Unraveling the Lignin Structural Variation in Different Bamboo Species.

The structure of cellulolytic enzyme lignin (CEL) prepared from three bamboo species (Neosinocalamus affinis, Bambusa lapidea, and Dendrocalamus brandisii) has been characterized by different analytical methods. The chemical composition analysis revealed a higher lignin content, up to 32.6% of B. lapidea as compared to that of N. affinis (20.7%) and D. brandisii (23.8%). The results indicated that bamboo lignin was a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin associated with p-coumarates and ferulates. Advanced NMR analyses displayed that the isolated CELs were extensively acylated at the γ-carbon of the lignin side chain (with either acetate and/or p-coumarate groups). Moreover, a predominance of S over G lignin moieties was found in CELs of N. affinis and B. lapidea, with the lowest S/G ratio observed in D. brandisii lignin. Catalytic hydrogenolysis of lignin demonstrated that 4-propyl-substituted syringol/guaiacol and propanol guaiacol/syringol derived from ß-O-4' moieties, and methyl coumarate/ferulate derived from hydroxycinnamic units were identified as the six major monomeric products. We anticipate that the insights of this work could shed light on the sufficient understanding of lignin, which could open a new avenue to facilitate the efficient utilization of bamboo.

[Content analysis and quality evaluation of main active components and mineral elements of Cynomorium songaricum in different habitats].

To clarify the content characteristics of the main active components and mineral elements of Cynomorium songaricum under different habitat conditions, and further explore the relationship between the quality of C. songaricum and habitats, this study took C. songaricum from 25 different habitats in China as the research object, and measured the contents of 8 main active components and 12 mineral elements separately. Diversity analysis, correlation analysis, principal component analysis and cluster analysis were carried out. The results showed that the genetic diversity of total flavonoids, ursolic acid, ether extract, potassium(K), phosphorus(P) and zinc(Zn) in C. songaricum was high. The coefficient of variation of crude polysaccharide, ether extract, gallic acid, protocatechuic aldehyde, catechin, epicatechin, calcium(Ca), sodium(Na), magnesium(Mg), sulfur(S), iron(Fe), manganese(Mn), selenium(Se) and nickel(Ni) were all over 36%, indicating that the quality of C. songaricum was significantly affected by habitats. There were strong synergistic and weak antagonistic effects among the contents of the 8 active components, and complex antagonistic and synergistic effects among the contents of the 12 mineral elements. Principal component analysis revealed that crude polysaccharide, ursolic acid, catechin, epicatechin and total flavonoids could be used as the characteristic components to evaluate the quality of C. songaricum, and Na, copper(Cu), Mn and Ni were the characteristic elements to evaluate the quality of C. songaricum. In cluster ana-lysis, the second group with the main active components as cluster center had better quality in terms of the content of active substances, and the second group with the mineral elements as cluster center had higher utilization potential in the exploitation of mineral elements. This study could provide a basis for resource evaluation and breeding of excellent varieties of C. songaricum in different habitats, and provide a reference for cultivation and identification of C. songaricum.

Phytochemical Profiles and Antioxidant Activity of Rehmannia glutinosa from Different Production Locations.

The chemical components and antioxidant activity of 16 Rehmannia glutinosa samples were investigated to reveal the high-quality raw resource for pharmaceutical products. 22 main chemical components were detected with significant content differences (P<0.05). The contents of 14 substances reached the maximum in S1 sample such as catalpol (6.74 mg g-1 ), rehmaionoside A (1.93 mg g-1 ) and rehmannioside D (5.13 mg g-1 ). However, the content distribution of the other eight substances had no obvious change regulation. Three antioxidant evaluation methods commonly showed that S1 sample had strong antioxidant activity with a low IC50 value of 0.022 mg mL-1 , a high ABTS value of 524.196 µmol equiv. Trolox g-1 , and a high FRAP value of 200.517 µmol equiv. Trolox g-1 . Considered the medicinal value, S1 had high quality based on the present phytochemical profiles and antioxidant activity. These results also indicated that the root extracts of R. glutinosa could become useful supplement for pharmaceutical products as new antioxidant agents.

Unlocking Structure-Reactivity Relationships for Catalytic Hydrogenolysis of Lignin into Phenolic Monomers.

Lignin depolymerization into aromatic monomers with high yields and selectivity is essential for the economic feasibility of biorefinery. However, the relationship between lignin structure and its reactivity for upgradeability is still poorly understood, in large part owing to the difficulty in quantitative characterization of lignin structural properties. To overcome these shortcomings, advanced NMR technologies [2D HSQC (heteronuclear single quantum coherence) and 31 P] were used to accurately quantify lignin functionalities. Diverse lignin samples prepared from Eucalyptus grandis with varying ß-O-4 linkages were subjected to Pd/C-catalyzed hydrogenolysis for efficient C-O bond cleavage to achieve theoretical monomer yields. Strong correlations were observed between the yield of monomeric aromatic compounds and the structural features of lignin, including the contents of ß-O-4 linkages and phenolic hydroxyl groups. Notably, a combined yield of up to 44.1 wt % was obtained from ß-aryl ether rich in native lignin, whereas much lower yields were obtained from technical lignins low in ß-aryl ether content. This work quantitatively demonstrates that the lignin reactivity for acquiring aromatic monomer yields varies depending on the lignin fractionation processes.

Targeting Inflammation and Downstream Protein Metabolism in Sarcopenia: A Brief Up-Dated Description of Concurrent Exercise and Leucine-Based Multimodal Intervention.

Sarcopenia is defined as the progressive loss of muscle mass with age, and poses a serious threat to the physiological and psychological health of the elderly population with consequential economic and social burdens. Chronic low-grade inflammation plays a central role in the development of sarcopenia such that it alters cellular protein metabolism to favor proteolysis over synthesis, and thereby accelerates muscular atrophy. The purpose of this review is to highlight how exercise and nutrition intervention strategies can attenuate or treat sarcopenia. Resistance exercise increases not only muscle mass but also muscle strength, while aerobic exercise is able to ameliorate the age-related metabolic disorders. Concurrent exercise training integrates the advantages of both aerobic and resistance exercise, and may exert a significant synergistic effect in the aging organism. Higher protein intakes rich in the amino acid leucine appear to restore skeletal muscle protein metabolism balance by rescuing protein synthesis in older adults. There is good reason to believe that a multimodal treatment, a combination of exercise and increased leucine consumption in the diet, can combat some of the muscle loss associated with aging. Future research is needed to consolidate these findings to humans, and to further clarify to what extent and by which mechanisms protein metabolism might be directly involved in sarcopenia pathogenesis and the multimodal treatment responses.

Hypertrophy-Promoting Effects of Leucine Supplementation and Moderate Intensity Aerobic Exercise in Pre-Senescent Mice.

Several studies have indicated a positive influence of leucine supplementation and aerobic training on the aging skeletal muscle signaling pathways that control muscle protein balance and muscle remodeling. However, the effect of a combined intervention requires further clarification. Thirteen month old CD-1(®) mice were subjected to moderate aerobic exercise (45 min swimming per day with 3% body weight workload) and fed a chow diet with 5% leucine or 3.4% alanine for 8 weeks. Serum and plasma were prepared for glucose, urea nitrogen, insulin and amino acid profile analysis. The white gastrocnemius muscles were used for determination of muscle size and signaling proteins involved in protein synthesis and degradation. The results show that both 8 weeks of leucine supplementation and aerobic training elevated the activity of mTOR (mammalian target of rapamycin) and its downstream target p70S6K and 4E-BP1, inhibited the ubiquitin-proteasome system, and increased fiber cross-sectional area (CSA) in white gastrocnemius muscle. Moreover, leucine supplementation in combination with exercise demonstrated more significant effects, such as greater CSA, protein content and altered phosphorylation (suggestive of increased activity) of protein synthesis signaling proteins, in addition to lower expression of proteins involved in protein degradation compared to leucine or exercise alone. The current study shows moderate aerobic training combined with 5% leucine supplementation has the potential to increase muscle size in fast-twitch skeletal muscle during aging, potentially through increased protein synthesis and decreased protein breakdown.

Altered microRNA expression in skeletal muscle results from high-fat diet-induced insulin resistance in mice.

Skeletal muscle insulin resistance induced by a high-fat diet has been implicated in the development of type 2 diabetes. However, the precise molecular mechanisms involved are only partially understood. Recently, studies have shown that microRNAs play an important role in insulin resistance in various tissues. In this study, microRNA expression profiles of skeletal muscle of mice fed a high-fat or normal diet were analyzed using microarrays and the results were confirmed by real-time reverse-transcription polymerase chain reaction. Gene Ontology (GO) and pathway mapping tools were employed to analyze systemically the biological processes and signaling pathways affected by the differential expression of microRNAs. In this study, we show that 30 microRNAs are differentially expressed between 2 groups of mice. Compared to the mice fed a normal diet, there were 8 microRNAs up-regulated and 22 microRNAs down-regulated in the high-fat diet-fed mice. Furthermore, we confirm that the MAPK signaling pathway highlighted in this study is involved in skeletal muscle insulin resistance. These results indicate that skeletal muscle insulin resistance induced by a high-fat diet is associated with a group of microRNAs. GO and pathway mapping are a valid and effective approach for analyzing the function of microRNAs and the results could be a guideline for further investigation.

Progress of research in cell-in-cell phenomena.

The discovery of a nonphagocytotic process of cell-in-cell phenomena can be traced to over a century ago. However, its biological significance remains poorly understood. Three types of cell-in-cell phenomena have been described so far, termed "cannibalism," "emperipolesis," and "entosis." These three kinds of cell-in-cell phenomena, apart from a common feature of one cell internal to another, are distinct both cytologically and biologically. In this review, we discussed them in their morphology, cell recognition, penetration mechanisms, and physiological roles, respectively.

[Effects of oxidative stress on MuRF1 expression in skeletal muscle of diabetic rats].

OBJECTIVE: To determine whether muscle-specific RING finger protein 1 (MuRF1) expression induced by oxidative stress lead to muscle wasting in diabetes rats. METHODS: The diabetes rat model was established by high-carbohydrate, high-fat diet and injection of streptozotocin. The expression of MuRF1 in gastrocnemius was detected by immunohistochemistry and real time PCR. The level of lipid peroxidation, SOD and fiber size of gastrocnemius was also detected. Further more, C2C12 myotubes were cultured with different concentration of H2O2 (0, 0.01, 0.05, 0.10 and 0.20 mmol/L), the level of MuRF1 protein was detected by western blot. RESULTS: Compared with the control group, the diabetes rats showed higher level of thiobarbituric acid reactive substances (TBARS) and MuRF1 mRNA and lower fiber size in gastrocnemius (P < 0.01). The oxidative stress induced by H2O2 (0.05, 0.10 and 0.20 mmol/L) upregulated the expression of MuRF1 (P < 0.01) in C2C12 myotube cells. CONCLUSION: Our results indicated that diabetes modulated the expression of MuRF1 leading to muscle wasting, and the mechanism might be involved with oxidative stress.

Exercise training has beneficial anti-atrophy effects by inhibiting oxidative stress-induced MuRF1 upregulation in rats with diabetes.

AIMS: MuRF1 E3 ubiquitin ligase has been identified as a mediator of skeletal muscle wasting in various skeletal muscle atrophy models, and its expression is upregulated by oxidative stress. Exercise training could decrease oxidative stress and restore the atrophied skeletal muscle. Here, our aim was to investigate whether exercise training has any effect on MuRF1 expression in rats with diabetes. MAIN METHODS: Rats with streptozotocin-induced diabetes were subjected to exercise training, after which oxidative stress was determined, and MuRF1 expression was analyzed by immunohistochemistry, real-time RT-PCR and Western blot analysis. In addition, we analyzed C2C12 myotubes in an in vitro model to examine the effects of oxidative stress on the protein levels of MuRF1 and myosin heavy chain (MHC). KEY FINDINGS: While oxidative stress and MuRF1 expression were increased in rats with diabetes, exercise training diminished the skeletal muscle wasting in diabetic rats by decreasing oxidative stress and inhibiting MuRF1 expression at both the mRNA and protein levels. In addition, oxidative stress-induced MuRF1 upregulation promoted proteasome dependent degradation of the myosin heavy chain (MHC) in C2C12 myotubes. SIGNIFICANCE: Our study provides the first evidence that the beneficial anti-atrophy effects of exercise training on diabetes might be mediated by inhibiting oxidative stress-induced MuRF1 upregulation and preventing MuRF1-mediated degradation of MHC.

Relationship between nm23H1 genetic instability and clinical pathological characteristics in Chinese digestive system cancer patients.

AIM: To study the relationship between nm23H1 gene genetic instability and its clinical pathological characteristics in Chinese digestive system cancer patients. METHODS: Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze the microsatellite instability (MSI) and loss of heterozygosity (LOH). Immunohistochemistry was employed to detect the expression of nm23H1. RESULTS: The MSI was higher in TNM stage I + II than in stage III + IV of gastric, colonic and gallbladder carcinomas. The LOH was higher in TNM stage III + IV than in stage I + II of gastric, colonic and hepatocellular carcinomas. Lymphatic metastasis was also observed. The expression of nm23H1 protein was lower in TNM stage III + IV than in stage I + II of these tumors and in patients with lymphatic metastasis.The nm23H1 protein expression was higher in the LOH negative group than in the LOH positive group. CONCLUSION: MSI and LOH may independently control the biological behaviors of digestive system cancers. MSI could serve as an early biological marker of digestive system cancers. Enhanced expression of nm23H1 protein could efficiently inhibit cancer metastasis and improve its prognosis. LOH mostly appears in late digestive system cancer.

[The relation between reg 1A mRNA expression and the clinicopathologic parameters in the patients with primary gastric carcinoma].

Using reverse transcriptase-polymerase chain reaction (RT-PCR), REG 1A mRNA expression was investigated in 235 primary gastric carcinoma samples. And the relation between these results with the clinicopathologic parameters of primary gastric carcinoma was discussed in experiment. The positive REG 1A mRNA is 78% (183/235) of primary gastric carcinoma which revealed by RT-PCR analysis. Moreover, patients with REG 1A-positive differentiated adenocarcinoma were found to have a significantly poorer prognosis compared with REG 1A-negative tumor patients. REG IA mRNA is closely linked to the infiltrative growth pattern and with signet ring cell carcinoma and poorly differentitated adencarcinoma. And the incidence of venous invasion of REG 1A-positive tumors was significantly higher than that of REG 1A-negative tumors. So the results of the experiment demonstrate that the expression of the REG 1A gene is closely related to the infiltrating property of primary gastric carcinoma, and may be as a prognostic indicator of differentiated adenocarcinoma of the stomach in clinic diagnosis.

[Correlation of genetic instability of nm23H1 gene to clinicopathologic features of epithelial ovarian carcinoma].

BACKGROUND & OBJECTIVE: Genetic instability, including microsatellite instability (MSI) and loss of heterozygosity (LOH), is the main reason for anti-oncogenes function maladjustment, and tumorigenesis. This research was to explore the correlation of genetic instability of nm23H1 gene to clinicopathologic features of epithelial ovarian carcinoma, and provide experimental basis for revealing the mechanism of nm23H1 gene function and tumor metastasis. METHODS: MSI and LOH of locus D17S396 in 25 specimens of epithelial ovarian carcinoma and relevant pericancerous tissues were detected by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) with ordinary silver staining. EnVision immuno-histochemistry and Leica-Qwin computer imaging techniques were used to assess the expression of nm23H1 protein. RESULTS: The detection rates of MSI and LOH of locus D17S396 in the 25 specimens of epithelial ovarian carcinoma were 16.00% and 24.00%, and the positive rate of nm23H1 protein was 56.00%. The frequency of LOH was significantly higher in the cases with lymph node metastasis than in those without metastasis (66.67% vs. 10.53%, P<0.01), and was significantly higher in the cases at FIGO stage III-IV than in those at stage I-II (50.00% vs. 11.76%, P<0.05). The positive rate of nm23H1 protein was significantly lower in the cases with lymph node metastasis than in those without lymph node metastasis (16.67% vs. 68.42%, P<0.05), and was significantly lower in the cases at FIGO stage III-IV than in those at stage I-II (25.00% vs. 70.59%, P<0.05). The expression intensity of nm23H1 protein had no correlation to clinicopathologic factors of epithelial ovarian carcinoma when analyzed by computer imaging techniques. The positive rate of nm23H1 protein was significantly lower in the cases with LOH of locus D17S396 than in those without LOH of locus D17S396 (0.00% vs. 73.68%, P<0.01). CONCLUSIONS: The occurrence of LOH may be a molecular marker for the canceration of ovarian tissues. MSI and LOH of nm23H1 gene regulate the development of epithelial ovarian tumor through different pathways. LOH could inhibit the expression of nm23H1 in epithelial ovarian carcinoma.

[Study on genetic instability of NM23H1 gene in Chinese with the epithelial ovarian tumor].

The aim of this study was to examine microsatellite instability (MSI) and loss of heterozygosity (LOH) of locus D17S396 on chromosome 17 and their influence on the expression of nm23H1 in the epithelial ovarian tumors, which may provide experimental basis for the mechanism of nm23H1 gene and tumor metastasis. Techniques such as DNA extraction from formalin-fixed paraffin-embedded tissues, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), ordinary silver stain were used to study MSI and LOH of locus D17S396. Envision immunohistochemistry and Leica-Qwin computer imaging techniques were used to assess the expression of nm23H1 gene. In our experiments, the frequency of heredity instability of malignant ovarian tumors was 40%, which is higher than that of borderline ovarian tumors, while there were no heredity instability occurred in benign ovarian tumors and normal ovarian tissue. Among 25 epithelial ovarian carcinomas, the frequency of LOH in lymph node metastasis cases (66.67%) was significantly higher than those without metastasis (10.53%). Moreover, the frequency of LOH was higher in FIGO stage III and IV than in stage I and II. However, the frequency of MSI showed no correlation with any clinicopathologic characteristics. The positive frequency of nm23H1 protein in the ovarian epithelial carcinoma and borderline tumors were 56.00% and 57.14%, respectively. They were both higher than those of the benign tumors and normal ovarian tissue. In the epithelial ovarian carcinomas, the positive frequency of nm23H1 protein in lymph node metastasis case was significantly lower than those without metastasis. FIGO stage III and IV also exhibited lower positive frequency of nm23H1 protein compared with stage I and II. Furthermore, there was no difference in nm23H1 protein expression intensity analyzed by computer imaging. In the epithelial ovarian carcinomas, the positive frequency of nm23H1 protein in LOH positive group was 0.00%, which is lower than that of LOH negative group (P < 0.01). The results indicated that the heredity instability of nm23H1 gene might be implicated in pathogenesis and progression of epithelial ovarian tumor. The occurrence of LOH might be the molecule marker of the deteriorism of ovarian tissue. Both MSI and LOH of nm23H1 gene controlled development of the epithelial ovarian tumor independently in different paths. LOH could inhibit the expression of nm23H1 in local tissue of the epithelial ovarian carcinoma, which endowed it with high aggressive and poor prognosis. Increasing the amount of nm23H1 protein expression could effectively restrain metastasis of the ovarian epithelial carcinoma and improve prognosis of patients.