UHPLC Q-Exactive MS-Based Serum Metabolomics to Explore the Effect Mechanisms of Immunological Activity of Astragalus Polysaccharides With Different Molecular Weights

Astragalus polysaccharides (APS) have a wide range of biological activities. Most researchers discuss total APS as the main research object. However, because the relative molecular weight of APS has a wide distribution, in-depth studies on the mechanisms of the biological activity of notable molecules are limited. For example, the relationship between the immunomodulatory effect of APS and its relative molecular weight has not been clearly defined. Therefore, in this paper, we separated and obtained APS of different molecular weights by ultrafiltration technology and then constructed a mouse cyclophosphamide-induced immunosuppression model to investigate the immune activity of APS of different molecular weights. The immune enhancement mechanism of APS was explored by examining changes in routine blood indicators, body weight, immune organs, and differential metabolites in mouse serum. Results showed that APS-I (molecular weight, >2,000 kDa), APS-II (molecular weight, 1.02 × 10⁴ Da) and APS-III (molecular weight, 286 Da) could increase the number of immune cells in mouse serum and improve immune organ damage to varying degrees. Among the samples obtained, APS-II showed the best effects. Compared with those in the blank group, 29 metabolites determined by UHPLC Q-Exactive MS in the serum of the model group changed remarkably, and APS-I, APS-II, and APS-III respectively restored 13, 25, and 19 of these metabolites to normal levels. Metabolomics analysis revealed that APS-II is mainly responsible for the immunomodulatory activity of APS. Metabolomics analysis revealed that the mechanisms of this specific molecule may involve the regulation of phenylalanine metabolism, cysteine and methionine metabolism, tricarboxylic acid cycle (TCA cycle) and arginine and proline metabolism.

Hepatic Cyp1a2 Expression Reduction during Inflammation Elicited in a Rat Model of Intermittent Hypoxia

BACKGROUND

Intermittent hypoxia (IH) is a key element of obstructive sleep apnea (OSA) that can lead to disorders in the liver. In this study, IH was established in a rat model to examine its effects on the expression of hepatic cytochrome P450 (CYP) and CYP regulators, including nuclear receptors.

METHODS

Hematoxylin and eosin staining was conducted to analyze the general pathology of the liver of rats exposed to IH. The messenger RNA (mRNA) expression levels of inflammatory cytokines, CYPs, nuclear factor-κB (NF-κB), and nuclear factors in the liver were measured by quantitative reverse transcription polymerase chain reaction.

RESULTS

We found inflammatory infiltrates in the liver of rats exposed to IH. The mRNA expression level of interleukin-1beta was increased in the liver of the IH-exposed rats (0.005 ± 0.001 vs. 0.038 ± 0.008, P = 0.042), whereas the mRNA expression level of Cyp1a2 was downregulated (0.022 ± 0.002 vs. 0.0050 ± 0.0002, P = 0.029). The hepatic level of transcription factor NF-κB was also reduced in the IH group relative to that in the control group, but the difference was not statistically significant and was parallel to the expression of the pregnane X receptor and constitutive androstane receptor. However, the decreased expression of the glucocorticoid receptor upon IH treatment was statistically significant (0.056 ± 0.012 vs. 0.032 ± 0.005, P = 0.035).

CONCLUSIONS

These results indicate a decrease in expression of hepatic CYPs and their regulator GR in rats exposed to IH. Therefore, this should be noted for patients on medication, especially those on drugs metabolized via the hepatic system, and close attention should be paid to the liver function of patients with OSA-associated IH.

Evolution and phylogenetic application of the MC1R gene in the Cobitoidea (Teleostei: Cypriniformes)

Fish of the superfamily Cobitoidea sensu stricto (namely loaches) exhibit extremely high diversity of color patterns, but so far little is known about their evolutionary mechanism. Melanocortin 1 receptor gene (MC1R) plays an important role during the synthesis of melanin and formation of animal body color patterns. In this study, we amplified and sequenced the partial MC1R gene for 44 loach individuals representing 31 species of four families. Phylogenetic analyses yielded a topology congruent with previous studies using multiple nuclear loci, showing that each of the four families was monophyletic with sister relationships of Botiidae+ (Cobitidae+(Balitoridae+Nemacheilidae)). Gene evolutionary analyses indicated that MC1R in loaches was under purifying selection pressure, with various sites having different dN/dS values. Both Botiidae and Cobitidae had lower dN/dS values than those of background lineages, suggesting their evolution might be strongly affected by purifying selection pressure. For Balitoridae and Nemacheilidae, both had larger dN/dS values than those of background lineages, suggesting they had a faster evolutionary rate under more relaxed selection pressure. Consequently, we inferred that the relatively stable color patterns in Botiidae and Cobitidae might result from the strong purifying selection pressure on the MC1R gene, whereas the complicated and diverse color patterns in Balitoridae and Nemacheilidae might be associated with the relaxed selection pressure. Given the easy experimental procedure for the partial MC1R gene and its excellent performance in reconstructing phylogeny, we suggest this gene could be used as a good molecular marker for the phylogenetic study of fish species.

Associations of depression with impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in Chinese adults

AIM

To examine the association between depression and impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in middle-aged and elderly Chinese people, and whether depression was associated with different treatment regimens or durations of diabetes.

METHODS

A cross-sectional study was performed among 229,047 adults living in the community aged ≥ 40 years from 25 centres in China. The self-reported depression rating scale Patient Health Questionnaire 9 (PHQ-9) was used to diagnose probable and sub-threshold depression. Glucose metabolism status was determined according to World Health Organization 1999 diagnostic criteria.

RESULTS

The numbers of participants with normal glucose regulation, impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes were 120,458, 59,512, 24,826 and 24,251, respectively. The prevalence of sub-threshold depression in the total sample of participants was 4.8% (4.8%, 4.8%, 4.4% and 5.6% from normal glucose regulation to previously diagnosed diabetes, respectively), and the prevalence of probable depression was 1.1% (1.1%, 1.0%, 0.9% and 1.8% from normal glucose regulation to previously diagnosed diabetes, respectively). Compared with participants with normal glucose regulation, those with previously diagnosed diabetes had increased odds of probable depression [odds ratio (OR) = 1.61, 95% confidence interval (CI) 1.39-1.87] and sub-threshold depression (OR = 1.14, 95% CI 1.06-1.24), after adjustment for multiple confounding factors. Newly diagnosed diabetes or impaired glucose regulation was not associated with depression. Among those with previously diagnosed diabetes, insulin treatment was associated with greater odds of depression compared with no treatment or oral anti-diabetic medicine.

CONCLUSION

Previously diagnosed diabetes, but not newly diagnosed diabetes or impaired glucose regulation, was associated with a higher prevalence of depression. Patients receiving insulin were more likely to have depression than those not receiving treatment or being treated with oral anti-diabetic medicine.

Effect of reduced energy, protein and entire substitution of inorganic phosphorus by phytase on performance and bone mineralisation of laying hens

1. The objective of this study was to evaluate the effects of total removal of dietary inorganic phosphorus and reduced energy and protein, without and with phytase supplementation, on the performance, egg quality and bone composition of laying hens. 2. Lohmann pink-shell hens were randomly assigned at 56 weeks of age to 5 treatments for 20 weeks as follows: (1) a positive control (PC) with 155 g CP/kg, 11·09 MJ ME/kg, calcium (Ca) 3·40% and non-phytic phosphorus (NPP) 0·26%, (2) a negative control (NC1) diet based on PC diet with Ca decreased to 3·30% and NPP to 0·14%, (3) NC2 diet was formulated on the basis of NC1 diet with 152·7 g CP/kg, 10·90 MJ/kg, (4) NC1 and (5) NC2 supplemented with phytase (300 FTU/kg) each. 3. Feed intake, hen-day or hen-housed egg production, egg number per hen-housed, and final body weight were depressed with NC1 and NC2 diets, but restored by phytase inclusion. There were no significant differences between the dietary treatments for feed conversion efficiency, rates of cracked and broken eggs, egg-shell thickness or egg-shell strength. Mortality was significantly increased by NC2 diet without phytase. Tibia ash was significantly decreased by both NC1 and NC2 diets. Bone strength, and Ca and P contents in tibia ash were significantly increased by phytase inclusion in the NC1 diet. 4. In conclusion, the NC1 and NC2 diets significantly depressed performance and tibia quality, but the addition of phytase (300 FTU/kg) significantly improved performance and tibia integrity.

The low molecular mass PsbW protein is involved in the stabilization of the dimeric photosystem II complex in Arabidopsis thaliana

Arabidopsis thaliana plants have been transformed with an antisense gene to the psbW of photosystem II (PSII). Eight transgenic lines containing low levels of psbW mRNA have been obtained. Transgenic seedlings with low contents of PsbW protein (more than 96% reduced) were selected by Western blotting and used for photosynthetic functional studies. There were no distinct differences in phenotype between the antisense and wild type plants during vegetative period under normal growth light intensities. However, a sucrose gradient separation of briefly solubilized thylakoid membranes revealed that no dimeric PSII supracomplex could be detected in the transgenic plants lacking the PsbW protein. Furthermore, analysis of isolated thylakoids demonstrated that the oxygen-evolving rate in antisense plants decreased by 50% compared with the wild type. This was found to be due to up to 40% of D1 and D2 reaction center proteins of PSII disappearing in the transgenic plants. The absence of the PsbW protein also altered the contents of other PSII proteins to differing extents. These results show that in the absence of the PsbW protein, the stability of the dimeric PSII is diminished and consequently the total number of PSII complexes is greatly reduced. Thus the nuclear encoded PsbW protein may play a crucial role in the biogenesis and regulation of the photosynthetic apparatus.

Characterisation of the PsbX protein from Photosystem II and light regulation of its gene expression in higher plants

The location and expression of the previously uncharacterised photosystem II subunit PsbX have been analysed in higher plants. We show that this protein is a component of photosystem II (PSII) core particles but absent from light-harvesting complexes or PSII reaction centres. PsbX is, however, localised to the near vicinity of the reaction centre because it can be cross-linked to cytochrome b559, which is known to be associated with the D1/D2 dimer. We also show that the expression of this protein is tightly regulated by light, since neither protein nor mRNA is found in dark-grown plants.

Diagnosis and treatment of adrenal tumours: a review of 35 years' experience

OBJECTIVE

To review and analyse clinical data on the diagnosis and management of patients with adrenal masses.

PATIENTS AND METHODS

Patients admitted with adrenal masses between 1960 and 1995 were reviewed. The series comprised 116 males (mean age 41.4 years, SD 10.5, range 3-77) and 95 females (mean 36.9 years, SD 11.6, range 1-62); eight patients were < 14 years old and the overall mean (SD) age was 39.4 (12.8) years. The diagnosis was based on symptoms, signs, hormone levels and imaging studies. All tumours were confirmed by surgery, and pathology and results of analysis assessed statistically.

RESULTS

Over the last 35 years, the incidence of adrenal tumours was 1.7% of all patients admitted with genitourological diseases or 9.7% of patients with genitourinary tumours at our institution. The prevalence of adrenal tumours in males and females was similar but Cushing's syndrome was 3.1 times more frequent in females than in males and phaeochromocytoma 1.9 times more frequent in males than females. Most patients with adrenal tumour were aged 30-50 years. Of 211 adrenal tumours, 151 (72%) were functional, with a prevalence of benign tumour, and 60 (28%) were nonfunctional, with 35% malignant. There were 78 'incidentalomas' which included 18 functional tumours. Overall, 210 tumours were removed and one was explored. Correlation analysis between tumour size and character or hormone levels showed that size was significantly positively correlated with tumour character (r = 0.4010, P < 0.001), but there was no relationship between tumour size and hormonal levels. The postoperative complication rate was 3.3% and the mortality 0.5%.

CONCLUSIONS

Based on this analysis we recommend that computed tomography is the first method used to define and localize the adrenal masses, that hormone levels should be determined in symptomatic or asymptomatic patients with adrenal masses, and that functional adrenal tumours and solid incidentalomas of any size should be removed surgically.

The nuclear-encoded PsbW protein subunit of photosystem II undergoes light-induced proteolysis

The repair of photoinhibitory damage to photosystem II involves the rapid degradation and turnover of the D1 reaction center subunit. Additional protein subunits which show a limited degradation at high light intensities are the complementary reaction center subunit, D2, and the two chlorophyll a binding proteins, CP 47 and CP 43. In this work, we provide the first evidence for light-induced degradation of a nuclear-encoded subunit of photosystem II, the recently discovered PsbW protein. This 6.1 kDa protein is predicted to have a single membrane span and was found to be closely associated with the photosystem II reaction center. The degradation of the PsbW protein was demonstrated by photoinhibitory experiments, both in vitro, using thylakoid membranes and photosystem II core particles, and in vivo using leaf discs. The PsbW protein showed almost the same rate and extent of degradation as the D1 protein, and its degradation was more pronounced compared to the D2 and CP 43 proteins. The degradation of the PsbW protein was shown to share many mechanistic similarities with the more well characterized D1 protein degradation, such as oxygen dependence, sensitivity to serine protease inhibitors, and high light triggering while the actual degradation could readily occur in total darkness. The degradation of the PsbW protein was impaired by protein phosphorylation, although this protein was not itself phosphorylated. This impairment was correlated to the phosphorylation of the D1 protein which has been shown to block its degradation during photoinhibitory conditions. It is concluded that the PsbW protein is not degraded as a direct consequence of primary photodamage but due to a general destabilization of the photosystem II complex under conditions were the D1 protein becomes degraded in the absence of a sufficient repair system. The results are discussed in terms of a requirement for coordination between degradation and protein synthesis/integration during the repair process of photodamaged photosystem II reaction centers.

A nuclear-encoded subunit of the photosystem II reaction center

A nuclear-encoded polypeptide of 6.1 kDa was identified in isolated photosystem II (PSII) reaction center from Spinacia oleracea. The hydrophobic membrane protein easily escapes staining procedures such as Coomassie R-250 or silver staining, but it is clearly detected by immunodecoration with peptide-directed IgG. This additional subunit was found to be present in PSII reaction centers previously known to contain only the D1/D2/cytb559 proteins and the psbI gene product. Furthermore, cross-linking experiments using 1-(3-dimethylaminopropyl-) 3-ethylcarbodiimide showed that the nearest neighbors were the D1 and D2 proteins and the cytb559. The 6.1-kDa protein was purified by immune affinity chromatography. N-terminal sequence analysis of the isolated protein confirmed the identity of the 6.1-kDa protein and enabled finding of strong similarities with a randomly obtained cDNA from Arabidopsis thaliana. Using enzyme-linked immunosorbent assay in combination with thylakoid membrane preparations of different orientation, the N terminus of the protein, predicted to span the membrane once, is suggested to be exposed at the lumen side of the membrane. Consequently the 6.1-kDa protein seems to be the only subunit in the PSII reaction center that is nuclear encoded and has its N terminus on the lumen side of the membrane. These findings open for new interesting suggestions concerning the properties of photosystem II reaction center with respect to the photosynthetic activity, regulation and assembly in higher plants.

[Influence of perinatal factors and sampling methods on thyroid stimulating hormone and thyroid hormone levels in cord blood]

The present study was designed to explore the influence of perinatal factors and sampling methods on fetal pituitary-thyroid axis. The results showed: (1) There was no linear relation between cord serum thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4) and either birth weight or the duration of labor (r = 0.03-0.12, P > 0.05). The mean cord serum TSH, T3 or T4 levels in the fetus delivered with uterotonic agents were no significant difference from those in fetus without these drugs and also there was no significant difference in the mean cord serum TSH, T3 or T4 levels according to the fetus sex (P > 0.05). (2) The mean cord serum TSH level of fetus in vacuum extraction group was significantly higher than that of fetus in normal vaginal delivery or caesarean section group (P < 0.01). However, the mean TSH levels of neonates on day 3-5 in heel blood spotted filter paper were no significant differences among the three groups (P > 0.05). (3) The mixed cord blood TSH level related quite well to the TSH level obtained from heel blood on day 3-5, or cord venous serum samples (r = 0.67-0.84, P < 0.01). Our results suggest that measuring cord blood TSH level might be a feasible alternative method for neonatal congenital hypothyroidism screening.

[Determination of urine iodine in school children in iodine deficiency disorders areas]

Twenty-four-hour urine iodine and afternoon casual urine iodine were determined in children aged 7-14 years grouped into A, B, C, and D at two-year interval in the areas where iodized salt prophylaxis had been instituted. Results showed there was no significant difference between urine iodine values expressed in median of microgram/g Cr x creatinine coefficient and in microgram/24 hr, and the former was considered to reflect the real iodine value in urine. Urine iodine in children of groups C and D (older) was greater than of A and B (younger). Urine iodine reached the lower limit only in 51.2% of the children aged 13-14 years in Heba Township where iodized salt prophylaxis was instituted, with 75 micrograms iodine intake daily as lower limit. It suggested iodine deficiency remained a problem in that area.