Nrf2-ARE Signaling Partially Attenuates Lipopolysaccharide-Induced Mammary Lesions via Regulation of Oxidative and Organelle Stresses but Not Inflammatory Response in Mice

The incidence of mastitis is high during the postpartum stage, which causes severe pain and hinders breast feeding in humans and reduces milk production in dairy cows. Studies suggested that inflammation in multiple organs is associated with oxidative stress and nuclear factor E2-related factor 2 (Nrf2)-antioxidant response element pathway is one of the most important antioxidant pathways, but the effects of Nrf2 on antioxidation in the mammary gland during mastitis are still unclear. In this study, intramammary lipopolysaccharide (LPS) challenge was carried out in wild-type (WT) and Nrf2 knockout mice. Results showed that the expression of Nrf2 affected the expression of milk protein genes (Csn2 and Csn3). Importantly, LPS treatment increased the expression of Nrf2 and HO-1 and the content of glutathione in the mammary gland of WT mice, but not in Nrf2(-/-) mice. The expression levels of glutathione synthesis genes (GCLC, GCLM, and xCT) were lower in Nrf2(-/-) mice than in WT mice. Moreover, mitochondrial-dependent apoptotic and endoplasmic reticulum stress were significantly relieved in WT mice compared with that in Nrf2(-/-) mice. In summary, the expression of Nrf2 may play an important role in prevention of oxidative and organelle stresses during endotoxin-induced mastitis in mouse mammary gland.

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Hypoxia preconditioning promotes endurance exercise capacity of mice by activating skeletal muscle Nrf2

Journal of Applied Physiology ◽

10.1152/japplphysiol.00347.2019 ◽

2019 ◽

Vol 127 (5) ◽

pp. 1267-1277

Author(s):

Linjia Wang ◽

Simin Yang ◽

Lu Yan ◽

Hao Wei ◽

Jianxiong Wang ◽

...

Keyword(s):

Skeletal Muscle ◽

Exercise Capacity ◽

Treadmill Exercise ◽

Related Factor ◽

Nuclear Factor ◽

Wild Type ◽

Hypoxia Preconditioning ◽

Nrf2 Knockout ◽

Exercise Induced ◽

Induced Changes

Elite endurance athletes are used to train under hypoxic/high-altitude conditions, which can elicit certain stress responses in skeletal muscle and helps to improve their physical performance. Nuclear factor erythroid 2-related factor 2 (Nrf2) regulates cellular redox homeostasis and metabolism in skeletal muscle, playing important roles in adaptation to various stresses. In this study, Nrf2 knockout (KO) and wild-type (WT) mice were preconditioned to 48 h of hypoxia exposure (11.2% oxygen), and the effects of hypoxia preconditioning (HP) on exercise capacity and exercise-induced changes of antioxidant status, energetic metabolism, and mitochondrial adaptation in skeletal muscle were evaluated. Nrf2 knockout (KO) and wild-type (WT) mice were exposed to normoxia or hypoxia for 48 h before taking incremental treadmill exercise to exhaustion under hypoxia. The skeletal muscles were collected immediately after the incremental treadmill exercise to evaluate the impacts of HP and Nrf2 on the exercise-induced changes. The results indicate the absence of Nrf2 did not affect exercise capacity, although the mRNA expression of certain muscular genes involved in antioxidant, glycogen and fatty acid catabolism was decreased in Nrf2 KO mice. However, 48-h HP enhanced exercise capacity in WT mice but not in Nrf2 KO mice, and the exercise capacity of WT mice was significantly higher than that of Nrf2 KO mice. These findings suggest HP promotes exercise capacity of mice with the participation of the Nrf2 signal in skeletal muscle. NEW & NOTEWORTHY Hypoxia preconditioning (HP) activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signal, which was involved in HP-elicited adaptation responses to hypoxia, oxidative, and metabolic stresses in skeletal muscle. On the other hand, Nrf2 deficiency abolished the enhanced exercise capacity after the 48-h HP. Our results indicate that Nrf2 plays an essential role in the exercise capacity-enhancing effect of HP, possibly by modulating muscular antioxidative responses, the mRNA expression of muscular genes involved in glycogen and fatty acid metabolism, as well as mitochondrial biogenesis, and through the cross talk with AMPK and hypoxia-inducible factor-1α signaling.

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Regression of mouse mammary gland anlagen in recombinants of Tfm and wild-type tissues: testosterone acts via the mesenchyme

Cell ◽

10.1016/0092-8674(77)90027-7 ◽

1977 ◽

Vol 10 (3) ◽

pp. 401-404 ◽

Cited By ~ 75

Author(s):

Ulrich Drews ◽

Ute Drews

Keyword(s):

Mammary Gland ◽

Mouse Mammary Gland ◽

Wild Type

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Oral Dimethyl Fumarate Reduces Peripheral Neuropathic Pain in Rodents via NFE2L2 Antioxidant Signaling

Anesthesiology ◽

10.1097/aln.0000000000003077 ◽

2020 ◽

Vol 132 (2) ◽

pp. 343-356 ◽

Cited By ~ 3

Author(s):

Jiahe Li ◽

Jiacheng Ma ◽

Michael J. Lacagnina ◽

Sabina Lorca ◽

Max A. Odem ◽

...

Keyword(s):

Oxidative Stress ◽

Neuropathic Pain ◽

Nerve Injury ◽

Dimethyl Fumarate ◽

Antioxidant Response ◽

Related Factor ◽

Wild Type ◽

Sprague Dawley ◽

Male And Female ◽

Stress Dependent

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Available treatments for neuropathic pain have modest efficacy and significant adverse effects, including abuse potential. Because oxidative stress is a key mechanistic node for neuropathic pain, the authors focused on the master regulator of the antioxidant response—nuclear factor erythroid 2-related factor 2 (NFE2L2; Nrf2)—as an alternative target for neuropathic pain. The authors tested whether dimethyl fumarate (U.S. Food and Drug Administration-approved treatment for multiple sclerosis) would activate NFE2L2 and promote antioxidant activity to reverse neuropathic pain behaviors and oxidative stress-dependent mechanisms. Methods Male Sprague Dawley rats, and male and female wild type and Nfe2l2-/- mice were treated with oral dimethyl fumarate/vehicle for 5 days (300 mg/kg; daily) after spared nerve injury/sham surgery (n = 5 to 8 per group). Allodynia was measured in von Frey reflex tests and hyperalgesia in operant conflict-avoidance tests. Ipsilateral L4/5 dorsal root ganglia were assayed for antioxidant and cytokine/chemokine levels, and mitochondrial bioenergetic capacity. Results Dimethyl fumarate treatment reversed mechanical allodynia (injury-vehicle, 0.45 ± 0.06 g [mean ± SD]; injury-dimethyl fumarate, 8.2 ± 0.16 g; P < 0.001) and hyperalgesia induced by nerve injury (injury-vehicle, 2 of 6 crossed noxious probes; injury-dimethyl fumarate, 6 of 6 crossed; P = 0.013). The antiallodynic effect of dimethyl fumarate was lost in nerve-injured Nfe2l2-/- mice, but retained in nerve-injured male and female wild type mice (wild type, 0.94 ± 0.25 g; Nfe2l2-/-, 0.02 ± 0.01 g; P < 0.001). Superoxide dismutase activity was increased by dimethyl fumarate after nerve injury (injury-vehicle, 3.96 ± 1.28 mU/mg; injury-dimethyl fumarate, 7.97 ± 0.47 mU/mg; P < 0.001). Treatment reduced the injury-dependent increases in cytokines and chemokines, including interleukin-1β (injury-vehicle, 13.30 ± 2.95 pg/mg; injury-dimethyl fumarate, 6.33 ± 1.97 pg/mg; P = 0.022). Injury-impaired mitochondrial bioenergetics, including basal respiratory capacity, were restored by dimethyl fumarate treatment (P = 0.025). Conclusions Dimethyl fumarate, a nonopioid and orally-bioavailable drug, alleviated nociceptive hypersensitivity induced by peripheral nerve injury via activation of NFE2L2 antioxidant signaling. Dimethyl fumarate also resolved neuroinflammation and mitochondrial dysfunction—oxidative stress-dependent mechanisms that drive nociceptive hypersensitivity after nerve injury.

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Bacterial Endotoxin Induces Oxidative Stress and Reduces Milk Protein Expression and Hypoxia in the Mouse Mammary Gland

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/3894309 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Alexander Jonathan Spitzer ◽

Qing Tian ◽

Ratan K. Choudhary ◽

Feng-Qi Zhao

Keyword(s):

Oxidative Stress ◽

Mammary Gland ◽

Protein Expression ◽

Oxygen Tension ◽

Cell Apoptosis ◽

Milk Protein ◽

Staining Intensity ◽

Bacterial Endotoxin ◽

Lps Challenge ◽

Lps Treatment

The aim of this study was to investigate the mechanisms underlying the reduced milk production during mastitis. We hypothesized that bacterial endotoxin induces hypoxia, oxidative stress, and cell apoptosis while inhibiting milk gene expression in the mammary gland. To test this hypothesis, the left and right sides of the 4th pair of mouse mammary glands were alternatively injected with either lipopolysaccharide (LPS, E. coli 055: B5, 100 μL of 0.2 mg/mL) or sterile PBS through the teat meatus 3 days postpartum. At 10.5 and 22.5 h postinjection, pimonidazole HCl, a hypoxyprobe, was injected intraperitoneally. At 12 or 24 h after the LPS injection, the 4th glands were individually collected (n=8) and analyzed. LPS treatment induced mammary inflammation at both 12 and 24 h but promoted cell apoptosis only at 12 h. Consistently, H2O2 content was increased at 12 h (P<0.01), but dropped dramatically at 24 h (P<0.01) in the LPS-treated gland. Nevertheless, the total antioxidative capacity in tissue tended to be decreased by LPS at both 12 and 24 h (P=0.07 and 0.06, respectively). In agreement with these findings, LPS increased or tended to increase the mRNA expression of antioxidative genes Nqo1 at 12 h (P=0.05) and SLC7A11 at 24 h (P=0.08). In addition, LPS inhibited mammary expression of Csn2 and Lalba across time and protein expression of Csn1s1 at 24 h (P<0.05). Furthermore, hypoxyprobe staining intensity was greater in the alveoli of the PBS-treated gland than the LPS-treated gland at both 12 and 24 h, demonstrating a rise in oxygen tension by LPS treatment. In summary, our observations indicated that while intramammary LPS challenge incurs inflammation, it induces oxidative stress, increases cell apoptosis and oxygen tension, and differentially inhibits the milk protein expression in the mammary gland.

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Methylenetetrahydrofolate reductase deficiency alters cellular response after ischemic stroke in male mice

10.1101/857938 ◽

2019 ◽

Author(s):

Jamie E. Abato ◽

Mahira Moftah ◽

Greg O. Cron ◽

Patrice D. Smith ◽

Nafisa M. Jadavji

Keyword(s):

Ischemic Stroke ◽

Brain Tissue ◽

Cellular Response ◽

Methylenetetrahydrofolate Reductase ◽

Critical Role ◽

Antioxidant Response ◽

Related Factor ◽

Wild Type ◽

Wild Type Littermate ◽

Damage Site

AbstractObjectiveElevated homocysteine concentrations are a risk factor for stroke. A common genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR 677 C➔T) results in elevated levels of homocysteine. MTHFR plays a critical role in the synthesis of S-adenosylmethionine (SAM), a global methyl donor. Our previous work has demonstrated that Mthfr+/− mice, which model the MTHFR polymorphism in humans, are more vulnerable to ischemic damage. The aim of this study was to investigate the cellular mechanisms by which the MTHFR-deficiency changes the brain in the context of ischemic stroke injury.MethodsIn the present study, three-month-old male Mthfr+/− and wild-type littermate mice were subjected to photothrombosis (PT) damage. Four weeks after PT damage, animals were tested on behavioral tasks, in vivo imaging was performed using T2-weighted MRI, and brain tissue was collected.ResultsMthfr+/− animals used their non-impaired forepaw more during to explore the cylinder and had a larger damage volume compared to wild-type littermates. In brain tissue of Mthfr+/− mice methionine adenosyltransferase II alpha (MAT2A) protein levels were decreased within the damage hemisphere and increased levels in hypoxia induced factor 1 alpha (HIF-1α) in non-damage hemisphere. There was an increased antioxidant response in the damage site as indicated by higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and superoxide dismutase 2 (SOD2).ConclusionsOur results suggest that Mthfr+/− mice are more vulnerable to PT-induced stroke damage through regulation of the cellular response. The increased antioxidant response we observed may be compensatory to the damage amount.

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Prolactin inhibits cell loss and decreases matrix metalloproteinase expression in the involuting mouse mammary gland but fails to prevent cell loss in the mammary glands of mice expressing IGFBP-5 as a mammary transgene

Journal of Molecular Endocrinology ◽

10.1677/jme.1.01873 ◽

2006 ◽

Vol 36 (3) ◽

pp. 435-448 ◽

Cited By ~ 20

Author(s):

D J Flint ◽

M Boutinaud ◽

C B A Whitelaw ◽

G J Allan ◽

A F Kolb

Keyword(s):

Mammary Gland ◽

Transgenic Mice ◽

Mammary Epithelium ◽

Transgenic Animals ◽

Cell Loss ◽

Mouse Mammary Gland ◽

Luciferase Reporter ◽

Wild Type ◽

Luciferase Reporter Gene ◽

Gland Weight

Insulin-like growth factor-binding protein 5 (IGFBP-5) mediates involution of the mammary gland. The decrease in DNA content and mammary gland weight which accompanies involution was inhibited by prolactin (PRL) in wild-type but not transgenic mice expressing IGFBP-5. Phospho-STAT5 protein levels were significantly lower in IGFBP-5 transgenic mice during lactation suggesting that IGFBP-5 antagonises PRL signalling in the mammary epithelium. In contrast, phospho-STAT3 levels increased during involution to a similar extent in both wild-type and transgenic mice and were unaffected by PRL. PRL inhibited gene expression of matrix metalloproteinases (MMPs) 3 and 12 but not tissue plasminogen activator or plasmin in wild-type and transgenic animals. The effects of PRL on MMPs appear to be indirect since PRL failed to inhibit MMP-3, -7 or -12 expression in HC-11 cells or in a co-transfection including an activated PRL receptor, STAT5 and a MMP-3-luciferase reporter gene. PRL is a potent inhibitor, both of cell death, an effect which is suppressed by IGFBP-5, and of MMP expression, which is independent of the actions of IGFBP-5.

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Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081097 ◽

1978 ◽

Vol 36 (2) ◽

pp. 46-47

Author(s):

Jan Zarzycki ◽

Joseph Szroeder

Keyword(s):

Mammary Gland ◽

Protein Denaturation ◽

Chemical Constituents ◽

Freeze Substitution ◽

Electron Microscopic Examination ◽

Mouse Mammary Gland ◽

Electron Microscopic ◽

Preparation Methods ◽

Microscopic Studies ◽

Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

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