Low caveolin-1 levels and symptomatic intracranial haemorrhage risk in large-vessel occlusive stroke patients after endovascular thrombectomy

BACKGROUND AND PURPOSE

Caveolin-1 (Cav-1) is reported to mediate blood-brain barrier integrity after ischaemic stroke. Our purpose was to assess the role of circulating Cav-1 levels in predicting symptomatic intracranial haemorrhage (sICH) amongst ischaemic stroke patients after endovascular thrombectomy (EVT).

METHODS

Patients with large-vessel occlusive stroke after EVT from two stroke centres were prospectively included. Serum Cav-1 level was tested after admission. sICH was diagnosed according to the Heidelberg Bleeding Classification.

RESULTS

Of 325 patients (mean age 68.6 years; 207 men) included, 47 (14.5%) were diagnosed with sICH. Compared with patients without sICH, those with sICH had a lower concentration of Cav-1. After adjusting for potential confounders, multivariate regression analysis demonstrated that the increased Cav-1 level was associated with a lower sICH risk (odds ratio 0.055; 95% confidence interval 0.005-0.669; p = 0.038). Similar results were obtained when Cav-1 levels were analysed as a categorical variable. Using a logistic regression model with restricted cubic splines, a linear and negative association of Cav-1 concentration was found with sICH risk (p = 0.001 for linearity). Furthermore, the performance of the conventional risk factors model in predicting sICH was substantially improved after addition of the Cav-1 levels (integrated discrimination index 2.7%, p = 0.002; net reclassification improvement 39.7%, p = 0.007).

CONCLUSIONS

Our data demonstrate that decreased Cav-1 levels are related to sICH after EVT. Incorporation of Cav-1 into clinical decision-making may help to identify patients at a high risk of sICH and warrants further consideration.

Single-Cell RNA-Sequencing Provides Insight into Skeletal Muscle Evolution during the Selection of Muscle Characteristics

Skeletal muscle comprises a large, heterogeneous assortment of cell populations that interact to maintain muscle homeostasis, but little is known about the mechanism that controls myogenic development in response to artificial selection. Different pig (Sus scrofa) breeds exhibit distinct muscle phenotypes resulting from domestication and selective breeding. Using unbiased single-cell transcriptomic sequencing analysis (scRNA-seq), the impact of artificial selection on cell profiles is investigated in neonatal skeletal muscle of pigs. This work provides panoramic muscle-resident cell profiles and identifies novel and breed-specific cells, mapping them on pseudotime trajectories. Artificial selection has elicited significant changes in muscle-resident cell profiles, while conserving signs of generational environmental challenges. These results suggest that fibro-adipogenic progenitors serve as a cellular interaction hub and that specific transcription factors identified here may serve as candidate target regulons for the pursuit of a specific muscle phenotype. Furthermore, a cross-species comparison of humans, mice, and pigs illustrates the conservation and divergence of mammalian muscle ontology. The findings of this study reveal shifts in cellular heterogeneity, novel cell subpopulations, and their interactions that may greatly facilitate the understanding of the mechanism underlying divergent muscle phenotypes arising from artificial selection.

Maternal consumption of l-malic acid enriched diets improves antioxidant capacity and glucose metabolism in offspring by regulating the gut microbiota

Maternal diets during pregnancy and lactation are key determinants that regulate the development of metabolic syndrome (MetS) in offspring. l-malic acid (MA) was previously reported to improve antioxidant capacity and aerobic metabolism. However, the effects of maternal MA consumption on the metabolic features of offspring remain largely unexplored. Herein, through pig models consuming MA-enriched diets during late pregnancy and lactation, we found that maternal MA consumption potentiated the anti-inflammatory and antioxidant capacity of sows, thereby improving their reproductive performance and the growth performance of piglets. Maternal MA consumption also induced a transition of slow-twitch to fast-twitch fibers in the early life of offspring. Along with muscle growth and fiber-type transition, insulin sensitivity and glucose metabolism, including aerobic metabolism and glycolysis, were improved in the skeletal muscle of offspring. An untargeted metabolomic analysis further revealed the contribution of modified amino acid metabolism to the improved aerobic metabolism. Mechanistically, maternal MA consumption remodeled colonic microbiota of their offspring. Briefly, the abundance of Colidextribacter, Romboutsia, and Family_XIII_AD3011_group increased, which were positively associated with the antioxidant capacity and glucose metabolism of skeletal muscles. A decreased abundance of Prevotella, Blautia, Prevotellaceae_NK3B31_group, and Collinsella was also detected, which were involved in less insulin sensitivity. Notably, milk metabolites, such as ascorbic acid (AA) and granisetron (GS), were found as key effectors regulating the gut microbiota composition of piglets. The properties of AA and GS in alleviating insulin resistance, inflammation, and oxidative stress were further verified through mice treated with high-fat diets. Overall, this study revealed that maternal MA consumption could modulate the inflammatory response, antioxidant capacity, and glucose metabolism by regulating the gut microbiota of offspring through the vertical transmission of milk metabolites. These findings suggest the potential of MA in the prevention and treatment of MetS in early life.

Dietary Supplementation with Lauric Acid Improves Aerobic Endurance in Sedentary Mice via Enhancing Fat Mobilization and Glyconeogenesis

BACKGROUND

Lauric acid (LA), a major, natural, medium-chain fatty acid, is considered an efficient energy substrate for intense exercise and in patients with long-chain fatty acid β-oxidation disorders. However, few studies have focused on the role of LA in exercise performance and related glucolipid metabolism in vivo.

OBJECTIVES

We aimed to investigate the effect of dietary supplementation with LA on exercise performance and related metabolic mechanisms.

METHODS

Male C57BL/6N mice (14 wk old) were fed a basal diet or a diet containing 1% LA, and a series of exercise tests, including a high-speed treadmill test, aerobic endurance exercises, a 4-limb hanging test, and acute aerobic exercises, were performed.

RESULTS

Dietary supplementation with 1.0% LA accelerated the recovery from fatigue after explosive exercise (P < 0.05) and improved aerobic endurance and muscle strength in sedentary mice (P = 0.039). Lauric acid intake not only changed muscle fatty acid profiles, including increases in C12:0 and n-6/n-3 PUFAs (P < 0.001) and reductions in C18:0, C20:4n-6, C22:6n-3, and n-3 PUFAs (P < 0.05) but also enhanced fat mobilization from adipose tissue and fatty acid oxidation in the liver, at least partly via the AMP-activated protein kinase-acetyl CoA carboxylase pathway (P < 0.05). Likewise, LA supplementation promoted liver glyconeogenesis and conserved muscular glycogen during acute aerobic exercise (P < 0.05), which was accompanied by an increase in the mitochondrial DNA copy number and Krebs cycle activity in skeletal muscle (P < 0.05).

CONCLUSIONS

Dietary supplemental LA serves as an efficient energy substrate for sedentary mice to improve aerobic exercise endurance and muscle strength through regulation of glucolipid metabolism. These findings imply that LA supplementation might be a promising nutritional strategy to improve aerobic exercise performance in sedentary people.

Dietary supplementation of laminarin improves the reproductive performance of sows and the growth of suckling piglets

BACKGROUND

Maternal nutrition is essential in keeping a highly efficient production system in the pig industry. Laminarin has been shown to improve antioxidant capacity, reduce the inflammatory response, and favor the homeostasis of intestinal microbiota. However, the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.

METHODS

A total of 40 Landrace × Yorkshire multiparous sows on d 85 of gestation, similar in age, body weight (BW), parity and reproductive performance, were randomly divided into four dietary treatments with 10 sows per treatment, receiving a control diet (basal pregnancy or lactating diets) and a basal diet supplemented with 0.025%, 0.05% and 0.10% laminarin, respectively. The experiment lasted from d 85 of gestation to d 21 of lactation.

RESULTS

Laminarin supplementation linearly increased number born alive per litter (P = 0.03), average daily feed intake (ADFI, P < 0.01), and total milk yield of sows during the lactation of 1-21 d (P = 0.02). Furthermore, maternal laminarin supplementation increased the average daily gain (ADG) of piglets while tending to reduce the culling and death rate before weaning. In addition, alterations to the composition of colostrum and milk, as well as to serum inflammatory cytokines and immunoglobulins of sows were observed. The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.

CONCLUSIONS

Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.

Nutritional regulation of skeletal muscle energy metabolism, lipid accumulation and meat quality in pigs

The quality of pork determines consumers' purchase intention, which directly affects the economic value of pork. Minimizing the proportion of inferior pork and producing high quality pork are the ultimate goals of the pig industry. Muscle energy metabolism, serving as a regulative hub in organism energy expenditure and storage as a fat deposit, is compatible with myofiber type composition, affecting meat color, intramuscular fat content, tenderness, pH values and drip loss. Increasing data illustrate that dietary nutrients and bioactive ingredients affect muscle energy metabolism, white adipose browning and fat distribution, and myofiber type composition in humans, and rodents. Recently, some studies have shown that modulating muscle energy metabolism and lipid accumulation through nutritional approaches could effectively improve meat quality. This article reviews the progress and development in this field, and specifically discusses the impacts of dietary supply of amino acids, lipids, and gut microbiota as well as maternal nutrition on skeletal muscle energy metabolism, lipid accumulation and meat quality of pigs, so as to provide comprehensive overview with respect to effective avenues for improving meat quality.

Carcass and meat quality traits and their relationships in Duroc × Landrace × Yorkshire barrows slaughtered at various seasons

To understand characteristics of carcass traits and meat quality in pig population, 22 indicators of carcass characteristics and meat quality traits were measured on 278 Duroc × Landrace × Yorkshire barrows that were slaughtered in different seasons (spring, summer, autumn and winter). The effects of body weight and season on carcass characteristics and meat quality were analyzed by GLM procedure, followed the Bonferroni multiple test. The phenotypic correlations among those traits were calculated by employing the CORR procedure. In addition, the linear regression equations were constructed by stepwise regression model in REG procedure. The results showed that pigs slaughtered in spring had the heaviest body weight among the four seasons (P < 0.05), pigs slaughtered in summer had the lowest backfat depth and shear force (P < 0.05), and pigs slaughtered in winter had the lowest drip loss (P < 0.05). The results showed more variation in backfat depth, drip loss, intramuscular fat content, and shear force, compared with other indicators across pigs. Body weight had a significant association with loin eye area, average backfat depth and L^⁎_{24 h} (P < 0.05). Furthermore, regression equations for drip loss, cooking loss, shear force, and intramuscular fat content were constructed using more accessible indicators. Collectively, this study provided an overall view of carcass and meat quality traits in a commercial pig population in China, and illustrated that season significantly affected carcass characteristics and meat quality traits independently of body weight.

Lack of adipocyte IP3R1 reduces diet-induced obesity and greatly improves whole-body glucose homeostasis

The normal function of skeletal muscle and adipose tissue ensures whole-body glucose homeostasis. Ca²⁺ release channel inositol 1,4,5-trisphosphate receptor 1 (IP3R1) plays a vital role in regulating diet-induced obesity and disorders, but its functions in peripheral tissue regulating glucose homeostasis remain unexplored. In this study, mice with Ip3r1 specific knockout in skeletal muscle or adipocytes were used for investigating the mediatory role of IP3R1 on whole-body glucose homeostasis under normal or high-fat diet. We reported that IP3R1 expression levels were increased in the white adipose tissue and skeletal muscle of diet-induced obese mice. Ip3r1 knockout in skeletal muscle improved glucose tolerance and insulin sensitivity of mice on a normal chow diet, but worsened insulin resistance in diet-induced obese mice. These changes were associated with the reduced muscle weight and compromised Akt signaling activation. Importantly, Ip3r1 deletion in adipocytes protected mice from diet-induced obesity and glucose intolerance, mainly due to the enhanced lipolysis and AMPK signaling pathway in the visceral fat. In conclusion, our study demonstrates that IP3R1 in skeletal muscle and adipocytes exerts divergent effects on systemic glucose homeostasis, and characterizes adipocyte IP3R1 as a promising target for treating obesity and type 2 diabetes.

Lamotrigine protects against cognitive deficits, synapse and nerve cell damage, and hallmark neuropathologies in a mouse model of Alzheimer’s disease

Lamotrigine (LTG) is a widely used drug for the treatment of epilepsy. Emerging clinical evidence suggests that LTG may improve cognitive function in patients with Alzheimer’s disease. However, the underlying molecular mechanisms remain unclear. In this study, amyloid precursor protein/presenilin 1 (APP/PS1) double transgenic mice were used as a model of Alzheimer’s disease. Five-month-old APP/PS1 mice were intragastrically administered 30 mg/kg LTG or vehicle once per day for 3 successive months. The cognitive functions of animals were assessed using Morris water maze. Hyperphosphorylated tau and markers of synapse and glial cells were detected by western blot assay. The cell damage in the brain was investigated using hematoxylin and eosin staining. The levels of amyloid-β and the concentrations of interleukin-1β, interleukin-6 and tumor necrosis factor-α in the brain were measured using enzyme-linked immunosorbent assay. Differentially expressed genes in the brain after LTG treatment were analyzed by high-throughput RNA sequencing and real-time polymerase chain reaction. We found that LTG substantially improved spatial cognitive deficits of APP/PS1 mice; alleviated damage to synapses and nerve cells in the brain; and reduced amyloid-β levels, tau protein hyperphosphorylation, and inflammatory responses. High-throughput RNA sequencing revealed that the beneficial effects of LTG on Alzheimer’s disease-related neuropathologies may have been mediated by the regulation of Ptgds, Cd74, Map3k1, Fosb, and Spp1 expression in the brain. These findings revealed potential molecular mechanisms by which LTG treatment improved Alzheimer’s disease. Furthermore, these data indicate that LTG may be a promising therapeutic drug for Alzheimer’s disease.

The Alzheimer’s disease-associated gene TREML2 modulates inflammation by regulating microglia polarization and NLRP3 inflammasome activation

Triggering receptor expressed on myeloid cells-like 2 (TREML2) is a newly identified susceptibility gene for Alzheimer’s disease (AD). It encodes a microglial inflammation-associated receptor. To date, the potential role of microglial TREML2 in neuroinflammation in the context of AD remains unclear. In this study, APP/PS1 mice were used to investigate the dynamic changes of TREML2 levels in brain during AD progression. In addition, lipopolysaccharide (LPS) stimulation of primary microglia as well as a lentivirus-mediated TREML2 overexpression and knockdown were employed to explore the role of TREML2 in neuroinflammation in the context of AD. Our results show that TREML2 levels gradually increased in the brains of APP/PS1 mice during disease progression. LPS stimulation of primary microglia led to the release of inflammatory cytokines including interleukin-1β, interleukin-6, and tumor necrosis factor-α in the culture medium. The LPS-induced microglial release of inflammatory cytokines was enhanced by TREML2 overexpression and was attenuated by TREML2 knockdown. LPS increased the levels of microglial M1-type polarization marker inducible nitric oxide synthase. This effect was enhanced by TREML2 overexpression and ameliorated by TREML2 knockdown. Furthermore, the levels of microglial M2-type polarization markers CD206 and ARG1 in the primary microglia were reduced by TREML2 overexpression and elevated by TREML2 knockdown. LPS stimulation increased the levels of NLRP3 in primary microglia. The LPS-induced increase in NLRP3 was further elevated by TREML2 overexpression and alleviated by TREML2 knockdown. In summary, this study provides the first evidence that TREML2 modulates inflammation by regulating microglial polarization and NLRP3 inflammasome activation. These findings reveal the mechanisms by which TREML2 regulates microglial inflammation and suggest that TREML2 inhibition may represent a novel therapeutic strategy for AD.

Effects of Dietary L-malic Acid Supplementation on Meat Quality, Antioxidant Capacity and Muscle Fiber Characteristics of Finishing Pigs

L-malic acid is a vital intermediate in the citric acid cycle and has been reported to improve the antioxidant capacity and aerobic oxidation of weaned piglets; however, its application in finishing pigs is limited at present. This study explored the effects of dietary L-malic acid supplementation on the carcass traits and meat quality of finishing pigs. In a 45-day experiment, 192 Duroc × Landrace × Yorkshire pigs (75.01 ± 0.51 kg) were divided into four treatments, i.e., a basal diet supplemented with 0, 0.5%, 1%, and 2% L-malic acid complex. The results showed that L-malic acid supplementation had no effects on the growth performance of finishing pigs. Importantly, L-malic acid significantly increased redness (a*) value at 24-h postmortem (quadratic, p < 0.05) and tended to increase the proportion of oxymyoglobin (OMb) (quadratic, p = 0.10), as well as the total antioxidant capacity (T-AOC) activity (quadratic, p = 0.08) in the longissimus dorsi (LD) muscle. Further, dietary supplementation of 1% L-malic acid markedly increased the protein expression level of slow skeletal myosin heavy chain (MyHC) in the LD muscle (p < 0.05). Moreover, 0.5% and 2% L-malic acid supplementation significantly increased carcass length and loin eye area (p < 0.05). In conclusion, dietary L-malic acid could effectively improve the meat color and carcass traits of finishing pigs.

Dietary Valine/Isoleucine Ratio Impact Carcass Characteristics, Meat Edible Quality and Nutritional Values in Finishing Crossbred Duroc × Landrace × Yorkshire Pigs With Different Slaughter Weights

The aim of this study was to investigate effects of dietary ratio of valine to isoleucine [R(V/I)] on carcass characteristics and meat quality of finishing pigs and whether slaughter weight influence the effect. We carried out a 2 × 3 factorial trial with two slaughter weight (105 vs. 130 kg) and three R(V/I) (0.58, 1.23, and 2.60 at 75–100 kg body weight, and 0.70, 1.24, and 2.39 at 100–135 kg body weight for L-, N- and H-R (V/I), respectively). Data show that increasing slaughter weight significantly increased meat color (a*_{45 min} and b*_{45 min}), drip loss and shear force (P < 0.05). Meanwhile, increasing slaughter weight reduced sarcomere length, the proportion of protein-bound water, and most kinds of muscular total amino acid contents except for tryptophan and arginine, while increased contents of muscular free lysine, tryptophan, leucine, isoleucine, valine, alanine, and arginine in the M. longissimus thoracis (P < 0.05). Health lipid indices based on fatty acid composition of intramuscular lipid were improved as the slaughter weight increased (P < 0.05). Notably, pigs received N-R (V/I) diet improved carcass traits in terms of thinner backfat thickness and higher fat-free lean index, as well as increased meat flavor-contributing amino acids at the cost of reduced intramuscular fat content and increased shear force of cooked meat compared with the pigs fed L-R (V/I) and H-R(V/I) diets (P < 0.05). H-R (V/I) diet decreased ultimate pH value and sarcomere length of the skeletal muscle but increased the proportion of free water (T₂₃), consequently, increased drip loss and cooking loss of fresh meat in pigs (P < 0.05). In conclusion, both slaughter weight and dietary ratio of valine to isoleucine exerted significant impacts on carcass characteristics, meat quality and nutrition values. In particular, carcass traits and meat color of lighter pigs were more susceptible to the influence of dietary R (V/I) relative to heavier pigs.

Ryanodine receptor RyR1-mediated elevation of Ca2+ concentration is required for the late stage of myogenic differentiation and fusion

Background

Cytosolic Ca²⁺ plays vital roles in myogenesis and muscle development. As a major Ca²⁺ release channel of endoplasmic reticulum (ER), ryanodine receptor 1 (RyR1) key mutations are main causes of severe congenital myopathies. The role of RyR1 in myogenic differentiation has attracted intense research interest but remains unclear.

Results

In the present study, both RyR1-knockdown myoblasts and CRISPR/Cas9-based RyR1-knockout myoblasts were employed to explore the role of RyR1 in myogenic differentiation, myotube formation as well as the potential mechanism of RyR1-related myopathies. We observed that RyR1 expression was dramatically increased during the late stage of myogenic differentiation, accompanied by significantly elevated cytoplasmic Ca²⁺ concentration. Inhibition of RyR1 by siRNA-mediated knockdown or chemical inhibitor, dantrolene, significantly reduced cytosolic Ca²⁺ and blocked multinucleated myotube formation. The elevation of cytoplasmic Ca²⁺ concentration can effectively relieve myogenic differentiation stagnation by RyR1 inhibition, demonstrating that RyR1 modulates myogenic differentiation via regulation of Ca²⁺ release channel. However, RyR1-knockout-induced Ca²⁺ leakage led to the severe ER stress and excessive unfolded protein response, and drove myoblasts into apoptosis.

Conclusions

Therefore, we concluded that Ca²⁺ release mediated by dramatic increase in RyR1 expression is required for the late stage of myogenic differentiation and fusion. This study contributes to a novel understanding of the role of RyR1 in myogenic differentiation and related congenital myopathies, and provides a potential target for regulation of muscle characteristics and meat quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00668-x.

Dietary Malic Acid Supplementation Induces Skeletal Muscle Fiber-Type Transition of Weaned Piglets and Further Improves Meat Quality of Finishing Pigs

The aim of this study was to investigate effects of dietary malic acid supplementation on skeletal muscle fiber-type transition during nursery period and the subsequent meat quality of finishing pigs. Results showed that malic acid supplementation for 28 days increased oxidative fiber percentage of weaned piglets, accompanied by the increased aerobic oxidation in serum and longissimus thoracis (LT) muscle. Additionally, activities of total antioxidant capacity and glutathione peroxidase in serum were increased. Moreover, dietary malic acid supplementation during nursery period tended to increase pH24h and significantly decreased drip loss in LT muscle of finishing pigs. The content of total saturated fatty acid (SFA) and total monounsaturated fatty acid in LT muscle was significantly decreased, whereas the ratio of polyunsaturated fatty acid to SFA tended to increase. Together, dietary malic acid supplementation during nursery period can effectively increase antioxidant capacity and oxidative fibers percentage of weaned piglets, and further improve water holding capacity and nutritional values of pork in finishing pigs.

Curcumin reduces oxidative stress and fat deposition in longissimus dorsi muscle of intrauterine growth-retarded finishing pigs

Dietary curcumin possessing multiple biological activities may be an effective way to alleviate oxidative damage and fat deposition in intrauterine growth retardation (IUGR) finishing pigs. Therefore, this study was conducted to evaluate effects of dietary curcumin on meat quality, antioxidant capacity, and fat deposition of longissimus dorsi muscle in IUGR finishing pigs. Twelve normal birth weight (NBW) and 24 IUGR female piglets at 26 days of age were divided into 3 dietary groups: NBW (basal diet), IUGR (basal diet), and IUGR + Cur (basal diet supplemented with 200 mg/kg curcumin). The trial lasted for 169 days. Results showed that IUGR increased concentrations of malondialdehyde (MDA) and protein carbonyls (PC) and fat deposition in longissimus dorsi muscle. However, curcumin decreased the intramuscular fat content and the levels of MDA and PC and improved meat quality in IUGR pigs. Furthermore, curcumin inhibited the decrease of nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression and decreased peroxisome pro liferator-activated receptors γ (PPARγ) expression in IUGR pigs. These findings suggested that dietary addition of 200 mg/kg curcumin could improve meat quality, alleviate oxidative stress through activating Nrf2 signaling pathway, and reduce fat deposition via inhibiting PPARγ expression in longissimus dorsi muscle of IUGR finishing pigs.

Dietary taurine supplementation attenuates lipopolysaccharide-induced inflammatory responses and oxidative stress of broiler chickens at an early age

This study was conducted to investigate the effect of taurine as a prophylactic treatment on antioxidant function and inflammatory responses of broilers challenged with lipopolysaccharide (LPS). A total of 256 one-day-old male Arbor Acres broiler chicks were randomly assigned to four treatments with eight replicates of eight birds (eight birds per cage). Four treatment groups were designated as follows: 1) in the CON group, broilers fed a basal diet; 2) in the LPS group, LPS-challenged broilers fed a basal diet; 3) in the LPS + T1 group, LPS-challenged broilers fed a basal diet supplemented with 5.0 g/kg taurine; and 4) in the LPS + T2 group, LPS-challenged broilers fed a basal diet supplemented with 7.5 g/kg taurine. The LPS-challenged broilers were intraperitoneally injected with 1 mg/kg body weight (BW) of LPS at 16, 18, and 20 d of age, whereas the CON group received an injection of sterile saline. The results showed that broilers injected with LPS exhibited decreased (P < 0.05) the average daily gain (ADG) and the 21-d BW (P < 0.05), while taurine supplementation alleviated the negative effects of LPS. Additionally, the LPS-induced increases (P < 0.05) in serum alanine transaminase and aspartate transaminase activities were reversed by taurine supplementation. The taurines could alleviate the hepatic oxidative stress, with the presence of lower content of malondialdehyde (P < 0.05), higher content of glutathione (P < 0.05), and an increased glutathione peroxidase (GSH-Px) activity (P < 0.05). The concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the liver were measured by ELISA kits, and the result showed that dietary taurine supplementation prevented these cytokines increases in the liver of LPS-induced broilers. Taurine reduced the genes expression of IL-1β, TNF-α, IL-6, cyclooxygenase-2, and inducible nitric oxide synthase, whereas it boosted the expression levels of antioxidant-related genes (nuclear factor erythroid 2-related factor 2, heme oxygenase-1, glutamate-cysteine ligase catalytic subunit, and GSH-Px) in the liver of LPS-induced broilers. In conclusion, dietary taurine supplementation in broilers mitigated LPS-induced defects in ADG, oxidative stress, and inflammatory responses.

Resveratrol improves meat quality, muscular antioxidant capacity, lipid metabolism and fiber type composition of intrauterine growth retarded pigs

This study investigated whether resveratrol could improve meat quality, muscular antioxidant capacity, lipid metabolism and fiber type composition of intrauterine growth retarded pigs. Thirty-six pairs of male normal birth weight and intrauterine growth retardation (IUGR) piglets were orally fed with 80 mg resveratrol/kg body weight/d or vehicle during the sucking period (7-21 d). Then the offspring were fed with a basal diet containing 300 mg resveratrol/kg or a basal diet from weaning to slaughter (150 d). The IUGR-impaired meat quality (luminance and yellowness) was associated with muscular oxidative stress via increased Keap1 protein level, fat accumulation, and higher MyHC IIb gene expression. Expectedly, resveratrol increased glutathione peroxidase activity and MyHC I gene expression, reduced protein carbonyl and malondialdehyde contents, enhanced fatty acid oxidation via upregulated PPARα and targeted genes expression, and thereby improving drip loss and yellowness. Results indicate that resveratrol improved meat quality of IUGR pigs through enhancing antioxidant capacity, increasing oxidative fiber composition, and suppressing lipid accumulation.

Dietary Supplemented Curcumin Improves Meat Quality and Antioxidant Status of Intrauterine Growth Retardation Growing Pigs via Nrf2 Signal Pathway

Simple Summary

More than 15% of piglets and about 10% of newborn humans suffer from intrauterine growth retardation (IUGR), which refers to growth lag, developmental restriction and impaired organs in the fetus. IUGR exhibits programming consequences and exerts permanent negative effects on postnatal growth and health. Dietary supplemented curcumin, as the main natural polyphenol isolated from the natural antioxidant (turmeric), might show possible effects on antioxidant capacity, and the meat quality of IUGR pigs. Therefore, in our present study, 12 normal birth weight (NBW) and 24 IUGR neonatal female piglets were selected and fed control diets supplemented 0 (NBW), 0 (IUGR) and 200 (IUGR + Cur) mg/kg curcumin from 26 to 115 days of age (n = 12). The growth performance, meat quality, redox status and its related Nrf2 pathway were determined to test the hypothesis that curcumin may play beneficial roles against IUGR-induced oxidative stress. This study suggested that curcumin could serve as a potential natural antioxidant in nutrition interventions of IUGR offspring to enhance the redox status and improve the meat quality of leg muscles. These results attained from IUGR pig models can also provide some useful theoretical references for IUGR offspring in humans.

Abstract

Intrauterine growth retardation (IUGR) exhibits programming consequences and may induce oxidative stress in growing animals and humans. This study was conducted to investigate the hypothesis that dietary curcumin may protect growing pigs from IUGR-induced oxidative stress via the Nrf2 pathway. Twelve normal birth weight (NBW) and 24 IUGR female piglets were selected and fed control diets supplemented 0 (NBW), 0 (IUGR) and 200 (IUGR + Cur) mg/kg curcumin from 26 to 115 days of age (n = 12). Growth performance, meat quality, redox status and its related Nrf2 pathway were determined. Results showed that IUGR pigs exhibited decreased body weight on 0 d, 26 d and 56 d (p < 0.01) but had no difference on 115 d among NBW, IUGR and IUGR + Cur groups (p > 0.05). Compared with NBW and IUGR groups, a significant decrease in drip loss (24 h and 48 h) was observed in the IUGR + Cur group (p < 0.01). IUGR pigs had higher concentrations of malondialdehyde (MDA) (p < 0.01) and protein carbonyl (PC) (p = 0.03) and lower activities of glutathione peroxidase (p = 0.02), catalase (p < 0.01) and peroxidase (p = 0.02) in leg muscles than NBW pigs. Dietary-added 200 mg/kg curcumin decreased concentrations of MDA and PC and improved the activities of catalase, superoxide dismutase (SOD) and peroxidase as compared to the IUGR group (p < 0.05). Additionally, dietary curcumin enhanced protein (NQO1) and mRNA expression of genes (Nrf2, NQO1, gamma-glutamyltransferase 1 (GGT1), heme oxygenase-1 (HO-1), glutathione S-transferase (GST) and catalase (CAT)) as compared to the IUGR group (p < 0.05). These results suggest that dietary curcumin could serve as a potential additive to enhance redox status and improve meat quality of IUGR growing pigs via the Nrf2 signal pathway.

Protective effect of resveratrol against hepatic damage induced by heat stress in a rat model is associated with the regulation of oxidative stress and inflammation

Heat stress jeopardizes humans and animals health, and results in enormous economic loss in public health care and livestock production. The aim of this study was to investigate the effects of resveratrol on hepatic oxidative stress and inflammation in heat-stressed rats. Male Sprague-Dawley rats were orally fed with 100 mg resveratrol/kg body weight/day prior to heat stress (40 ∘C per day for 1.5 h) exposure for 3 consecutive days. Serum and liver samples were collected for the analysis of hepatic injury, redox status and immune response. The results showed that the heat-stress-induced increased aspartate aminotransferase activities in the serum, aberrant hepatic histology, excessive hepatic malondialdehyde and tumor necrosis factor alpha concentrations, and up-regulation of heat shock protein 70, superoxide dismutase 1, glutathione peroxidase 1, toll-like receptor 4 and interleukin 10 mRNA expression in the liver were mitigated by oral resveratrol treatment. Collectively, the beneficial effects of resveratrol on hepatic damage induced by heat stress were associated with the regulation of oxidative stress and inflammation.

Phase 1 dose-escalation study of a siRNA targeting the RTP801 gene in age-related macular degeneration patients

BACKGROUND

To evaluate the safety, tolerability, pharmacokinetics, and dose-limiting toxicities of a single intravitreal (IVT) injection of PF-04523655, a 19-nucleotide, O-methyl stabilized, double-stranded small interfering ribonucleic acid targeting the RTP801 gene in patients with neovascular age-related macular degeneration (AMD).

METHODS

Prospective, phase 1, clinical multicentre trial, enrolled 27 patients with neovascular AMD unresponsive to prior treatment and best corrected visual acuity (BCVA) ≤ 20/200 in the study eye in stratum 1: (dose-escalating, open-label: 50 to 3000 μg of PF-04523655) and 27 patients who had potential to benefit from therapy and BCVA of ≤ 20/100 and ≥ 20/800 in stratum 2 (parallel, masked study of 1000, 1500, 2250, and 3000 μg of PF-04523655). The primary outcome was safety and tolerability assessment as well as pharmacokinetic profiling following a single IVT injection of PF-04523655.

RESULTS

Doses of PF-04523655 ≥ 400 μg were generally detectable in the plasma at 1, 4, and 24 h post-injection. And all doses were below the lowest level of quantification by day 14. A single IVT injection of 50 to 3000 μg of PF-045237655 was generally safe and well tolerated over 24 months. There were no dose-limiting toxicities.

CONCLUSION

A single IVT injection of PF-0523655 ≤ 3000 μg seems safe and well tolerated in eyes with neovascular AMD.

Response surface optimization of microwave-assisted extraction for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii

Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii. The optimized extraction procedure was achieved by soaking the sample with 70% methanol (1:15, v/v) for 30 min, and then microwave irradiation for 11 min at a power of 600 W. Coupling the extraction process with HPLC-fluorescence presented good recovery, satisfactory precision, and good linear relation. Compared with a method from the Chinese Pharmacopoeia, the proposed method enables higher extraction efficiency and more aecurate analytical results. It can be of Potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.

Animal models of traumatic brain injury: is there an optimal model to reproduce human brain injury in the laboratory?

Compared to other neurological diseases, the research surrounding traumatic brain injury (TBI) has a more recent history. The establishment and use of animal models of TBI remains vital to understand the pathophysiology of this highly complex disease. Such models share the ultimate goals of reproducing patterns of tissue damage observed in humans (thus rendering them clinically relevant), reproducible and highly standardised to allow for the manipulation of individual variables, and to finally explore novel therapeutics for clinical translation. There is no doubt that the similarity of cellular and molecular events observed in human and rodent TBI has reinforced the use of small animals for research. When confronted with the choice of the experimental model it becomes clear that the ideal animal model does not exist. This limitation derives from the fact that most models mimic either focal or diffuse brain injury, whereas the clinical reality suggests that each patient has an individual form of TBI characterised by various combinations of focal and diffuse patterns of tissue damage. This is additionally complicated by the occurrence of secondary insults such as hypotension, hypoxia, ischaemia, extracranial injuries, modalities of traumatic events, age, gender and heterogeneity of medical treatments and pre-existing conditions. This brief review will describe the variety of TBI models available for laboratory research beginning from the most widely used rodent models of focal brain trauma, to complex large species such as the pig. In addition, the models mimicking diffuse brain damage will be discussed in relation to the early primate studies until the use of most common rodent models to elucidate the intriguing and less understood pathology of axonal dysfunction. The most recent establishment of in vitro paradigms has complemented the in vivo modelling studies offering a further cellular and molecular insight of this pathology.

Leptomeningeal disease from oligodendroglioma: Clinical and molecular analysis

2019

Background: Leptomeningeal disease (LMD) is a late complication of malignant glioma, mostly of glioblastoma, that usually responds poorly to treatment and is rapidly fatal. A long surviving case led us to review our experience with LMD in patients with oligodendrogliomas. Methods: A 10-year retrospective chart review was performed. Patients with both oligodendroglial tumors and LMD were identified. A single neuro-pathologist reviewed all histological sections, a single neuro-radiologist reviewed all available images and 1p/19q status was assessed. Results: Seven patients with an oligodendroglioma and LMD were identified. Six were male. Median age at tumor diagnosis was 41 years (range, 28–50). None had radiographic or pathological evidence of leptomeningeal or subependymal tumor at initial diagnosis. Most patients had pure anaplastic oligodendrogliomas (4/7); 6/7 had 1p/19q co-deletion. The median time to first relapse was 41 months (range, 19–127). LMD was diagnosed at first relapse in one case and subsequently in six. The median time to LMD was 76 months (range, 19–151) from initial diagnosis and 28 months (range, 0–36) from first relapse, respectively. LMD treatments included spinal radiation and intrathecal and systemic chemotherapy. After progression, some patients with LMD remained stable clinically. The median survival from initial diagnosis was 104 months (range, 19–183) and from LMD diagnosis was 32 months (range, 2–43). Conclusions: LMD is a complication of oligodendroglioma that may occur preferentially in long surviving patients with 1p/19q co-deletion. LMD in patients with oligodendrogliomas appears to be relatively indolent which may have implications for their treatment and be related to 1p/19q status.

No significant financial relationships to disclose.

Quinolinic acid promotes albumin deposition in Purkinje cell, astrocytic activation and lipid peroxidation in fetal brain

In high concentrations or after prolonged exposure, the N-methyl-D-aspartate receptor agonist quinolinic acid (QUIN) induces lipid peroxidation, oxidative stress, and cell death in the adult brain, and after i.c.v. injection induces seizures and increases blood-brain barrier permeability. As QUIN is substantially increased in plasma and brain of fetal sheep after endotoxin treatment or maternal tryptophan loading, we examined the effects of increasing plasma QUIN concentrations on the brain of late gestation fetal sheep. Continuous fetal infusion of QUIN (0.1 mmol/h i.v.; n=4) for 12 h increased plasma QUIN concentrations from 22.3+/-6.0-210.8+/-31.4 microM; the infusion of vehicle [normal saline] had no effect on QUIN concentrations (n=4). At 24 h after QUIN infusion glial fibrillary acidic protein immunoreactivity was significantly increased in cerebral gray matter and the granule cell layer of cerebellum, and the lipid peroxide product 4-hydroxynonenal-immunoreactivity and albumin-immunoreactivity were present throughout the cytoplasm of cerebellar Purkinje cells. Extravasation of albumin into the brain was not observed, indicating the cerebral microvasculature with respect to permeability to plasma proteins was normal at the time of analysis. We suggest that increased glial fibrillary acidic protein and 4-hydroxynonenal result from oxidative stress induced by QUIN, and that the increased intracellular albumin in cerebellar Purkinje cells may be an adaptive response.

Expression and localization of cyclin-dependent kinase 5 in apoptotic human glioma cells

Cyclin-dependent kinase 5 (Cdk5), a member of the cyclin-dependent kinase family, is expressed predominately in mature neurons and is implicated in neurite extension, neuronal migration, and neuronal differentiation. Cdk5 protein expression also has been associated with apoptosis in a number of nonneuronal model systems. In normal brain, substrates for Cdk5 include neurofilament and tau proteins. Because human tumors of glial origin can express neuronal proteins, we examined whether Cdk5 and its activator protein, P35, are present in early passage human glioblastoma multiforme (GBM) cells lines and primary tumor specimens. Here we report the expression of Cdk5 and an "active" proteolytic form of P35 in human GBM cells and demonstrate kinase activity of the holoenzyme. We also show that Cdk5 kinase activity and expression of its activator protein, P35, is increased in the human GBM cell line M059J after exposure to ionizing radiation and that P35 is localized within M059J cells undergoing apoptosis. These results suggest a possible role for Cdk5 in mediating apoptosis in human GBM cells.