Upregulation of HO-1 Attenuates LPS-Stimulated Proinflammatory Responses Through Downregulation of p38 Signaling Pathways in Rat Ovary

miR-21/SMAD2 Is Involved in the Decrease in Progesterone Synthesis Caused by Lipopolysaccharide Exposure in Follicular Granulosa Cells of Laying Goose

Lipopolysaccharide (LPS) is one of the important pathogenic substances of E. coli and Salmonella, which causes injury to the reproductive system. Ovarian dysfunction due to Gram-negative bacterial infections is a major cause of reduced reproductive performance in geese. However, the specific molecular mechanisms of LPS-induced impairment of sex steroid hormone synthesis have not been determined. The regulatory mechanism of miRNA has been proposed in many physiological and pathogenic mechanisms. Therefore, the role of miRNA in breeding geese exposed to LPS during the peak laying period was investigated. In this study, twenty Yangzhou geese at peak laying period were injected with LPS for 0 h, 24 h, and 36 h. The follicular granulosa layer was taken for RNA-seq and analyzed for differentially expressed miRNAs. It was observed that LPS changed the appearance of hierarchical follicles. miRNA sequencing analysis was applied, and miR-21 and SMAD2 (SMAD family member 2) were selected from 51 differentially expressed miRNAs through bioinformatics prediction. The results showed that miR-21 down-regulated SMAD2 expression and progesterone (P4) production in LPS-treated goose granulosa cells (GCs). It also determined that overexpression of miR-21 or silence of SMAD2 suppressed the sex steroid biosynthesis pathway by decreasing STAR and CYP11A1 expression. Down-regulation of miR-21 exacerbates the LPS-induced decline in P4 synthesis and vice versa. The findings indicated that miR-21 was involved in LPS regulation of P4 synthesis in goose granulosa cells by down-regulating SMAD2. This study provides theoretical support for the prevention of LPS-induced ovarian dysfunction in geese.

The Pharmacological Effect of Hemin in Inflammatory-Related Diseases: A Systematic Review

BACKGROUND

Hemin is clinically used in acute attacks of porphyria; however, recent evidence has also highlighted its capability to stimulate the heme oxygenase enzyme, being associated with cytoprotective, antioxidant, and anti-inflammatory effects. Indeed, current preclinical evidence emphasizes the potential anti-inflammatory role of hemin through its use in animal models of disease. Nevertheless, there is no consensus about the underlying mechanism(s) and the most optimal therapeutic regimens. Therefore, this review aims to summarize, analyze, and discuss the current preclinical evidence concerning the pharmacological effect of hemin.

METHODS

Following the application of the search expression and the retrieval of the articles, only nonclinical studies in vivo written in English were considered, where the potential anti-inflammatory effect of hemin was evaluated.

RESULTS

Forty-nine articles were included according to the eligibility criteria established. The results obtained show the preference of using 30 to 50 mg/kg of hemin, administered intraperitoneally, in both acute and chronic contexts. This drug demonstrates significant anti-inflammatory and antioxidant activities considering its capacity for reducing the expression of proinflammatory and oxidative markers.

CONCLUSIONS

This review highlighted the significant anti-inflammatory and antioxidant effects of hemin, providing a clearer vision for the medical community about the use of this drug in several human diseases.

Administration of hemin ameliorates ovarian ischemia reperfusion injury via modulation of heme oxygenase-1 and p-JNK/p-NF-κBp65/iNOS signaling pathway

AIMS

Ovarian torsion is the fifth common gynecological emergency that can affect females of all ages particularly during reproductive age and its management by detorsion leads to ovarian ischemia reperfusion (IR) injury. Therefore, prophylactic measures are required to protect the ovarian function after detorsion. So that, our study aimed to assess the effect and underlying mechanisms of heme oxygenase-1 (HO-1) inducer; hemin against ovarian damage induced by IR injury in rats.

MAIN METHODS

Female rats were divided into: sham group, hemin group, ovarian IR (OIR) groups with and without hemin treatment. Serum levels of reduced glutathione (GSH) and interleukin 1 β (IL-1β) were measured in addition to ovarian levels of malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD). Ovarian phospho-Janus kinase (p-JNK) levels and gene expressions of HO-1 and inducible nitric oxide synthase (iNOS) were determined. Moreover, histopathological changes and expressions of phospho-nuclear factor kappa B p65 (p-NF-κB p65) and cleaved caspase-3 were done.

KEY FINDINGS

Treatment of OIR rats with hemin led to significant attenuation of ovarian damage through histological examination which was associated with significant increase in ovarian expression of HO-1, ovarian SOD and serum GSH levels with significant decrease in ovarian p-JNK levels, expressions of p-NF-κB p65, iNOS and cleaved caspase-3 in addition to serum IL-1β levels.

SIGNIFICANCE

The protective effect of hemin can be attributed to the increased expression of HO-1 which showed antioxidant, anti-inflammatory and anti-apoptotic effects. Therefore, hemin can be administered to prevent ovarian IR injury which occurs after detorsion.

Methyl palmitate reversed estradiol benzoate-induced endometrial hyperplasia in female rats

Early detection and treatment of endometrial hyperplasia (EH) is mandatory for endometrial cancer prevention. Several bioactive agents of plant origin have been shown to elicit their chemotherapeutic effect against tumors and cancer via induction of mitochondrial permeability transition(mPT) pore opening. This research was therefore aimed at evaluating the potential chemopreventive effect of methyl palmitate (MP), on estradiol benzoate(EB)-induced EH, looking at the mitochondrial-mediated pathway and other possible mechanisms of action. Mitochondria were isolated using differential centrifugation. The mPT pore, mitochondrial ATPase (mATPase) activity, lipid peroxidation and cytochrome c release were determined by standard methods using spectrophotometer. Uterine interleukin 1b, MDA levels and SOD, GSH activities, were determined using commercially available kits. The uterine histological and immunohistochemical assessment of estrogen receptor (ERα), IL-1b and caspas-3 were carried out. The fibroblast cell count density was determined using histomorphometry. At all the concentrations of MP used, there was no significant induction of mPT pore opening, neither any enhancement of mATPase activity nor release of cytochrome c when compared to the control. Similar pattern of results were recorded for the in vivo study. However, there was marked increase in the uterine MDA and interleukin 1b levels, with concurrent decrease in SOD and GSH activities, in the EB-treated group, which was significantly reversed by MP co-administration. Endometrial Hyperplasia observed in the EB-treated group was ameliorated by MP co-administration. The immunoexpression of ERα and IL-1b in the EB-treated group was reversed by MP co-administration. This study suggests anti-inflammatory, antioxidant and anti-proliferative potential of MP against EB-induced EH.

Omega-3 fatty acids protect against acetaminophen-induced hepatic and renal toxicity in rats through HO-1-Nrf2-BACH1 pathway

Although acetaminophen (APAP) is a commonly used analgesic antipyretic drug, hepatotoxicity and nephrotoxicity are common after the overdose. The main mechanism of APAP toxicity is oxidative stress based. Stress may induce the production of heme oxygenase 1 (HO)-1 which is regulated by interleukin (IL)-10 and inhibit the production of tumor necrosis factor-alpha (TNF-α). HO-1 expression is further regulated by nuclear factor erythroid 2-related factor 2 (Nrf2) and the transcription factor BTB and CNC homology 1 (BACH1). Drug-induced toxicity can be relieved by several natural products, which are preferred due to their dietary nature and less adverse reactions. Of these natural products, omega-3 (ω-3) fatty acids are known for anti-inflammatory and antioxidant actions. However, effects of ω-3fatty acids on APAP-induced hepatic and renal toxicity are not well addressed. We designed this study to test the potential protecting actions of ω-3 fatty acids (270 mg/kg Eicosapentaenoic acid and 180 mg/kg docosahexaenoic acid, orally, for 7 days) in hepatotoxicity and nephrotoxicity induced by APAP (2 g/kg, once orally on day 7) in rats. Moreover, we focused on the molecular mechanism underlying APAP hepatotoxicity and nephrotoxicity. Pre-treatment with ω-3 fatty acids enhanced liver and kidney functions indicated by decreased serum aminotransferases activities and serum creatinine and urea concentrations. These results were further confirmed by histopathological examination. Moreover, ω-3 fatty acids showed antioxidant properties confirmed by decreased malondialdehyde level and increased total antioxidant capacity. Antioxidant Nrf2, its regulators (HO-1 and BACH1) and the anti-inflammatory cytokine (IL-10) were up-regulated by APAP administration as a compensatory mechanism and they were normalized by ω-3 fatty acids. ω-3 fatty acids showed anti-inflammatory actions through down-regulating nuclear factor kappa B (NF-ĸB) and its downstream TNF-α. Moreover, Western blot analysis showed that ω-3 fatty acids promoted Nrf2 translocation to the nucleus; BACH1 exit from the nucleus and inhibited NF-ĸB nuclear translocation. These findings suggested the protecting actions of ω-3 fatty acids against APAP-induced hepatic and renal toxicity through regulation of antioxidant Nrf2 and inflammatory NF-ĸB pathways.

Amelioration of estrogen-induced endometrial hyperplasia in female rats by hemin via heme-oxygenase-1 expression, suppression of iNOS, p38 MAPK, and Ki67

Although heme oxygenase-1 (HO-1) is part of an endogenous defense system implicated in the homeostatic response, its role in cell proliferation and tumor progression is still controversial. Endometrial hyperplasia (EH) is associated with high risk of endometrial cancer (EC). Therefore, we aimed to evaluate the effect of hemin, a HO-1 inducer, against EH. Thirty-two female rats (60-70 days old) were divided into 4 groups treated for 1 week: vehicle control group, hemin group (25 mg/kg; i.p. 3 times/week), estradiol valerate (EV) group (2 mg/kg per day, p.o.), and hemin plus EV group. Sera were obtained for reduced glutathione level. Uterine malondialdehyde, superoxide dismutase, total nitrite/nitrate, and interleukin-1β levels were estimated. HO-1 and p38 mitogen-activated protein kinase expressions were obtained in uterine tissue. Uterine histological and immunohistochemical assessment of iNOS and Ki67 were also done. Results demonstrated that upregulation of HO-1 expression in hemin plus EV rats led to amelioration of EH which was confirmed with histological examination. This was associated with significant decrease in oxidative stress parameters, p38 mitogen-activated protein kinase expression, and interleukin-1β level. Also, uterine iNOS and Ki67 expressions were markedly suppressed. In conclusion, upregulation of HO-1 expression via hemin has ameliorative effect against EH through its antioxidant, anti-inflammatory, and antiproliferative actions.

Role of endoplasmic reticulum stress in lipopolysaccharide-inhibited mouse granulosa cell estradiol production

The decrease in the level of estradiol (E₂) in granulosa cells caused by lipopolysaccharide (LPS) is one of the major causes of infertility underlying postpartum uterine infections; the precise molecular mechanism of which remains elusive. This study investigated the role of endoplasmic reticulum (ER) stress in LPS-induced E₂ decrease in mouse granulosa cells. Our results showed that LPS increased the pro-inflammatory cytokines [(interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α)], activated ER stress marker protein expression [(glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP)], and decreased cytochrome P450 family 19 subfamily A member 1 (Cyp19a1) expression and E₂ production. Moreover, inhibition of ER stress by 4-phenylbutyrate (4-PBA) attenuated thapsigargin-(TG, ER stress agonist) or LPS-induced reduction of Cyp19a1 and E₂, pro-inflammatory cytokines expression (IL-1β, IL-6, IL-8, and TNF-α), and the expression of CHOP and GRP78. Additionally, inhibition of toll-like receptor 4 (TLR4) by resatorvid (TAK-242) reversed the inhibitory effects of LPS on Cyp19a1 expression and E₂ production, activation of GRP78 and CHOP, and expression of IL-1β, IL-6, IL-8, and TNF-α. In summary, our study suggests that ER stress is involved in LPS-inhibited E₂ production in mouse granulosa cells.

Pathophysiological changes in experimental polycystic ovary syndrome in female albino rats: Using either hemin or L-arginine

Polycystic ovary syndrome (PCOS), one of the important endocrine disorders affecting females in the reproductive age, is caused mainly by an abnormal oxidation status that subsequently causes inflammatory conditions. Thus, this study aims to examine the possible individual prophylactic effects of gasotransmitters, hemin, or L-arginine in letrozole-induced PCOS. Fifty adult female albino rats were used and separated into a control group, which received the vehicle; a letrozole-induced PCOS group (L), which received letrozole orally at a dose level of 1 mg/kg for 21 days; a letrozole+hemin (L+H) group, which received letrozole plus hemin at a dose level of 25 mg/kg injected IP twice per week for 21 days; and a letrozole+L-arginine (L+A) group, which received letrozole plus L-arginine at a dose level of 200 mg/kg orally for 21 days. During PCO induction, the body weight and Lee index were measured. Serum glucose, insulin, lipid profile, gonadotrophic hormones, testosterone, estrogen, and tumor necrosis factor alpha were assayed, while ovarian tissues were analyzed to measure the oxidative state and histopathological changes. Our results proved that either hemin or L-arginine administration could improve the oxidative state, the inflammatory reaction, the hormonal imbalance, and the metabolic disturbances in PCO rats, which was confirmed by a histopathological examination of the rats' ovaries. In conclusion, either hemin or L-arginine had protective effects against PCOS with better pathophysiological changes with hemin.

Changes in expression and production of heme oxygenase-1 in rats with acute liver injury induced by lipopolysaccharide

To investigate the changes of heme oxygenase-1 (HO-1) expression and production in rats with acute liver injury induced by lipopolysaccharide (LPS), and explore the role of HO-1 in the pathogenesis of liver injury. Liver injury was assessed histologically and the serum level of alanine transaminase (ALT) and aspartate transaminase (AST) were examined. The activity of super oxide dismutase (SOD) and the content of malondialdehyde (MDA) and carbon monoxide (CO) in liver tissues were also examined at the same time. HO-1 mRNA expression was examined at different time points following LPS treatment and the expression of HO-1 protein was determined by immunohistochemical staining. Administration of LPS caused severe hepatic damage, characterized by significant elevation of serum ALT and AST levels and hepatic MDA content as well as a remarkable reduction of liver SOD activity at 24 hr as compared with those in the control group. HO-1 activity was elevated significantly after modeling, showing a time-dependent manner from 6 to 24 hr, while expression of HO-1 protein was increased remarkably from 6 to 24 hr. Endogenous CO concentration in the liver of control rats remained very low but was elevated significantly after LPS treatment (6, 12, 24 hr), which was in accordance with the changes of HO-1. HO-1 activity and protein are increased significantly in rats with acute liver injury induced by LPS, suggesting that HO-1 plays an important role in the pathogenesis of acute hepatic damage.

Induction of heme oxygenase-1 by hemin protects lung against orthotopic autologous liver transplantation-induced acute lung injury in rats

BACKGROUND

Post-liver transplantation acute lung injury (ALI) severely affects patients' survival, whereas the mechanism is unclear and effective therapy is lacking. The authors postulated that reperfusion-induced increased oxidative stress plays a critical role in mediating post-liver transplantation ALI and that induction of heme oxgenase-1 (HO-1), an enzyme with anti-oxidative stress properties, can confer effective protection of lung against ALI.

METHODS

Male Sprague-Dawley rats underwent autologous orthotopic liver transplantation (OALT) in the absence or presence of treatments with the selective HO-1 inducer (Hemin) or HO-1 inhibitor (ZnPP). Lung tissues were collected at 8 h after OALT, pathological scores and lung water content were evaluated; survival rate of rats was analyzed; protein expression of HO-1 was determined by western blotting, and nuclear translocation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor(NF)-κB p65 were detected by Immunofluorescence staining. The inflammatory cytokines and oxidative indexes of lung tissue were determined.

RESULTS

In lungs harvested at the early stage i.e. 8 h after OALT, Hemin treatment significantly increased superoxide dismutase activities, and reduced malondialdehyde, hydrogen peroxide, interleukin-6, myeloperoxidase, and tumor necrosis factor-α production,which were associated with increased HO-1 protein expression and lower pathological scores and increased survival rate of rats. The underline mechanisms might associate with activation of Nrf2 and inhibition of NF-κB p65 nuclear translocation. However, these changes were aggravated by ZnPP.

CONCLUSIONS

Hemin pretreatment, by enhancing HO-1 induction, increased lung antioxidant capacity and reduced inflammatory stress,protected the lung from OALT-induced ALI at early stage of reperfusion.