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Homolak J, Varvaras K, Sciacca V, Babic Perhoc A, Virag D, Knezovic A, Osmanovic Barilar J, Salkovic-Petrisic M. Insights into Gastrointestinal Redox Dysregulation in a Rat Model of Alzheimer's Disease and the Assessment of the Protective Potential of D-Galactose. ACS OMEGA 2024; 9:11288-11304. [PMID: 38496956 PMCID: PMC10938400 DOI: 10.1021/acsomega.3c07152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/14/2023] [Accepted: 01/04/2024] [Indexed: 03/19/2024]
Abstract
Recent evidence suggests that the gut plays a vital role in the development and progression of Alzheimer's disease (AD) by triggering systemic inflammation and oxidative stress. The well-established rat model of AD, induced by intracerebroventricular administration of streptozotocin (STZ-icv), provides valuable insights into the GI implications of neurodegeneration. Notably, this model leads to pathophysiological changes in the gut, including redox dyshomeostasis, resulting from central neuropathology. Our study aimed to investigate the mechanisms underlying gut redox dyshomeostasis and assess the effects of D-galactose, which is known to benefit gut redox homeostasis and alleviate cognitive deficits in this model. Duodenal rings isolated from STZ-icv animals and control groups were subjected to a prooxidative environment using 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) or H2O2 with or without D-galactose in oxygenated Krebs buffer ex vivo. Redox homeostasis was analyzed through protein microarrays and functional biochemical assays alongside cell survival assessment. Structural equation modeling and univariate and multivariate models were employed to evaluate the differential response of STZ-icv and control samples to the controlled prooxidative challenge. STZ-icv samples showed suppressed expression of catalase and glutathione peroxidase 4 (GPX4) and increased baseline activity of enzymes involved in H2O2 and superoxide homeostasis. The altered redox homeostasis status was associated with an inability to respond to oxidative challenges and D-galactose. Conversely, the presence of D-galactose increased the antioxidant capacity, enhanced catalase and peroxidase activity, and upregulated superoxide dismutases in the control samples. STZ-icv-induced gut dysfunction is characterized by a diminished ability of the redox regulatory system to maintain long-term protection through the transcription of antioxidant response genes as well as compromised activation of enzymes responsible for immediate antioxidant defense. D-galactose can exert beneficial effects on gut redox homeostasis under physiological conditions.
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Affiliation(s)
- Jan Homolak
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
- Interfaculty
Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, 72074 Tübingen, Germany
| | - Konstantinos Varvaras
- Department
of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Vittorio Sciacca
- Faculty
of Medicine, University of Catania, 95131 Catania, Italy
| | - Ana Babic Perhoc
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Davor Virag
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Ana Knezovic
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Melita Salkovic-Petrisic
- Department
of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
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2
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Homolak J, Babic Perhoc A, Knezovic A, Osmanovic Barilar J, Virag D, Salkovic-Petrisic M. Exploratory Study of Gastrointestinal Redox Biomarkers in the Presymptomatic and Symptomatic Tg2576 Mouse Model of Familial Alzheimer's Disease: Phenotypic Correlates and Effects of Chronic Oral d-Galactose. ACS Chem Neurosci 2023; 14:4013-4025. [PMID: 37932005 PMCID: PMC10655039 DOI: 10.1021/acschemneuro.3c00495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023] Open
Abstract
The gut might play an important role in the etiopathogenesis of Alzheimer's disease (AD) as gastrointestinal alterations often precede the development of neuropathological changes in the brain and correlate with disease progression in animal models. The gut has an immense capacity to generate free radicals whose role in the etiopathogenesis of AD is well-known; however, it remains to be clarified whether gastrointestinal redox homeostasis is associated with the development of AD. The aim was to (i) examine gastrointestinal redox homeostasis in the presymptomatic and symptomatic Tg2576 mouse model of AD; (ii) investigate the effects of oral d-galactose previously shown to alleviate cognitive deficits and metabolic changes in animal models of AD and reduce gastrointestinal oxidative stress; and (iii) investigate the association between gastrointestinal redox biomarkers and behavioral alterations in Tg2576 mice. In the presymptomatic stage, Tg2576 mice displayed an increased gastrointestinal electrophilic tone, characterized by higher lipid peroxidation and elevated Mn/Fe-SOD activity. In the symptomatic stage, these alterations are rectified, but the total antioxidant capacity is decreased. Chronic oral d-galactose increased the antioxidant capacity and reduced lipid peroxidation in the Tg2576 but had the opposite effects in the wild-type animals. The total antioxidant capacity of the gastrointestinal tract was associated with greater spatial memory. Gut redox homeostasis might be involved in the development and progression of AD pathophysiology and should be further explored in this context.
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Affiliation(s)
- Jan Homolak
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
- Interfaculty
Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
- Cluster
of Excellence “Controlling Microbes to Fight Infections”, University of Tübingen, Tübingen 72076, Germany
| | - Ana Babic Perhoc
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
| | - Ana Knezovic
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
| | - Jelena Osmanovic Barilar
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
| | - Davor Virag
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
| | - Melita Salkovic-Petrisic
- Department
of Pharmacology, University of Zagreb School
of Medicine, Zagreb 10000, Croatia
- Croatian
Institute for Brain Research, University of Zagreb School of Medicine, Zagreb 10000, Croatia
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Alves SS, Servilha-Menezes G, Rossi L, da Silva Junior RMP, Garcia-Cairasco N. Evidence of disturbed insulin signaling in animal models of Alzheimer's disease. Neurosci Biobehav Rev 2023; 152:105326. [PMID: 37479008 DOI: 10.1016/j.neubiorev.2023.105326] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 06/02/2023] [Accepted: 07/17/2023] [Indexed: 07/23/2023]
Abstract
Since glucose reuptake by neurons is mostly independent of insulin, it has been an intriguing question whether insulin has or not any roles in the brain. Consequently, the identification of insulin receptors in the central nervous system has fueled investigations of insulin functions in the brain. It is also already known that insulin can influence glucose reuptake by neurons, mostly during activities that have the highest energy demand. The identification of high density of insulin receptors in the hippocampus also suggests that insulin may present important roles related to memory. In this context, studies have reported worse performance in cognitive tests among diabetic patients. In addition, alterations in the regulation of central insulin pathways have been observed in the brains of Alzheimer's disease (AD) patients. In fact, some authors have proposed AD as a third type of diabetes and recently, our group proposed insulin resistance as a common link between different AD hypotheses. Therefore, in the present narrative review, we intend to revise and gather the evidence of disturbed insulin signaling in experimental animal models of AD.
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Affiliation(s)
- Suélen Santos Alves
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Brazil
| | - Gabriel Servilha-Menezes
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil
| | - Leticia Rossi
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil
| | - Rui Milton Patrício da Silva Junior
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil; Institute of Neuroscience of Castilla y León, University of Salamanca, Salamanca, Spain
| | - Norberto Garcia-Cairasco
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Brazil; Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Brazil.
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From Determining Brain Insulin Resistance in a Sporadic Alzheimer's Disease Model to Exploring the Region-Dependent Effect of Intranasal Insulin. Mol Neurobiol 2023; 60:2005-2023. [PMID: 36596966 DOI: 10.1007/s12035-022-03188-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 12/25/2022] [Indexed: 01/05/2023]
Abstract
Impaired response to insulin has been linked to many neurodegenerative disorders like Alzheimer's disease (AD). Animal model of sporadic AD has been developed by intracerebroventricular (icv) administration of streptozotocin (STZ), which given peripherally causes insulin resistance. Difficulty in demonstrating insulin resistance in this model led to our aim: to determine brain regional and peripheral response after intranasal (IN) administration of insulin in control and STZ-icv rats, by exploring peripheral and central metabolic parameters. One month after STZ-icv or vehicle-icv administration to 3-month-old male Wistar rats, cognitive status was determined after which rats received 2 IU of fast-acting insulin aspart intranasally (CTR + INS; STZ + INS) or saline only (CTR and STZ). Rats were sacrificed 2 h after administration and metabolic and glutamatergic parameters were measured in plasma, CSF, and the brain. Insulin and STZ increased amyloid-β concentration in plasma (CTR + INS and STZ vs CTR), while there was no effect on glucose and insulin plasma and CSF levels. INS normalized the levels of c-fos in temporal cortex of STZ + INS vs STZ (co-localized with neurons), while hypothalamic c-fos was found co-localized with the microglial marker. STZ and insulin brain region specifically altered the levels and activity of proteins involved in cell metabolism and glutamate signaling. Central changes found after INS in STZ-icv rats suggest hippocampal and cortical insulin sensitivity. Altered hypothalamic metabolic parameters of STZ-icv rats were not normalized by INS, indicating possible hypothalamic insulin insensitivity. Brain insulin sensitivity depends on the affected brain region and presence of metabolic dysfunction induced by STZ-icv administration.
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Osmanović Barilar J, Babić Perhoč A, Knezović A, Homolak J, Virag D, Šalković-Petrišić M. The Effect of the Sodium-Glucose Cotransporter Inhibitor on Cognition and Metabolic Parameters in a Rat Model of Sporadic Alzheimer's Disease. Biomedicines 2023; 11:1025. [PMID: 37189641 PMCID: PMC10135566 DOI: 10.3390/biomedicines11041025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/16/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Type 2 diabetes mellitus increases the risk of sporadic Alzheimer's disease (sAD), and antidiabetic drugs, including the sodium-glucose cotransporter inhibitors (SGLTI), are being studied as possible sAD therapy. We have explored whether the SGLTI phloridzin may influence metabolic and cognitive parameters in a rat model of sAD. Adult male Wistar rats were randomized to a control (CTR), an sAD-model group induced by intracerebroventricular streptozotocin (STZ-icv; 3 mg/kg), a CTR+SGLTI, or an STZ-icv+SGLTI group. Two-month-long oral (gavage) SGLTI treatment (10 mg/kg) was initiated 1 month after STZ-icv and cognitive performance tested prior to sacrifice. SGLTI treatment significantly decreased plasma glucose levels only in the CTR group and failed to correct STZ-icv-induced cognitive deficit. In both the CTR and STZ-icv groups, SGLTI treatment diminished weight gain, decreased amyloid beta (Aβ) 1-42 in duodenum, and decreased the plasma levels of total glucagon-like peptide 1 (GLP-1), while the levels of active GLP-1, as well as both total and active glucose-dependent insulinotropic polypeptide, remained unchanged, compared to their respective controls. The increment in GLP-1 levels in the cerebrospinal fluid and its effect on Aβ 1-42 in duodenum could be one of the molecular mechanisms by which SGLTIs indirectly induce pleiotropic beneficial effects.
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Affiliation(s)
- Jelena Osmanović Barilar
- Department of Pharmacology and Croatian, Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
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6
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Grünblatt E, Homolak J, Babic Perhoc A, Davor V, Knezovic A, Osmanovic Barilar J, Riederer P, Walitza S, Tackenberg C, Salkovic-Petrisic M. From attention-deficit hyperactivity disorder to sporadic Alzheimer's disease-Wnt/mTOR pathways hypothesis. Front Neurosci 2023; 17:1104985. [PMID: 36875654 PMCID: PMC9978448 DOI: 10.3389/fnins.2023.1104985] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder with the majority of patients classified as sporadic AD (sAD), in which etiopathogenesis remains unresolved. Though sAD is argued to be a polygenic disorder, apolipoprotein E (APOE) ε4, was found three decades ago to pose the strongest genetic risk for sAD. Currently, the only clinically approved disease-modifying drugs for AD are aducanumab (Aduhelm) and lecanemab (Leqembi). All other AD treatment options are purely symptomatic with modest benefits. Similarly, attention-deficit hyperactivity disorder (ADHD), is one of the most common neurodevelopmental mental disorders in children and adolescents, acknowledged to persist in adulthood in over 60% of the patients. Moreover, for ADHD whose etiopathogenesis is not completely understood, a large proportion of patients respond well to treatment (first-line psychostimulants, e.g., methylphenidate/MPH), however, no disease-modifying therapy exists. Interestingly, cognitive impairments, executive, and memory deficits seem to be common in ADHD, but also in early stages of mild cognitive impairment (MCI), and dementia, including sAD. Therefore, one of many hypotheses is that ADHD and sAD might have similar origins or that they intercalate with one another, as shown recently that ADHD may be considered a risk factor for sAD. Intriguingly, several overlaps have been shown between the two disorders, e.g., inflammatory activation, oxidative stress, glucose and insulin pathways, wingless-INT/mammalian target of rapamycin (Wnt/mTOR) signaling, and altered lipid metabolism. Indeed, Wnt/mTOR activities were found to be modified by MPH in several ADHD studies. Wnt/mTOR was also found to play a role in sAD and in animal models of the disorder. Moreover, MPH treatment in the MCI phase was shown to be successful for apathy including some improvement in cognition, according to a recent meta-analysis. In several AD animal models, ADHD-like behavioral phenotypes have been observed indicating a possible interconnection between ADHD and AD. In this concept paper, we will discuss the various evidence in human and animal models supporting the hypothesis in which ADHD might increase the risk for sAD, with common involvement of the Wnt/mTOR-pathway leading to lifespan alteration at the neuronal levels.
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Affiliation(s)
- Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich (PUK), University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Jan Homolak
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Virag Davor
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Peter Riederer
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital Würzburg, Würzburg, Germany.,Department and Research Unit of Psychiatry, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich (PUK), University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Christian Tackenberg
- Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren, Switzerland
| | - Melita Salkovic-Petrisic
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
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7
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Osmanovic Barilar J, Knezovic A, Homolak J, Babic Perhoc A, Salkovic-Petrisic M. Divergent Effect of Central Incretin Receptors Inhibition in a Rat Model of Sporadic Alzheimer's Disease. Int J Mol Sci 2022; 23:ijms23010548. [PMID: 35008973 PMCID: PMC8745186 DOI: 10.3390/ijms23010548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 02/01/2023] Open
Abstract
The incretin system is an emerging new field that might provide valuable contributions to the research of both the pathophysiology and therapeutic strategies in the treatment of diabetes, obesity, and neurodegenerative disorders. This study aimed to explore the roles of central glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) on cell metabolism and energy in the brain, as well as on the levels of these incretins, insulin, and glucose via inhibition of the central incretin receptors following intracerebroventricular administration of the respective antagonists in healthy rats and a streptozotocin-induced rat model of sporadic Alzheimer's disease (sAD). Chemical ablation of the central GIP receptor (GIPR) or GLP-1 receptor (GLP-1R) in healthy and diseased animals indicated a region-dependent role of incretins in brain cell energy and metabolism and central incretin-dependent modulation of peripheral hormone secretion, markedly after GIPR inhibition, as well as a dysregulation of the GLP-1 system in experimental sAD.
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Affiliation(s)
- Jelena Osmanovic Barilar
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; (J.O.B.); (J.H.); (A.B.P.); (M.S.-P.)
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; (J.O.B.); (J.H.); (A.B.P.); (M.S.-P.)
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
- Correspondence: ; Tel.: +38-514-566-832
| | - Jan Homolak
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; (J.O.B.); (J.H.); (A.B.P.); (M.S.-P.)
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; (J.O.B.); (J.H.); (A.B.P.); (M.S.-P.)
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Melita Salkovic-Petrisic
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; (J.O.B.); (J.H.); (A.B.P.); (M.S.-P.)
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
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Homolak J, Babic Perhoc A, Knezovic A, Osmanovic Barilar J, Virag D, Joja M, Salkovic-Petrisic M. The Effect of Acute Oral Galactose Administration on the Redox System of the Rat Small Intestine. Antioxidants (Basel) 2021; 11:37. [PMID: 35052541 PMCID: PMC8773155 DOI: 10.3390/antiox11010037] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 12/16/2022] Open
Abstract
Galactose is a ubiquitous monosaccharide with important yet incompletely understood nutritive and physiological roles. Chronic parenteral d-galactose administration is used for modeling aging-related pathophysiological processes in rodents due to its ability to induce oxidative stress (OS). Conversely, chronic oral d-galactose administration prevents and alleviates cognitive decline in a rat model of sporadic Alzheimer's disease, indicating that galactose may exert beneficial health effects by acting in the gut. The present aim was to explore the acute time-response of intestinal redox homeostasis following oral administration of d-galactose. Male Wistar rats were euthanized at baseline (n = 6), 30 (n = 6), 60 (n = 6), and 120 (n = 6) minutes following orogastric administration of d-galactose (200 mg/kg). The overall reductive capacity, lipid peroxidation, the concentration of low-molecular-weight thiols (LMWT) and protein sulfhydryls (SH), the activity of Mn and Cu/Zn superoxide dismutases (SOD), reduced and oxidized fractions of nicotinamide adenine dinucleotide phosphates (NADPH/NADP), and the hydrogen peroxide dissociation rate were analyzed in duodenum and ileum. Acute oral administration of d-galactose increased the activity of SODs and decreased intestinal lipid peroxidation and nucleophilic substrates (LMWT, SH, NADPH), indicating activation of peroxidative damage defense pathways. The redox system of the small intestine can acutely tolerate even high luminal concentrations of galactose (0.55 M), and oral galactose treatment is associated with a reduction rather than the increment of the intestinal OS. The ability of oral d-galactose to modulate intestinal OS should be further explored in the context of intestinal barrier maintenance, and beneficial cognitive effects associated with long-term administration of low doses of d-galactose.
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Affiliation(s)
- Jan Homolak
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Davor Virag
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Mihovil Joja
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| | - Melita Salkovic-Petrisic
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia; (A.B.P.); (A.K.); (J.O.B.); (D.V.); (M.J.); (M.S.-P.)
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
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9
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Homolak J, Babic Perhoc A, Knezovic A, Kodvanj I, Virag D, Osmanovic Barilar J, Riederer P, Salkovic-Petrisic M. Is Galactose a Hormetic Sugar? An Exploratory Study of the Rat Hippocampal Redox Regulatory Network. Mol Nutr Food Res 2021; 65:e2100400. [PMID: 34453395 DOI: 10.1002/mnfr.202100400] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/24/2021] [Indexed: 01/22/2023]
Abstract
SCOPE Galactose, a ubiquitous monosaccharide with incompletely understood physiology is often exploited for inducing oxidative-stress mediated aging in animals. Recent research demonstrates that galactose can conserve cellular function during periods of starvation and prevent/alleviate cognitive deficits in a rat model of sporadic Alzheimer's disease. The present aim is to examine the acute effects of oral galactose on the redox regulatory network (RRN). METHODS AND RESULTS Rat plasma and hippocampal RRNs are analyzed upon acute orogastric gavage of galactose (200 mg kg-1 ). No systemic RRN disbalance is observed; however, a mild pro-oxidative shift accompanied by a paradoxical increment in tissue reductive capacity suggesting overcompensation of endogenous antioxidant systems is observed in the hippocampus. Galactose-induced increment of reductive capacity is accompanied by inflation of the hippocampal pool of nicotinamide adenine dinucleotide phosphates indicating ROS detoxification through disinhibition of the oxidative pentose phosphate pathway flux, reduced neuronal activity, and upregulation of Leloir pathway gatekeeper enzyme galactokinase-1. CONCLUSION Based on the observed findings, and in the context of previous work on galactose, a hormetic hypothesis of galactose is proposed suggesting that the protective effects may be inseparable from its pro-oxidative action at the biochemical level.
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Affiliation(s)
- Jan Homolak
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ivan Kodvanj
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Davor Virag
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Peter Riederer
- Clinic and Polyclinic for Psychiatry, Psychosomatics and Psychotherapy, University Hospital Wuerzburg, Wuerzburg, Germany.,University of Southern Denmark Odense, Odense, Denmark
| | - Melita Salkovic-Petrisic
- Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.,Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
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Barilar JO, Knezovic A, Perhoc AB, Homolak J, Riederer P, Salkovic-Petrisic M. Shared cerebral metabolic pathology in non-transgenic animal models of Alzheimer's and Parkinson's disease. J Neural Transm (Vienna) 2020; 127:231-250. [PMID: 32030485 PMCID: PMC7035309 DOI: 10.1007/s00702-020-02152-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 01/24/2020] [Indexed: 12/25/2022]
Abstract
Parkinson's disease (PD) and Alzheimer's disease (AD) are the most common chronic neurodegenerative disorders, characterized by motoric dysfunction or cognitive decline in the early stage, respectively, but often by both symptoms in the advanced stage. Among underlying molecular pathologies that PD and AD patients have in common, more attention is recently paid to the central metabolic dysfunction presented as insulin resistant brain state (IRBS) and altered cerebral glucose metabolism, both also explored in animal models of these diseases. This review aims to compare IRBS and alterations in cerebral glucose metabolism in representative non-transgenic animal PD and AD models. The comparison is based on the selectivity of the neurotoxins which cause experimental PD and AD, towards the cellular membrane and intracellular molecular targets as well as towards the selective neurons/non-neuronal cells, and the particular brain regions. Mitochondrial damage and co-expression of insulin receptors, glucose transporter-2 and dopamine transporter on the membrane of particular neurons as well as astrocytes seem to be the key points which are further discussed in a context of alterations in insulin signalling in the brain and its interaction with dopaminergic transmission, particularly regarding the time frame of the experimental AD/PD pathology appearance and the correlation with cognitive and motor symptoms. Such a perspective provides evidence on IRBS being a common underlying metabolic pathology and a contributor to neurodegenerative processes in representative non-transgenic animal PD and AD models, instead of being a direct cause of a particular neurodegenerative disorder.
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Affiliation(s)
- Jelena Osmanovic Barilar
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Jan Homolak
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Peter Riederer
- Center of Mental Health, Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital, Würzburg, Füchsleinstrasse 15, 97080, Würzburg, Germany
- Department and Research Unit of Psychiatry, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Melita Salkovic-Petrisic
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia.
- Institute of Fundamental Clinical and Translational Neuroscience, Research Centre of Excellence, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 12, 10 000, Zagreb, Croatia.
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