Comparison of the effects of monounsaturated fatty acids and polyunsaturated fatty acids on the lipotoxicity of islets.

Background: Monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) have been reported to combat saturated fatty acid (SFA)-induced cellular damage, however, their clinical effects on patients with metabolic diseases such as diabetes and hyperlipidemia are still controversial. Since comparative studies of the effects of these two types of unsaturated fatty acids (UFAs) are still limited. In this study, we aimed to compare the protective effects of various UFAs on pancreatic islets under the stress of SFA-induced metabolic disorder and lipotoxicity. Methods: Rat insulinoma cell line INS-1E were treated with palmitic acid (PA) with or without UFAs including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), and oleic acid (OA) to determine cell viability, apoptosis, endoplasmic reticulum (ER) stress, and inflammatory. In vivo, male C57BL/6 mice were fed a 60% high-fat diet (HFD) for 12 w. Then the lard in HFD was partially replaced with fish oil (FO) and olive oil (OO) at low or high proportions of energy (5% or 20%) to observe the ameliorative effects of the UFA supplement. Results: All UFAs significantly improved PA-induced cell viability impairment in INS-1E cells, and their alleviation on PA induced apoptosis, ER stress and inflammation were confirmed. Particularly, OA had better effects than EPA, DHA, and AA on attenuating cellular ER stress. In vivo, the diets with a low proportion of UFAs (5% of energy) had limited effects on HFD induced metabolic disorder, except for a slight improved intraperitoneal glucose tolerance in obese mice. However, when fed diets containing a high proportion of UFAs (20% of energy), both the FO and OO groups exhibited substantially improved glucose and lipid metabolism, such as decrease in total cholesterol (TC), low-density lipoprotein (LDL), fasting blood glucose (FBG), and fasting blood insulin (FBI)) and improvement of insulin sensitivity evidenced by intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT). Unexpectedly, FO resulted in abnormal elevation of the liver function index aspartate aminotransferase (AST) in serum. Pathologically, OO attenuated HFD-induced compensatory hyperplasia of pancreatic islets, while this effect was not obvious in the FO group. Conclusions: Both MUFAs and PUFAs can effectively protect islet ß cells from SFA-induced cellular lipotoxicity. In particular, both OA in vitro and OO in vivo showed superior activities on protecting islets function and enhance insulin sensitivity, suggesting that MUFAs might have greater potential for nutritional intervention on diabetes.

Improving the circulation time and renal therapeutic potency of extracellular vesicles using an endogenous ligand binding strategy.

Kidney diseases are a serious health issue worldwide, and novel therapeutics are urgently needed. Extracellular vesicles (EVs) have emerged as potent drug delivery systems (DDSs), but their therapeutic potential is limited by short circulation times and insufficient renal retention. Here, we report that endogenous ligand (albumin, ALB) binding is an efficient modification strategy to improve the therapeutic potency of EV-based DDSs for kidney diseases. Surface albumin-binding peptide (ABP)-displayed EVs (ABP-EVs) were produced by transfecting parent cells with the ABP-Lamp2b fusion plasmid. Compared with unmodified EVs (NC-EVs), ABP-EVs showed increased binding to ALB in vitro and elevated circulation time and multiple organ retention in vivo after systemic (iv) injection. Moreover, ABP-EVs had higher renal retention than NC-EVs in mice with acute kidney injury through a complex mechanism involving microvascular injury and megalin-mediated endocytosis. As a result, delivery of small molecule drugs (e.g., curcumin) or proteins (e.g., hepatocyte growth factor) by ABP-EVs had superior therapeutic (e.g., anti-apoptotic, antioxidant, anti-inflammatory) effects in vitro and in vivo. This study highlights that ABP-EVs are versatile DDSs for kidney diseases and provides insights into the new strategies of engineering EVs for drug delivery.

Regulatory Effects of N-3 PUFAs on Pancreatic ß-cells and Insulin-sensitive Tissues.

The N-3 polyunsaturated fatty acids (PUFAs) have a wide range of health benefits, including antiinflammatory effects, improvements in lipids metabolism and promoting insulin secretion, as well as reduction of cancer risk. Numerous studies support that N-3 PUFAs have the potentials to improve many metabolic diseases, such as diabetes, nonalcoholic fatty liver disease and obesity, which are attributable to N-3 PUFAs mediated enhancement of insulin secretion by pancreatic ß-cells and improvements in insulin sensitivity and metabolic disorders in peripheral insulin-sensitive tissues such as liver, muscles, and adipose tissue. In this review, we summarized the up-to-date clinical and basic studies on the regulatory effects and molecular mechanisms of N-3 PUFAs mediated benefits on pancreatic ß-cells, adipose tissue, liver, and muscles in the context of glucose and/or lipid metabolic disorders. We also discussed the potential factors involved in the inconsistent results from different clinical researches of N-3 PUFAs.

An overview of dietary supplements on obesity and type 2 diabetes: efficacy and mechanisms.

Obesity is a common nutritional disorder, associated with a variety of chronic diseases, among them, type 2 diabetes (T2DM) has emerged as a serious worldwide health problem. Insulin resistance and ß cell dysfunction are the main pathological characteristics of T2DM, and obesity and hyperlipidemia are the critical causal factors. It is commonly accepted that dietary factors are of paramount importance in the management of obesity and T2DM. Particularly, many botanic products and their extracts are endowed with a wide spectrum of biological activities, making them extensively studied as anti-obesity and anti-diabetes dietary supplements or new drug candidates. In this review, we aimed to summarize the effects, related mechanisms, and safety issues of dietary continents on obesity and T2DM, to provide theoretical support for better research and development of dietary therapy strategy for the treatment of obesity and T2DM. Based on a bunch of clinical investigations, specific carbohydrates and fatty acids, such as dietary fibers, polysaccharides, unsaturated fatty acids, have hypoglycemic and hypolipidemic effects. Vitamin D plays important role in metabolism and immunity modulation. Apart from them, natural bioactive ingredients from plants, such as flavonoids, polyphenols, alkaloids, terpenoids, polysaccharides, and quinones are efficient in helping weight loss and improving insulin sensitivity and glycemic control. They can protect ß cell function by anti-inflammation, anti-oxidation, and anti-apoptosis properties, as well as regulating lipid metabolism. Therefore, promoting the consumption of diverse natural bioactive ingredients-rich products could be an effective nutritional strategy to benefit patients with obesity and type 2 diabetes.

Phloretin ameliorates hyperuricemia-induced chronic renal dysfunction through inhibiting NLRP3 inflammasome and uric acid reabsorption.

BACKGROUND: Hyperuricemia (HUA) is an important risk factor for renal diseases and contributes to renal fibrosis. It has been proved that phloretin has antioxidant and anti-inflammatory properties and could inhibit uric acid (UA) uptake in vitro. However, whether phloretin has a renal protective role in vivo remains unknown. PURPOSE: This study aims to evaluate the therapeutic effect of phloretin on HUA-induced renal injury in mice and to reveal its underlying mechanism. METHODS: Mice were induced hyperuricemic by oral gavage of adenine/potassium oxonate. The effects of phloretin on renal function, fibrosis, oxidative stress, inflammation, and UA metabolism in HUA mice were evaluated. The effect of phloretin on NLRP3 pathway was analyzed in human renal tubular cell lines (HK-2). RESULTS: HUA mice showed renal dysfunction with increased renal fibrosis, inflammation and mitochondrial stress. By contrast, phloretin reduced the level of serum blood urea nitrogen (BUN), urinary albumin to creatinine ratio (UACR), tubular necrosis, extracellular matrix (ECM) deposition and interstitial fibroblasts in HUA mice. The renal infiltration of inflammatory cells, cytokines such as NOD-like receptor family pyrin domain containing 3 (NLRP3) and interleukin-1ß (IL-1ß) release, mitochondrial reactive oxygen species (ROS) and morphological lesions in HUA mice also decreased. Furthermore, phloretin partly inhibited renal glucose transporter 9 (GLUT9) and promoted urinary UA excretion in HUA mice. In vitro, phloretin suppressed the NLPR3 pathway under LPS or UA stimulation in HK-2 cells. CONCLUSIONS: Phloretin could effectively attenuate UA-induced renal injury via co-inhibiting NLRP3 and UA reabsorption, and thus it might be a potential therapy to hyperuricemia-related renal diseases.

Resveratrol exerts dose-dependent anti-fibrotic or pro-fibrotic effects in kidneys: A potential risk to individuals with impaired kidney function.

BACKGROUND: Renal fibrosis is the pathological feature of chronic kidney disease (CKD) which leads to end-stage renal disease (ESRD) and renal failure. Resveratrol [3,5,4'-trihydroxy-trans-stilbene (RSV)] has shown benefits for metabolic diseases and anti-cancer therapy, but its potential risk on renal health has not been fully evaluated. PURPOSE: To investigate the global effects of RSV on renal fibrosis in human tubular epithelial cell (TEC) line HK-2, and in mice with unilateral ureteral obstruction (UUO). METHODS: A TGF-ß-induced in vitro model of epithelial-mesenchymal transition (EMT) in TEC was established. The effects of RSV on cell viability, pro-fibrotic factors, oxidative stress, mitochondria function, and underlying pathway proteins were analyzed. In vivo, the effects of RSV on renal function and fibrosis were assayed in UUO mice. RESULTS: Our results showed that low concentrations of RSV (5-20 µM) decreased TGF-ß-induced EMT via Sirt1-dependent deacetylation of Smad3/Smad4 mechanism. By contrast, long-term (72 h) exposure to high concentrations of RSV (≥ 40 µM) promoted EMT in HK-2 cells via mitochondrial oxidative stress and ROCK1-mediated disordered cytoskeleton remodeling. In vivo, low-dose treatment of RSV (≤ 25 mg/kg) partly improved renal function, whereas high-dose treatment of RSV (≥ 50 mg/kg) lost its anti-fibrotic role and even aggravated renal fibrosis. However, mice with UUO were more susceptible to high RSV-induced renal injury than normal mice. CONCLUSION: Dependent on dose, RSV activated either anti-fibrotic or pro-fibrotic effects in kidneys. The risk of RSV consumption in individuals with impaired kidney function should be carefully considered.

Oleic acid protects insulin-secreting INS-1E cells against palmitic acid-induced lipotoxicity along with an amelioration of ER stress.

PURPOSE: It is demonstrated that unsaturated fatty acids can counteract saturated fatty acids-induced lipotoxicity, but the molecular mechanisms are unclear. In this study, we investigated the protective effects of monounsaturated oleic acid (OA) against saturated palmitic acid (PA)-induced cytotoxicity in rat ß cells as well as islets, and mechanistically focused on its regulation on endoplasmic reticulum (ER) stress. METHODS: Rat insulinoma cell line INS-1E cells and primary islets were treated with PA with or without OA for 24 h to determine the cell viability, apoptosis, and ER stress. SD rats were fed with high-fat diet (HFD) for 16 w, then, HFD was half replaced by olive oil to observe the protective effects of monounsaturated fatty acids rich diet. RESULTS: We demonstrated that PA impaired cell viability and insulin secretion of INS-1E cells and rat islets, but OA robustly rescued cells from cell death. OA substantially alleviated either PA or chemical ER stressors (thapsigargin or tunicamycin)-induced ER stress. Importantly, OA attenuated the activity of PERK-eIF2α-ATF4-CHOP pathway and regulated the ER Ca2+ homeostasis. In vivo, only olive oil supplementation did not cause significant changes, while high-fat diet (HFD) for 32 w obviously induced islets ER stress and impaired insulin sensitivity in SD rats. Half replacement of HFD with olive oil (a mixed diet) has ameliorated this effect. CONCLUSION: OA alleviated PA-induced lipotoxicity in INS-1E cells and improved insulin sensitivity in HFD rats. The amelioration of PA triggered ER stress may be responsible for its beneficial effects in ß cells.

Oleic acid protects saturated fatty acid mediated lipotoxicity in hepatocytes and rat of non-alcoholic steatohepatitis.

Aim This study aims to demonstrate the protective effects of monounsaturated oleic acid (OA) against saturated palmitic acid (PA) induced cellular lipotoxicity in hepatocytes and rats with non-alcoholic steatohepatitis (NASH). MAIN METHODS: Human hepatoma cell line HepG2 cells and neonatal rat primary hepatocytes were treated with PA or/and OA for 24 h. SD rats were fed with high fat diet (HFD) to induce NASH. From the 16th w, the HFD was full or half replaced by olive oil to observe the protective effects. KEY FINDINGS: In vitro, OA substantially alleviated PA induced cellular apoptosis, oxidative stress, ER stress, mitochondrial dysfunction, as well as inflammation in hepatocytes. In vivo, only olive oil supplementation had no detrimental effects, while HFD developed NASH in normal rats. Full replacement of HFD with olive oil had profoundly reversed NASH. Noteworthily, half replacement of HFD with olive oil (a mixed diet) has ameliorated NASH injury as well. It strikingly changed the hepatic histology from macrovesicular-steatosis into entire microvesicular-steatosis, and significantly reduced inflammation, ballooning and fibrosis. SIGNIFICANCE: Our study has demonstrated in both hepatocytes and NASH rats that oleic acids had great potential to combat the saturated fatty acids induced hepatic lipotoxicity. Only half replacement of HFD by monounsaturated fatty acids rich diet still had significant therapeutic outcome in NASH rats. Redirecting the toxic saturated fatty acids into triglyceride storage and reduction of cholesterol accumulation might be the possible explanation of OA driven protection in this scenario.

Mesenchymal stem cell-conditioned media ameliorate diabetic endothelial dysfunction by improving mitochondrial bioenergetics via the Sirt1/AMPK/PGC-1α pathway.

Vasculopathy is a major complication of diabetes. Impaired mitochondrial bioenergetics and biogenesis due to oxidative stress are a critical causal factor for diabetic endothelial dysfunction. Sirt1, an NAD+-dependent enzyme, is known to play an important protective role through deacetylation of many substrates involved in oxidative phosphorylation and reactive oxygen species generation. Mesenchymal stem cell-conditioned medium (MSC-CM) has emerged as a promising cell-free therapy due to the trophic actions of mesenchymal stem cell (MSC)-secreted molecules. In the present study, we investigated the therapeutic potential of MSC-CMs in diabetic endothelial dysfunction, focusing on the Sirt1 signalling pathway and the relevance to mitochondrial function. We found that high glucose-stimulated MSC-CM attenuated several glucotoxicity-induced processes, oxidative stress and apoptosis of endothelial cells of the human umbilical vein. MSC-CM perfusion in diabetic rats ameliorated compromised aortic vasodilatation and alleviated oxidative stress in aortas. We further demonstrated that these effects were dependent on improved mitochondrial function and up-regulation of Sirt1 expression. MSC-CMs activated the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt), leading to direct interaction between Akt and Sirt1, and subsequently enhanced Sirt1 expression. In addition, both MSC-CM and Sirt1 activation could increase the expression of peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), as well as increase the mRNA expression of its downstream, mitochondrial, biogenesis-related genes. This indirect regulation was mediated by activation of AMP-activated protein kinase (AMPK). Overall our findings indicated that MSC-CM had protective effects on endothelial cells, with respect to glucotoxicity, by ameliorating mitochondrial dysfunction via the PI3K/Akt/Sirt1 pathway, and Sirt1 potentiated mitochondrial biogenesis, through the Sirt1/AMPK/PGC-1α pathway.

[Affection of acupotomy lysis on leu-enkephalin (L-ENK) content in different parts of centrum of rats with knee osteoarthritis].

OBJECTIVE: To study the analgesia mechanism of needle-knife lysis in spinal cord and other parts of central nervous system by comparing the changes of Leu-Enkephalin (L-ENK) content in different parts of centrium of rats undergone needle-knife lysis and electro-acupuncture respectively. METHODS: Sixty healthy SD rats were randomly devided into normal control group, model group, needle-knife lysis (NKL) group and electro-acupuncture (EA) group. 4% papain solution mixed with 0.3 mol/L cysteine solutin in the ratio of 1:1, paused for 0.5 h,injected the mixture, 20 microl each time,into the left knee joint cavities of rats in model, NKL, EA groups at the 1st, 4th, 7th day. After 4 weeks in NKL group and EA group were treated with needle-knife lysis and electro-acupuncture, respectively. Three weeks after treatment, samples of spinal cord of the swollen part of rat waists and rat brains were taken from and the content of L-ENK of medulla oblongata, midbrain, pituitary gland, and hippocampus were measured. RESULTS: L-ENK content of model group increased higher than that of normal control group in spinal cord, hippocampus and midbrain (P < 0.01); there were no significant difference between normal control group and modle group on L-ENK in medulla oblongata and thalamus (P > 0.05). After intervening of NKL or EA, L-ENK content of NKL group increased higher in hippocampus than that of model group and EC group (P < 0.05); but L-ENK content of NKL group in midbrain was lower than that of model group (P < 0.05). CONCLUSION: Needle-knife lysis has characteristic of regulation for the L-ENK content in different parts of central nervous system of rats with knee osteoarthritis, and analgesic effect of needle-knife was possibly related with regulation of center L-ENK.

[Debating some issues on the formulation and application of standardized manipulations of acupuncture and moxibustion-part 6: acupoint injection].

Some issues on the formulation of Standardized manipulations of acupuncture and moxibustion-part 6: acupoint injection are debated in this paper, including the definition of acupoint injection, characteristics of the standard and application of technical index etc. In the paper, the authors suggest that the issues on the selecting acupoints and drugs should be paid attention during the standard in use. Finally, the authors propose that the technical description of the acupoint injection in the reported literatures needs to be improved in order to better serve for clinical and scientific research.

A brief on pain and its patterns in Chinese medicine.

Pain is the most common symptom in clinics. Therefore, the quality, time course and location of pain are important for the diagnosis and treatment. However, pain is very difficult to define, and it is one of the conditions poorly understood by the medical sciences. In Western medicine pain is often described in terms of a penetrating or tissue-destructive process and/or emotional reactions, but in Chinese medicine the pathogenesis and description of pain are different. It is described based on the theories and pathogenesis of Chinese medicine, and the patients' feeling according to their languages and cultures. Thus, when taking the history and conducting physical examination in patients in China and treating them according to Chinese medicine, we have to know how these patients express and describe their pain when they go to clinics. This article will explain some terms and words in the Chinese language and their corresponding terms in the English language.

Full-length cDNA cloning and protein three-dimensional structure modeling of factor VII of rhesus monkey, Macaca mulatta.

FVII is a vitamin K dependent serine protease that plays a key role in extrinsic coagulation pathway. In this paper, we report the full-length cDNA sequences of rhesus monkey FVII. The full-length cDNA has 2424 bp, and predicts an open reading frame of 1416 bp corresponding to 472 amino acids. The deduced protein sequence of rhesus monkey FVII indicates the functional domains including signal peptide, Gla domain, two EGF domains, and catalytic domain. Rhesus monkey FVII is highly homologous to human FVII with amino acid identity of 91.0%. Comparison of three-dimensional protein structure shows high conservation between them. The important functional sites such as the N-terminal gamma-carboxyglutamic acids of the Gla domain, the Ca(2+) binding region of the EGF I domain, the TF binding region, the active site binding cleft, and the macromolecular substrate binding exosite of trypsin domain are all well conserved in FVII of rhesus monkey. Prothrombin time test shows rhesus monkey FVII has a similar clotting time with that of human. This study of rhesus monkey FVII might be helpful for understanding the function compatibility of human and rhesus monkey FVII, which is beneficial for the study of xenotransplantation.

[Systematic assessment of acupuncture for treatment of herpes zoster in domestic clinical studies].

OBJECTIVE: To assess the effectiveness of acupuncture for treatment of herpes zoster. METHODS: According to the requirement of evidence-based medicine, acupuncture, body acupuncture, electroacupuncture, head acupuncture, three edged needle, plum-blossom needle, fire needle, elongated needle, encircling needling, herpes zoster, etc. were selected as subject words to retrieve the relative medical database at home, and clinically randomized controlled trials were used as enrolled criteria, the treatment group were treated with acupuncture or acupuncture plus other therapies, and the control group with medicine, the cured rate and the time of killing pain for herpes zoster were used as assessment indexes. Altogether 43 papers were enrolled. Among them 10 papers were conducted for Meta-analysis by RevMan 4.2.9. RESULTS: The total OR was 4.27 with 95% CI [2.90, 6.29] of the clinically cured rate in the 10 studies, and the total OR was -7.64 with 95% CI [-8.12, -7.15] of the time of killing pain in the 4 studies. The therapeutic effect in the treatment group on herpes zoster was superior to that of the western medicine (P < 0.01). CONCLUSION: Acupuncture therapy for herpes zoster is effective, but more high-quality studies are required to prove this view point.

[On relationship of acupoint-injection with injury of peripheral nerves].

OBJECTIVE: To provide basis for strengthening safety of acupoint-injection and increasing clinical therapeutic effect. METHODS: Analyze and study on the relative articles from the databank of whole articles of Chinese periodicals of CNKI by information retrieval with computer, with acupoint-injection, nerve injury as key words. RESULTS: Most of clinical reports focus on acupoint-injection for treatment of nervous injury induced by trauma and birth injury. The studies indicate that the injuries of the peripheral nerves induced by acupoint-injection can be divided into 3 grades and the injury mechanisms can be divided into 3 classifications. The injuring causes include improper posture of the patients, improper angle and depth of injection and improper medicine selection. CONCLUSION: Acupoint-injection can be applied more widely as soon as the accomplishment of the standardization of operation.

Full-length cDNA cloning and protein three-dimensional structure modeling of porcine prothrombin.

Prothrombin is a vitamin K-dependent serine protease and plays pivotal roles in both procoagulant and anticoagulant pathway of hemostasis. In this study, we cloned the full-length cDNA of porcine prothrombin by cDNA library screening and SMART RACE technique. The full-length cDNA is 2027 bp, with a 1869 bp Open Reading Frame (ORF) coding 623 amino acids. The deduced protein of porcine prothrombin contains signal peptide, propeptide, Gla domain, two kringle domains and trypsin domain. Porcine prothrombin shares 86.15% nucleotide similarity and 83% amino acid similarity with human prothrombin. The trypsin domain is highly conserved between the two species with 92.1% amino acid identity. Macromolecular interaction sites comparison between porcine and human prothrombin suggests that the Gla domain in porcine prothrombin contains an additional potential gamma-carboxyglutamic acid site. However, a thrombin cleavage site (Arg284-Thr285) in its light chain is lost. When thrombin heavy chain is concerned, the most important functional sites such as catalytic triad DHS, RGD site, Na+ binding site and anion-binding exosite-I and II are highly conserved. However, great differences have been observed between residues 145 and 158 of heavy chain which is associated with thrombomodulin binding. Two important limited proteolysis sites at Ala150 and Lys154 were lost in porcine sequence, which would affect epsilon-thrombin and gammaT-thrombin generation. Comparison on 3-D protein models demonstrates that these proteins are obviously different in autolysis loop (Lys145 to Gly155). Compared with that of human prothrombin, variation at critical recognition sites would likely alter its binding affinity and reaction velocity, which would contribute to coagulation disorder when porcine liver is transplanted into human body.