Application of urinary N-acetyl-β-D-glucosaminidase combined with serum retinol-binding protein in early detection of diabetic nephropathy

BACKGROUND Diabetic nephropathy(DN)is a microangiopathy of type 2 diabetes mellitus(T2DM),which can damage the kidney through various ways and mechanisms due to the nature of the disease,involving the renal interstitium and glomeruli.However,in the early stage of the disease,patients only showed kidney volume increase and glomerular hyperthyroidism,and typical symptoms that are difficult to arouse individual attention were noticed.AIM To observe the expression of serum retinol-binding protein(RBP)and urinary Nacetyl-β-D-glucosaminidase(NAG)in patients with DN,and to analyze their value in disease prediction,so as to provide new targets for early diagnosis and treatment of DN.METHODS The baseline data of 50 T2DM patients treated in our hospital between January 2021 and December 2022 were retrospectively reviewed and included in group A.The baseline data of 50 patients with type 2 DN admitted to our hospital during the same period were collected and included in group B.The baseline data and serum RBP and urine NAG expression were compared between the two groups to analyze their value in the early prediction of DN.RESULTS There was no significant difference in age,gender,duration of diabetes,combined hyperlipidemia and combined hypertension between the two groups(P>0.05);the expression of urinary NAG and serum RBP in group B was higher than that in group A,and the difference was statistically significant(P<0.05);a multiple logistic regression model was established,and the results showed that urinary NAG and serum RBP were related to the presence or absence of injury in diabetic patients,and overexpression of urinary NAG and serum RBP may be risk factors for renal injury in T2DM patients(OR>1,P<0.05);receiver operating curve curve was plotted,and the results showed that the area under the curve of urinary NAG and serum RBP expression alone and in combination for predicting DN was>0.80,and the predictive value was satisfactory;bivariate Spearman linear correlation analysis showed that there was a positive correlation between urinary NAG and serum RBP expression in patients with DN(r=0.566,P=0.000).CONCLUSION The increased expression of urinary NAG and serum RBP may be the risk factors leading to the progression of T2DM to DN.The possibility of DN can be considered in patients with urinary NAG and serum RBP overexpression by examining the expression of urinary NAG and serum RBP in patients with T2DM in clinical practice.

Serum Amyloid A Protein: A Potential Biomarker Correlated With Clinical Stage of Lung Cancer

Objective To identify serum diagnosis or progression biomarkers in patients with lung cancer using protein chip profiling analysis. Method Profiling analysis was performed on 450 sera collected from 213 patients with lung cancer, 19 with pneumonia, 16 with pulmonary tuberculosis, 65 with laryngeal carcinoma, 55 with laryngopharyngeal carcinoma patients, and 82 normal individuals. A new strategy was developed to identify the biomarkers on chip by trypsin pre-digestion. Results Profiling analysis demonstrated that an 11.6kDa protein was significandy elevated in lung cancer patients, compared with the control groups （P〈0.001）. The level and percentage of 11.6kDa protein progressively increased with the clinical stages Ⅰ-Ⅳ and were also higher in patients with squamous cell carcinoma than in other subtypes. This biomarker could be decreased after operation or chemotherapy. On the other hand, 11.6kDa protein was also increased in 50% benign diseases of lung and 13% of other cancer controls. After trypsin pre-digestion, a set of new peptide biomarkers was noticed to appear only in the samples containing a 11.6kDa peak. Further identification showed that 2177Da was a fragment of serum amyloid A （SAA, MW 11.6kDa）. Two of the new peaks, 1550Da and 1611Da, were defined from the same protein by database searching. This result was further confirmed by partial purification of 11.6kDa protein and MS analysis. Conclusion SAA is a useful biomarker to monitor the progression of lung cancer and can directly identify some biomarkers on chip.

Decrease in Serum Amyloid a Protein Levels Following Three-month Stays in Negatively Charged Particle-dominant Indoor Air Conditions

Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air conditions（NCPDIAC）.Methods Seven volunteers participated in the study,which included ‘OFF to 3 months ON’ periods（ON trials） for a total of 16 times,and ‘ON to 3 months OFF’（OFF trials） periods for a total of 13 times.Results With the exception of one case,serum amyloid A（SAA） levels decreased significantly during the ON trials.Conclusion Considering that SAA is an acute phase reactive protein such as C reactive protein（CRP）,this observed decrease might indicate the prevention of cardiovascular and atherosclerotic changes,since an increase in high-sensitive CRP is associated with the subsequent detection of these events.

The prognostic value of serum C-reactive protein-bound serum amyloid A in early-stage lung cancer

Background:Elevated levels of serum C-reactive protein(CRP) have been reported to have prognostic significance in lung cancer patients.This study aimed to further identify CRP-bound components as prognostic markers for lung cancer and validate their prognostic value.Methods:CRP-bound components obtained from the serum samples from lung cancer patients or healthy controls were analyzed by differential proteomics analysis.CRP-bound serum amyloid A(CRP-SAA) was evaluated by coimmunoprecipitation(IP).Serum samples from two independent cohorts with lung cancer(retrospective cohort,242patients;prospective cohort,222 patients) and healthy controls(159 subjects) were used to evaluate the prognostic value of CRP-SAA by enzyme-linked immunosorbent assay.Results:CRP-SAA was identified specifically in serum samples from lung cancer patients by proteomic analysis.CRP binding to SAA was confirmed by co-IP in serum samples from lung cancer patients and cell culture media.The level of CRP-SAA was significantly higher in patients than in healthy controls(0.37 ± 0.58 vs.0.03 ± 0.04,P < 0.001).Elevated CRP-SAA levels were significantly associated with severe clinical features of lung cancer.The elevation of CRPSAA was associated with lower survival rates for both the retrospective(hazard ration[HR]= 2.181,95%confidence interval[CI]= 1.641-2.897,P < 0.001) and the prospective cohorts(HR = 2.744,95%CI = 1.810-4.161,P < 0.001).Multivariate Cox analysis showed that CRP-SAA was an independent prognostic marker for lung cancer.Remarkably,in stages l-ll patients,only CRP-SAA,not total SAA or CRP,showed significant association with overall survival in two cohorts.Moreover,univariate and multivariate Cox analyses also showed that only CRP-SAA could be used as an independent prognostic marker for early-stage lung cancer patients.Conclusion:CRP-SAA could be a better prognostic marker for lung cancer than total SAA or CRP,especially in earlystage patients.

Comparative evaluation of acute phase proteins by C-reactive protein(CRP)and serum amyloid A(SAA)in nonhuman primates and feline carnivores

The feasibility of a commercially available assay for C-reactive protein(CRP,CRP for humans:hCRP,and CRP for dogs:vCRP)and a trial reagent of serum amyloid A(SAA,vSAA for animals)were applied to the measurement of acute phase proteins in zoo animals,particularly in nonhuman primates and feline carnivores was evaluate.Results showed that hCRP and vSAA methods were applicable to measure CRP and SAA in Haplorhini.There was a highly signifcant correlation between both parameters with remarkably high correlation coefcient.A higher proportion of Bonnet macaques in Haplorhini,and the linear regression with good correlation between hCRP and vSAA levels were observed.Reference values in healthy Bonnet macaques were hCRP(46.86±30.97 nmol/L)and vSAA(9.06±1.95μg/mL).Although Ring-tailed lemur,which belonging to Strepsirrhini,showed low vSAA concentrations(reference values:1.08±0.47μg/mL),vSAA in patients was apparently elevated.The vCRP and vSAA methods were applicable to measurements of CRP and SAA in feline carnivores for highly signifcant correlation between both parameters.Theses two methods were also been deteded in lions,tigers and cheetahs.vSAA assays can be applied to measure SAA levels in other carnivores and herbivores.In conclusion,vSAA systems have potential utility as diagnostic tools for health screening and prediction in zoo animals.

Roles of Serum Amyloid A 1 Protein Isoforms in Rheumatoid Arthritis

Secondary amyloid A amyloidosis,a lethal complication,is induced when acute or chronic infection coexists with over-secretion of the serum amyloid A 1(SAA1)protein and deposition in key internal organs.Previously,using the whole-exome sequencing method,we identified a novel deleterious mutation SAA1.2 in rheumatoid arthritis(RA)patients.However,the role of SAA1 in RA pathogenesis and its complications remains unknown.The purpose of this study was to determine the pathogenetic roles of SAA1 protein isoforms in RA progression.We modified an experimental adenovirus infection protocol to introduce SAA1.2 gene alleles into the knee joints of mice and used SAA1.3 and SAA1.5 as controls.Microcomputed tomography analysis was applied to determine changes in bone morphology and density.Immunohistochemical(IHC)analysis,flow cytometry,enzyme-linked immunosorbent assay(ELISA),and real-time polymerase chain reaction(RT-PCR)were used to investigate disease progression and cytokine alterations in the course of adenoviral SAA-induced knee joint inflammation and bone destruction.We found that the arthritis-inducing effect of SAA1.2 transcription in the knee joints and mutant SAA1 protein secretion in blood resulted in the stimulation of immune responses,leading to CD8^(+)T cell and pro-inflammatory cytokine elevation,such as interleukin(IL)-6,IL-22,matrix metalloproteinase(MMP)-3,MMP-9,with subsequent synovial inflammation and bone destruction.These findings indicate that SAA1 protein isoforms,particularly SAA1.2,play a significant role in the induction and progression of RA and may have potential value in the early diagnosis and severity prediction of RA.

Effect of Chaiqinchengqi decoction on serum amyloid A in severe acute pancreatitis patients

Objective:To investigate the effect of Chaiqinchengqi decoction(CQCQD) on serum amyloid A (SAA) in severe acute pancreatitis(SAP) patients.Methods:Thirty-five participants enrolled and were randomly assigned into either a treatment condition(n=17,treated with CQCQD) or a control condition(n=18,treated with placebo) 24 hours following the onset of the disease. No statistical difference was observed in either group at baseline.Upon admission,the Acute Physiology and Chronic Health Evaluation scoreⅡ(APACHEⅡ),SAA,serum C-reactive protein (CRP) and interleukin-6(IL-6) were measured,as well as on the first,3rd and 7lh day and were compared between the two groups.Organ complications,infection,operation rate,mortality and hospital stay were also compared.Results:The duration of acute respiratory distress syndrome, acute hepatitis,acute renal failure,gastrointestinal failure and blood coagulation dysfunction were shorter in the treatment group than in those in the control group(P【0.05).The secondary infection rates and the hospital fees in the treatment group were lower than those in the control group(P【0.05) as well as length of hospital stay(P【0.01).After 3 days of hospitalization,the APACHEⅡ,score SAA levels,serum CRP and IL-6 in the treatment group was lower than those in the control group(P【0.05).SAA was positively correlated with serum CRP(R = 0.346,P = 0.042),Ranson score(R = 0.442,P = 0.008) and serum IL-6(R=0.359,P =0.034).The area under the receiver operating characteristic curve of admission SAA predict pancreatic necrosis(PN) was 0.815(95%CI:0.625-0.954;P =0.006).The best cut-off value of admission SAA was 7.85 mg/L with the sensitivity 84.6%and specificity 68.2%.Conclusions:The CQCQD can reduce the duration of organ damage through lowering the SAA in SAP patients and the SAA can early predict the PN and severity of SAP patients.

Serum amyloid A levels in patients with liver diseases

BACKGROUND Serum amyloid A(SAA)is an acute phase protein mainly synthesized by the liver.SAA induces inflammatory phenotype and promotes cell proliferation in activated hepatic stellate cells,the major scar forming cells in the liver.However,few studies have reported on the serum levels of SAA in human liver disease and its clinical significance in various liver diseases.AIM To investigate the serum levels of SAA in patients with different liver diseases and analyze the factors associated with the alteration of SAA levels in chronic hepatitis B(CHB)patients.METHODS Two hundred and seventy-eight patients with different liver diseases and 117 healthy controls were included in this study.The patients included 205 with CHB,22 with active autoimmune liver disease(AILD),21 with nonalcoholic steatohepatitis(NASH),14 with drug-induced liver injury(DILI),and 16 with pyogenic liver abscess.Serum levels of SAA and other clinical parameters were collected for the analysis of the factors associated with SAA level.Mann-Whitney U test was used to compare the serum SAA levels of patients with various liver diseases with those of healthy controls.Bonferroni test was applied for post hoc comparisons to control the probability of type 1 error(alpha=0.05/6=0.008).For statistical tests of other variables,P<0.05 was considered statistically significant.Statistically significant factors determined by single factor analysis were further analyzed by binary multivariate logistic regression analysis.RESULTS All patients with active liver diseases had higher serum SAA levels than healthy controls and the inactive CHB patients,with the highest SAA level found in patients with pyogenic liver abscess(398.4±246.8 mg/L).Patients with active AILD(19.73±24.81 mg/L)or DILI(8.036±5.685 mg/L)showed higher SAA levels than those with active CHB(6.621±6.776 mg/L)and NASH(6.624±4.891 mg/L).Single(P<0.001)and multivariate logistic regression analyses(P=0.039)for the CHB patients suggested that patients with active CHB were associated with an SAA serum level higher than 6.4 mg/L.Serum levels of SAA and CRP(C-reactive protein)were positively correlated in patients with CHB(P<0.001),pyogenic liver abscess(P=0.045),and active AILD(P=0.02).Serum levels of SAA(0.80-871.0 mg/L)had a broader fluctuation range than CRP(0.30-271.3 mg/L).CONCLUSION Serum level of SAA is a sensitive biomarker for inflammatory activity of pyogenic liver abscess.It may also be a weak marker reflecting milder inflammatory status in the liver of patients with CHB and other active liver diseases.

Effect of Panax notoginseng saponins on the expression of beta-amyloid protein in the cortex of the parietal lobe and hippocampus, and spatial learning and memory in a mouse model of senile dementia

BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.

Mutations of beta-amyloid precursor protein alter the consequence of Alzheimer's disease pathogenesis

Alzheimer's disease is pathologically defined by accumulation of extracellular amyloid-β(Aβ). Approximately 25 mutations in β-amyloid precursor protein(APP) are pathogenic and cause autosomal dominant Alzheimer's disease. To date, the mechanism underlying the effect of APP mutation on Aβ generation is unclear. Therefore, investigating the mechanism of APP mutation on Alzheimer's disease may help understanding of disease pathogenesis. Thus, APP mutations(A673T, A673 V, E682 K, E693 G, and E693Q) were transiently co-transfected into human embryonic kidney cells. Western blot assay was used to detect expression levels of APP, beta-secretase 1, and presenilin 1 in cells. Enzyme-linked immunosorbent assay was performed to determine Aβ_(1–40) and Aβ_(1–42) levels. Liquid chromatography-tandem mass chromatography was used to examine VVIAT, FLF, ITL, VIV, IAT, VIT, TVI, and VVIA peptide levels. Immunofluorescence staining was performed to measure APP and early endosome antigen 1 immunoreactivity. Our results show that the protective A673 T mutation decreases Aβ_(42)/Aβ_(40) rate by downregulating IAT and upregulating VVIA levels. Pathogenic A673 V, E682 K, and E693 Q mutations promote Aβ_(42)/Aβ_(40) rate by increasing levels of CTF99, Aβ_(42), Aβ_(40), and IAT, and decreasing VVIA levels. Pathogenic E693 G mutation shows no significant change in Aβ_(42)/Aβ_(40) ratio because of inhibition of γ-secretase activity. APP mutations can change location from the cell surface to early endosomes. Our findings confirm that certain APP mutations accelerate Aβ generation by affecting the long Aβ cleavage pathway and increasing Aβ_(42/40) rate, thereby resulting in Alzheimer's disease.

Contrast-enhanced ultrasonographic findings of serum amyloid A-positive hepatocellular neoplasm: Does hepatocellular adenoma arise in cirrhotic liver?

Hepatocellular adenoma(HCA) was recently classified into four pathological subtypes. There have been few studies describing the findings of contrast-enhanced ultrasonography(CEUS) of each type. Our case concerns a 78-year-old man who had undergone routine medical check-ups for hepatitis C for 11 years. Abdominal ultrasonography showed a 28 mm, hypo-echoic mass in the segment 4 of the liver. His integrating amount of drinking was 670 kg convert into ethanol. CEUS with Sonazoid demonstrated mild uniform hypo-enhancement with inflow of microbubbles from the periphery of the tumor in the arterial phase, and heterogeneously hypo-enhancement in the post vascular phase. Because the mass increased in size within 3 mo, a well differentiated hepatocellular carcinoma was suspected, and hepatic resection was performed. Microscopic findings showed homogeneous cell proliferation with low grade atypia, infiltration of inflammatory cells, ductular reactions, fatty deposit in part, and sinusoidal dilation. Immunohistochemistry revealed geographic positive for serum amyloid A(SAA), focal positive for glutaminesynthetase, diffuse and strong positive for C-reactive protein, and positive for liver-type fatty acid binding protein. These pathological features corresponded to that of an inflammatory HCA. However, we could not make a clear diagnosis, because HCAs were defined as not to arise in cirrhotic liver. Finally, this tumor was diagnosed as a SAA positive hepatocellular neoplasm.

Compound Danshen tablets downregulate amyloid protein precursor mRNA expression in a transgenic cell model of Alzheimer's disease Effects and a comparison with donepezil

After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.

Key gene and protein changes in the beta-amyloid pathway following Longyanshen polysaccharides treatment in a mouse model of Alzheimer's disease

BACKGROUND： During onset and development of Alzheimer＇s disease, β-amyloid （Aβ） precursor protein （APP）, β-site amyloid precursor protein cleaving enzyme （BACE）, and β-amyloid are key genes and proteins in the Aβ pathway, and over-expression of these genes can lead to Aβ deposit/on in the brain. OBJECTIVE： To observe the influence of Longyanshen polysaccharides on expression of BACE, APP, and Aβ in the senescence-accelerated mouse prone/8 （SAMP8） brain, and to compare these effects with huperzine A treatment. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiochemical experiment was performed at the Department of Pharmacology and Scientific Experimental Center of Guangxi Medical University from September 2005 to January 2008. MATERIALS： Longyanshen polysaccharfdes powder was extracted from the dried slices of the medicinal plant Longyanshen. The active component, Longyanshen polysaccharides, was provided by the Department of Pharmacology, Guangxi Medical University; huperzine A was purchased from Yuzhong Drug Manufactory, China. METHODS： Healthy SAMP8 mice were used to establish a model of Alzheimer＇s disease. A total of 50 SAMP8 mice were randomly assigned to 5 groups （n = 10）： SAMP8, huperzine A, low-, middle-, and high-dose polysaccharides. In addition, 10 senescence-accelerated mouse resistant 1 （SAMR1） mice were selected as normal controls. SAMP8 and SAMR1 mice were administered 30 mL/kg normal saline; the huperzine A group was administered 0.02 mg/kg huperzine A; the low-, middle-, and high-dose polysaccharides groups were respectively administered 45, 90, and 180 mg/kg Longyanshen polysaccharides. Each group was treated by intragastric administration, once per day, for 50 consecutive days. MAIN OUTCOME MEASURES： One hour after the final administration, immunohistochemical analysis was used to determine Aβ expression in the cortex and hippocampus of SAMP8 mice. Reverse-transcription polymerase chain reaction was used to determine mRNA levels of BACE and APP in SAMP8 brain tissue. RESULTS： Compared with the SAMR1 group, Aβ expression in the cerebral cortex and hippocampus, as well as expression of BACE, APP mRNA in the brain was significantly increased in the SAMP8 group （P 〈 0.05-0.01）. Compared with the SAMP8 group, Aβ expression, as well as BACE and APP mRNA expression, were significantly decreased in the cerebral cortex and hippocampus of huperzine A and low-, middle-, and high-dose polysaccharides groups （P 〈 0.05-0.01）. In particular, the effect of high-dose polysaccharides was the most significant （P 〈 0.05-0.01 ）. CONCLUSION： Longyanshen polysaccharides reduced or inhibited over-expression of BACE, APP, and Aβ in SAMP8 mice in a dose-dependent manner, and the effect was not worse than huperzine A.

Impact of Sub-chronic Aluminium-maltolate Exposure on Catabolism of Amyloid Precursor Protein in Rats

Objective To investigate the impact of sub-chronic Aluminium-maltolate [Al（mal）s] exposure on the catabolism of amyloid precursor protein （APP） in rats. Methods Forty adult male Sprague-Dawley （SD） rats were randomly divided into five groups： the control group, the maltolate group （7.56 mg/kg BW）, and the Al（mal）s groups （0.27, 0.54, and 1.08 mg/kg BW, respectively）. Control rats were administered with 0.9% normal saline through intraperitoneal （i.p.） injection. Maltolate and Al（mal）s were administered to the rats also through i.p. injections. Administration was conducted daily for two months. Rat neural behavior was examined using open field tests （OFT）. And the protein expressions and their mRNAs transcription related with APP catabolism were studied using enzyme-linked immunosorbent assay （ELISA） and real-time polymerase chain reaction （RT-PCR）. Results The expressions of APP, 13-site APP cleaving enzyme 1 （BACEI） and presenilin-1 （PSi） proteins and their mRNAs transcription increased gradually with the increase of Al（mal）3 doses （P〈0.05）. The enzyme activity of BACEI in the 0.54 and 1.08 mg/kg Al（mal）s groups increased significantly （P〈0.05）. The expression of 8-amyloid protein （AS） 1-40 gradually decreased while the protein expression of A81-42 increased gradually with the increase of Al（mal）s doses （P〈0.05）. Conclusion Result from our study suggested that one of the possible mechanisms that Al（mal）s can cause neurotoxicity is that Al（mal）s can increase the generation of A81-42 by facilitating the expressions of APP, β-, and γ-secretase.

Amyloid precursor protein and growth-associated protein 43 expression in brain white matter and spinal cord tissues in a rat model of experimental autoimmune encephalomyelitis

Studies have demonstrated that amyloid precursor protein （APP） expression increases in multiple sclerosis tissues during acutely and chronically active stages. To determine the relationship between axonal injury and regeneration in multiple sclerosis, an animal model of experimental autoimmune encephalomyelitis was induced using different doses of myelin basic protein peptide. APP and growth-associated protein 43 （GAP-43）, which is considered a specific marker of neural regeneration, were assessed by western blot analysis. Expression of APP and GAP-43, as well as the correlation between these two proteins, in brain white matter and spinal cord tissues of experimental autoimmune encephalomyelitis rats at different pathological stages was analyzed. Results showed that APP and GAP-43 expression increased during the acute stage and decreased during remission, with a positive correlation between APP and GAP-43 expression in brain white matter and spinal cord tissues. These results suggest that APP and GAP-43 could provide nutritional and protective effects on damaged neurons.

Study on The Method of Quantitative Analysis of Serum Ferritin and Soluble Transferrin Receptor with Protein Microarray Technology

Objective To establish and evaluate a protein serum ferritin （SF） and soluble transferrin receptor microarray method for combined measurement of （sTfR）. Methods Microarrayer was used to print both anti-SF antibodies I and anti-sTfR antibodies I on each protein microarray. Anti-SF antibodies II and anti-sTfR antibodies II were used as detection antibodies and goat antibodies coupled to Cy3 were used as antibodies Ill. The detection conditions of the quantitative analysis method for simultaneous measurement of SF and sTfR with protein microarray were optimized and evaluated. The protein microarray was compared with commercially available traditional tests with 26 serum samples. Results By comparison experiment, mouse monoclonal antibodies were chosen as the probes and contact printing was chosen as the printing method. The concentrations of SF and sTfR probes were 0.5 mg/mL and 0.5 mg/mL respectively, while those of SF and sTfR detection antibodies were 5 μg/mL and 0.36 μg/mL respectively. Intra- and inter-assay variability was between 3.26% and 18.38% for all tests. The regression coefficients comparing protein microarray with traditional test assays were better than 0.81 for SF and sTfR. Conclusion The present study has established a protein microarray method for combined measurement of SF and sTfR.

miR-15b-5p targeting amyloid precursor protein is involved in the anti-amyloid eflect of curcumin in swAPP695-HEK293 cells

Curcumin exerts a neuroprotective effect on Alzheimer’s disease;however,it is not known whether microRNAs are involved in this protective effect.This study was conducted using swAPP695-HEK293 cells as an Alzheimer’s disease cell model.swAPP695-HEK293 cells were treated with 0,0.5,1,2,5,and 10μM curcumin for 24 hours.The changes in miR-15b-5p,miR-19a-3p,miR-195-5p,miR-101-3p,miR-216b-5p,miR-16-5p and miR-185-5p expression were assessed by real-time quantitative polymerase chain reaction.The mRNA and protein levels of amyloid precursor protein,amyloid-β40 and amyloid-β42 were evaluated by quantitative real-time polymerase chain reaction,western blot assays and enzyme-linked immunosorbent assays.swAPP695-HEK293 cells were transfected with miR-15b-5p mimic,or treated with 1μM curcumin 24 hours before miR-15b-5p inhibitor transfection.The effects of curcumin on amyloid precursor protein,amyloid-β40 and amyloid-β42 levels were evaluated by western blot assays and enzyme-linked immunosorbent assay.Luciferase assays were used to analyze the interaction between miR-15b-5p and the 3′-untranslated region of amyloid precursor protein.The results show that amyloid precursor protein and amyloid-βexpression were enhanced in swAPP695-HEK293 cells compared with HEK293 parental cells.Curcumin suppressed the expression of amyloid precursor protein and amyloid-βand up-regulated the expression of miR-15b-5p in swAPP695-HEK293 cells.In addition,we found a negative association of miR-15b-5p expression with amyloid precursor protein and amyloid-βlevels in the curcumin-treated cells.Luciferase assays revealed that miR-15b-5p impaired the luciferase activity of the plasmid harboring the 3′-untranslated region of amyloid precursor protein.These findings indicate that curcumin down-regulates the expression of amyloid precursor protein and amyloid-βin swAPP695-HEK293 cells,which was partially mediated by miR-15b-5p via targeting of the 3′-untranslated region of amyloid precursor protein.

Physiological effects of amyloid precursor protein and its derivatives on neural stem cell biology and signaling pathways involved

The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of APP are still poorly understood.APP is considered a multimodal protein due to its role in a wide variety of processes,both in the embryo and in the adult brain.Specifically,APP seems to play a key role in the proliferation,differentiation and maturation of neural stem cells.In addition,APP can be processed through two canonical processing pathways,generating different functionally active fragments:soluble APP-α,soluble APP-β,amyloid-β peptide and the APP intracellular C-terminal domain.These fragments also appear to modulate various functions in neural stem cells,including the processes of proliferation,neurogenesis,gliogenesis or cell death.However,the molecular mechanisms involved in these effects are still unclear.In this review,we summarize the physiological functions of APP and its main proteolytic derivatives in neural stem cells,as well as the possible signaling pathways that could be implicated in these effects.The knowledge of these functions and signaling pathways involved in the onset or during the development of Alzheimer’s disease is essential to advance the understanding of the pathogenesis of Alzheimer’s disease,and in the search for potential therapeutic targets.

The Effect of Silica Dust Exposure on the Serum Clara Cell Protein 16 Levels in Chinese Workers

Pneumoconiosis is a systemic occupational disease that commonly manifests as diffuse fibrosis of the lungs caused by long-term inhalation of silica dust in the production process. The development of pneumoconiosis is a chronic and progressive process;once it occurs, it is irreversible, and gradually develops into lung injury and respiratory failure, and can cause death regardless of exposure to dust. The incidence of pneumoconiosis is the highest in China and the direct and indirect economic loss as a result of pneumoconiosis is approximately 9 billion yuan per year.

Immune infiltration-associated serum amyloid A1 predicts favorable prognosis for hepatocellular carcinoma

BACKGROUND Serum amyloid A1(SAA1)is an acute-phase protein involved in acute or chronic hepatitis.Its function is still controversial.In addition,the effect of the expression of SAA1 and its molecular function on the progression in hepatocellular carcinoma(HCC)is still unclear.AIM To demonstrate the expression of SAA1 and its effect on the prognosis in HCC and explain further the correlation of SAA1 and immunity pathways.METHODS SAA1 expression in HCC was conducted with The Cancer Genome Atlas-Liver Hepatocellular Carcinoma(TCGA-LIHC)in GEPIA tool,and the survival analysis based on the SAA1 expression level was achieved in the Kaplan-Meier portal.The high or low expression group was then drawn based on the median level of SAA1 expression.The correlation of SAA1 and the clinical features were conducted in the UALCAN web-based portal with TCGA-LIHC,including tumor grade,patient disease stage,and the TP53 mutation.The correlation analysis between SAA1 expression and TP53 mutation was subjected to the TCGA portal.The tumor purity score and the immune score were analyzed with CIBERSORT.The correlation of SAA1 expression and tumor-infiltrating lymphocytes was achieved in TISIDB web-based integrated repository portal for tumor-immune system interactions.GSE125336 dataset was used to test the SAA1 expression in the responsive or resistant group with anti-PD1 therapy.Gene set enrichment analysis was applied to evaluate the gene enrichment signaling pathway in HCC.The similar genes of SAA1 in HCC were identified in GEPIA,and the proteinprotein interaction of SAA1 was conducted in the Metascape tool.The expression of C-X-C motif chemokine ligand 2,C-C motif chemokine ligand 23,and complement C5a receptor 1 was studied and overall survival analysis in HCC was conducted in GEPIA and Kaplan-Meier portal,respectively.RESULTS SAA1 expression was decreased in HCC,and lower SAA1 expression predicted poorer overall survival,progression-free survival,and disease-specific survival.Furthermore,SAA1 expression was further decreased with increased tumor grade and patient disease stage.Also,SAA1 expression was further downregulated in patients with TP53 mutation compared with patients with wild type TP53.SAA1 expression was negatively correlated with the TP53 mutation.Lower SAA1 predicted poorer survival rate,especially in the patients with no hepatitis virus infection,other than those with hepatitis virus infection.Moreover,the SAA1 expression was negatively correlated with tumor purity.In contrast,SAA1 expression was positively correlated with the immune score in HCC,and the correlation analysis between SAA1 expression and tumor-infiltrating lymphocytes also showed a positive correlation in HCC.Decreased SAA1 was closely associated with the immune tolerance of HCC.C-X-C motif chemokine ligand 2 and C-C motif chemokine ligand 23 genes were identified as the hub genes associated with SAA1,which could also serve as favorable prognosis markers for HCC.CONCLUSION SAA1 is downregulated in the liver tumor,and it is closely involved in the progression of HCC.Lower SAA1 expression indicates lower survival rate,especially for those patients without hepatitis virus infection.Lower SAA1 expression also suggests lower immune infiltrating cells,especially for those with immune cells exerting anti-tumor immune function.SAA1 expression is closely associated with the anti-tumor immune pathways.