Seasonal nitrogen uptake strategies in a temperate desert ecosystem depends on N form and plant species

Symbiotic plants might be able to regulate a limited nitrogen (N) pool, thus avoiding and reducing competition for resources, through the uptake of different chemical N forms. Our aim was to see whether coexisting herbs showed preference for different forms of N in a temperate desert. We conducted a situ experiment using the ¹⁵ N labeling method in the Gurbantunggut Desert of Northwestern China dominated by Erodium oxyrrhynchum, Hyalea pulchella, Nonea caspica and Lactuca undulata during their growing period (April and May). Four desert herb species preferentially relied on ¹⁵ N-NO₃ for their N nutrition. Multi-factor analysis of variance (ANOVA) analysis results showed that species, N forms, months, and soil depths strongly affected N uptake rate. The uptake rate by herbs was higher in May than in April, and higher at 0-5 cm than at 5-15 cm soil layers. Erodium oxyrrhynchum, N. caspica and L. undulata showed different preference on N form over months. Erodium oxyrrhynchum and L. undulata changed their uptake preference from more ¹⁵ N-Glycine in April to more ¹⁵ N-NH4 in May. Although the N uptake rate of four desert herbs varied across different soil depths and months, all species absorbed more inorganic N compared with organic N. The higher preference for ¹⁵ N-NO₃ and ¹⁵ N-NH4 over ¹⁵ N-Gly possibly reflects adaptation to different N forms in temperate desert.

Bio-inspired fabrication of Ester-functionalized imprinted composite membrane for rapid and high-efficient recovery of lithium ion from seawater

Lithium ion (Li⁺) is one of the important sustainable resource and it's urgently demanded to develop high-selectivity and high-efficient method to extract of Li⁺ from seawater. Hence, we propose the ester-functionalized ion-imprinted membrane (IIMs) with high selectivity and stability for the rebinding and separation of Li⁺ in aqueous medium via ion imprinted technology and membrane separation technology. In this work, the hydrophilic polydimethylsiloxane membranes (PDMS) are synthesized by self-polymerization of dopamine (DA) in aqueous solution, resulting in the fabrication of dense poly-dopamine (PDA) layer on the surface of PDMS (PDMS-PDA). In view of weak bonding forces (such as hydrogen bond, ionic bond and Van der Waals' force) between traditional imprinted polymer and ligand, the ester groups are formed between modified PDMS-PDA and ligand by surface grafting. The obtained Li⁺ imprinted membranes (Li-IIMs) have a suitable cavity and high adsorption capacity toward Li⁺ which reveal a high rebinding capacity (50.872 mg g^-1) toward Li⁺ based on ample rebinding sites and strong affinity force. The superior relative selectivity coefficients (α_Na/Li, α_K/Li and α_Rb/Li are 1.71, 4.56 and 3.80, respectively) can be also achieved. The selectivity factors of Li-IIMs for Na⁺, K⁺ and Rb⁺ are estimated to be 2.52, 2.8 and 3.03 times larger than Li⁺ non-imprinted membranes (Li-NIMs), which imply the superior selectivity of Li-IIMs toward Li⁺. The regeneration ability of Li-IIMs is observed by systematic batch experiments. In summary, it can be concluded that the rebinding capacities of Li-IIMs is slightly decrease after eluting process, owing to the Li-IIMs with outstanding stability performance. Presentation of the method pave a fine prospect for coming true the long-term use of imprinted membrane.

[Birth weight predicts physical indicators in adulthood: a large population-based study in Chinese twins]

Objective: To quantitate the association between birth weight and phenotypes of physical indicators in adulthood, i.e. BMI and waist circumference (WC) and to what degree genetic or environmental factors affect birth weight-obesity association. Methods: A total of 6 623 gender matched twin pairs aged 25 to 79 years were recruited through the Chinese National Twin Registry. The twins reported their own birth weight, current height and weight, and WC using a self-administered questionnaire. BMI was calculated according to the self-reports of body height and weight. Within twin-pair design was used to quantitate the association between birth weight and phenotypes related to obesity while bivariate structural equation models were used to decompose the phenotype correlation. Results: After adjusted for multiple factors, twin-pair analyses within monozygotic (MZ) showed that, on average, a 1.0 kg increase in birth weight corresponded to an increase of 0.33 kg/m(2) in BMI and 0.95 cm in WC in adulthood (P<0.001). Bivariate structural equation models showed significant positive unique environmental correlation between birth weight and the two obesity-related phenotypes. Conclusion: The study supported the role of twin-specific supply line factors on relationship between birth weight and physical indicators in adulthood.

Plasma fluoroacetic acid concentrations: Symptoms, hematological, and biochemical characteristics in patients with fluoroacetic acid poisoning in the emergency department

Fluoroacetic acid (FAcOH) was once a highly toxic rodenticide widely used in the world. In the past, studies on the toxicity of FAcOH have focused on animal experiments. The toxicity of FAcOH to humans and the changes of FAcOH in plasma have not been studied. Therefore, the present study aimed to describe the changes of plasma FAcOH concentrations, hematological, and biochemical characteristics in patients with FAcOH intoxication. According to clinical symptoms, 68 patients from the emergency department were divided into different groups: convulsion group, unconsciousness group, death group, and control groups. Plasma FAcOH concentrations, hematological, and biochemical parameters were investigated. Results demonstrated that patients in the convulsion group and the unconsciousness group had a significant increase (p < 0.01) in the level of neuron-specific enolase (NSE), creatine kinase MB (CKMB), glucose (GLU), and white blood cell count (WBC) and a significant decrease (p < 0.01) in serum potassium compared with the control group, respectively. Moreover, patients in the death group had a significant increase (p < 0.01) in the level of NSE, CKMB, N-terminal pro-brain natriuretic peptide, GLU, and WBC and a significant decrease (p < 0.01) in serum potassium and total calcium compared with the survival group. The concentrations of FAcOH in plasma in the convulsion group, the unconsciousness group, and the death group were 72.31 ± 42.29, 118.33 ± 55.41, and 163.78 ± 43.32 μg/mL, respectively. These changes and the plasma FAcOH concentrations may increase our understanding of the toxicity of FAcOH to humans and may help doctors to judge the clinical prognosis of patients with FAcOH intoxication.

Analysis of related factors of orolingual angioedema after rt-PA intravenous thrombolytic therapy

OBJECTIVE

Orolingual angioedema (OA) is a rare clinical complication with a potentially fatal risk that occurs after the intravenous application of alteplase (rt-PA) in patients with acute ischemic stroke. The purpose of this work is to investigate the related factors of OA in patients with acute ischemic stroke after the administration of intravenous thrombolytic therapy, to improve the predictive ability of OA during intravenous thrombolytic therapy, and to reduce the prevalence of complications.

PATIENTS AND METHODS

We recruited 1223 cases of patients with acute ischemic stroke that were treated in the Department of Neurology No. 4 of the Tianjin Huanhu Hospital from June 2014 to April 2015. The clinical manifestations of rt-PA related OA were recorded, the clinical prevalence was counted, related factors of OA after intravenous thrombolytic therapy were analyzed, and the risk assessment of rt-PA related OA was conducted.

RESULTS

14 cases of patients developed OA, with a prevalence rate of 1.14%. Among them, 5 had a history of urticaria, 4 of drug allergy, and 3 of food allergy. Among the 14 cases of patients, 10 developed OA in the process of intravenous thrombolysis and 4 after intravenous thrombolysis, 12 showed lip edema, 9 showed extensive swelling of tongue, 3 showed swelling of lateral tongue, 3 were complicated by respiratory distress, 10 showed infarction in the middle cerebral artery territory, and 6 had previously been given oral ACEI drugs.

CONCLUSIONS

Orolingual angioedema is a rare complication that occurs after rt-PA intravenous thrombolytic therapy; when serious, it may endanger a patient's life. If patients take an oral hypotension such as ACEI drugs before the onset of OA, they have a history of allergies, or the lesion is an infraction in the dominated area of the middle cerebral artery, the risk of OA after rt-PA intravenous thrombolytic therapy will be increased. The prevalence of OA should be monitored during the rt-PA intravenous thrombolytic therapy process; timely detection and early intervention should be conducted, which can avoid serious adverse consequences.

Obesity Prevalence in Alabama: Trends from 2011 to 2017 and Evaluation of a State Obesity Program

Background

Alabama, one of the southeastern states in the US, suffers from a heavy burden of obesity. In 2014, Alabama launched a state program named ’ALProHealth’, aiming to prevent and reduce obesity prevalence. The objective of this study is to evaluate the potential impact of the ALProHealth Program on the prevalence of obesity in Alabama from 2014 to 2017.

Methods

Data for this study come from the Behavioral Risk Factor Surveillance System (BRFSS). An interrupted time series design was employed. The state obesity prevalence trend for the pre-program period (2011-2014) was estimated and compared with the post-program period (2015-2017). Statistical analyses were conducted using segmented linear regression. Indiana was chosen as the control group in this study.

Results

The obesity prevalence in Alabama significantly increased from 31.8% in 2011 to 36.2% in 2017, increasing by 0.81% on average each year (95% CI: 0.47 to 1.15, p = 0.002). Before the ALProHealth Program, the obesity prevalence increased by 0.59% (p = 0.11) and 0.32% (p = 0.34) in both Alabama and Indiana respectively, though it is not statistically significant. After the program implementation, the slope of obesity prevalence increased by 0.43 (p = 0.45) and 0.03 (p = 0.96) in Alabama and Indiana respectively, though change is not significant. When comparing Alabama and Indiana, the rate of slope change is higher in Alabama (0.73) compared with Indiana (0.093), indicating the rate of slope change in obesity prevalence increased faster in Alabama than Indiana.

Conclusions

To sum up, the study found no evidence that the ALProHealth Program contributed to the decrease of obesity prevalence in Alabama. One possible reason is that there was low program coverage. Future studies should examine the potential effectiveness of other programs using a similar conceptual model as ALProHealth Program.

Key messages

In 2014, Alabama launched a state program named ‘ALProHealth’, aiming to prevent and reduce obesity prevalence. The study found no evidence that the ALProHealth Program contributed to the statewide decrease of obesity prevalence in Alabama, which may attribute to low program coverage.

P11.07 LAPTM5 functions as a tumor suppressor via CD40 - NFêB pathway inhibition and represents a potential biomarker for temozolomide sensitivity in CD40 proficient glioblastoma

BACKGROUND

Glioma therapy is challenged by the invasive nature of glioma resulting in tumor recurrence and treatment resistance. Lysosomal protein transmembrane 5 (LAPTM5) was identified to inhibit invasion by screening for invasion-associated genes in glioma. The aim of this study was to decipher the function of LAPTM5 in glioblastoma and its interaction with the CD40 receptor which was shown to be highly expressed in up to 40% of glioblastoma.

METHODS

LAPTM5 expression was correlated with clinical outcome of glioma patients. Knockdown of LAPTM5 was performed in different glioma cell lines to analyze the impact on clonogenicity, invasiveness, sensitivity to temozolomide chemotherapy and tumorigenicity in-vitro and in-vivo in a subcutaneous xenograft mouse model. Expression array was used to elucidate the underlying pathways. CD40 knockdown and overexpression was induced to prove the crosstalk of LAPTM5 and CD40.

RESULTS

LAPTM5 expression correlated with better overall survival in high grade glioma patients and acted as a tumor suppressor in CD40 positive glioblastoma cells. LAPTM5 inhibited CD40-mediated NFκB activation resulting in anti-invasive, anti-clonogenic and temozolomide sensitizing effects in-vitro and in-vivo. Vice-versa, knockdown of LAPTM5 enhanced tumorigenicity by activation of the NFκB pathway which was overcome by NFκB inhibition. Importantly, CD40 expression was required for LAPTM5-mediated tumor suppressive activity.

CONCLUSION

LAPTM5 conveyed tumor suppressive and temozolomide sensitizing effects in CD40-positive glioblastoma by inhibition of CD40-mediated NFκB activation and thereby might provide a reasonable biomarker for sensitivity to temozolomide in CD40-positive glioblastoma.

The Chinese National Twin Registry: a 'gold mine' for scientific research

The Chinese National Twin Registry (CNTR) currently includes data from 61 566 twin pair from 11 provinces or cities in China. Of these, 31 705, 15 060 and 13 531 pairs are monozygotic, same-sex dizygotic and opposite-sex dizygotic pairs, respectively, determined by opposite sex or intrapair similarity. Since its establishment in 2001, the CNTR has provided an important resource for analysing genetic and environmental influences on chronic diseases especially cardiovascular diseases. Recently, the CNTR has focused on collecting biologic specimens from disease-concordant or disease-discordant twin pairs or from twin pairs reared apart. More than 8000 pairs of these twins have been registered, and blood samples have been collected from more than 1500 pairs. In this review, we summarize the main findings from univariate and multivariate genetic effects analyses, gene-environment interaction studies, omics studies exploring DNA methylation and metabolomic markers associated with phenotypes. There remains further scope for CNTR research and data mining. The plan for future development of the CNTR is described. The CNTR welcomes worldwide collaboration.

Integrated analysis of differentially expressed genes in esophageal squamous cell carcinoma using bioinformatics

Esophageal squamous cell carcinoma (ESCC) is a deadly disease. To identify key genes in esophageal squamous cell carcinoma, we followed a strategy utilizing the laiurger microarray dataset (GSE38129) as the training set and another independent microarray dataset (GSE20347) as the validation set. Following quality control, differentially expressed genes (DEGs) were obtained using R software. Functional enrichment analysis was performed using DAVID database and the DEG co-expression network was established with Weighted Gene Co-Expression Network Analysis (WGCNA) and visualized by Cytoscape. The prognosis-related hub genes were then identified by Kaplan-Meier analysis based on the TCGA database. A total of 188 DEGs were obtained; 88 up-regulated genes and 100 down-regulated. The up-regulated DEGs were significantly associated with extracellular matrix organization and disassembly while down-regulated DEGs were significantly related to keratinocyte differentiation. Blue and turquoise co-expression modules were established and 18 hub genes were identified. The blue module was associated with mitotic nuclear division, cell division and mitotic cytokinesis and the turquoise module was associated with collagen catabolic process, extracellular matrix organization and keratinocyte differentiation. We established that the TPX2, CDK1 and CEP55 blue module hub genes were associated with relapse-free survival, and our overall results not only identify key genes but also provide potential novel biomarkers for ESCC diagnosis and treatment.

[Changes of eye care use among rural adults under the reform of New Rural Cooperative Medical Scheme: the Handan Eye Study]

Objective: To assess the utilization of eye care services in the rural area of Handan, China under the New Rural Cooperative Medical Scheme, and to analyze the factors associated with the uptake of these services. Methods: In a cohort population-based study, subjects who joined both the baseline (2006-2007) and follow-up (2012-2013) were included. Information of demographic characteristics, participation in the New Rural Cooperative Medical Insurance and use of eye care services, comprehensive ophthalmic examinations, blood pressure and fasting was collected. The protocol got approved by the ethics committee of Beijing Tongren Hospital, and each subject signed the informed consent. Results: Of 5 193 eligible participants, 549 [10.6%; 95% confidence interval (CI), 9.8%-11.4%] had used eye care services, and the prevalence had no significant difference from baseline surveys (P=0.20). The municipal hospitals undertook 50.1% of eye care services. "No need" (4 422, 95.2%) was the most common reason cited for not using an eye care service; 2 875 (65.0%) of these participants had at least one type of eye diseases, 3 505 (79.3%) had at least one type of ocular complaints. In the multiple binary logistics regression model, participants who were elder [adjusted odds ratio (OR), 1.319; 95%CI, 1.177-1.478], were female (adjusted OR, 1.466; 95%CI, 1.085-1.981), had a diabetes history (adjusted OR, 1.930; 95%CI, 1.381-2.696), had a low income (adjusted OR, 0.826; 95%CI, 0.688-0.922), had ocular complaints (adjusted OR, 3.556; 95%CI, 2.484-5.091), had refractive errors (adjusted OR, 1.256; 95%CI, 1.007-1.567), had visual impairment (adjusted OR, 4.398; 95%CI, 2.667-7.253) or had cataract (adjusted OR, 1.278; 95%CI, 1.013-1.612) were more likely to take an eye care service. Conclusions: Under the New Rural Cooperative Medical Scheme, the prevalence of New Rural Cooperative Medical Insurance was increased significantly, but the rate of eye care use in the rural area was still low. Further efforts towards higher quality medical service in county hospitals and village clinics as well as better education about eye disease among the rural population may raise the eye care use in rural areas. (Chin J Ophthalmol, 2018, 54:570-579).

Increased Phosphatidylserine on Blood Cells in Oral Squamous Cell Carcinoma

The specific function of phosphatidylserine (PS) in the context of the development of a hypercoagulable state among individuals with oral squamous cell carcinoma (OSCC) is uncertain. The goal of this study was therefore to assess the exposure of PS on microparticles (MPs) as well as on endothelial and blood cells and to assess procoagulant activity (PCA) as a function of the stage of OSCC progression. We recruited patients with OSCC (n = 63) as well as healthy controls (n = 26) to participate in this study. PS exposure was then assessed via confocal microscopy and flow cytometry, revealing that patients with stage III/IV OSCC exhibited higher frequencies of PS-exposing blood cells, MPs, and serum-cultured endothelial cells (ECs) than did patients with stage I/II OSCC or healthy controls. When we conducted functional coagulation assays, we discovered that PS⁺ blood cells, MPs, and serum-cultured ECs from patients with stage III/IV OSCC mediated more rapid coagulation and more substantial production of FXa, thrombin, and fibrin as compared with controls. When samples were treated with the PS antagonist lactadherin, this resulted in an 80% disruption of PCA. Strikingly, when pre- and postoperative samples were compared from patients with stage III/IV OSCC undergoing resective surgery, PCA was significantly reduced in the postoperative samples. After stimulating ECs with inflammatory cytokines, we found by confocal microscopy that they expose PS on their cell membranes, thus generating FVa and FXa binding sites and mediating the formation of fibrin. Together our findings provide evidence that PS⁺ blood cells and MPs are important mediators of the development of a hypercoagulable and prothrombotic state among individuals afflicted by advanced-stage OSCC. As such, a PS blockade may be a viable therapeutic strategy for treating such patients.

[Analysis on the heritability of diabetes, based on data from the Chinese adult twins]

Objective: To analyze the heritability of diabetes among the Chinese twin adults. Methods: A total of 10 253 same-sex twin pairs aged 25 years and older, were selected from the Chinese National Twin Registry (CNTR) program. Heritability of diabetes was calculated by using the structural equation model. Results: After adjusted for age and gender, the overall heritability rates of diabetes were 0.41 (0.15-0.75), 0.83 (0.72-0.91) and 0.34 (0.04-0.73) in the <45 and ≥45 years twin pairs, respectively. After adjusted for age, rates of heritability appeared as 0.37 (0.05-0.78) and 0.88 (0.79-0.94) in men and women, respectively. Conclusions: Diabetes is affected by both genetic and environmental factors. The genetic effect of diabetes seemed stronger on female than that on male twins but was dying down along with ageing.

Implication of lymph node staging in migration and different treatment strategies for stage T2N0M0 and T1N1M0 resected gastric cancer: a SEER population analysis

PURPOSE

The purpose of this study was to explore the differences between stage T2N0M0 and stage T1N1M0 gastric cancer (GC) and to identify the necessity of adjuvant treatment (AT) for these stages.

METHODS

Between years 2004 and 2015, 1971 stage IB GC patients who underwent radical surgery were recruited using the Surveillance, Epidemiology and End Results database. We conducted univariate/multivariate analyses, the propensity score matching and evaluated gastric cancer-specific survival (GCSS) and overall survival (OS) with the log-rank test.

RESULTS

T1N1M0 had a significantly worse survival than T2N0M0 in both GCSS and OS before and after the propensity score matching. Examined lymph nodes (ELN) ≤ 15 and T1N1M0 were independent risk factors for worse GCSS and OS in stage IB GC. The absence of adjuvant chemotherapy (CT) was an independent risk factor for worse GCSS and OS in T1N1M0 but not in T2N0M0. AT demonstrated similar GCSS and OS with surgery alone (SA) for T2N0M0 but better survival for T1N1M0. Compared to CT and adjuvant chemoradiotherapy (CRT) group, SA demonstrated significantly worse GCSS and OS for T1N1M0. There was no significant difference between CT and CRT in both T2N0M0 and T1N1M0 stages. T2N0M0 had a better survival than T1N1M0 in ELN ≤ 15 subgroup. However, similar survival was demonstrated in ELN > 15 subgroup.

CONCLUSIONS

T2N0M0 GC has a better survival rate than T1N1M0 GC when ELN are ≤ 15. Moreover, T2N0M0 GC may not benefit from AT. T1N1M0 GC requires CT but not adjuvant radiotherapy.

CRISPR/Cas9-mediated disruption of the immediate early-0 and 2 as a therapeutic approach to Bombyx mori nucleopolyhedrovirus in transgenic silkworm

The CRISPR/Cas9 system is a powerful tool for the treatment of infectious diseases. In our previous study, we knocked out the Bombyx mori nucleopolyhedrovirus (BmNPV) key genes and BmNPV-dependent host factor to generate transgenic antiviral strains. To further expand the range of target genes for BmNPV and more effectively prevent and control pathogenic infections, we performed gene editing and antiviral analysis by constructing a target-directed baculovirus early transcriptional activator immediate early-0 (ie-0) and 2 (ie-2) transgenic silkworm line. We hybridized it with Cas9 transgenic line to produce a double-positive transgenic Cas9(+)/sgIE0-sgIE2(+) line that could activate the CRISPR gene editing system. We first demonstrated that the system is capable of efficiently editing target genes and resulting in fragment deletions in the BmNPV genome. Survival rate of the transgenic Cas9(+)/sgIE0-sgIE2(+) line reached 65% after inoculation with 1 × 10⁶ occlusion bodies/larva. Molecular analysis showed that BmNPV DNA replication and viral gene expression level in the transgenic Cas9(+)/sgIE0-sgIE2(+) line were significantly inhibited compared with the control Cas9(-)/sgIE0-sgIE2(-) line. These results indicated that IE-0 and IE-2, as baculovirus early transcriptional activators, can be used as target sites for gene therapy and that multigene editing could expand the range of target sites for research to create silkworm resistance breeds.

[The applications of "Lacha" in Sheng Ji Zonglu]

The earliest appearance of "Lacha" was in the Tang Dynasty. At first, it was only served as a type of tribute tea to the emperor and the royal families.Since the Song Dynasty, "Lacha" was viewed as a kind of medicine or drug.Sheng Ji Zonglu(, Comprehensive Record of Sagely Beneficence) is the most abundant literature of the medicinal formulas of "Lacha" since the Song Dynasty. The book presented 72 prescriptions, which involved 62 diseases.Its application forms were diverse, including decoction, pill, powder and so on.The main functions included resuscitating, clearing up the heads, aiding digestion, dissipating phlegm, detoxifying and treating sores, eliminating miasma, and reducing the toxicity of other drugs.

Phylogenetic identification of lactic acid bacteria isolates and their effects on the fermentation quality of sweet sorghum (Sorghum bicolor) silage

AIM

To isolate, screen and identify the lactic acid bacteria (LAB) from elephant silage during the process of the fermentation and their effects on the fermentation quality of sweet sorghum silage.

METHODS AND RESULTS

The isolated strains were identified based on morphological, physiological and biochemical characteristics as well as 16S rRNA analysis. Seven LAB strains were isolated from elephant grass silage. Three strains (Pediococcus acidilactici (AZZ1), Lactobacillus plantarum subsp. plantarum (AZZ4), L. plantarum subsp. argentoratensis (AZZ7) and one commercial bacteria L. plantarum, ecosyl MTD/1(CB)) were chosen as additives at 6 log colony forming units per gram of fresh sweet sorghum grass in laboratory silos (680 g). Silos for each treatment were opened after 5, 7, 14, 30 and 60 days, respectively. All isolates were characterized as Gram-positive, catalase-negative and grow normally in 6·5% NaCl. The strains AZZ1, AZZ2 and AZZ5, were identified as Pediococcus genus while AZZ3, AZZ4, AZZ6 and AZZ7 were Lactobacillus genus. Compared to the control, all the isolates improved the silage quality of sweet sorghum silage, indicated by significantly (P < 0·05) lower pH and ammonia-nitrogen contents and undesirable micro-organism counts, and higher lactic acid (LA) contents and ratios of lactic acid/acetic acid. During ensiling, AZZ4 performed better among all of inoculants, indicated by significantly (P < 0·05) decreased on pH and ammonia-N contents and higher increased on LA contents.

CONCLUSION

Strain AZZ4 is recommended as starter culture for sweet sorghum.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first time to investigate the effects of LAB isolates from elephant grass silage and use them as additives, which is to find out how LAB inoculants improve the fermentation quality of sweet sorghum silage.

Serum Stem Cell Factor Level Predicts Decline in Kidney Function in Healthy Aging Adults

BACKGROUND AND OBJECTIVES

Stem cell factor (SCF), the ligand of the c-kit receptor, actively participates in the organ reconstruction and fibrosis associated with various diseases, including kidney disease. However, it remains unclear whether SCF plays a role in kidney aging.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

In the present study, we measured the serum SCF level, estimated glomerular filtration rate (eGFR), and other biological parameters in a Chinese Han group of 892 subjects, and explored the relationship between SCF level and renal function during aging; we sought to define novel biomarkers of kidney aging.

RESULTS

Multiple linear regression was used to select potential indicators of decline in renal function. Only age, SCF level, and 25% maximum expiratory flow (25% MEF) were significant predictors after redundancy analysis (|r| > 0.70 and P < 0.05). Multiple linear regression showed that the relationship among eGFR, SCF level, and age could be described as follows: eGFR = 154.486 - (0.846 × age) - (0.011 × SCF level).

CONCLUSIONS

We found no between-gender difference in the effect of SCF on kidney aging. In conclusion, the SCF level is an ideal biomarker of renal aging and may help to predict changes in eGFR during aging.

The fungal-resistance factors BmSPI38 and BmSPI39 predominantly exist as tetramers, not monomers, in Bombyx mori

Previous studies have indicated that trypsin inhibitor-like cysteine-rich domain (TIL)-type protease inhibitors, BmSPI38 and BmSPI39, suppress conidial germination and integument penetration of entomopathogenic fungi by inhibiting their cuticle-degrading proteases and might functions as fungal-resistance factors in the silkworm. To date, the physiological forms and functional significance of multimerization of BmSPI38 and BmSPI39 remain unknown. In this study, we investigated the physiological forms of BmSPI38 and BmSPI39 in Bombyx mori silkworms using multiple complementary methods, including activity staining, reducing and nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, western blotting and immunofluorescence. We found that recombinant BmSPI38 and BmSPI39 tend to form homologous multimers, and their dimers, trimers and tetramers possessed intense inhibitory activity against subtilisin A from Bacillus licheniformis. In contrast, their monomers showed no detectable inhibitory activity. Both BmSPI38 and BmSPI39 also exist mainly as stable tetramers in silkworm tissues, and they also predominantly function as a tetramer in these tissues. This study is the first to demonstrate this preferred quaternary form of a TIL-type protease inhibitor and will likely help to elucidate the mechanisms of BmSPI38 and BmSPI39 in the innate immune response of the silkworm.