiliation(s)
- Samia Afzal
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany.
| | - Nora Dürrast
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany
| | - Iman Hassan
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany
| | - Elaheh Soleimanpour
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany
| | - Pei-Ling Tsai
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany
| | - Daniela C Dieterich
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany; Center of Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany
| | - Markus Fendt
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany; Center of Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany
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Hernandez AR, Parker E, Babar M, Banerjee A, Ding S, Simley A, Buford TW. Microbiome-driven alterations in metabolic pathways and impaired cognition in aged female TgF344-AD rats. AGING BRAIN 2024; 5:100119. [PMID: 38881651 PMCID: PMC11179252 DOI: 10.1016/j.nbas.2024.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/09/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024] Open
Abstract
Alzheimer's disease (AD) not only affects cognition and neuropathology, but several other facets capable of negatively impacting quality of life and potentially driving impairments, including altered gut microbiome (GMB) composition and metabolism. Aged (20 + mo) female TgF344-AD and wildtype rats were cognitively characterized on several tasks incorporating several cognitive domains, including task acquisition, object recognition memory, anxiety-like behaviors, and spatial navigation. Additionally, metabolic phenotyping, GMB sequencing throughout the intestinal tract (duodenum, jejunum, ileum, colon, and feces), neuropathological burden assessment and marker gene functional abundance predictions (PICRUSt2) were conducted. TgF344-AD rats demonstrated significant cognitive impairment in multiple domains, as well as regionally specific GMB dysbiosis. Relationships between peripheral factors were investigated using Canonical Correspondence Analysis (CCA), revealing correlations between GMB changes and both cognitive and metabolic factors. Moreover, communities of gut microbes contributing to essential metabolic pathways were significantly altered in TgF344-AD rats. These data indicate dysbiosis may affect cognitive outcomes in AD through alterations in metabolism-related enzymatic pathways that are necessary for proper brain function. Moreover, these changes were mostly observed in intestinal segments required for carbohydrate digestion, not fecal samples. These data support the targeting of intestinal and microbiome health for the treatment of AD.
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Affiliation(s)
- Abbi R Hernandez
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Erik Parker
- Department of Epidemiology and Biostatistics, School of Public Health, Indiana University-Bloomington, Bloomington, IN 47405, USA
| | - Maham Babar
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Anisha Banerjee
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Sarah Ding
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Alexis Simley
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Thomas W Buford
- Department of Medicine, Division of Geriatrics, Gerontology & Palliative Care, University of Alabama at Birmingham, Birmingham, AL 35205, USA
- Birmingham/Atlanta VA GRECC, Birmingham VA Medical Center, Birmingham, AL 35244, USA
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Krishnan I, Chan AML, Law JX, Ng MH, Jayapalan JJ, Lokanathan Y. Proteomic Analysis of Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Systematic Review. Int J Mol Sci 2024; 25:5340. [PMID: 38791378 PMCID: PMC11121203 DOI: 10.3390/ijms25105340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 05/26/2024] Open
Abstract
Numerous challenges remain within conventional cell-based therapy despite the growing trend of stem cells used to treat various life-debilitating diseases. These limitations include batch-to-batch heterogeneity, induced alloreactivity, cell survival and integration, poor scalability, and high cost of treatment, thus hindering successful translation from lab to bedside. However, recent pioneering technology has enabled the isolation and enrichment of small extracellular vesicles (EVs), canonically known as exosomes. EVs are described as a membrane-enclosed cargo of functional biomolecules not limited to lipids, nucleic acid, and proteins. Interestingly, studies have correlated the biological role of MSC-EVs to the paracrine activity of MSCs. This key evidence has led to rigorous studies on MSC-EVs as an acellular alternative. Using EVs as a therapy was proposed as a model leading to improvements through increased safety; enhanced bioavailability due to size and permeability; reduced heterogeneity by selective and quantifiable properties; and prolonged shelf-life via long-term freezing or lyophilization. Yet, the identity and potency of EVs are still relatively unknown due to various methods of preparation and to qualify the final product. This is reflected by the absence of regulatory strategies overseeing manufacturing, quality control, clinical implementation, and product registration. In this review, the authors review the various production processes and the proteomic profile of MSC-EVs.
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Affiliation(s)
- Illayaraja Krishnan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (I.K.); (A.M.L.C.); (J.X.L.); (M.H.N.)
| | - Alvin Man Lung Chan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (I.K.); (A.M.L.C.); (J.X.L.); (M.H.N.)
| | - Jia Xian Law
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (I.K.); (A.M.L.C.); (J.X.L.); (M.H.N.)
| | - Min Hwei Ng
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (I.K.); (A.M.L.C.); (J.X.L.); (M.H.N.)
| | | | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (I.K.); (A.M.L.C.); (J.X.L.); (M.H.N.)
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Wilk SS, Michalak K, Owczarek EP, Winiarczyk S, Zabielska-Koczywąs KA. Proteomic Analyses Reveal the Role of Alpha-2-Macroglobulin in Canine Osteosarcoma Cell Migration. Int J Mol Sci 2024; 25:3989. [PMID: 38612805 PMCID: PMC11011979 DOI: 10.3390/ijms25073989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/25/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Canine osteosarcoma (OSA) is an aggressive bone neoplasia with high metastatic potential. Metastasis is the main cause of death associated with OSA, and there is no current treatment available for metastatic disease. Proteomic analyses, including matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI TOF/TOF MS), are widely used to select molecular targets and identify proteins that may play a key role in primary tumours and at various steps of the metastatic cascade. The main aim of this study was to identify proteins differently expressed in canine OSA cell lines with different malignancy phenotypes (OSCA-8 and OSCA-32) compared to canine osteoblasts (CnOb). The intermediate aim of the study was to compare canine OSA cell migration capacity and assess its correlation with the malignancy phenotypes of each cell line. Using MALDI-TOF/TOF MS analyses, we identified eight proteins that were significantly differentially expressed (p ≤ 0.05) in canine OSA cell lines compared to CnOb: cilia- and flagella-associated protein 298 (CFAP298), general transcription factor II-I (GTF2I), mirror-image polydactyly gene 1 protein (MIPOL1), alpha-2 macroglobulin (A2M), phosphoglycerate mutase 1 (PGAM1), ubiquitin (UB2L6), ectodysplasin-A receptor-associated adapter protein (EDARADD), and leucine-rich-repeat-containing protein 72 (LRRC72). Using the Simple Western technique, we confirmed high A2M expression in CnOb compared to OSCA-8 and OSCA-32 cell lines (with intermediate and low A2M expression, respectively). Then, we confirmed the role of A2M in cancer cell migration by demonstrating significantly inhibited OSA cell migration by treatment with A2M (both at 10 and 30 mM concentrations after 12 and 24 h) in a wound-healing assay. This study may be the first report indicating A2M's role in OSA cell metastasis; however, further in vitro and in vivo studies are needed to confirm its possible role as an anti-metastatic agent in this malignancy.
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Affiliation(s)
- Sylwia S. Wilk
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
| | - Katarzyna Michalak
- Department of Epizootiology and Clinic of Infectious Diseases, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland; (K.M.); (S.W.)
| | - Ewelina P. Owczarek
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology in Warsaw, 4 Ks. Trojdena, 02-109 Warsaw, Poland
| | - Stanisław Winiarczyk
- Department of Epizootiology and Clinic of Infectious Diseases, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland; (K.M.); (S.W.)
- National Veterinary Research Institute, Aleja Partyzantów 5, 24-100 Puławy, Poland
| | - Katarzyna A. Zabielska-Koczywąs
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
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Chi H, Sun Y, Lin P, Zhou J, Zhang J, Yang Y, Qiao Y, Liu D. Glucose Fluctuation Inhibits Nrf2 Signaling Pathway in Hippocampal Tissues and Exacerbates Cognitive Impairment in Streptozotocin-Induced Diabetic Rats. J Diabetes Res 2024; 2024:5584761. [PMID: 38282656 PMCID: PMC10817812 DOI: 10.1155/2024/5584761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 12/25/2023] [Accepted: 01/09/2024] [Indexed: 01/30/2024] Open
Abstract
Background This research investigated whether glucose fluctuation (GF) can exacerbate cognitive impairment in streptozotocin-induced diabetic rats and explored the related mechanism. Methods After 4 weeks of feeding with diets containing high fats plus sugar, the rat model of diabetes mellitus (DM) was established by intraperitoneal injection of streptozotocin (STZ). Then, GF was triggered by means of alternating satiety and starvation for 24 h. The weight, blood glucose level, and water intake of the rats were recorded. The Morris water maze (MWM) test was carried out to appraise the cognitive function at the end of week 12. Moreover, the morphological structure of hippocampal neurons was viewed through HE and Nissl staining, and transmission electron microscopy (TEM) was performed for ultrastructure observation. The protein expression levels of Nrf2, HO-1, NQO-1, Bax, Bcl-2, and Caspase-3 in the hippocampal tissues of rats were measured via Western blotting, and the mRNA expressions of Nrf2, HO-1, and NQO-1 were examined using qRT-PCR. Finally, Western blotting and immunohistochemistry were conducted to detect BDNF levels. Results It was manifested that GF not only aggravated the impairment of spatial memory in rats with STZ-induced type 2 DM but also stimulated the loss, shrinkage, and apoptosis of hippocampal neurons. Regarding the expressions in murine hippocampal tissues, GF depressed Nrf2, HO-1, NQO-1, Bcl-2, and BDNF but boosted Caspase-3 and Bax. Conclusions GF aggravates cognitive impairment by inhibiting the Nrf2 signaling pathway and inducing oxidative stress and apoptosis in the hippocampal tissues.
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Affiliation(s)
- Haiyan Chi
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
- Department of Endocrinology, Weihai Municipal Hospital, Cheeloo College of Medicine, Shandong University, Weihai, Shandong, China
| | - Yujing Sun
- Department of Traditional Chinese Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Peng Lin
- Department of Traditional Chinese Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Junyu Zhou
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Jinbiao Zhang
- Department of Neurology, Weihai Municipal Hospital, Cheeloo College of Medicine, Shandong University, Weihai, Shandong, China
| | - Yachao Yang
- Department of Endocrinology, Weihai Municipal Hospital, Cheeloo College of Medicine, Shandong University, Weihai, Shandong, China
| | - Yun Qiao
- Department of Traditional Chinese Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Deshan Liu
- Department of Traditional Chinese Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
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Milham LT, Morris GP, Konen LM, Rentsch P, Avgan N, Vissel B. Quantification of AMPA receptor subunits and RNA editing-related proteins in the J20 mouse model of Alzheimer's disease by capillary western blotting. Front Mol Neurosci 2024; 16:1338065. [PMID: 38299128 PMCID: PMC10828003 DOI: 10.3389/fnmol.2023.1338065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 12/29/2023] [Indexed: 02/02/2024] Open
Abstract
Introduction Accurate modelling of molecular changes in Alzheimer's disease (AD) dementia is crucial for understanding the mechanisms driving neuronal pathology and for developing treatments. Synaptic dysfunction has long been implicated as a mechanism underpinning memory dysfunction in AD and may result in part from changes in adenosine deaminase acting on RNA (ADAR) mediated RNA editing of the GluA2 subunit of AMPA receptors and changes in AMPA receptor function at the post synaptic cleft. However, few studies have investigated changes in proteins which influence RNA editing and notably, AD studies that focus on studying changes in protein expression, rather than changes in mRNA, often use traditional western blotting. Methods Here, we demonstrate the value of automated capillary western blotting to investigate the protein expression of AMPA receptor subunits (GluA1-4), the ADAR RNA editing proteins (ADAR1-3), and proteins known to regulate RNA editing (PIN1, WWP2, FXR1P, and CREB1), in the J20 AD mouse model. We describe extensive optimisation and validation of the automated capillary western blotting method, demonstrating the use of total protein to normalise protein load, in addition to characterising the optimal protein/antibody concentrations to ensure accurate protein quantification. Following this, we assessed changes in proteins of interest in the hippocampus of 44-week-old J20 AD mice. Results We observed an increase in the expression of ADAR1 p110 and GluA3 and a decrease in ADAR2 in the hippocampus of 44-week-old J20 mice. These changes signify a shift in the balance of proteins that play a critical role at the synapse. Regression analysis revealed unique J20-specific correlations between changes in AMPA receptor subunits, ADAR enzymes, and proteins that regulate ADAR stability in J20 mice, highlighting potential mechanisms mediating RNA-editing changes found in AD. Discussion Our findings in J20 mice generally reflect changes seen in the human AD brain. This study underlines the importance of novel techniques, like automated capillary western blotting, to assess protein expression in AD. It also provides further evidence to support the hypothesis that a dysregulation in RNA editing-related proteins may play a role in the initiation and/or progression of AD.
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Affiliation(s)
- Luke T. Milham
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Gary P. Morris
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Lyndsey M. Konen
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
| | - Peggy Rentsch
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Nesli Avgan
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
| | - Bryce Vissel
- Centre for Neuroscience and Regenerative Medicine, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
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