Proteomic Identification of Serum Proteins Associated with Stress-Induced Gastric Ulcers in Fasted Rats

Advances in Apolipoprotein-A4 Biosensing Assays for Depression Diagnosis

Apolipoprotein-A4 (Apo-A4) is a plasma protein that plays a role in various physiological and behavioral-emotional reactions when faced with stress. Studies have shown a close relationship between Apo-A4 and the onset of depression and its symptoms. However, there is currently no reliable laboratory approach to confirm the diagnosis of depression. Therefore, the development of a precise and effective technique to assess Apo-A4 might help in the early detection and screening of depression and other related psychiatric diseases, as well as in tracking and managing the course of treatment. As technology advances, biosensors have become quick, accurate, and sensitive tools for personal care and illness diagnosis. Biosensors for measuring and detecting Apo-A4 levels have recently been designed. These studies emphasized the development of accurate and sensitive diagnostic and measurement techniques. This review attempts to give a general overview of the role of Apo-A4 in depression and introduce established biosensors for its detection and measurement.

Changes in saliva analytes in equine gastric ulcer syndrome (EGUS) after treatment: a pilot study

Equine gastric ulcer syndrome (EGUS) is a prevalent condition in horses, affecting up to 93% of racehorses. Comprising the equine squamous gastric disease (ESGD) and the equine glandular gastric disease (EGGD), EGUS poses significant health challenges. Saliva, a non-invasive and easily obtainable sample, is increasingly recognized for its potential as a source of biomarkers in horses. This study investigates changes in saliva analytes using automated assays before and after EGUS treatment, aiming to identify biomarkers indicative of treatment success or failure. A total of 28 horses diagnosed with EGUS were treatment with omeprazole for six weeks and further divided into successful (n = 15) or unsuccessful (n = 13) treatment group. Saliva samples were collected before and after treatment, and analytes related to enzymes, metabolites, proteins, redox biomarkers, and minerals were measured using an automated chemistry analyzer. Results revealed that horses with successful treatment, indicated by reduced EGGD and ESGD scores, showed significant increases in bicarbonate and urea, and decreases in adenosine deaminase (ADA), and creatine kinase (CK). Conversely, horses with non-successful treatment showed no significant changes in salivary analytes. These analytes have the advantages of an easy and fast measurement and the possibility of being applied in routine. Further studies with larger populations should be performed to establish the possible practical application of these analytes as biomarkers of treatment.

A novel electrochemical immunosensor for sensitive detection of depression marker Apo-A4 based on bipyridine-functionalized covalent organic frameworks

A novel electrochemical immunosensor for detecting potential depression biomarker Apolipoprotein A4 (Apo-A4) was developed using a multi-signal amplification approach. Firstly, the sensor utilized a modified electrode material, NG-PEI-COF, combining bipyridine-functionalized covalent organic framework (COF) and polyethyleneimine-functionalized nitrogen-doped graphene (NG-PEI), providing high surface area and excellent electron transfer capability for the first-stage amplification in electrical signal conduction. Subsequently, gold nanoparticles (AuNPs) were further electrodeposited onto the electrode, providing good biocompatibility and abundant binding sites for immobilizing the target antigen, thus achieving the second-stage amplification in target recognition and binding. To address the lack of redox properties of the antigen, a tracer probe was formed by loading AuNPs, anti-Apo-A4, and toluidine blue (TB) successively onto COF, leading to the third-stage amplification in signal conversion. The constructed electrochemical immunosensor TB/Ab/AuNPs/COF-Apo-A4/AuNPs/NG-PEI-COF/GCE exhibited excellent detection performance against Apo-A4 with a linear range of 0.01 to 300 ng mL-1 and had a low detection limit of 2.16 pg mL-1 (S/N = 3). In addition, the biosensor had good reproducibility (RSD = 2.31%), stability, and significant anti-interference performance toward other depression biomarkers. The sensor has been successfully used for the quantitative detection of Apo-A4 in serum, providing potential applications for detecting Apo-A4 in the clinic and serving as a reference for constructing sensing methods based on COF.

Proximity hybridization induced bipedal DNA walker and rolling circle amplification for label-free electrochemical detection of apolipoprotein A4

Apolipoprotein A4 (Apo-A4) is considered as a prospective molecular biomarker for diagnosis of depression due to its neurosynaptic toxicity. We develop a proximity hybridization-induced DNAzyme-driven bipedal DNA walker strategy for Apo-A4 quantification based on rolling circle amplification (RCA) triggered by poly adenine binding to Ag nanoparticles (AgNPs). With the help of DNAzyme, the free-running bipedal DNA walker can quickly and sequentially shear a molecular beacon that acts as a primer to initiate the RCA process, producing a large number of long DNA strands containing numerous adenines. The long repetitive adenine strands then absorb large amounts of AgNPs on the electrode interface, which is then electrochemically stripped of the AgNPs. The method has a linear detection range of 0.001 ∼ 100 ng mL-1 and a detection limit of 0.46 pg mL-1. The presented detection strategy is label-free, which allows high sensitivity and selectivity for detection of a wide range of protein targets by corresponding DNA-based affinity probes, which have potential applications in bioanalysis.

Label-free SERS detection of apolipoprotein A4 based on DNAzyme-driven molecular machine

Apolipoprotein A4 has a wide range of synaptic toxicity and can be used as a reliable molecular biomarker for the detection of depressive disorder. It has certain clinical requirements for simple, rapid and selective detection of apolipoprotein A4. Here, based on the DNA biped walker driven by DNAzyme, we designed a label-free surface-enhanced Raman scatting sensor for rapid detection of apolipoprotein A4. Compared with the typical DNA walker, the biped DNA walker has the advantages of large walking range and high magnification efficiency. The magnesium-dependent DNAzyme drives the DNA walker, which can cut the MBs sequentially. The resulting MBs fragments were then hybridized with AuNPs modified by repetitive adenine to make Au NPs proliferate on the substrate surface, resulting in a large number of cycles. Using 736 cm-1 adenine as the internal marker, surface enhanced Raman scattering analysis showed that the linear detection range of human apolipoprotein A4 was 10∼1000 ng mL-1, the detection limit was 4.7 pg/mL, and it had significant specificity, which could meet the needs of clinical detection and showed great application potential.

Proximity hybridization induced bipedal DNA walker for label-free electrochemical detection of apolipoprotein A4 based on DNA meditated Ag nanoparticles growth

Apolipoprotein A4 (Apo-A4) is considered as a prospective molecular biomarker for diagnosis of depression due to its neurosynaptic toxicity. Here, we propose a neighboring hybridization induced catalyzed hairpin assembly (CHA) driven bipedal DNA walker that mediates hybridization of Ag nanoparticles (Ag NPs) with DNA probes for highly sensitive electrochemical quantitative detection of Apo-A4. Driven by CHA, this bipedal DNA walker can spread all over the surface of the sensor, induce the HP1-HP2 double chain structure, make the surface of the sensor negatively charged, and adsorb a large number of Ag ions. After chemical reduction with hydroquinone, the Ag NPs formed provide signal tracers for electrochemical dissolution analysis of the target. The Ag NPs formed by chemical reduction of hydroquinone can provide signal traces for electrochemical stripping analysis of target thrombin. The linear range of this method is from 10 pg mL-1 to 1000 ng mL-1, and the detection limit is 5.1 pg mL-1. This enzyme-free and labeling detection method provides a new strategy for rapid clinical detection of Apo-A4 and accurate identification of depression.

Evaluation of a Comprehensive Profile of Salivary Analytes for the Diagnosis of the Equine Gastric Ulcer Syndrome

In this report, the measurement of salivary biomarkers as an aid for diagnosis of equine gastric ulcer syndrome (EGUS) was studied. A comprehensive panel of 23 salivary analytes was measured in the saliva of horses affected by EGUS and compared to healthy animals and horses with other diseases clinically similar to EGUS but with a negative diagnosis at gastroscopic examination. A total of 147 horses were included in the study and divided into heathy population (n = 12), the EGUS group (n = 110), and the group of horses with other diseases (n = 25). From the 23 analytes studied, 17 showed increased values in EGUS horses when compared to healthy ones, and uric acid, triglycerides, and calcium were significantly increased in horses with EGUS compared to the group of other diseases. The receiver operating characteristic curve analyses showed a modest but significant discriminatory power of those three analytes to identify EGUS from other diseases with similar symptoms. The discriminatory power enhanced when the results of the three analytes were combined. In conclusion, the results showed that selected salivary analytes could have potential use as biomarkers in horses with EGUS.

Label-free electrochemical homogeneous detection of the depression marker human apolipoprotein A4 based on proximity hybridization triggered rolling circle amplification

In this paper, we developed a label-free homogeneous electrochemical sensor for detection of apolipoprotein A4 based on proximity hybridization triggered rolling circle amplification induced G-quadruplex formation. The presence of apolipoprotein A4 promoted the formation of a proximate complex via the proximity hybridization of the aptamer DNA strands, which unfolded the molecular beacon, the stem part of molecular beacon as a primer to initiate the RCA process. Thus, with the electrochemical indicator hemin selectively intercalated into the multiple G-quadruplexes, a significant electrochemical signal drop is observed, which is dependent on the concentration of the target apolipoprotein A4. Thus, using this "signal-off" mode, label-free homogeneous electrochemical strategy for sensitive apolipoprotein A4 assay with a wide range from 1 pg mL^-1 to 100 ng mL^-1, with a low detection limit of 0.51 pg mL^-1. And it rendered satisfactory analytical performance for the determination of apolipoprotein A4 in serum samples. Furthermore, this method also exhibits additional advantages of simplicity and low cost, since both expensive labeling and sophisticated probe immobilization processes are avoided. The satisfactory results indicated that the proposed sensor had promising potential in the clinical diagnosis of depression.

A novel electrochemical immunosensor for the highly sensitive and selective detection of the depression marker human apolipoprotein A4

The fabrication of electrochemical biosensors to directly, rapidly and ultrasensitively detect disease markers in urine or blood samples has become a new and competitive challenge in the field of sensor research. In this paper, a novel electrochemical immunosensor with high selectivity and sensitivity for the detection of the depression marker human apolipoprotein A4 (Apo-A4) was successfully constructed using zeolite imidazole ester metal organic skeleton-nitrogen doped graphene composites (ZIF-8@N-Gr). To this end, because of the higher surface area and biocompatibility, ZIF-8 with abundant biomolecular binding sites provided a good microenvironment for effectively immobilizing antigens. ZIF-8@N-Gr presented a flake structure, as the electrode displayed excellent electrical conductivity, which enhanced the electron transfer and significantly amplified the current signal of the immunosensor. More importantly, these immunosensors are capable of assaying human apolipoprotein A4 (Apo-A4) in 100% serum without suffering from any significant biological interference. Under optimized experimental conditions, the sensor was used for the analysis of whole serum samples and presented a wide linear range from 1.47 × 10^-10 g/mL to 3.00 × 10^-7 g/mL with a low detection limit of 8.33 × 10^-11 g/mL (3σ, n = 15). The satisfactory results of human serum sample analysis indicated that the proposed immunosensor had promising potential in the clinical diagnosis of depression.

Gastro-protective and Anti-stress Efficacies of Monomethyl Fumarate and a Fumaria indica Extract in Chronically Stressed Rats

Results of the very first experiments conducted to evaluate therapeutic potentials of a fumarate containing Fumaria indica extract and of fairly low daily oral doses of monomethyl fumarate for prevention of chronic unavoidable foot-shock stress-induced gastric ulcers, and possible involvement of diverse neuro-hormonal and oxidative process in their stress response desensitizing effects are reported and discussed in this article. Preventive effects of 21 daily oral 60, 120, and 240 mg/kg doses of a standardized 50 % methanolic F. indica extract (MFI) and 1.25, 2.50, and 5.00 mg/kg/day of pure monomethyl fumarate (MMF) were compared in rats subjected to one hour daily unavoidable foot-shocks. A pharmaceutically well-standardized Withania somnifera (WS) root extract was used as a reference herbal anti-stress agent in all experiments. Effects of the treatments on stress-induced alterations in body weight, adrenal and spleen weights, gastric ulcer and ulcer index, weight of glandular stomach, protective mucosal glycoprotein content, cellular proliferation, oxidative stress on stomach fundus, and brain tissues of male rats were quantified. Other parameters quantified were plasma corticosterone levels, brain monoamine levels, and expressions of the cytokines TNF-α, IL-10, and IL-1β in blood and brain of stressed and treated rats. Most but not every observed stress-induced anomalies were suppressed or completely prevented by both MFI and pure MMF treatments in dose-dependent manner. Qualitatively, the observed activity profiles of both of them were similar to those of WS dose tested. These results reveal that both MFI and MMF are potent gastro-protective agents against chronic unavoidable stress-induced ulcers and strongly suggest that they act as regulators or modulators of monoamine, corticosterone, and cytokine homeostasis.

Depressive symptoms of female nursing staff working in stressful environments and their association with serum creatine kinase and lactate dehydrogenase - a preliminary study

Background

The activity of creatine kinase (CK) in serum has recently been reported to be potentially associated with several types of depression. The aim of this study is to evaluate whether serum enzymes, including CK, vary even in a healthy population with depressive symptoms caused by work-related stress. We gave questionnaires and blood examinations to 93 healthy female nursing home workers and did an enzyme-linked immunosorbent assay for the quantitative detection of CK isozyme muscle-type M chain (CK-MM) in serum.

Findings

Depressive symptoms were determined using the Center for Epidemiologic Studies Depression (CES-D) scale and compared with the results of the blood examination and serum CK-MM levels. The CES-D results showed significant negative correlations with total CK and lactate dehydrogenase (LDH) activities and CK-MM level (r = -0.29, p = 0.0062; r = -0.29, p = 0.0065; r = -0.33, p = 0.0016, respectively).

Conclusions

Total CK and LDH activities and serum CK-MM level appear to be associated with the depressive symptoms of healthy nurses working in stressful environments, although the significance level was relatively low. The simultaneous detection of serum CK and LDH activities or serum CK-MM level and LDH activity may be useful as an indicator of depressive symptoms, at least for female nursing staff with work-related stress.

Bidirectional crosstalk between stress-induced gastric ulcer and depression under chronic stress

Stress contributes to a variety of diseases and disorders such as depression and peptic ulcer. The present study aimed to investigate the correlation between stress ulcer and depression in pathogenesis and treatment by using chronic stress depression (CSD), chronic psychological stress ulcer (CPSU) and water immersion restrain stress models in rats. Our data showed that the ulcer index of the animals after CSD exposure was significantly higher than that of controls. Depression-like behaviors were observed in rat after CPSU exposure. Fluoxetine hydrochloride significantly reduced the ulcer index of rats exposed to CPSU stress, while ranitidine inhibited depression-like behavior of the animals in CSD group. The ulcer index of rats administered with mifepristone after CPSU stress was markedly reduced compared to CPSU group, although there was no significant difference in the depression-like behavior between mifepristone-treated CSD group and naive controls. We also found that the rats exposed to CPSU or CSD stress displayed a lower level of corticosterone than naive controls, however, the acute stress (AS) group showed an opposite result. Additionally, in order to study the relevance of H(2) receptors and depression, we treated the CSD group with cimetidine and famotidine respectively. The data showed that cimetidine inhibited depression-like behavior in CSD rats, and famotidine had no impact on depression. Overall our data suggested that the hypothalamic-pituitary-adrenal (HPA) axis dysfunction may be the key role in triggering depression and stress ulcer. Acid-suppressing drugs and antidepressants could be used for treatment of depression and stress ulcer respectively. The occurrence of depression might be inhibited by blocking the central H(2) receptors.