TSH Combined with TSHR Aggravates Diabetic Peripheral Neuropathy by Promoting Oxidative Stress and Apoptosis in Schwann Cells

Subclinical hypothyroidism (SCH) is associated with diabetic peripheral neuropathy (DPN); however, the mechanism underlying this association remains unknown. This study is aimed at examining neurofunctional and histopathological alterations in a type 2 diabetes (T2DM) mouse model of SCH and investigating the impact of thyroid-stimulating hormone (TSH) in an in vitro DPN cell model established using RSC96 cells under high glucose (HG) and palmitic acid (PA) stimulation. Our results indicated that T2DM, in combination with SCH, aggravated abnormal glucose and lipid metabolism in T2DM and dramatically destroyed the peripheral nervous system by increasing paw withdrawal latency, decreasing motor nerve conduction velocity, and exacerbating ultrastructural deterioration of the damaged sciatic nerve caused by diabetes. Furthermore, the results of our in vitro experiments showed that TSH intensified HG/PA-induced RSC96 cell damage by inducing oxidative stress, mitochondrial dysfunction, and apoptosis. More importantly, TSHR knockout or inhibition of PA-induced TSHR palmitoylation could alleviate the apoptosis induced by TSH. Overall, in this study, the novel mechanisms by which TSH, as an independent risk factor for DPN progression, aggravating Schwann cell apoptosis and demyelination, are elucidated. These findings indicate that TSHR could be a potential target for both the prevention and treatment of DPN and, possibly, other microvascular diseases, and have implication in the clinical management of patients with DPN.

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Impact of Glucocorticoid on a Cellular Model of Parkinson’s Disease: Oxidative Stress and Mitochondrial Function

Brain Sciences ◽

10.3390/brainsci11081106 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1106

Author(s):

Silvia Claros ◽

Antonio Gil ◽

Mauro Martinelli ◽

Nadia Valverde ◽

Estrella Lara ◽

...

Keyword(s):

Oxidative Stress ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mitochondrial Function ◽

Cell Model ◽

Cell Damage ◽

Neuronal Cell ◽

Cellular Markers ◽

The Impact

Stress seems to contribute to the neuropathology of Parkinson’s disease (PD), possibly by dysregulation of the hypothalamic–pituitary–adrenal axis. Oxidative distress and mitochondrial dysfunction are key factors involved in the pathophysiology of PD and neuronal glucocorticoid-induced toxicity. Animal PD models have been generated to study the effects of hormonal stress, but no in vitro model has yet been developed. Our aim was to examine the impact of corticosterone (CORT) administration on a dopaminergic neuronal cell model of PD induced by the neurotoxin MPP+, as a new combined PD model based on the marker of endocrine response to stress, CORT, and oxidative-mitochondrial damage. We determined the impact of CORT, MPP+ and their co-incubation on reactive oxygen species production (O2−•), oxidative stress cellular markers (advanced-oxidation protein products and total antioxidant status), mitochondrial function (mitochondrial membrane potential and mitochondrial oxygen consumption rate) and neurodegeneration (Fluoro-Jade staining). Accordingly, the administration of MPP+ or CORT individually led to cell damage compared to controls (p < 0.05), as determined by several methods, whereas their co-incubation produced strong cell damage (p < 0.05). The combined model described here could be appropriate for investigating neuropathological hallmarks and for evaluating potential new therapeutic tools for PD patients suffering mild to moderate emotional stress.

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Anti-Melanogenic Mechanism of Tetrahydrocurcumin and Enhancing Its Topical Delivery Efficacy Using a Lecithin-Based Nanoemulsion

Pharmaceutics ◽

10.3390/pharmaceutics13081185 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1185

Author(s):

Xudong Tang ◽

Qiaoru Dong ◽

Jun Li ◽

Fang Li ◽

Bozena B. Michniak-Kohn ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Model ◽

Antioxidant Properties ◽

Topical Delivery ◽

Related Protein ◽

B16f10 Melanoma ◽

Keratinocyte Cell ◽

The Impact ◽

Tyrosinase Related Protein

Tetrahydrocurcumin (THC) has been well known for its superior antioxidant properties. Therefore, it is speculated that it might be effective to relieve oxidative stress-induced diseases, such as skin hyperpigmentation. In this work, an in vitro B16F10 melanoma cell model was used to study the impact of THC on the melanogenic process under stressed conditions. It was demonstrated that THC could effectively inhibit the α-MSH (melanocyte-stimulating hormone) induced melanin production in B16F10 melanoma cells and the expressions of three key enzymes involved with the biosynthetic process of melanin, tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2), were all significantly reduced. In addition, an in vitro human keratinocyte cell model was used to investigate the potential protective role of THC on H2O2-induced cytotoxicity. It was found that THC could prevent H2O2-induced oxidative stress based on the results of both the cell viability study and the intracellular ROS (reactive oxygen species) study assessed by the flow cytometry. Last, THC was formulated into a lecithin based nanoemulsion, and an in vitro Franz diffusion cell study using Strat-M® membrane concluded that the nanoemulsion could significantly enhance the membrane permeation compared to the unformatted THC suspension. This research demonstrated the anti-melanogenic benefits of THC on the melanoma and keratinocyte cell models and the topical delivery efficacy could be significantly enhanced using a lecithin based nanoemulsion.

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Sensory-Motor Mechanisms Increasing Falls Risk in Diabetic Peripheral Neuropathy

Medicina ◽

10.3390/medicina57050457 ◽

2021 ◽

Vol 57 (5) ◽

pp. 457

Author(s):

Neil D. Reeves ◽

Giorgio Orlando ◽

Steven J. Brown

Keyword(s):

Peripheral Neuropathy ◽

Diabetic Peripheral Neuropathy ◽

Motor Nerve ◽

Step Length ◽

Falls Prevention ◽

Motor Deficits ◽

Falls Risk ◽

Walking Gait ◽

Risk Of Falls ◽

Diabetes Patients

Diabetic peripheral neuropathy (DPN) is associated with peripheral sensory and motor nerve damage that affects up to half of diabetes patients and is an independent risk factor for falls. Clinical implications of DPN-related falls include injury, psychological distress and physical activity curtailment. This review describes how the sensory and motor deficits associated with DPN underpin biomechanical alterations to the pattern of walking (gait), which contribute to balance impairments underpinning falls. Changes to gait with diabetes occur even before the onset of measurable DPN, but changes become much more marked with DPN. Gait impairments with diabetes and DPN include alterations to walking speed, step length, step width and joint ranges of motion. These alterations also impact the rotational forces around joints known as joint moments, which are reduced as part of a natural strategy to lower the muscular demands of gait to compensate for lower strength capacities due to diabetes and DPN. Muscle weakness and atrophy are most striking in patients with DPN, but also present in non-neuropathic diabetes patients, affecting not only distal muscles of the foot and ankle, but also proximal thigh muscles. Insensate feet with DPN cause a delayed neuromuscular response immediately following foot–ground contact during gait and this is a major factor contributing to increased falls risk. Pronounced balance impairments measured in the gait laboratory are only seen in DPN patients and not non-neuropathic diabetes patients. Self-perception of unsteadiness matches gait laboratory measures and can distinguish between patients with and without DPN. Diabetic foot ulcers and their associated risk factors including insensate feet with DPN and offloading devices further increase falls risk. Falls prevention strategies based on sensory and motor mechanisms should target those most at risk of falls with DPN, with further research needed to optimise interventions.

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Oxidative Stress Compromises Lymphocyte Function in Neonatal Dairy Calves

Antioxidants ◽

10.3390/antiox10020255 ◽

2021 ◽

Vol 10 (2) ◽

pp. 255

Author(s):

Wilmer Cuervo ◽

Lorraine M. Sordillo ◽

Angel Abuelo

Keyword(s):

Oxidative Stress ◽

Immune Responses ◽

Immune Cell ◽

Lymphocyte Activation ◽

Dairy Calves ◽

Lymphocyte Function ◽

Newborn Calves ◽

Ifn Γ ◽

The Impact

Dairy calves are unable to mount an effective immune response during their first weeks of life, which contributes to increased disease susceptibility during this period. Oxidative stress (OS) diminishes the immune cell capabilities of humans and adult cows, and dairy calves also experience OS during their first month of life. However, the impact that OS may have on neonatal calf immunity remains unexplored. Thus, we aimed to evaluate the impact of OS on newborn calf lymphocyte functions. For this, we conducted two experiments. First, we assessed the association of OS status throughout the first month of age and the circulating concentrations of the cytokines interferon-gamma (IFN-γ) and interleukin (IL) 4, as well as the expression of cytokine-encoding genes IFNG, IL2, IL4, and IL10 in peripheral mononuclear blood cells (PBMCs) of 12 calves. Subsequently, we isolated PBMCs from another 6 neonatal calves to investigate in vitro the effect of OS on immune responses in terms of activation of lymphocytes, cytokine expression, and antibody production following stimulation with phorbol 12-myristate 13-acetate or bovine herpesvirus-1. The results were compared statistically through mixed models. Calves exposed to high OS status in their first month of age showed higher concentrations of IL-4 and expression of IL4 and IL10 and lower concentrations of IFN-γ and expression of IFNG and IL2 than calves exposed to lower OS. In vitro, OS reduced lymphocyte activation, production of antibodies, and protein and gene expression of key cytokines. Collectively, our results demonstrate that OS can compromise some immune responses of newborn calves. Hence, further studies are needed to explore the mechanisms of how OS affects the different lymphocyte subsets and the potential of ameliorating OS in newborn calves as a strategy to augment the functional capacity of calf immune cells, as well as enhance calves’ resistance to infections.

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Protective Effect of Butylphthalide on Neuronal Apoptosis in Parkinson Rats and Its Effect on miR-146a-5p Expression and Phosphatidylinositide 3-Kinases/Protein Kinase B Pathway

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2021.2766 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1908-1917

Author(s):

Rongkang Mai ◽

Yiyao Cao ◽

Huitian Yu ◽

Yong Zheng ◽

Juke Huang

Keyword(s):

Cell Model ◽

Morphological Changes ◽

Neuroblastoma Cell ◽

Neuroblastoma Cell Line ◽

Vehicle Group ◽

Human Neuroblastoma Cell ◽

Human Neuroblastoma ◽

Oil Emulsion ◽

The Impact

80 male Wistar rats were stochastically assigned to Sham + Vehicle group, Sham + BUT group, PD + Vehicle group and PD + BUT group. Rotenone PD model rats were prepared by subcutaneous injection of rotenone sunflower oil emulsion 2 mg/(kg · d) for 5 consecutive weeks. Butylphthalide 80 mg/(kg · d) were given to the rats in Sham + BUT group and PD + BUT group by gavage from the first day of rotenone injection for 5 weeks. Subsequently, the motor retardation ability and the morphological changes of the substantia nigra (SN) of each group were evaluated. Meanwhile, the levels of neuronal injury, apoptosis, inflammation and oxidative stress in each group of rats were assayed. The impact of BUT treatment on miR-146a-5p expression and PI3K/AKT signal pathway in rat brain tissue was assayed. Finally, by constructing a PD cell model of the neurotoxin 6-hydroxydopamine (6-OHDA)-treated human neuroblastoma cell line SH-SY5Y, the in vitro anti-PD pharmacological effect of BUT was further verified.

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Antioxidative 1,4-Dihydropyridine Derivatives Modulate Oxidative Stress and Growth of Human Osteoblast-Like Cells In Vitro

Antioxidants ◽

10.3390/antiox7090123 ◽

2018 ◽

Vol 7 (9) ◽

pp. 123 ◽

Cited By ~ 8

Author(s):

Lidija Milkovic ◽

Tea Vukovic ◽

Neven Zarkovic ◽

Franz Tatzber ◽

Egils Bisenieks ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Growth ◽

Cell Model ◽

Second Messengers ◽

Human Osteoblast ◽

Tert Butyl Hydroperoxide ◽

Human Stress ◽

Set Up ◽

Dihydropyridine Derivatives

Oxidative stress has been implicated in pathophysiology of different human stress- and age-associated disorders, including osteoporosis for which antioxidants could be considered as therapeutic remedies as was suggested recently. The 1,4-dihydropyridine (DHP) derivatives are known for their pleiotropic activity, with some also acting as antioxidants. To find compounds with potential antioxidative activity, a group of 27 structurally diverse DHPs, as well as one pyridine compound, were studied. A group of 11 DHPs with 10-fold higher antioxidative potential than of uric acid, were further tested in cell model of human osteoblast-like cells. Short-term combined effects of DHPs and 50 µM H2O2 (1-h each), revealed better antioxidative potential of DHPs if administered before a stressor. Indirect 24-h effect of DHPs was evaluated in cells further exposed to mild oxidative stress conditions induced either by H2O2 or tert-butyl hydroperoxide (both 50 µM). Cell growth (viability and proliferation), generation of ROS and intracellular glutathione concentration were evaluated. The promotion of cell growth was highly dependent on the concentrations of DHPs used, type of stressor applied and treatment set-up. Thiocarbatone III-1, E2-134-1 III-4, Carbatone II-1, AV-153 IV-1, and Diethone I could be considered as therapeutic agents for osteoporosis although further research is needed to elucidate their bioactivity mechanisms, in particular in respect to signaling pathways involving 4-hydroxynoneal and related second messengers of free radicals.

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The Impact of Oxidative Stress on Dental Implants

European Journal of Dental and Oral Health ◽

10.24018/ejdent.2021.2.1.37 ◽

2021 ◽

Vol 2 (1) ◽

pp. 1-8

Author(s):

César Esquivel-Chirino ◽

Juan Carlos Gómez-Landeros ◽

Erika Patricia Carabantes-Campos ◽

Daniela Carmona-Ruiz ◽

Yolanda Valero-Princet ◽

...

Keyword(s):

Oxidative Stress ◽

Dental Implants ◽

Alveolar Bone ◽

Inflammatory Responses ◽

Cell Damage ◽

Pathological Condition ◽

Periodontal Diseases ◽

Tissue Destruction ◽

Waste Products ◽

The Impact

Periodontal disease is an inflammatory condition that alters the periodontium, resulting in destruction of the alveolar bone; without treatment the condition may lead to tooth loss. Dental implants are an alternative for substitution of naturally lost teeth as they have high success rates; however, some factors are related to its failure. Peri-implantitis (PI) is a pathological condition that affects the tissues surrounding dental implants and has been reported as the major cause of implant failure; PI and periodontal diseases are characterized by tissue inflammation and bone damage. In homeostasis conditions, reactive oxygen species (ROS) have been shown to be involved in cell maintenance, signal transduction, and repair of all tissues, but ROS overaccumulation leads to oxidative stress, which generates cell damage and tissue destruction; likewise, antioxidants protect against the destructive effects of ROS by turning free radicals into waste products. The main purpose of this review was to determine some aspects of inflammatory responses and oxidative stress and analyze their relationship with the lack of osseointegration and PI.

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Phytochemicals from the Cocoa Shell Modulate Mitochondrial Function, Lipid and Glucose Metabolism in Hepatocytes via Activation of FGF21/ERK, AKT, and mTOR Pathways

Antioxidants ◽

10.3390/antiox11010136 ◽

2022 ◽

Vol 11 (1) ◽

pp. 136

Author(s):

Miguel Rebollo-Hernanz ◽

Yolanda Aguilera ◽

Maria A. Martin-Cabrejas ◽

Elvira Gonzalez de Gonzalez de Mejia

Keyword(s):

Oxidative Stress ◽

Mitochondrial Function ◽

Phosphoenolpyruvate Carboxykinase ◽

Fatty Acid Synthase ◽

Cell Model ◽

Fibroblast Growth Factor 21 ◽

Alcoholic Fatty Liver ◽

Atp Production ◽

Cocoa Shell

The cocoa shell is a by-product that may be revalorized as a source of bioactive compounds to prevent chronic cardiometabolic diseases. This study aimed to investigate the phytochemicals from the cocoa shell as targeted compounds for activating fibroblast growth factor 21 (FGF21) signaling and regulating non-alcoholic fatty liver disease (NAFLD)-related biomarkers linked to oxidative stress, mitochondrial function, and metabolism in hepatocytes. HepG2 cells treated with palmitic acid (PA, 500 µmol L−1) were used in an NAFLD cell model. Phytochemicals from the cocoa shell (50 µmol L−1) and an aqueous extract (CAE, 100 µg mL−1) enhanced ERK1/2 phosphorylation (1.7- to 3.3-fold) and FGF21 release (1.4- to 3.4-fold) via PPARα activation. Oxidative stress markers were reduced though Nrf-2 regulation. Mitochondrial function (mitochondrial respiration and ATP production) was protected by the PGC-1α pathway modulation. Cocoa shell phytochemicals reduced lipid accumulation (53–115%) and fatty acid synthase activity (59–93%) and prompted CPT-1 activity. Glucose uptake and glucokinase activity were enhanced, whereas glucose production and phosphoenolpyruvate carboxykinase activity were diminished. The increase in the phosphorylation of the insulin receptor, AKT, AMPKα, mTOR, and ERK1/2 conduced to the regulation of hepatic mitochondrial function and energy metabolism. For the first time, the cocoa shell phytochemicals are proved to modulate FGF21 signaling. Results demonstrate the in vitro preventive effect of the phytochemicals from the cocoa shell on NAFLD.

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Dietary Supplement Enriched in Antioxidants and Omega-3 Promotes Glutamine Synthesis in Müller Cells: A Key Process against Oxidative Stress in Retina

Nutrients ◽

10.3390/nu13093216 ◽

2021 ◽

Vol 13 (9) ◽

pp. 3216

Author(s):

Maryvonne Ardourel ◽

Chloé Felgerolle ◽

Arnaud Pâris ◽

Niyazi Acar ◽

Khaoula Ramchani Ben Othman ◽

...

Keyword(s):

Oxidative Stress ◽

Müller Cells ◽

Nutritional Supplement ◽

Glutamine Metabolism ◽

Muller Cells ◽

Omega 3 ◽

Glutamine Synthesis ◽

The Impact

To prevent ocular pathologies, new generation of dietary supplements have been commercially available. They consist of nutritional supplement mixing components known to provide antioxidative properties, such as unsaturated fatty acid, resveratrol or flavonoids. However, to date, only one preclinical study has evaluated the impact of a mixture mainly composed of those components (Nutrof Total®) on the retina and demonstrated that in vivo supplementation prevents the retina from structural and functional injuries induced by light. Considering the crucial role played by the glial Müller cells in the retina, particularly to regulate the glutamate cycle to prevent damage in oxidative stress conditions, we questioned the impact of this ocular supplement on the glutamate metabolic cycle. To this end, various molecular aspects associated with the glutamate/glutamine metabolism cycle in Müller cells were investigated on primary Müller cells cultures incubated, or not, with the commercially mix supplement before being subjected, or not, to oxidative conditions. Our results demonstrated that in vitro supplementation provides guidance of the glutamate/glutamine cycle in favor of glutamine synthesis. These results suggest that glutamine synthesis is a crucial cellular process of retinal protection against oxidative damages and could be a key step in the previous in vivo beneficial results provided by the dietary supplementation.

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Long Non-coding RNA XIST Attenuates Diabetic Peripheral Neuropathy by Inducing Autophagy Through MicroRNA-30d-5p/sirtuin1 Axis

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.655157 ◽

2021 ◽

Vol 8 ◽

Author(s):

Bei-Yan Liu ◽

Lin Li ◽

Li-Wei Bai ◽

Chang-Shui Xu

Keyword(s):

Oxidative Stress ◽

Peripheral Neuropathy ◽

Schwann Cells ◽

Diabetic Peripheral Neuropathy ◽

Beclin 1 ◽

Diabetic Mice ◽

Non Coding Rna ◽

Non Coding Rnas ◽

Long Non Coding Rna

Diabetic peripheral neuropathy (DPN) is a prevalent diabetes mellitus (Feldman et al., 2017) complication and the primary reason for amputation. Meanwhile, long non-coding RNAs (lncRNAs) are a type of regulatory non-coding RNAs (ncRNAs) that broadly participate in DPN development. However, the correlation of lncRNA X-inactive specific transcript (XIST) with DPN remains unclear. In this study, we were interested in the role of XIST in the modulation of DPN progression. Significantly, our data showed that the expression of XIST and sirtuin1 (SIRT1) was inhibited, and the expression of microRNA-30d-5p (miR-30d-5p) was enhanced in the trigeminal sensory neurons of the diabetic mice compared with the normal mice. The levels of LC3II and Beclin-1 were inhibited in the diabetic mice. The treatment of high glucose (HG) reduced the XIST expression in Schwann cells. The apoptosis of Schwann cells was enhanced in the HG-treated cells, but the overexpression of XIST could block the effect in the cells. Moreover, the levels of LC3II and Beclin-1 were reduced in the HG-treated Schwann cells, while the overexpression of XIST was able to reverse this effect. The HG treatment promoted the production of oxidative stress, while the XIST overexpression could attenuate this result in the Schwann cells. Mechanically, XIST was able to sponge miR-30d-5p and miR-30d-5p-targeted SIRT1 in the Schwann cells. MiR-30d-5p inhibited autophagy and promoted oxidative stress in the HG-treated Schwann cells, and SIRT1 presented a reversed effect. MiR-30d-5p mimic or SIRT1 depletion could reverse XIST overexpression-mediated apoptosis and autophagy of the Schwann cells. Thus, we concluded that XIST attenuated DPN by inducing autophagy through miR-30d-5p/SIRT1 axis. XIST and miR-30d-5p may be applied as the potential targets for DPN therapy.

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