1
|
Homolak J, Joja M, Grabaric G, Schiatti E, Virag D, Babic Perhoc A, Knezovic A, Osmanovic Barilar J, Salkovic-Petrisic M. The Absence of Gastrointestinal Redox Dyshomeostasis in the Brain-First Rat Model of Parkinson's Disease Induced by Bilateral Intrastriatal 6-Hydroxydopamine. Mol Neurobiol 2024; 61:5481-5493. [PMID: 38200352 PMCID: PMC11249596 DOI: 10.1007/s12035-023-03906-7] [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: 06/26/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024]
Abstract
The gut-brain axis plays an important role in Parkinson's disease (PD) by acting as a route for vagal propagation of aggregated α-synuclein in the gut-first endophenotype and as a mediator of gastrointestinal dyshomeostasis via the nigro-vagal pathway in the brain-first endophenotype of the disease. One important mechanism by which the gut-brain axis may promote PD is by regulating gastrointestinal redox homeostasis as overwhelming evidence suggests that oxidative stress plays a key role in the etiopathogenesis and progression of PD and the gastrointestinal tract maintains redox homeostasis of the organism by acting as a critical barrier to environmental and microbiological electrophilic challenges. The present aim was to utilize the bilateral intrastriatal 6-hydroxydopamine (6-OHDA) brain-first PD model to study the effects of isolated central pathology on redox homeostasis of the gastrointestinal tract. Three-month-old male Wistar rats were either not treated (intact controls; CTR) or treated bilaterally intrastriatally with vehicle (CIS) or 6-OHDA (6-OHDA). Motor deficits were assessed with the rotarod performance test, and the duodenum, ileum, and colon were dissected for biochemical analyses 12 weeks after the treatment. Lipid peroxidation, total antioxidant capacity, low-molecular-weight thiols, and protein sulfhydryls, the activity of total and Mn/Fe superoxide dismutases, and total and azide-insensitive catalase/peroxidase were measured. Both univariate and multivariate models analyzing redox biomarkers indicate that significant disturbances in gastrointestinal redox balance are not present. The findings demonstrate that motor impairment observed in the brain-first 6-OHDA model of PD can occur without concurrent redox imbalances in the gastrointestinal system.
Collapse
Affiliation(s)
- Jan Homolak
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia.
- Interfaculty Institute of Microbiology and Infection Medicine & Cluster of Excellence "Controlling Microbes to Fight Infections,", University of Tübingen, Tübingen, Germany.
| | - Mihovil Joja
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
- Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg
- Faculty of Science, Technology and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Gracia Grabaric
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Emiliano Schiatti
- Faculty of Medicine and Surgery, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Davor Virag
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Melita Salkovic-Petrisic
- Department of Pharmacology & Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Homolak J. Weighing in on heavy metals - the importance of differentiating between soluble and total metals in tattoo inks. CHEMOSPHERE 2023; 331:138803. [PMID: 37150459 DOI: 10.1016/j.chemosphere.2023.138803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/27/2023] [Indexed: 05/09/2023]
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.
| |
Collapse
|
5
|
Homolak J. Possible mechanisms mediating complete regrowth of hair following scalp tattooing in alopecia universalis. JAAD Case Rep 2023; 34:10-11. [PMID: 36936862 PMCID: PMC10015113 DOI: 10.1016/j.jdcr.2023.01.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
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
- Correspondence to: Jan Homolak, MD, Department of Pharmacology, University of Zagreb School of Medicine, Šalata 11, 10 000, Zagreb, Croatia
| |
Collapse
|
6
|
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:biomedicines11041025. [PMID: 37189641 DOI: 10.3390/biomedicines11041025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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.
Collapse
|
7
|
Homolak J. Metals Come in Many Flavors-Is Inference about the Health Effects of Tattoo Inks Based on the Analysis of Inorganic Elements Justified? Chem Res Toxicol 2023; 36:332-333. [PMID: 36791313 DOI: 10.1021/acs.chemrestox.3c00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- Jan Homolak
- Department of Pharmacology, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10 000 Zagreb, Croatia
| |
Collapse
|