Puerarin ameliorates heat stress–induced oxidative damage and apoptosis in bovine Sertoli cells by suppressing ROS production and upregulating Hsp72 expression

Molecular insight into the binding properties of marine algogenic dissolved organic matter for polybrominated diphenyl ethers and their combined effect on marine zooplankton

Polybrominated diphenyl ethers (PBDEs) are widespread in marine ecosystems, despite the limits placed on several congeners, and pose a threat to marine organisms. Many coexisting factors, especially dissolved organic matter (DOM), affect the environmental behavior and ecological risk of PBDEs. Since blooms frequently occur in coastal waters, we used algogenic DOM (A-DOM) from the diatom Skeletonem costatum and examined the interaction of A-DOM with 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). Moreover, their combined effect on the rotifer Brachionus plicatilis was analyzed. During the stationary period, A-DOM had more proteins than polysaccharides, and 7 extracellular proteins were identified. A-DOM fluorescence was statically quenched by BDE-47, and amide, carbonyl, and hydroxyl groups in A-DOM were involved. Molecular docking analysis showed that all 5 selected proteins of A-DOM could spontaneously bind with BDE-47 and that hydrophobic interactions, van der Waals forces and pi-bond interactions existed. The reproductive damage, oxidative stress and inhibition of mitochondrial activity induced by BDE-47 in rotifers were relieved by A-DOM addition. Transcriptomic analysis further showed that A-DOM could activate energy metabolic pathways in rotifers and upregulate genes encoding metabolic detoxification proteins and DNA repair. Moreover, A-DOM alleviated the interference effect of BDE-47 on lysosomes, the extracellular matrix pathway and the calcium signaling system. Alcian blue staining and scanning electron microscopy showed that A-DOM aggregates were mainly stuck to the corona and cuticular surface of the rotifers; this mechanism, rather than a real increase in uptake, was the reason for enhanced bioconcentration. This study reveals the complex role of marine A-DOM in PBDEs bioavailability and enhances the knowledge related to risk assessments of PBDE-like contaminants in marine environments.

Plant Extracts to Alleviating Heat Stress in Dairy Cows

Heat stress (HS) in cows is a critical issue in the dairy industry. Dairy cows accumulate heat from body metabolism, along with that imposed by air temperature, humidity, air flow and solar radiation. HS in animals can occur during hot and humid summers when the ambient temperature is extremely high. Dairy cows have relatively high feed intakes and metabolic heat production and are thus susceptible to HS, leading to reductions in feed intake, lower milk yield, affected milk quality, reduced animal health and even shortening the productive lifespan of cows. Therefore, alleviating HS is a top priority for the dairy industry. Suitable plant extracts have advantages in safety, efficiency and few toxic side effects or residues for applications to alleviate HS in dairy cows. This paper reviews the effects of some plant extract products on alleviating HS in dairy cows and briefly discusses their possible mechanisms of action.

Never in mitosis gene A-related kinase-6 deficiency deteriorates diabetic cardiomyopathy via regulating heat shock protein 72

NIMA (never in mitosis, gene A)-related kinase-6 (NEK6), a cell cycle regulatory gene, was found to regulate cardiac hypertrophy. However, its role in diabetes-induced cardiomyopathy has not been fully elucidated. This research was designed to illustrate the effect of NEK6 involved in diabetic cardiomyopathy. Here we used a streptozotocin (STZ)-induced mice diabetic cardiomyopathy model and NEK6 knockout mice to explore the role and mechanism of NEK6 in diabetic-induced cardiomyopathy. NEK6 knockout mice and wild-type littermates were subjected to STZ injection (50 mg/kg/day for 5 days) to induce a diabetic cardiomyopathy model. As a result, 4 months after final STZ injection, DCM mice revealed cardiac hypertrophy, fibrosis, and systolic and diastolic dysfunction. NEK6 deficiency causes deteriorated cardiac hypertrophy, fibrosis, and cardiac dysfunction. Furthermore, we observed inflammation and oxidative stress in the hearts of NEK6 deficiency mice under diabetic cardiomyopathy pathology. Adenovirus was used to upregulate NEK6 in neonatal rat cardiomyocytes, and it was found that NEK6 ameliorated high glucose-induced inflammation and oxidative stress. Our findings revealed that NEK6 increased the phosphorylation of heat shock protein 72 (HSP72) and increased the protein level of PGC-1α and NRF2. Co-IP assay experiment confirmed that NEK6 interacted with HSP72. When HSP72 was silenced, the anti-inflammation and anti-oxidative stress effects of NEK6 were blurred. In summary, NEK6 may protect diabetic-induced cardiomyopathy by interacting with HSP72 and promoting the HSP72/PGC-1α/NRF2 signaling. KEY MESSAGES: NEK6 knockout deteriorated cardiac dysfunction, cardiac hypertrophy, fibrosis as well as inflammation response, and oxidative stress. NEK6 overexpression attenuated high glucose induced inflammation and oxidative stress. The underlying mechanisms of the protective role of NEK6 in the development of diabetic cardiomyopathy seem to involve the regulation of HSP72-NRF2- PGC-1α pathway. NEK6 may become a new therapeutic target for diabetic cardiomyopathy.

Mechanisms Underlying the Protective Effect of Maternal Zinc (ZnSO4 or Zn-Gly) against Heat Stress-Induced Oxidative Stress in Chicken Embryo

Environmental factors such as high temperature can cause oxidative stress and negatively affect the physiological status and meat quality of broiler chickens. The study was conducted to evaluate the effects of dietary maternal Zn-Gly or ZnSO4 supplementation on embryo mortality, hepatocellular mitochondrial morphology, liver antioxidant capacity and the expression of related genes involved in liver oxidative mechanisms in heat-stressed broilers. A total of 300 36-week-old Lingnan Yellow broiler breeders were randomly divided into three treatments: (1) control (basal diet, 24 mg zinc/kg); (2) inorganic ZnSO4 group (basal diet +80 mg ZnSO4/kg); (3) organic Zn-Gly group (basal diet +80 mg Zn-Gly/kg). The results show that maternal zinc alleviated heat stress-induced chicken embryo hepatocytes’ oxidative stress by decreasing the content of ROS, MDA, PC, 8-OHdG, and levels of HSP70, while enhancing T-SOD, T-AOC, CuZn-SOD, GSH-Px, CTA activities and the content of MT. Maternal zinc alleviated oxidative stress-induced mitochondrial damage in chick embryo hepatocytes by increasing mitochondrial membrane potential and UCP gene expression; and Caspase-3-mediated apoptosis was alleviated by increasing CuZn-SOD and MT gene expression and decreasing Bax gene expression and reducing the activity of caspase 3. Furthermore, maternal zinc treatment significantly increased Nrf2 gene expression. The results above suggest that maternal zinc can activate the Nrf2 signaling pathway in developing chick embryos, enhance its antioxidant function and reduce the apoptosis-effecting enzyme caspase-3 activities, thereby slowing oxidative stress injury and tissue cell apoptosis.

High Temperature-Induced Oxidative Stress Affects Systemic Zinc Homeostasis in Broilers by Regulating Zinc Transporters and Metallothionein in the Liver and Jejunum

To investigate the change in zinc homeostasis of broilers under heat stress, 512 broiler chickens were raised to the age of 28 days. The broilers were then assigned to heat stress and normal temperature (36.0°C vs. 26.0°C) groups for 7 days. The results showed that oxidative stress induced by high temperature had a negative effect on the growth performance of broilers. Heat stress altered zinc homeostasis and led to a redistribution of zinc in broilers, which was reflected in increased zinc concentrations in the jejunum, liver, and tibia. Upregulation of the expression of the zinc exporter ZnT1 and importers ZIP8 and ZIP14 in the jejunum indicated that more zinc was absorbed and transported from the jejunum into the blood, while the liver increased its capacity to hold zinc through upregulation of metallothionein (MT) expression, which was achieved by reducing ZnT1 expression and upregulating the expression of the importer ZIP3. The pathway was mediated by zinc transporters, but the capacity of MT to chelate and release zinc ions also played a crucial role. The mechanism of alterations in zinc homeostasis under heat stress was revealed by the changes in zinc transporters and MT levels in the intestine and liver. Heat stress also altered cecal microbial diversity and reduced the relative abundances of Bilophila and Dialister. In conclusion, broilers altered systemic zinc homeostasis through the regulation of zinc transporters and MT in the liver and jejunum to resist oxidative stress induced by high temperature.

Effects of Resveratrol on Growth Performance, Intestinal Development, and Antioxidant Status of Broilers under Heat Stress

Simple Summary

Broilers have unique physiological characteristics, no sweat glands and full of feathers, which makes it difficult to dissipate heat in high-temperature environments and is prone to heat stress (HS). HS has strong adverse effects on the meat production, growth performance, intestinal morphology, mortality and welfare of broilers, which can be alleviated by nutrition regulation. Resveratrol has been found to reduce the damage of HS on meat quality, immune and inflammatory response of broilers. However, there are few reports on the effects of resveratrol on the intestinal development and antioxidant capacity of broilers under HS. We demonstrated that resveratrol could improve the intestinal development and growth performance of broilers under HS. Besides, these findings suggest that resveratrol may offer an effective nutritional strategy to improve intestinal antioxidant function by regulating the expression of critical factors in the Nrf2 signaling pathway.

Abstract

The study investigated resveratrol’s effect on growth performance, intestinal development, and antioxidant capacity of broilers subjected to heat stress (HS). A total of 162 21-day-old male AA broilers were randomly divided into 3 treatment groups with 6 replicates of 9 birds each. The 3 treatment groups were as follows: the control (CON), in which broilers were housed at 22 ± 1 °C for 24 h day⁻¹, and the HS and HS + resveratrol (400 mg/kg) groups, in which broilers were housed at 33 ± 1 °C for 10 h a day from 8:00 to 18:00 and 22 ± 1 °C for rest of the time. Results indicated that birds in the HS group exhibited lower (p < 0.05) final body weight (BW) and average daily gain (ADG) compared with birds in the CON group. HS birds also had lower (p < 0.05) relative jejunum weight, relative ileum and jejunum length, jejunal villus height, and villus height to crypt depth ratios than the CON group. The activities of glutathione peroxidase (GPX), glutathione S-transferase (GST), superoxide dismutase (SOD), and the mRNA levels of NF-E2-related factor 2 (Nrf2), SOD1, and GPX were also lower (p < 0.05) in the HS than CON group. The HS group had higher (p < 0.05) protein carbonyl (PC) contents and Kelch-like ECH-associated protein 1 (Keap1) mRNA levels. Compared with HS group, the HS + resveratrol group exhibited higher (p < 0.05) BW and ADG, relative jejunum weight, relative length of ileum, jejunal villus height, activities of GPX and GST, and mRNA levels of Nrf2 and SOD1, but they had lower (p < 0.05) PC content and Keap1 mRNA levels. In conclusion, resveratrol can improve the intestinal development and antioxidant function of broilers under HS, and therefore improve growth performance. The mechanism by which resveratrol enhances the intestinal antioxidant capacity is mediated by Nrf2 signaling pathway.

Puerarin improved growth performance and postmortem meat quality by regulating lipid metabolism of cattle under hot environment

This study aims to evaluate the effect of puerarin on performance, meat quality, and serum indexes of beef cattle under hot environment. Thirty-two bulls were divided into four groups and fed diet supplemented with puerarin at 0, 200, 400, or 800 mg/kg. Results showed that heat stress was employed for 54 out of 60 days, 400 mg/kg group declined serum cortisol (COR) contents, all treatments increased the contents of total cholesterol, high density lipoprotein cholesterol, and total superoxide dismutase activity; in addition, glutathione peroxidase activity of 200 mg/kg group were enhanced, only 800 mg/kg group enhanced immunoglobulin (IgA, IgM, and IgG) and low density lipoprotein cholesterol contents compared with the control (p < .05). Moreover, 400-mg/kg puerarin increased serum growth hormone levels compared with 200 mg/kg group but declined COR concentrations compared with 200 mg/kg and 800 mg/kg groups (p < .05). More importantly, average daily gain and daily matter intake, and intramuscular fat contents of 400 mg/kg group were enhanced, but the shear force of beef in 400 mg/kg and 800 mg/kg groups were declined compared with the control (p < .05). These findings indicated that supplemental with puerarin enhanced immune and antioxidant, and 400 mg/kg of puerarin improved performance and meat quality by normalizing levels of stress hormones and increasing intramuscular fat deposition of beef cattle under hot environment.

Radix Puerarin Extract (Puerarin) Could Improve Meat Quality of Heat-Stressed Beef Cattle Through Changing Muscle Antioxidant Ability and Fiber Characteristics

The experiment was conducted to investigate the effects of dietary supplementation with Puerarin on meat quality, muscle antioxidant ability, and muscle fiber characteristics of beef cattle under a hot environment in summer. Thirty-two 15 ± 1.5-month-old Jinjiang bulls (291.65 ± 8.84 kg) were randomly divided into four groups with dietary Puerarin at 0 (control), 200 (Pue200), 400 (Pue400), and 800 (Pue800) mg/kg in the feed concentrate (n = 8). The feeding trial lasted for 60 days after a 10-day adaptation period (July 1-September 8); the average values of temperature, relative humidity and temperature, and humidity index were 30.68°C, 68.05%, and 81.81, respectively. The growth performance on day 40 of the experiment period was calculated. After 60 days' experimental period, four Jinjiang cattle per treatment from the control group, Pue400 group, and Pue800 group were slaughtered. Compared with the control group, the Pue400 and Pue800 groups improved the growth performance of beef cattle; the Pue800 group elevated the activities of superoxide dismutase, total antioxidant capacity, and glutathione peroxidase in the M. longissimus thoracis (LT) muscle. In the control group, the cell membrane was incomplete, and most of the mitochondria were elongated and in a fission state, while in the Pue400 and Pue800 groups, the cell membrane was clear and complete, and the mitochondria presented with round and oval shapes. Compared with the control group, the Pue400 and Pue800 groups reduced the shear force of the LT muscle, and the Pue400 group decreased the muscle fiber diameter and the myosin heavy-chain (MyHC)-IIb gene expression. Furthermore, the Pue400 and Pue800 groups decreased the ratio of AMP/ATP, the Pue800 group reduced the AMP-activated protein kinase α2 mRNA expression, and the Pue400 group improved the nuclear respiratory factor 1 mRNA expression. These results indicated that dietary supplementation with Puerarin might be beneficial to the meat quality of heat-stressed beef cattle by improving muscle antioxidant ability and reducing the MyHC-IIb muscle fiber composition. Based on the results of this study, we recommended 400 mg/kg Puerarin in the feed concentrate of beef cattle (~300 kg) for mitigation of heat stress.

Amelioration of heat stress-induced damage to testes and sperm quality

Heat stress (HS) occurs when temperatures exceed a physiological range, overwhelming compensatory mechanisms. Most mammalian testes are ∼4-5 °C cooler than core body temperature. Systemic HS or localized warming of the testes affects all types of testicular cells, although germ cells are more sensitive than either Sertoli or Leydig cells. Increased testicular temperature has deleterious effects on sperm motility, morphology and fertility, with effects related to extent and duration of the increase. The major consequence of HS on testis is destruction of germ cells by apoptosis, with pachytene spermatocytes, spermatids and epididymal sperm being the most susceptible. In addition to the involvement of various transcription factors, HS triggers production of reactive oxygen species (ROS), which cause apoptosis of germ cells and DNA damage. Effects of HS on testes can be placed in three categories: testicular cells, sperm quality, and ability of sperm to fertilize oocytes and support development. Various substances have been given to animals, or added to semen, in attempts to ameliorate heat stress-induced damage to testes and sperm. They have been divided into various groups according to their composition or activity, as follows: amino acids, antibiotics, antioxidant cocktails, enzyme inhibitors, hormones, minerals, naturally produced substances, phenolic compounds, traditional herbal medicines, and vitamins. Herein, we summarized those substances according to their actions to mitigate HS' three main mechanisms: oxidative stress, germ cell apoptosis, and sperm quality deterioration and testicular damage. The most promising approaches are to use substances that overcome these mechanisms, namely reducing testicular oxidative stress, reducing or preventing apoptosis and promoting recovery of testicular tissue and restoring sperm quality. Although some of these products have considerable promise, further studies are needed to clarify their ability to preserve or restore fertility following HS; these may include more advanced sperm analysis techniques, e.g. sperm epigenome or proteome, or direct assessment of fertilization and development, including in vitro fertilization or breeding data (either natural service or artificial insemination).

Analyses of the function of DnaJ family proteins reveal an underlying regulatory mechanism of heat tolerance in honeybee

There is clear evidence of severe honeybee declines in recent years, and parallel declines of plant community and crop productivity that rely on them. Different stresses, including heat stress, are among the primary drivers of this decline. However, the mechanisms by which honeybees respond to heat stress are elusive. Though heat shock proteins (Hsps) play important roles in heat stress response, the function of DnaJs (a subfamily of Hsps) is unclear. Here, we aimed to determine the underlying regulatory mechanism of honeybees to heat stress mediated by DnaJs. We found that several DnaJ genes, including DnaJA1, DnaJB12 and DnaJC8, are key for honeybee heat tolerance. DnaJA1 and DnaJB12 are cytoplasmic proteins, and DnaJC8 is a nuclear protein. The expression of DnaJA1, DnaJB12 and DnaJC8 was induced at different levels under short-term and long-term heat stress. Phenotypic analysis indicated that DnaJA1, DnaJB12 and DnaJC8 knockdown attenuated honeybee heat resistance. In addition, DnaJA1 participated in the heat stress response by upregulating many heat-inducible genes at the transcriptome-wide level, especially LOC108002668 and LOC107995148. Importantly, the upregulation of LOC108002668 and LOC107995148 was significantly repressed under heat stress when DnaJA1 was knocked down. We also found that knockdown of DnaJA1, DnaJB12 and DnaJC8 decreased antioxidant defense ability and increased the degree of oxidative damage in the honeybee. Taken together, our results indicate that DnaJ genes play important roles under heat stress in the honeybee. Overexpression of DnaJ genes may protect honeybees from heat stress-induced injuries and increase their survival rate.

Standard Puerarin Prevents Diabetic Renal Damage by Inhibiting miRNA-140-5p Expression

AIM

This study was designed to use in vivo and in vitro approaches to evaluate puerarin in diabetes-induced renal injury.

MATERIALS AND METHODS

SD rats were divided into NC (normal control), Model (diabetic induced renal injury model), SP-L (model rats treated with low-dose standard puerarin), SP-M (model rats treated with middle-dose standard puerarin), and SP-H (model rats treated with high-dose standard puerarin) groups. We evaluated fasting blood-glucose (FBG), urinary albumin/creatinine ratio (UACR), body weight, and kidney index (KI) in the different groups. TNF-α, IL-1β, and IL-6 concentrations were measured using Elisa assays. HE staining and TUNEL assays were used to evaluate pathology and apoptosis in kidney tissues, respectively. Relative gene and protein expression was measured using RT-qPCR and Western blot assays. Apoptosis was measured using flow cytometry. The correlation between miRNA-145-5p and TLR4 was assessed using dual-luciferase reporter gene assays.

RESULTS

The pathology and apoptosis cell number were deteriorate in Model group; TNF-α, IL-1β and IL-6 concentrations, FGB, UACR and KI were increased and body weight was depressed; meanwhile, relative gene and proteins expressions (miRNA-145-5p, TLR4, MyD88 and NF-κB p65) were significantly different in Model group in vivo and vitro study compared with NC group. SP treatment significantly improved the pathology and apoptosis levels in the tissues, as well as TNF-α, IL-1β and IL-6 concentrations, FGB, UACR, body weight, and KI. In vitro cell studies revealed that SP could prevent renal injury induced by diabetes through the miRNA-145-5p/TLR4 axis.

CONCLUSION

SP prevents diabetes-induced renal damage via miRNA-145-5p overexpression and reduces TLR4/MyD88/NF-κB (p65) pathway activation in vitro and in vivo.

Puerarin attenuates hypoxia-resulted damages in neural stem cells by up-regulating microRNA-214

Puerarin has been reported to be useful in protection against hypoxia-induced injury. In our current study, we attempted to explore the protective effects of puerarin against hypoxia-caused damages in neural stem cells (NSCs). Additionally, the relative molecular underpinning studies preliminarily proceeded. NSCs were pre-incubated with puerarin before the hypoxic stimulus. MicroRNA-214 (miR-214) inhibitor was transfected into NSCs. Subsequently, the viability of NSCs was assessed by CCK-8 assay. Flow cytometry was employed to detect apoptotic cells after staining. qRT-PCR was performed to quantify miR-214. Western blot was applied for analyzing the expression of apoptosis-relative proteins and regulators. We found that puerarin alleviated hypoxia-induced apoptosis and maintained cell viability. Hypoxia-evoked up-regulation of miR-214 was further enhanced by puerarin. By contrast, miR-214-deficient NSCs showed the reduction in cell viability and the facilitation in apoptosis progress after pre-treatment with puerarin and stimulation in a hypoxia circumstance. Additionally, puerarin restored the phosphorylation of relative regulators, which was originally blunted by hypoxia. However, puerarin did not evidently restore the phosphorylation for response to hypoxia in miR-214-silenced NSCs. In conclusion, puerarin might be applied as a novel agent to ameliorate hypoxia-evoked damages in NSCs. Molecularly, miR-214 might be implicated in the protective roles of puerarin.

Effect of Curcumin Supplement in Summer Diet on Blood Metabolites, Antioxidant Status, Immune Response, and Testicular Gene Expression in Hu Sheep

Simple Summary

Heat stress can induce oxidative stress and has an adverse effect on the growth and reproductive performance in animals. Curcumin, a plant-derived substance, with the effect of scavenging oxidative free radicals, improving immune response and anti-apoptosis, has been widely used as a dietary supplement in the livestock industry. The present study aims to investigate the effect of a curcumin dietary supplement on the blood metabolites, antioxidant status, immune response, and testicular gene expression in Hu Sheep in summer. The results show that dietary curcumin supplementation (450 and 900 mg/per sheep daily) can promote lipid metabolism, antioxidant capacity, and immune response as well as testicular development in Hu sheep, which provides evidence for the protective role of curcumin against heat stress in sheep.

Abstract

In summer, the high temperature affects animal growth and reproductive performance. Curcumin is a flavonoid with anti-oxidant and anti-inflammatory effects. To evaluate the effects of dietary curcumin supplement on the blood biochemical parameters and testicular gene expressions in Hu sheep in summer, a total of 144 male Hu sheep aged four months were randomly divided into three groups (Con, Cur1, and Cur2, n = 48). Sheep in Con, Cur1, and Cur2 groups were fed a basal diet supplement with 0, 450, and 900 mg (per sheep) curcumin daily, respectively. Sheep were fed for 35 days, including a pre-feed for seven days. The results showed that the supplement with 450 mg and 900 mg curcumin increased serum free fatty acid (NEFA) and glutathione peroxidase (GPX), as well as IgA and IgM. The supplement with 450 mg curcumin increased the IgG level, while the supplement with 900 mg curcumin had a lower IgG level than the supplement with 450 mg curcumin (p < 0.05). Dietary curcumin supplement increased testicular organ index, serum testosterone level, and testicular star mRNA expression (p < 0.05). Furthermore, dietary curcumin supplement linearly inhibited testicular apoptosis with increased testicular bcl-2 mRNA expression and decreased caspase-3 mRNA expression (p < 0.05). In conclusion, dietary curcumin supplement can promote lipid metabolism, antioxidant capacity, and immune response, as well as testicular development, in Hu sheep, which provides evidence of application of curcumin in sheep production.

Baicalin protects mouse testis from injury induced by heat stress

Heat stress has been documented to reduce reproductive performance of female animals through injury to germ cells, with few studies available in male animals. The objectives of this study were to evaluate protective effects of baicalin on testicular tissue damage of mice subjected to heat stress and its related mechanisms. In this experiment, A total of forty mice were divided into four groups, including control group (C), baicalin group (B), heat stressed group (H) and heat stress with baicalin treatment (H + B) group. Morphological changes, activities of antioxidant enzymes and apoptosis-related parameters in the mice testes tissue were monitored. The results showed that the process of spermatogenesis in mice testis was impaired and the cellular apoptosis increased due to acute heat stress at 41 °C. Interestingly, the tissue damage was alleviated with the significant (P < 0.05) increase in the activities of SOD, CAT and GSH-Px enzymes, decrease (P < 0.05) in MDA content and number of cellular apoptosis recorded in mice of H + B group compared with those in mice from H group. In addition, the Fas, FasL and P-JNK protein expressions were significantly (P < 0.05) increased; and apaf-1, caspase-3, -9 were slightly expressed in the H group, while there was no difference in Bcl-2 expression, compared with C, B and H + B groups. The above results clearly indicate that heat stress induces macroscopic/apoptotic and oxidative changes in the testicular tissue of mice; these changes are alleviated by Baicalin through increasing anti-oxidative enzyme activities and possibly through blocking Fas/FasL pathway.

Suppression of puerarin on polymethylmethacrylate-induced lesion of peri-implant by inhibiting NF-κB activation in vitro and in vivo

Puerarin (PR), a natural isoflavone isolated from Chinese traditional plant pueraria lobata, has attracted considerable attention due to its important biological and pharmacological activities. However, its effects on lesion of peri-implant and related mechanism of action are still not clear, which require further investigation. In this study, we evaluated the effects of PR on polymethylmethacrylate (PMMA)-induced lesion of peri-implant in vitro and in vivo, and explored its possible mechanism of action. Our results indicated that PR could inhibit PMMA-induced osteoclastogenesis in RAW264.7 cells with a dose-dependent manner in vitro and effectively down-regulate mRNA and protein expressions of matrix metalloprotein 9 (MMP-9), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and receptor activator of nuclear factor (NF)-κB (RANK), primarily via the suppression of NF-κB signaling. Furthermore, we found that PMMA induction could directly cause the phosphorylation of IκB and significantly promote the nuclear translocation of p65 in RAW264.7 cells. In other words, PR was able to dose-dependently attenuate the PMMA-induced nuclear translocation of p65 in RAW264.7 cells. In vivo, PR was observed to attenuate PMMA-induced osteoclastogenesis, osteolysis, mRNA expressions of receptor activator of nuclear factor (NF)-κB ligand (RANKL) and RANK, as well as protein levels of MMP-9, TNF-α, IL-6, and p65 in a murine calvarial osteolysis model. These findings suggested that PR might be a potential therapeutic drug to lesion of peri-implant, and provided new insights for understanding its possible mechanism.

Rosemary Reduces Heat Stress by Inducing CRYAB and HSP70 Expression in Broiler Chickens

Heat stress negatively affects poultry production and animal health. In response, animals invoke a heat stress response by inducing heat shock proteins (HSPs). Scientists are actively seeking natural products that can enhance the heat shock response. The present study aimed at assessing the effects of a purified rosemary extract comprising antioxidant compounds on the heat shock response and HSP expression profile in broiler chickens. The response of broilers to HS in the presence of purified rosemary extract was assessed using an in vivo myocardial cell model. Pathological lesions of heart tissue were examined microscopically. The levels and activities of enzymes associated with heart damage and oxidative damage were detected. Immunohistochemical staining was performed for HSPs in myocardial cells. The results showed that lactate dehydrogenase (LDH), creatine kinase (CK), and myocardial CK (CKMB) levels were reduced by the purified rosemary extract before and during heat stress. Heat stress alone increased CK and CKMB levels. The levels of oxidative damage-associated enzymes were compared between the rosemary + heat stress and heat stress-alone groups. The results indicated that in terms of these enzymes, the purified rosemary extract induced a more antioxidative state. Pathological examinations showed that heat stress caused myocardial fiber fracture, karyopyknosis, and degeneration. The addition of purified rosemary extract ameliorated these lesions to some degree, preserving more of the basic structure. Heat stress decreased the cellular levels of crystallin alpha B (CRYAB) and HSP70. The addition of the purified rosemary extract significantly increased the levels of CRYAB and HSP70 during heat stress (p < 0.0001). Immunohistochemistry showed that after rosemary treatment, CRYAB and HSP70 showed more intense staining compared with the no heat stress control group. In the rosemary + heat group, after 10 hours of heat stress, the staining intensity of these two proteins remained higher than in the heat stress group. Thus, purified rosemary extract could induce high levels of HSP70 and CRYAB in chicken hearts before and during heat stress. Purified rosemary extract could be used to alleviate heat stress in broiler chickens.

Effects of saturated palmitic acid and omega-3 polyunsaturated fatty acids on Sertoli cell apoptosis

Obesity is believed to negatively affect male semen quality and is accompanied by dysregulation of free fatty acid (FFA) metabolism in plasma. However, the implication of dysregulated FFA on semen quality and the involvement of Sertoli cells remain unclear. In the present study, we report obesity decreased Sertoli cell viability through dysregulated FFAs. We observed an increased rate of apoptosis in Sertoli cells, accompanied with elevated FFA levels, in the testes of obese mice that were provided a high-fat diet (HFD). Moreover, the levels of reactive oxygen species were elevated. Furthermore, we demonstrated by in vitro assays that saturated palmitic acid (PA), which is the most common saturated FFA in plasma, led to decreased cell viability of TM4 Sertoli cells in a time- and dose-dependent manner. A similar finding was noted in primary mouse Sertoli cells. In contrast to saturated FFA, omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) protected Sertoli cells from PA-induced lipotoxicity at the physiologically relevant levels. These results indicated that the lipotoxicity of saturated fatty acids might be the cause of obesity-induced Sertoli cell apoptosis, which leads to decreased semen quality. In addition, ω-3 PUFAs could be classified as protective FFAs.

ABBREVIATIONS

FFA: free fatty acid; HFD: high-fat diet; SD: standard diet; PA: palmitic acid; PUFA: polyunsaturated fatty acid; AI: apoptotic index; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide; ROS: reactive oxygen species; HE: Hematoxylin and eosin; WT1: Wilm Tumor 1; NAFLD: non- alcoholic fatty liver disease; DCFH-DA: 2', 7' dichlorofluorescin diacetate; 36B4: acidic ribosomal phosphoprotein P0; SD: standard deviation; EPA: eicosapentaenoic acid; PI: propidium iodide; DHA: docosahexenoic acid.

Melatonin promotes sheep Leydig cell testosterone secretion in a co-culture with Sertoli cells

Leydig cells synthesize and secrete testosterone, and are regulated by Sertoli cells. These two cell types may work together to regulate testicular androgen production. Studies have shown that Leydig cell androgen synthesis can be dramatically enhanced by Sertoli cells in the presence of melatonin, which can regulate the secretory function of Leydig and Sertoli cells. However, the molecular mechanism of melatonin-regulated Leydig cell androgen production via Sertoli cells remains unclear. Here, we found that 10^-7 M melatonin increased testosterone production in co-cultured Leydig and Sertoli cells isolated from sheep. Melatonin increased the expression of stem cell factor and insulin-like growth factor-1 and decreased estrogen synthesis in Sertoli cells. Melatonin promoted insulin-like growth factor-1 and decreased estrogen content via the membrane melatonin receptor 1. It also enhanced stem cell factor expression via the retinoic acid receptor-related orphan receptor alpha. Addition of PD98059, a MEK inhibitor, to Sertoli cell culture demonstrated that the melatonin upregulation of insulin-like growth factor-1 and downregulation of estrogen may be through the MEK/extracellular signal-regulated kinase pathway. Together, these results suggest that melatonin may function through modulating melatonin receptor 1-regulated insulin-like growth factor-1 expression, as well as melatonin receptor 1-induced suppression of estrogen synthesis to increase androgen production in co-cultured Leydig and Sertoli cells.