Anti-necroptosis and anti-ferroptosis compounds from the Deep-Sea-Derived fungus Aspergillus sp. MCCC 3A00392

Eight undescribed (1-8) and 46 known compounds (9-54) were isolated from the deep-sea-derived Aspergillus sp. MCCC 3A00392. Compounds 1-3 were three novel oxoindolo diterpenoids, 4-6 were three bisabolane sesquiterpenoids, while 7 and 8 were two monocyclic cyclopropanes. Their structures were established by exhaustive analyses of the HRESIMS, NMR, and theoretical calculations of the NMR data and ECD spectra. Compounds 10, 33, 38, and 39 were able to inhibit tumor necrosis factor (TNF)-induced necroptosis in murine L929 cell lines. Functional experiments verified that compounds 10 and 39 inhibited necroptosis by downregulating the phosphorylation of RIPK3 and MLKL. Moreover, compound 39 also reduced the phosphorylation of RIPK1. Compounds 10, 33, and 34 displayed potent inhibitory activities against RSL-3 induced ferroptosis with the EC50 value of 3.0 μM, 0.4 μM, and 0.1 μM, respectively. Compound 10 inhibited ferroptosis by the downregulation of HMOX1, while compounds 33 and 34 inhibited ferroptosis through regulation of NRF2/SLC7A11/GCLM axis. However, these compounds only showed weak effect in either the necroptosis or ferroptosis relative mouse disease models. Further studies of pharmacokinetics and pharmacodynamics might improve their in vivo bioactivities.

Interpretable CT radiomics model for invasiveness prediction in patients with ground-glass nodules

AIM

To evaluate the performance of an interpretable computed tomography (CT) radiomic model in predicting the invasiveness of ground-glass nodules (GGNs).

MATERIALS AND METHODS

The study was conducted retrospectively from 1 August 2017 to 1 August 2022, at three different centres. Two hundred and thirty patients with GGNs were enrolled at centre I as a training cohort. Centres II (n=157) and III (n=156) formed two external validation cohorts. Radiomics features extracted based on CT were reduced by a coarse-fine feature screening strategy. A radiomic model was developed through the use of the LASSO (least absolute shrinkage and selection operator) and XGBoost algorithms. Then, a radiological model was established through multivariate logistic regression analysis. Finally, the interpretability of the model was explored using SHapley Additive exPlanations (SHAP).

RESULTS

The radiomic XGBoost model outperformed the radiomic logistic model and radiological model in assessing the invasiveness of GGNs. The area under the curve (AUC) values for the radiomic XGBoost model were 0.885 (95% confidence interval [CI] 0.836-0.923), 0.853 (95% CI 0.790-0.906), and 0.838 (95% CI 0.773-0.902) in the training and the two external validation cohorts, respectively. The SHAP method allowed for both a quantitative and visual representation of how decisions were made using a given model for each individual patient. This can provide a deeper understanding of the decision-making mechanisms within the model and the factors that contribute to its prediction effectiveness.

CONCLUSIONS

The present interpretable CT radiomics model has the potential to preoperatively evaluate the invasiveness of GGNs. Furthermore, it can provide personalised, image-based clinical-decision support.

[Risk factors of systemic allergic reactions caused by subcutaneous allergen immunotherapy]

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.

Chemical Constituents of the Deep-sea Gammarid Shrimp-Derived Fungus Penicillium citrinum XIA-16

One new alkaloid, (S)-2-acetamido-4-(2-(methylamino)phenyl)-4-oxobutanoic acid (1), was isolated from the deep-sea-derived Penicillium citrinum XIA-16, together with 25 known compounds including ten polyketones (2-11), eight alkaloids (12-19), six steroids (20-25), and a fatty acid (26). Their planar and relative structures were determined by an analysis of 1D and 2D nuclear magnetic resonance (NMR) as well as high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) data. The absolute configuration of 1 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Penicitrinol B (6) significantly inhibited RSL3-induced ferroptosis (EC50 =2.0 μM) by reducing lipid peroxidation and heme oxygenase 1 (HMOX1) expression. Under the concentration of 10 μM, penicitrinol A (7) was able to inhibit cuproptosis with the cell viabilities of 68.2 % compared to the negative control (copper and elesclomol) with the cell viabilities of 14.8 %.

[Influence of the severity and treatment of allergic rhinitis and asthma on SARS-CoV-2 infection]

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected 660 million people and resulted in 6.7 million deaths. At present, a variety of risk factors related to the severity of COVID-19 have been identified, but whether allergic rhinitis and asthma will affect SARS-CoV-2 infection remains controversial. In general, there is no sufficient evidence to support that allergic rhinitis or asthma is a risk factor for increasing the rate of SARS-CoV-2 infection or aggravating the disease. Some studies even show that atopy may be a protective factor to alleviate SARS-CoV-2 infection, which is related to the decreased expression of angiotensin-converting enzyme 2, the receptor required for SARS-CoV-2 to enter cells, in atopic individuals. This paper reviews the influence of the severity and treatment of allergic rhinitis and asthma on SARS-CoV-2 infection, in order to provide some references for establishing strategies for prevention, risk stratification and treatment of COVID-19.

[Research progress of Eubacterium and its metabolite short-chain fatty acids in regulating type 2 diabetes mellitus]

Intestinal flora and its metabolites are closely related to the progression of type 2 diabetes mellitus(T2DM). Eubacterium is one of the dominant intestinal flora, and its metabolites short-chain fatty acids (SCFAs) play a leading role in regulating intestinal metabolic balance. It has been reported that SCFAs can regulate the secretion of glucagon-like peptide-1, improve the function of pancreatic β cells, participate in bile acids metabolism and regulate the production of inflammatory factors in T2DM. Based on the above research background, this article mainly reviews the relationship between Eubacterium and its metabolite SCFAs and T2DM and its regulatory mechanism.

[Prenatal genetic diagnosis of the fetuses with isolated corpus callosum abnormality]

Objective: To explore the application value of chromosome karyotype analysis, chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in prenatal diagnosis of isolated corpus callosum abnormality (CCA) fetus. Methods: Fetuses diagnosed with isolated CCA by ultrasound and MRI and receiving invasive prenatal diagnosis in Guangzhou Women and Children's Medical Center and Qingyuan People's Hospital from January 2010 to April 2021 were selected. Karyotype analysis and/or CMA [or copy number variation sequencing (CNV-seq)] were performed on all fetal samples, and WES was performed on fetal samples and their parents whose karyotype analysis and/or CMA (or CNV-seq) results were not abnormal. Results: Among 65 fetuses with isolated CCA, 38 cases underwent karyotype analysis, and 3 cases were detected with abnormal karyotypes, with a detection rate of 8% (3/38). A total of 49 fetuses with isolated CCA underwent CMA (or CNV-seq) detection, and 6 cases of pathogenic CNV were detected, the detection rate was 12% (6/49). Among them, the karyotype analysis results were abnormal, and the detection rate of further CMA detection was 1/1. The karyotype results were normal, and the detection rate of further CMA (or CNV-seq) detection was 14% (3/21). The detection rate of CMA as the first-line detection technique was 7% (2/27). A total of 25 fetuses with isolated CCA with negative results of karyotyping and/or CMA were tested by WES, and 9 cases (36%, 9/25) were detected with pathogenic genes. The gradient genetic diagnosis of chromosomal karyotyping, CMA and WES resulted in a definite genetic diagnosis of 26% (17/65) of isolated CCA fetuses. Conclusions: Prenatal genetic diagnosis of isolated CCA fetuses is of great clinical significance. The detection rate of CMA is higher than that of traditional karyotyping. CMA detection could be used as a first-line detection technique for fetuses with isolated CCA. WES could increase the pathogenicity detection rate of fetuses with isolated CCA when karyotype analysis and/or CMA test results are negative.

Current status of immunotherapy for non-small cell lung cancer

Nowadays, lung cancer is still the deadliest oncological disease in the world. Among them, non-small cell lung cancer (NSCLC) accounts for 80%∼85% of all lung cancers, and its 5-year survival rate is less than 15%, making the situation critical. In the past decades, despite some clinical advances in conventional treatments, the overall survival rate of NSCLC is still not optimistic due to its unique physiological conditions and the frequent occurrence of tumor escape. In recent years, immunotherapy has become a new hot spot in lung cancer research, including antibody therapy and cell therapy, which have been developed and utilized one after another, especially immune checkpoint inhibitor (ICI). These approaches have effectively improved the overall survival rate and objective response rate of NSCLC patients by enhancing the immune capacity of the body and targeting tumor cells more effectively, which is more specific and less toxic compared with conventional chemotherapy, and providing more strategies for NSCLC treatment. In this paper, we reviewed the relevant targets, clinical progress and adverse reaction in monoclonal antibodies, antibody-drug conjugates, ICI, bispecific antibodies, T-cell receptor engineered T cell therapy (TCR-T), Chimeric antigen receptor T-cell immunotherapy (CAR-T), and also report on their combination therapy from the immune-related background to provide better NSCLC treatment and prospective.

[Analysis of families with fetal congenital abnormalities but negative prenatal diagnosis by whole exome sequencing]

Objective: To evaluate the value of whole exome sequencing (WES) in prenatal clinical application. Methods: A total of 1 152 cases of congenital abnormal [including structural malformation, nuchal translucency (NT) thickening and intrauterine growth restriction] with traditional prenatal diagnosis [including G-band karyotype analysis and chromosome microarray analysis (CMA)] negative were analyzed. The congenital abnormal fetuses were divided into retrospective group and prospective group according to the time of WES detection, that is whether the pregnancy termination or not. According to the specific location of fetal malformation and their family history, the cohort was divided into subgroups. The clinical prognosis of all fetuses were followed up, and the effect of WES test results on pregnancy decision-making and clinical intervention were analyzed. According to the follow-up results, the data of fetuses with new phenotypes in the third trimester or after birth were re-analyzed. Results: Among 1 152 families who received WES, 5 families were excluded because of nonbiological parents. Among the remaining 1 147 families, 152 fetuses obtained positive diagnosis (13.3%,152/1 147), including 74 fetuses in the retrospective group (16.1%,74/460) and 78 fetuses in the prospective group (11.4%,78/687). In fetuses with negative CMA and G-band karyotype analysis results but new phenotypes in the third trimester or after birth, the positive rate by WES data re-analysis was 4.9% (8/163). A total of 34 (21.3%, 34/160) fetuses were directly affected by the corresponding positive molecular diagnosis. Among 68 cases of live births with diagnostic variation grade 4, 29 cases (42.7%, 29/68) received appropriate medical intervention through rapid review of WES results. Conclusions: WES could increase the detection rate of abnormal fetuses with negative G-banding karyotype analysis and CMA by 13.3%. Prenatal WES could guide pregnancy decision-making and early clinical intervention. It might be an effective strategy to pay attention to the special follow-up of the third trimester and postnatal fetus and to re-analyze the WES data.

[The effect on patient life quality of prophylactic treatment to seasonal allergic rhinitis and related transcriptomics research]

Objective: The preseason prophylactic treatment of seasonal allergic rhinitis (AR) caused by pollens could alleviate AR symptoms during the pollen season. This study aimed to evaluate the effect of prophylaxis usage of suplatast tosilate on the life quality of AR patients in the pollen season, and investigate the potential mechanism of action through transcriptomic analysis. Methods: This is a randomized controlled study. AR patients allergic to weed pollens were recruited from Allergy Clinic of Peking Union Medical College Hospital from January 2020 to June 2020, and divided into prophylactic group who started to take suplatast tosilate as prophylaxis 2 weeks before the spread of weed pollens[n=10, 4 men and 6 women with age range of (34±6) years old] and control group who did not use any prophylactic treatment[n=24, 12 men and 12 women with age range of (33±9) years old]. The differences of age (t=0.381, P=0.706) and gender (χ²=0.595, P=0.715) distribution between the patients of two groups were not statistically significant. All the subjects filled in the rhinoconjunctivitis quality of life questionnaire (RQLQ) while onset of AR symptoms, and peripheral blood was drawn for transcriptomic analysis 1 month before and during the pollen season. Differences between groups were statistically analyzed through chi-square test and t test. Results: There was no significant difference in visual analogue scale of rhinitis symptom in the last pollen season between prophylactic group and control group[ 8.0 (6.4, 9.3) vs 7.3 (6.1, 8.0), Z=1.180, P=0.254]. The RQLQ score of prophylactic group was superior to that of control group in the weed pollen season (2.9±0.9 vs 3.7±0.9, t=-2.438, P=0.026). 210 differentially expressed genes of fold change ≥2 were identified, with 147 genes upregulated and 63 genes downregulated in the prophylactic group compared to the control group. Gene Ontology annotation showed that IL-12 and IL-23 related pathways were downregulated in prophylactic group (P=0.006 48). Polymerase Chain Reaction (PCR) verification of differentially expressed genes indicated that the relative expression level of HLA-G in prophylactic group was significantly lower than that in control group (0.23±0.19 vs 1.00±0.49,t=4.016, P=0.006). Conclusion: The prophylactic treatment of suplatast tosilate showed some benefit to the life quality of seasonal AR patients during the pollen season, and the potential mechanism might be related with the downregulation of IL-12 and IL-23 pathways and decreased expression of HLA-G.

[Appropriate protocol of treatment modulation for seasonal allergic rhinitis caused by cypress pollens]

Objective: To investigate appropriate protocol of treatment modulation for seasonal allergic rhinitis (AR) patients, in order to promote the implementation of personalized medicine. Methods: Total of 124 AR patients allergic to cypress pollens were recruited from January to February 2020 in Department of Allergy in Peking Union Medical College Hospital, 43 males and 81 females with an average age of (41±9) years. The patients were divided into two groups with block randomization method. In the first group, treatment was modulated every two days according to the average daily rhinoconjunctivitis symptom score of the last two days (short-term symptom-score group); while in the second group, therapy regimen was adjusted every week based on the Allergic Rhinitis Control Test (ARCT) score of the last week (long-term ARCT group). The treatment level was up-regulated when the cypress pollen count increased and stayed at a high level (step-up pharmacotherapy stage); and treatment was down-regulated while the pollen count decreased (step-down pharmacotherapy stage). Daily symptom scores, medicine scores, and ARCT scores of the two groups were recorded and compared. Results: During the whole cypress pollen season, the daily rhinoconjunctivitis symptom score of short-term symptom-score group was significantly lower than that in long-term ARCT group(2.4±1.0 vs 2.7±1.0, P<0.01), and the difference between the two groups was more pronounced in the step-up pharmacotherapy stage than that in the step-down pharmacotherapy stage, while there was no statistical difference between the daily medicine scores of the two groups (P>0.05). During the pollen rising period, the ARCT score of short-term symptom-score group was significantly better than that of long-term ARCT group (21(19, 22) vs 20 (17, 21), P=0.049); while in the pollen peak period and decreasing period, the ARCT scores of the two groups showed no statistical difference (P>0.05). The proportion of incompliance with doctor's advice was higher in long-term ARCT group compared to that in short-term symptom-score group (30.1% vs 6.7%, P<0.001). Conclusion: The protocol of treatment modulation for seasonal AR patients allergic to pollens should be developed flexibly according to the variation trend of pollen allergen exposure, so as to implement the idea of personalized medicine.

New insight into function and dysfunction of gut microfold cells

Microfold cells (M cells), derived from intestinal crypt Lgr5⁺ stem cells, are distributed in gut-associated lymphoid tissue (GALT), nasopharyngeal-associated lymphoid tissue (NALT), and bronchial-associated lymphoid tissue (BALT). The basement membrane of mature M cells protrudes upward, showing a "pocket-like" shape. M cell differentiation is mainly regulated by two pathways, one is the non-canonical NF-κB pathway, and the other is the canonical NF-κB pathway. The differentiation and maturation of M cells are closely related to RANKL and S100A4. M cells can not only transport antigens and trigger an immune response, but also are the gateway for various pathogens to invade the body. The occurrence and development of tuberculosis, prion disease, and Crohn's disease are closely related to M cells.

[The comparison of step-down pharmacotherapy and maintaining dose therapy for seasonal allergic rhinitis]

Objective:There is no standard algorithm for the modulation of pharmacologic treatment of allergic rhinitis. This study aimed to recruited allergic rhinitis patients caused by cypress pollens, and compare the step-down pharmacotherapy guided by pollen count and the maintaining therapy which keeps the previous medicine dose when the pollen count decreased. Method:This was a randomized, open-labelled, parallel control study. During the period after the pollen peak when the cypress pollen count decreased and stayed at a low level, allergic rhinitis patients were randomly divided into two groups. In the step-down group（n=67） medicine dose was reduced, while the maintaining group（n=68） kept taking the same dose as in the peak season. The rhinitis symptom score and medicine score of these two groups were recorded and compared. Result:The daily rhinitis symptom score of the step-down group showed no significant difference with the symptom score of the maintaining group, 2.45±0.32 vs 2.43±0.41, P=0.788. But the medicine score of step-down group（3.67±0.98） was significantly lower than that of maintaining group（4.78±0.70）, P<0.001. The compliance of step-down group（80.6%） was also better than maintaining group（60.3%）, P=0.014. However, in the subgroup of patients with severe rhinitis symptoms, the symptoms of patients taking step-down therapy tended to be more severe than those maintaining the same dose. Conclusion:During the later period of the pollen season when the pollen count was relatively low, the step-down pharmacotherapy guided by pollen count could reduce the medication use, increase the compliance of patients while controlling their rhinitis symptoms effectively. But this strategy might be more suitable for patients with milder symptoms, the severe rhinitis sufferers should be cautious before reducing their medicine dose.

Regulation of intestinal epithelial barrier by and dysfunction of intestinal glial cells

The enteric glia is an important component of the enteric nervous system and forms a broad network in the mucosa of the gastrointestinal tract. Enteric glial cells (EGC) are located in all layers of the intestinal wall and respond to neurotransmitters and neuromodulators through signal transduction pathways. The enteric nervous system interacts with resident glial cells in the gut, and there is increasing evidence that EGC are involved in the regulation of epithelial function. Epithelial cells have important absorption and secretion functions and are also involved in the formation of intestinal epithelial barrier. Studies have found that the enteric glia is not only involved in the regulation of gastrointestinal motility and epithelial barrier function, but also in the formation of cellular molecular bridges between intestinal neurons, enteroendocrine cells, immune cells, and epithelial cells. This article reviews the recent progress in the understanding of the role of EGC in the intestinal barrier and defense functions.

[Analysis of sensitization spectrum and clinical features of children with adenoid hypertrophy and perennial rhinitis]

Objective:To investigate the sensitization spectrum and clinical features of children with adenoid hypertrophy and perennial rhinitis.Method:A total of 121 children with adenoidal hypertrophy and perennial rhinitis were enrolled in the ENT Department of the Children's Hospital of the Capital Institute of Pediatrics and the Allergy Department of Peking Union Medical College Hospital from July to October in 2017. Nasopharyngoscopy was performed, and specific IgE were measured by blood sampling, and the sensitization spectrum and clinical characteristics of the children were analyzed. Result: Adenoid hypertrophy combined with allergic rhinitis accounted for 64.5% of the total, mold sensitization was the most common, accounting for 78.2% of allergic rhinitis patients, including boys accounted for 67.2%, gender differences were statistically significant(P<0.05). Patients with allergic rhinitis had a more severe endoscopic appearance, with a higher proportion of 4 degree, accounting for 75.0% of the total number of children with 4 degree under the nasopharyngoscopy, and only 25.0% of children without defined allergens. There was a significant difference between this two groups(P<0.05). Conclusion: Allergic rhinitis is closely related to adenoid hypertrophy, and the effect of allergen on the clinical manifestations of patients with adenoid hypertrophy should be emphasized.

Function and dysfunction of plasma cells in intestine

As the main player in humoral immunity, antibodies play indispensable roles in the body’s immune system. Plasma cells (PCs), as antibody factories, are important contributors to humoral immunity. PCs, recognized by their unique marker CD138, are always discovered in the medullary cords of spleen and lymph nodes and in bone marrow and mucosal lymphoid tissue. This article will review the origin and differentiation of PCs, characteristics of short- and long-lived PCs, and the secretion of antibodies, such as IgA, IgM, and IgG. PCs play a crucial role in the maintenance of intestinal homeostasis using immunomodulation though complex mechanisms. Clearly, PCs play functional roles in maintaining intestinal health, but more details are needed to fully understand all the other effects of intestinal PCs.

Progress in understanding relationship between bile acid metabolic disorder and gut diseases

There are a large number of microorganisms in the human intestine, which rely on the nutrition in the digestive tract to survive. At the same time, they affect the intestinal neuro-immune function through the metabolism substances produced by themselves. The enteric neuro-immune system regulates the functions of digestion and absorption so as to maintain the homeostasis in the intestine. Intestinal bile acid metabolism disorder might induce gut dysfunction or intestinal immune imbalance. This review describes the effect of intestinal microbes on the enteric nervous system or other signal molecules of the bile acid pathway linked to some intestinal disorders, with an aim to provide a theoretical basis for clinical treatment of the related diseases.

Enterochromaffin cells and gastrointestinal diseases

Enterochromaffin cells (ECs), known for their special histochemical characteristics, originate from enteroblasts. For their important role in physiological and pathophysiological conditions, ECs in the gut could synthesize and secrete about 95% of 5-hydroxytryptamine (5-HT) in the body, which is an important humoral factor. As a chemosensor, ECs can regulate nutrition absorption and satiety through the sensory neural pathways. In addition, ECs participate in immune regulation. What's more, ECs and 5-HT are closely related to many kinds of gastrointestinal diseases.

Dendrobium nobile Lindl. Alkaloids Decreases the Level of Intracellular β-Amyloid by Improving Impaired Autolysosomal Proteolysis in APP/PS1 Mice

As the major degradation pathway for long-lived proteins and organelles, macroautophagy is a decisive factor for the survival and longevity of cells. The existing evidence indicates that the disruption of substrate proteolysis in autolysosomes is the main mechanism underlying autophagy failure in Alzheimer’s disease (AD). Thus, the restoration of normal lysosomal proteolysis and autophagy efficiency is a novel therapeutic strategy in the treatment of AD. In this study, 9-month-old APPswe/PS1ΔE9 transgenic (APP/PS1) mice were administered Dendrobium nobile Lindl. alkaloids (DNLA, 40 and 80 mg/kg) or Metformin (80 mg/kg), and age-matched wild-type mice were administered an isovolumic vehicle orally once a day for 4 months. The results demonstrated that DNLA significantly improved learning and memory function in APP/PS1 transgenic mice in the Morris water maze. Furthermore, DNLA could increase the expression of the v-ATPase A1 subunit to facilitate lysosomal acidification, prompt the dissociation of the cation independent-mannose-phosphate receptor from cathepsin (cat) D, promote the proteolytic maturation of cat D, increase the degradation of accumulated autophagic vacuoles (AVs) and β-amyloid (Aβ) contained in the AVs, and alleviate neuronal and synaptic injury. These findings demonstrate that DNLA improves learning and memory function in APP/PS1 mice, and the mechanisms appear to be due to the promotion of intracellular Aβ degradation by increasing the protein level of v-ATPase A1 and then improving autolysosomal acidification and proteolysis.

Intestinal mast cells and their function

Mast cells develop from the CD34⁺ precursor cells in bone marrow, are activated in the gut, and can release a variety of bioactive mediators, including histamine, 5-hydroxytryptamine, and tryptase. They play a crucial role in intestinal innate and adaptive immunity because of their diverse secretory granules and unique mature characteristics. Many studies have shown that a variety of intestinal diseases have close relationship with mast cells, especially inflammatory bowel disease, irritable bowel syndrome, and intestinal allergic diseases, which has attracted extensive attention. In this paper, we review the function and mechanism of intestinal mast cells and their role in the treatment of related clinical diseases.

Functional macrophages and gastrointestinal disorders

Macrophages (MΦ) differentiate from blood monocytes and participate in innate and adaptive immunity. Because of their abilities to recognize pathogens and activate bactericidal activities, MΦ are always discovered at the site of immune defense. MΦ in the intestine are unique, such that in the healthy intestine, they possess complex mechanisms to protect the gut from inflammation. In these complex mechanisms, they produce anti-inflammatory cytokines, such as interleukin-10 and transforming growth factor-β, and inhibit the inflammatory pathways mediated by Toll-like receptors. It has been demonstrated that resident MΦ play a crucial role in maintaining intestinal homeostasis, and they can be recognized by their unique markers. Nonetheless, in the inflamed intestine, the function of MΦ will change because of environmental variation, which may be one of the mechanisms of inflammatory bowel disease (IBD). We provide further explanation about these mechanisms in our review. In addition, we review recent discoveries that MΦ may be involved in the development of gastrointestinal tumors. We will highlight the possible therapeutic targets for the management of IBD and gastrointestinal tumors, and we also discuss why more details are needed to fully understand all other effects of intestinal MΦ.

[The clinical value of China Savin pollen extract used for skin prick test]

Objective:The aim of this study is to evaluate the effectiveness and safety of China Savin pollen extract which was used for skin prick test (SPT) in the diagnosis of China Savin pollen allergy. Method:Patients with diagnosis of allergic diseases were collected from Allergy Department of Peking Union Medical College Hospital. All patients were given SPT with China Savin pollen extract, and the mean wheal diameter (MWD) was measured after 15 minutes. Receiver operating characteristic curve (ROC) analysis was performed based on the results of serum specific immunoglobulin E (sIgE). The effectiveness of SPT in the diagnosis of China Savin pollen allergy was evaluated under different diagnostic cutoff values. Adverse events were also recorded to evaluate the safety. Result:A total of 1 029 patients were enrolled in this study without drop out case. There were 1 007 patients in full analysis set (FAS) and 765 patients in per protocol analysis set (PPS). The elimination rate was 25.66%. The area under the ROC curve of FAS is 0.814 (95%CI: 0.788-0.839); which of PPS is 0.829 (95%CI: 0.801-0.857). Based on the ROC curve of PPS, the optimal and the 95% specificity diagnostic cutoff values of MWD were 3.25 mm and 4.75 mm respectively. Based on different diagnostic cutoff value (3.00, 3.25 and 4.75 mm), the sensitivities of SPT with China Savin pollen extract were 0.740 0 (95%CI: 0.701 6-0.778 4), 0.700 (95%CI: 0.659 8-0.740 2) and 0.532 (95%CI: 0.488 3-0.575 7) respectively, whereas the specificity was gradually increased in sequence, which was 0.769 8 (95%CI: 0.719 1-0.820 5), 0.826 4 (95%CI: 0.780 8-0.872 0) and 0.950 9 (95%CI: 0.924 9-0.976 9) respectively. There were 7 adverse events observed among 6 patients (rate: 0.583%, 6/1 029). The manifestation was mild. There was no severe adverse event. Conclusion:SPT with China Savin pollen extract is an effective and safe tool for the diagnosis of China Savin pollen allergy. The effectiveness of diagnosis could be improved based on integration of medical history and different diagnostic threshold values of SPT.

Biological characteristics of intestinal IgE and gut diseases

Immunoglobulin E (IgE), a crucial protective substance for the intestinal tract, plays an important role in gut immunity. IgE is secreted by plasma cells in the submucosal lamina propria upon antigenic invasion and, together with certain cytokines and immune cells, is involved in the regulation of gastrointestinal immunity in normal or abnormal conditions via the high affinity IgE receptor (FcεR I) and low affinity IgE receptor (CD23⁺). In this paper, we review the structure, synthetic transport, secretory regulation, receptor classification, and function of intestinal IgE as well as the related gut diseases.

Continuous Veno-Venous Hemofiltration in the Treatment of Acute Severe Hyponatremia: A Report of 11 Cases

Objectives

To evaluate the treatment effect of continuous veno-venous hemofiltration (CVVH) in patients with acute severe hyponatremia.

Methods

Eleven patients with severe acute hyponatremia, including 6 males and 5 females, aged 25–61 years (mean age 48.36), were treated with CVVH. Hyponatremia occurred 38–48 hours prior to the initiation of CVVH.

Results

All patients tolerated CVVH well, with an average treatment duration of 57.19 (45.6–86) hours. During CVVH, the serum sodium concentration increased significantly from 100.9±3.99 mmol/L at initiation of CVVH to 140.3±1.6 mmol/L after 48 hours of treatment (P<0.01). The serum osmolarity increased concurrently, from 216.7±7.4 mOsm/kgH2O to 295.0±4.2 mOsm/kgH2O (P<0.01). The Glasgow scores and APACHE II scores in these patients improved significantly during treatment.

Conclusions

CVVH is a safe and effective option for the treatment of patients with severe acute hyponatremia due to its slow and continuous nature.

[Effects of double-dose antihistamine or combined therapy in allergic rhinitis]

Objective:To compare the efficacy and side effects of combined therapy with single-dose oral antihistamine and intranasal corticosteroid to monotherapy with double-dose oral antihistamine in the treatment of seasonal allergic rhinitis. Method:Eighty-two patients with seasonal allergic rhinitis caused by cypress pollen were enrolled in a randomized, parallel-group studycomparing 2 weeks therapy of either 10mg oral ebastine plus 200 μg intranasal mometasone furoate once daily (combined group) or 20 mg oral ebastine once daily (double-dose group) during the pollen season. Daily rhinoconjunctivitis symptom score and rescue medication use were recorded in both groups. After the treatment period, questionnaires were used to survey the side effects of medicines and dosage form preference of the patients. The levels of IL-6, IL-8 and TNF-α in the peripheral blood were measured before and after the therapy. Result:During the cypress pollen season, the daily rhinoconjunctivitis symptom score of the combined group (n=42, 3.7±0.4) was significantly lower than that of double-dose group (n=40, 4.5±0.5), P<0.001. The daily rescue medication score of the combined group (1.3±0.6) was also significantly lower than double-dose group(1.7±0.7), P<0.001. The daily medication cost of combined group was 7.08±0.33 Yuan, which was less than that of double-dose group (7.28±0.51 Yuan, P=0.002). There was no statistical difference in the rate of adverse reactions between the two groups. The peripheral levels of IL-6, IL-8 and TNF-α in two groups did not show significant difference at the end of therapy . Conclusion:The combined therapy with single-dose oral antihistamine and intranasal corticosteroid was superior to the monotherapy with double-dose oral antihistamine in the treatment of seasonal allergic rhinitis in our study.

Dendrobium nobile Lindl alkaloid, a novel autophagy inducer, protects against axonal degeneration induced by Aβ25-35 in hippocampus neurons in vitro

AIMS

Axonal degeneration is a pathological symbol in the early stage of Alzheimer's disease (AD), which can be triggered by amyloid-β (Aβ) peptide deposition. Growing evidence indicates that deficit of autophagy eventually leads to the axonal degeneration. Our previous studies have shown that Dendrobium nobile Lindl alkaloid (DNLA) had protective effect on neuron impairment in vivo and in vitro; however, the underlying mechanisms is still unclear.

METHODS

We exposed cultured hippocampus neurons to Aβ_25-35 to investigate the effect of DNLA in vitro. Axonal degeneration was evaluated by immunofluorescence staining and MTT assay. Neurons overexpressing GFP-LC3B were used to measure the formation of autophagosome. Autophagosome-lysosome fusion, the lysosomal pH, and cathepsin activity were assessed to reflect autophagy process. Proteins of interest were analyzed by Western blot.

RESULTS

DNLA pretreatment significantly inhibited axonal degeneration induced by Aβ_25-35 peptide in vitro. Further studies revealed DNLA treatment increased autophagic flux through promoting formation and degradation of autophagosome in hippocampus neurons. Moreover, enhancement of autophagic flux was responsible for the protective effects of DNLA on axonal degeneration.

CONCLUSIONS

DNLA prevents Aβ_25-35 -induced axonal degeneration via activation of autophagy process and could be a novel therapeutic target.

[Treatment effect of sodium pyruvate nasal spray on allergic rhinitis]

Objective:Pyruvate is a key intermediate in several metabolic pathways of human body Sodium pyruvate possesses anti-oxidation and anti-inflammatory effects, which make it a possible novel therapy for allergic rhinitis. However, the relevant clinical research is rare. The aim of the present study is to evaluate the treatment effect of sodium pyruvate nasal spray on allergic rhinitis.Method:This was a randomized, parallel-group, single-center study, and 53 adult patients with seasonal allergic rhinitis caused by Artemisia pollen were recruited. In the pollen season, all the participants were given corticosteroid nasal spray of standard dose for two weeks, and during the next two weeks they were randomized to treatment group (n = 23) taking nasal sodium pyruvate, and control group (n = 30) without sodium pyruvate. Daily rhinoconjunctivitis symptom score and daily rescue medication score were analyzed. Also the fraction of exhaled nitric oxide of the upper airway was measured before and after the treatment of sodium pyruvate. Result:The demographic characteristics and baseline disease severity were not significantly different between the treatment group and control group. Both the daily symptom score (1.4±0.6 vs 1.7±0.4, P= 0.006) and rescue medication score (4.8±1.2 vs 5.8±1.2, P= 0.000) of the treatment group was significantly lower than the scores of control group. In addition, nasal fraction of exhaled nitric oxide of the treatment group (596.3±134.6)ppb tended to be lower than control group (709.6±311.3)ppb, although the difference was not significant, P= 0.408. Conclusion:Sodium pyruvate nasal spray was effective in attenuating the rhinoconjunctivitis symptoms and reducing the rescue medication use of allergic rhinitis patients. The application value and mechanism of action of sodium pyruvate are worth further studying.

Dendrobium alkaloids prevent Aβ25-35-induced neuronal and synaptic loss via promoting neurotrophic factors expression in mice

BACKGROUND

Neuronal and synaptic loss is the most important risk factor for cognitive impairment. Inhibiting neuronal apoptosis and preventing synaptic loss are promising therapeutic approaches for Alzheimer's disease (AD). In this study, we investigate the protective effects of Dendrobium alkaloids (DNLA), a Chinese medicinal herb extract, on β-amyloid peptide segment 25-35 (Aβ_25-35)-induced neuron and synaptic loss in mice.

METHOD

Aβ_25-35(10 µg) was injected into the bilateral ventricles of male mice followed by an oral administration of DNLA (40 mg/kg) for 19 days. The Morris water maze was used for evaluating the ability of spatial learning and memory function of mice. The morphological changes were examined via H&E staining and Nissl staining. TUNEL staining was used to check the neuronal apoptosis. The ultrastructure changes of neurons were observed under electron microscope. Western blot was used to evaluate the protein expression levels of ciliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF) in the hippocampus and cortex.

RESULTS

DNLA significantly attenuated Aβ_25-35-induced spatial learning and memory impairments in mice. DNLA prevented Aβ_25-35-induced neuronal loss in the hippocampus and cortex, increased the number of Nissl bodies, improved the ultrastructural injury of neurons and increased the number of synapses in neurons. Furthermore, DNLA increased the protein expression of neurotrophic factors BDNF, CNTF and GDNF in the hippocampus and cortex.

CONCLUSIONS

DNLA can prevent neuronal apoptosis and synaptic loss. This effect is mediated at least in part via increasing the expression of BDNF, GDNF and CNTF in the hippocampus and cortex; improving Aβ-induced spatial learning and memory impairment in mice.

2-(3',5'-Dimethoxybenzylidene) cyclopentanone, a novel synthetic small-molecule compound, provides neuroprotective effects against ischemic stroke

2-(3',5'-Dimethoxybenzylidene) cyclopentanone (DMBC) is a novel small-molecule compound synthesized by our group. Here, we found that in rat models of permanent middle cerebral artery occlusion (pMCAO), intraperitoneal injection (ip) of DMBC at 1h after ischemia reduced infarct volume, improved neurological deficits and increased the protein levels of microtubule-associated protein 2 (MAP 2) and glial fibrillary acid protein (GFAP) in the ischemic cortex. Post-treatment of DMBC still produced neuroprotective effects even when administered at 6h after ischemia. In the oxygen-glucose deprivation (OGD)-induced astrocytes or HT22 cell injury, DMBC treatment decreased the OGD-induced lactate dehydrogenase (LDH) leakage and increased the GFAP levels in astrocytes. In addition, Annexin-V-Fluos staining analysis revealed that DMBC treatment attenuated both OGD-induced apoptosis and necrosis in astrocytes. Western blotting analysis showed DMBC treatment inhibited the ischemia or OGD-induced increases in active cathepsin B in the ischemic cortex or in astrocytes or HT22 cells. Immunofluorescence analysis demonstrated that DMBC treatment blocked the ischemia or OGD-induced release of cathepsin B from the lysosomes into the cytoplasm in the ischemic cortex or in astrocytes or HT22 cells. Taken together, our results indicate that DMBC can offer neuroprotective effects against cerebral ischemia with an extended therapeutic window and its mechanism might be associated with inhibition of the cathepsin B activation.

Effect of entacapone on colon motility and ion transport in a rat model of Parkinson’s disease

AIM: To study the effects of entacapone, a catechol-O-methyltransferase inhibitor, on colon motility and electrolyte transport in Parkinson’s disease (PD) rats.

METHODS: Distribution and expression of catechol-O-methyltransferase (COMT) were measured by immunohistochemistry and Western blotting methods. The colonic smooth muscle motility was examined in vitro by means of a muscle motility recording device. The mucosal electrolyte transport of PD rats was examined by using a short-circuit current (I_SC) technique and scanning ion-selective electrode technique (SIET). Intracellular detection of cAMP and cGMP was accomplished by radioimmunoassay testing.

RESULTS: COMT was expressed in the colons of both normal and PD rats, mainly on the apical membranes of villi and crypts in the colon. Compared to normal controls, PD rats expressed less COMT. The COMT inhibitor entacapone inhibited contraction of the PD rat longitudinal muscle in a dose-dependent manner. The β₂ adrenoceptor antagonist ICI-118,551 blocked this inhibitory effect by approximately 67% (P < 0.01). Entacapone increased mucosal I_SC in the colon of rats with PD. This induction was significantly inhibited by apical application of Cl^- channel blocker diphenylamine-2, 2’-dicarboxylic acid, basolateral application of Na⁺-K⁺-2Cl^-co-transporter antagonist bumetanide, elimination of Cl^- from the extracellular fluid, as well as pretreatment using adenylate cyclase inhibitor MDL12330A. As an inhibitor of prostaglandin synthetase, indomethacin can inhibit entacapone-induced I_SC by 45% (P < 0.01). When SIET was applied to measure Cl^- flux changes, this provided similar results. Entacapone significantly increased intracellular cAMP content in the colonic mucosa, which was greatly inhibited by indomethacin.

CONCLUSION: COMT expression exists in rat colons. The β₂ adrenoceptor is involved in the entacapone-induced inhibition of colon motility. Entacapone induces cAMP-dependent Cl^- secretion in the PD rat.

An enhanced cAMP pathway is responsible for the colonic hyper-secretory response to 5-HT in acute stress rats

5-hydroxytryptamine (5-HT) is involved in the stress-induced alteration of colonic functions, specifically motility and secretion, but its precise mechanisms of regulation remain unclear. In the present study, we have investigated the effects of 5-HT on rat colonic mucosal secretion after acute water immersion restraint stress, as well as the underlying mechanism of this phenomenon, using short circuit current recording (I(SC)), real-time polymerase chain reaction, Western blot analysis, and enzyme-linked immunosorbance assays. After 2 h of water immersion restraint stress, the baseline I(SC) and 5-HT-induced I(SC) responses of the colonic mucosa were significantly increased. Pretreatment with selective 5-HT(4) receptor antagonist, SB204070, inhibited the 5-HT-induced colonic I(SC) response by 96 % in normal rats and 91.2 % in acute-stress rats. However, pretreatment with the selective antagonist of 5-HT(3) receptor, MDL72222 or Y-25130, had no obvious effect on 5-HT-induced I(SC) responses under either set of conditions. Total protein expression of both the mucosal 5-HT(3) receptors and the 5-HT(4) receptors underwent no significant changes following acute stress. Both colonic basal cAMP levels and foskolin-induced I(SC) responses were significantly enhanced in acute stress rats. 5-HT significantly enhanced the intracellular cAMP level via 5-HT(4) receptors in the colonic mucosa from both control and stressed animals, and 5-HT-induced cAMP increase in stressed rats was not more than that in control rats. Taken together, the present results indicate that acute water immersion restraint stress enhances colonic secretory responses to 5-HT in rats, a process in which increased cellular cAMP accumulation is involved.

Effect of icariin on UDP-glucuronosyltransferases in mouse liver

Icariin is a flavonol glycoside isolated from Epimedium genus and has been used in the treatment of sexual dysfunction and osteoporosis. Our laboratory has shown that icariin is beneficial in brain disorders and cardiovascular diseases. Since icariin is widely used with other herbs and drugs, to understand its potential herb-drug interactions is of importance. Recently, icariin was shown to inhibit UDP-glucuronosyltransferases, particularly the Ugt1 family enzymes in vitro, but little is known about such effects in vivo. This study investigated the effects of icariin on the expression of UDP-glucuronosyltransferases and cytochrome P450 enzymes in the livers of mice. Adult mice were treated with icariin at doses of 0, 40, 80, 160, and 320 mg/kg, p. o., for 7 days. Phenobarbital (120 mg/kg, p.o.) and rifampin (360 mg/kg, p. o.) were given twice daily for 3 days as positive controls. The livers were removed to determine UDP-glucuronosyltransferase activity and total RNA isolation. The UDP-glucuronosyltransferase activities towards 2-aminophenol were basically unaltered by the treatments. The expression of Cyp2b10 was increased 35-fold by phenobarbital, and Cyp3a11 was increased 4.5-fold by rifampin. Icariin did not affect Cyp2b10 and Cyp3a11 expression, but unexpectedly increased Cyp4a14 expression. Both phenobarbital and rifampin increased Ugt1a1, Ugt1a6, Ugt1a9, and icariin but did not show any suppressive effects on the Ugt1 family genes. Icariin at the highest dose (320 mg/kg) slightly increased Ugt2b1, Ugt2b5, and Ugt2b36. These findings indicate that icariin did not suppress UDP-glucuronosyltransferase expression, instead, it increased the mRNA of Cyp4a14 and slightly increased Ugt2b isoforms in mouse livers.

Butyrate promotes the recovering of intestinal wound healing through its positive effect on the tight junctions

Postweaning diarrhea is one of the most common causes of morbidity and mortality in weanling piglets. Feeding sodium butyrate to weanling piglets decreased the incidence of diarrhea, but the mechanism has not been fully elucidated. The present study was to evaluate the effect of sodium butyrate on diarrhea in relation to wound healing of intestinal barrier using IPEC-J2 cell model. Cultured cells were scratched to induce wound and then were treated with 4 mM sodium butyrate. The results showed that supplementation of the cells with sodium butyrate significantly promoted the process of wound healing, indicating the protective effects of butyrate on the intestinal mucosa. Butyrate treatment enhanced mRNA expression of the intestinal mucosal tight junction proteins occludin and zonula occluden protein-1 (P < 0.05), which suggested that the promotion of wound healing by butyrate is related to the maintenance of the function of the intestinal barrier. In addition, in the butyrate-treated group, intestinal total superoxide dismutase and glutathione peroxidase (P < 0.05), two of the main antioxidant enzymes, as well as glutathione (P < 0.05), one of the nonenzymatic antioxidant components, were enhanced whereas the malondialdehyde level, a marker of free radical mediated lipid peroxidation injury, was decreased (P < 0.05) compared with the control group. Collectively, these results indicate that dietary sodium butyrate might, at least partly, play an important role in recovering the intestinal tight junctions having a positive effect on maintaining the gut integrity.

Dopamine D1 receptors mediate dopamine-induced duodenal epithelial ion transport in rats

Dopamine (DA) is synthesized in gastrointestinal epithelial cells and performs important regulatory effects on the duodenal mucosa. However, the underlying mechanism remains largely unknown. The present study investigated the effect of DA on the duodenal epithelial ion transport in rats by means of short-circuit current (ISC), real-time pH titration, enzyme-linked immunosorbent assay, and immunohistochemistry. The results indicate that basolateral, but not apical, application of DA induced a concentration-dependent ISC downward deflection with an apparent IC50 of 5.34 μmol/L. Basolateral application of dopaminergic receptor D1 (D1) antagonist, SCH-23390, inhibited DA-induced change in ISC (△ISC) in a dose-dependent manner. D1 agonist, SKF38393, mimicked the effect of DA on the ISC. The clear immunoreactivity of D1 subtype D5 (D1b) was at the both apical and basolatoral sides of Brunner's glands and intestinal crypts. Basolateral pretreatment with adenylate cyclase inhibitor, MDL12330A, significantly inhibited DA- and forskolin-induced △ISC. DA and SKF38393 increased the level of intracellular cyclic adenosine monophosphate (cAMP) from 1.55 ± 0.11 to 2.07 ± 0.11 and 5.91 ± 0.25 pmol/L·mg(-1), respectively. Furthermore, the serosal DA-induced △ISC was remarkably inhibited by apical administration of K(+) channel blockers, Ba(2+) and tetraethylammonium, but not by Cl(-) channel blockers. Serosal DA and D1 agonist did not affect duodenal HCO3(-) secretion. In conclusion, the present results demonstrate that serosal DA is able to promote rat duodenal epithelial K(+) secretion, not HCO3(-) secretion through D1-mediated and cAMP-dependent pathway. The study provides a new insight in the modulation of DA on the ion transport of duodenal epithelia in rats.

Nonlinear interaction of voluntary breathing and cardiovascular regulation

To investigate the effects of voluntary breathing on respiratory sinus arrhythmia and nonlinearity of heart rate variability (HRV), two kinds of voluntary breathing, speech and breath-holding, were used. The results showed that both types of voluntary breathing diminished the high frequency component of HRV, but speech decreased, while breath-holding enhanced the nonlinearity of HRV as detected by the Volterra series method. This finding indicates that respiratory patterns have a variety of influences on cardiovascular regulation.

Clinical characteristics and prognosis of diffuse proliferative lupus nephritis with thrombotic microangiopathy

We retrospectively analyzed the clinicopathologic characteristics and prognosis of 33 patients with diffuse proliferative lupus nephritis (class IV LN) complicated with thrombotic microangiopathy (TMA). Eighty-one percent of patients had renal dysfunction (mean Scr 3.1 ± 2.0 mg/dl), among whom 42.4% needed acute hemodialysis. Nephrotic proteinuria, gross hematuria and hypertension were presented in 57.6%, 24.2% and 93.9% of the patients. Microangiopathic hemolytic anemia, serum anti-dsDNA and anticardiolipin antibodies were found in 60.6%, 75.8% and 33.3% of the patients. Renal biopsy showed IV-G in 75.8%, class IV with class V in 21.2%, and IV-S in 1.23% of the patients. Glomerular segmental necrosis, microthrombi, crescents and arteriolar thrombosis were found in 51.5%, 69.7%, 60.6% and 60.7% of the patients, respectively. The follow up was 1 to 101 months (median 13 months). Only 50% of patients showed response to treatment. Three patients died, 10 developed end-stage renal failure (ESRF). The 5-year patient and renal survival rate was 69.2% and 46.7%, respectively. Major risks for ESRF included: a need for acute dialysis on admission, no response to the treatment and high renal chronic index. The results showed that class IV lupus nephritis with TMA has high mortality and low renal survival.

Activation of submucosal 5-HT(3) receptors elicits a somatostatin-dependent inhibition of ion secretion in rat colon

BACKGROUND AND PURPOSE

5-Hydroxytryptamine (5-HT) is a key regulator of the gastrointestinal system and we have shown that submucosal neuronal 5-HT(3) receptors exerted a novel inhibitory effect on colonic ion transport. The aim of the present study was to investigate the precise mechanism(s) underlying this inhibitory effect.

EXPERIMENTAL APPROACH

Mucosa/submucosa or mucosa-only preparations from rat distal colon were mounted in Ussing chambers for measurement of short-circuit current (I(sc)) as an indicator of ion secretion. Somatostatin release was determined with radioimmunoassay. Intracellular cAMP content was measured with enzyme-linked immunoadsorbent assay (elisa). Immunohistochemical techniques were used to study the expression of 5-HT(3) receptors, somatostatin and somatostatin receptors in colonic tissue.

KEY RESULTS

In rat distal colonic mucosa/submucosa preparations, pretreatment with 5-HT(3) receptor antagonists enhanced 5-HT-induced increases in I(sc). However, in mucosa-only preparations without retained neural elements, pretreatment with 5-HT(3) receptor antagonists inhibited 5-HT-induced DeltaI(sc). Pretreatment with a somatostatin-2 (sst(2)) receptor antagonist in mucosa/submucosa preparations augmented 5-HT-induced DeltaI(sc). Combination of sst(2) and 5-HT(3) receptor antagonists did not cause further enhancement of 5-HT-induced DeltaI(sc). Moreover, both sst(2) and 5-HT(3) receptor antagonists enhanced 5-HT-induced increase in intracellular cAMP concentration in the mucosa/submucosa preparations. 5-HT released somatostatin from rat colonic mucosa/submucosa preparations, an effect prevented by pretreatment with 5-HT(3) receptor antagonists. Immunohistochemical staining demonstrated the presence of 5-HT(3) receptors on submucosal somatostatin neurons and of sst(2) receptors on colonic mucosa.

CONCLUSION AND IMPLICATIONS

Activation of neuronal 5-HT(3) receptors in the submucosal plexus of rat colon suppressed 5-HT-induced ion secretion by releasing somatostatin from submucosal neurons.

Clinicopathological characteristics of familial SLE patients with lupus nephritis

This study aimed to analyze the clinicopathological characteristics of familial SLE patients with lupus nephritis (LN). A total of 136 Chinese patients with lupus nephritis diagnosed by renal biopsy, including 34 familial patients and 102 sporadic cases, were recruited. Their demographic information, age of onset, disease duration, clinical features, laboratory data and histological manifestations were compared. The first-degree relatives (17 sibling cases and eight parent-offspring cases) of familial SLE patients were primarily affected. The prevalence of fever, rash and arthritis in familial subjects was higher than that in sporadic subjects. Familial patients had lower platelet counts and higher low-density lipoprotein. In familial patients, class V lupus nephritis was less common. After adjusted with the Benjamini and Hochberg procedure, however, fever was the only feature occurring significantly and more frequently in familial patients (58.8% vs 26.5%, P = 0.001). Moreover, SLEDAI and other clinicopathological features did not differ significantly between the two groups. Multivariate analysis showed that a higher prevalence of fever was an independent predictor of familial SLE. Most clinicopathological features in familial SLE patients were not significantly different from those in sporadic patients; the severity of LN in familial SLE patients was similar to that of sporadic cases. Thus, familial SLE may not be a different clinical entity.

Paired box 6 (PAX6) regulates glucose metabolism via proinsulin processing mediated by prohormone convertase 1/3 (PC1/3)

AIMS/HYPOTHESIS

Human patients with aniridia caused by heterozygous PAX6 mutations display abnormal glucose metabolism, but the underlying molecular mechanism is largely unknown. Disturbed islet architecture has been proposed as the reason why mice with complete inactivation of paired box 6 (PAX6) in the pancreas develop diabetes. This is not, however, the case in human aniridia patients with heterozygous PAX6 deficiency and no apparent defects in pancreatic development. We investigated the molecular mechanism underlying the development of abnormal glucose metabolism in these patients.

METHODS

A human aniridia pedigree with a PAX6 R240Stop mutation was examined for abnormal glucose metabolism using an OGTT. The underlying mechanism was further investigated using Pax6 R266Stop mutant small-eye mice, which also have abnormal glucose metabolism similar to that in PAX6 R240Stop mutation human aniridia patients.

RESULTS

Paired box 6 (PAX6) deficiency, both in aniridia patients with a heterozygous PAX6 R240Stop mutation and in mice with a heterozygous Pax6 R266Stop mutation, causes defective proinsulin processing and abnormal glucose metabolism. PAX6 can bind to the promoter and directly upregulate production of prohormone convertase (PC)1/3, an enzyme essential for conversion of proinsulin to insulin. Pax6 mutations lead to PC1/3 deficiency, resulting in defective proinsulin processing and abnormal glucose metabolism.

CONCLUSIONS/INTERPRETATION

This study indicates a novel function for PAX6 in the regulation of proinsulin processing and glucose metabolism via modulation of PC1/3 production. It also provides an insight into the abnormal glucose metabolism caused by heterozygous PAX6 mutations in humans and mice.

Circulating thrombomodulin and vascular cell adhesion molecule-1 and renal vascular lesion in patients with lupus nephritis

Currently, the detection of renal vascular lesions (VLS) in lupus nephritis (LN) mainly depends on biopsy examination, and lack surrogate biomarkers for clinical dynamic evaluation. The aim of the present study is to explore the correlation between circulatory endothelial damage biomarkers and VLS. Soluble E-selectin, thrombomodulin (TM) and vascular cell adhesion molecule-1 (VCAM-1) were measured by ELISA. TM and VCAM-1 levels both were significantly elevated in LN with VLS than in LN without VLS (P < 0.01). However, the serum E-selectin was not significantly changed in LN patients with and without VLS. A positive correlation was found between TM and serum creatinine (r = 0.617, P < 0.05) in patients with vascular lesions. In order to further analyse the relationship between TM level and severity degree of vascular lesions in LN patients, we subdivided the patients with vascular lesions into two groups: with thrombotic microangiopathy (TMA) and without TMA. TM level of the patients with TMA is significantly higher than those without TMA (P < 0.01). In conclusion, combined with renal pathological examination, monitoring the circulatory levels of TM and VCAM-1, can provide circulating biomarkers of VLS in LN patients.

Involvement of endogenous prostaglandin in emodin-evoked rat colonic anion secretion

It has been reported that emodin is able to promote gastrointestinal motility and stimulate large intestinal water secretion; however, the mechanism is still not clear. The aim of the present study is to examine the effects of emodin on the rat colonic transepithelial ion transport and the underlying mechanism. The study was carried out by means of the short circuit current (I(SC)) recording. Basolateral application of emodin induced a concentration-dependent I(SC) increase, and the EC(50) was 76.0 micromol/l. Pretreatment with epithelial Na(+) channel blocker, amiloride (10 micromol/l), did not affect the I(SC) responses elicited by emodin, but removal of extracellular Cl(-) or apical pretreatment with Cl(-) channel blocker, glibenclamide (1 mmol/l) inhibited emodin-elicited I(SC) responses by 76.3% and 83.8% respectively. Inhibiting basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC) with bumetanide (100 micromol/l) decreased emodin-induced I(SC) from 118.1+/-6.7 microA/cm(2) to 16.7+/-2.0 microA/cm(2), which was reduced by 85.9%. Basolateral pretreatment with neuronal Na(+) channel blocker tetrodotoxin (TTX) (1 micromol/l) did not affect emodin-induced I(SC) increase, but pretreatment with indomethacin (10 micromol/l) alone or with both TTX and indomethacin significantly decreased emodin-induced I(SC) increase by 88.4 and 81.2%, respectively. The present study demonstrated that emodin was able to stimulate rat colonic epithelial Cl(-) secretion, which was predominantly mediated by endogenous prostaglandin release.

Amylin deposition in the kidney of patients with diabetic nephropathy

Amylin (islet amyloid peptide) plays a critical role in islet amyloidosis and in the development of beta-cell dysfunction in patients with diabetes; however, the involvement of amylin in renal amyloidosis has not been studied. For this reason, we surveyed 149 patients with biopsy-proven diabetic nephropathy (DN). The results were compared to 95 renal disease control patients, which included membranoproliferative glomerulonephritis, light-chain deposition, IgA nephropathy, and obesity-related glomerulopathy (ORG). Seventy-two of the 149 patients with DN showed amylin deposition in their renal tissue. Amylin was mainly distributed in the expanded mesangial area, Kimmelstiel-Wilson nodules, Bowman's capsule, and in blood vessels. The frequencies of mesangial proliferation, glomerular nodule lesions, and glomerular sclerosis were higher in DN patients with amylin deposits. Furthermore, the tubular interstitial lesions were more severe in these patients. Of the 95 disease-control patients, four with ORG were positive for renal amylin deposits. Our study has found renal amylin deposition in patients with DN and that the deposition was associated with disease severity. We suggest that strict metabolic control and reversing insulin resistance in patients with diabetes may blunt the process of amylin deposition in the kidney and possibly protect renal function in these patients.

Association of interleukin-10 gene -592 A/C polymorphism with the clinical and pathological diversity of lupus nephritis

OBJECTIVE

To investigate the interleukin-10 (IL-10) gene -592 A/C polymorphism in Chinese patients with lupus nephritis (LN) and evaluate the role of lL-10 in the pathogenesis and clinical/pathological diversity of LN.

METHODS

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses were used to detect the IL-10 gene -592 A/C polymorphism in 265 LN patients and 100 ethnically matched controls. Frequencies of the genotypes were compared between LN patients and controls and among LN patients with different pathological classes. The clinical and pathological characteristics of the patients with different genotypes were also analyzed. Serum IL-10 levels of the patients were determined by ELISA.

RESULTS

No significant differences were found in the distribution of the polymorphism between healthy controls and LN patients. The parameters of disease activity index (DAI), percentage of positive serum anti-dsDNA antibodies, proteinuria and hematuria, and frequency of glomerular thrombi were all higher in patients with -592 AC/CC genotypes than those with AA genotype. AC/CC genotypes were more frequent in patients with LN-IV than in those with LN-II and Va. There was no significant difference in the serum IL-10 levels in patients with these three genotypes.

CONCLUSION

The IL-10 gene -592 A/C polymorphism appears to be associated with disease activity and renal pathology of LN, but not associated with LN susceptibility or serum IL-10 levels. Patients carrying the -592 C allele had a higher risk of diffuse proliferative glomerulonephritis, indicating the genetic influence of the IL-10 gene polymorphism in the renal lesions of LN.

C4d-positive acute humoral renal allograft rejection: Rescue therapy by immunoadsorption in combination with tacrolimus and mycophenolate mofetil

OBJECTIVE

We investigated the efficacy of immunoadsorption (IA) in combination with tacrolimus (FK506) and mycophenolate mofetil (MMF) rescue therapy for C4d-positive acute humoral rejection (AHR) of renal transplants.

METHODS

Six of 185 cadaveric renal allograft recipients developed AHR at a mean of 4.8 +/- 0.8 days after the operation. C4d deposits were observed in peritubular capillaries (PTC) with accumulation of granulocytes. IA with staphylococcal protein A and FK506-MMF combination therapy were administered.

RESULTS

After treatment with IA for 6.3 +/- 1.03 sessions combined with FK506 (0.14 to 0.16 mg.kg(-1).d(-1)) and MMF (1.5 g/d) therapy, renal function recovered in all the patients. The mean duration of treatment to a serum creatinine decrease was 14 +/- 2.9 days. The pre-IA panel reactive antibody reactivity (PRA) peaked at 50.2% +/- 6.1%, and was significantly reduced to 8.3% +/- 2.9% after IA. In four of six patients repeat allograft biopsy revealed a remission of AHR. With a mean follow-up of 18.8 +/- 5.46 months, patient and allograft survival are 100% and renal function remains stable with a mean serum creatinine of 1.2 +/- 0.22 mg/dL.

CONCLUSION

The optimal treatment for alloantibody-mediated AHR remains uncertain. Our findings suggest that a therapeutic approach combining IA and FK506-MMF rescue improves the outcome of AHR.