Objective To investigate the role of Notch signaling in the progression of peritoneal fibrosis in a rat model induced by high glucose dialysate. Methods Male Sprague Dawley rats were subjected to daily peritoneal dialysis (PD) with a lactate-buffered solution containing 4.25% glucose. They were sacrificed at 2 and 4 weeks after PD. The parietal thickness was measured with Masson staining. The expression of TGF-β1, E-cadherin, α-SMA and collagen Ⅰ was examined by immunoblotting. The expression of Notch ligand Jagged-1 and the negative Notch signaling regulato--Numb was analyzed by both immunoblotting and RT-PCR. The expression of a Notch nuclear target gene Hcs-1 was examined by RT-PCR. Results Both HE and Masson trichrome staining revealed an increase in peritoneal thickness with a loss of mesothelial cells and a rich of collagen matrix deposition in the submesothelial zone was evident at 4 weeks after PD. Meanwhile, compared to healthy rats, the expression of TGF-β1, ct-SMA and collagen Ⅰ was significantly increased, but the expression of E-cadherin was decreased in peritoneum after PD treatment. It was difficult to detect the Jagged-1 and Hes-1 expression in normal peritoneum, but their expression was graduaUy increased after PD. In contrast, the expression level of Numb, a negative regulator of Notch signaling, was dramatically decreased after PD. Conclusions Notch signaling is activated during the process of PD-induced peritoneal fibrosis and the activation of Notch signaling is associated with the loss of negative regulation of Notch signaling via decreased expression of Numb. Inhibition of Notch signaling via overexpression of its negative regulators such as Numb may be a novel therapeutic approach for peritoneal fibrosis in PD patients.

Objective To explore the mechanisms of ligament of Marshall (LOM) initiat and sustain atrial fibrillation (AF).Methods The electrophysiologic properties of canine LOM were investigated using multipolar catheter mapping(normal canines,n =4,group A;AF canines,n =5,group B).The programmed stimulation were performed in the LOM,PV-left atrium(LA)junction and LA,respectively.Activations maps of LOM were analyzed from episodes of spontaneous onset of AF and initiation of induced AF by a single extrastimulus.The effectives refractory period of each part was compared and statistically analyzed among three parts in each group and between the two groups.LOM were cutted with surgical incision technology.The inducing rate of AF and the mapping rate of double potential and fragmented electrocardiogram were compared and statistically analyzed pro and post isolation of LOM.Results The incidence of abnormal potential of LOM in the two groups was significantly different(P ＜0.01),re-entry cycle(group A 25％ vs.B group 80％),tachycardia(group A 25％ vs.B 100％),double potential(group A 25％ vs.group B 80％),fragmentation potential(group A 25％ vs.group 80％).There was a significant difference in the rate of LOM tachycardia induction before and after LOM intervention in group B (P ＜ 0.05,before 100％ vs.after 20％).Conclusion There are two possible mechanisms of LOM involved in the occurrence and maintenance of AF:one is that LOM induces AF through spontaneous excitation,the other is that LOM participates in the reentry of left atrium and pulmonary vein in the form of bypass to induce and maintain AF.

Macrophage as a crucial component of innate immunity, plays an important role in inflammation and infection immunity. Notch signal pathway is a highly conserved pathway, which regulates cellular fate and participates in numerous pathological processes. At present, a lot of literature has confirmed the role of Notch signaling in regulating the differentiation, activation and metabolism of macrophage during inflammation and infection. This review focuses on how Notch signaling promotes macrophage pro-inflammatory and anti-infective immune function in different inflammatory and infectious diseases. In this regulation, Notch signaling interact with TLR signaling in macrophages or inflammatory-related cytokines including IL-6, IL-12, and TNF-α. Additionally, the potential application and challenges of Notch signaling as a therapeutic target against inflammation and infectious diseases are also discussed.
Humans ; Signal Transduction ; Macrophages ; Cytokines/metabolism* ; Inflammation/metabolism* ; Communicable Diseases ; Receptors, Notch/metabolism*

Phytoremediation plays an important role in the treatment of heavy metal pollution in soil. In order to elucidate the mechanism of salicylic acid (SA) on copper absorption, seedlings from Xuzhou (with strong Cu-tolerance) and Weifang Helianthus tuberosus cultivars (with weak Cu-tolerance) were selected for pot culture experiments. 1 mmol/L SA was sprayed upon 300 mg/kg soil copper stress, and the photosynthesis, leaf antioxidant system, several essential mineral nutrients and the changes of root upon copper stress were analyzed to explore the mechanism of copper resistance. The results showed that Pn, Tr, Gs and Ci upon copper stress decreased significantly compared to the control group. Meanwhile, chlorophyll a, chlorophyll b and carotenoid decreased with significant increase in initial fluorescence (F₀), maximum photochemical quantum yield of PSⅡ (Fv/Fm), electron transfer rate (ETR) and photochemical quenching coefficient (qP) content all decreased. The ascorbic acid (AsA) content was decreased, the glutathione (GSH) value was increased, the superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity in the leaves were decreased, and the peroxidase (POD) activity was significantly increased. SA increased the Cu content in the ground and root system, and weakened the nutrient uptake capacity of K, Ca, Mg, and Zn in the root stem and leaves. Spray of exogenous SA can maintain the opening of leaf stomata, improve the adverse effect of copper on photosynthetic pigment and PSⅡ reaction center. Mediating the SOD and APX activity started the AsA-GSH cycle process, effectively regulated the antioxidant enzyme system in chrysanthemum taro, significantly reduced the copper content of all parts of the plant, and improved the ion exchange capacity in the body. External SA increased the content of the negative electric group on the root by changing the proportion of components in the root, promoted the absorption of mineral nutrient elements and the accumulation of osmoregulatory substances, strengthened the fixation effect of the root on metal copper, and avoided its massive accumulation in the H. tuberosus body, so as to alleviate the inhibitory effect of copper on plant growth. The study revealed the physiological regulation of SA upon copper stress, and provided a theoretical basis for planting H. tuberosus to repair soil copper pollution.
Antioxidants ; Copper ; Helianthus/metabolism* ; Salicylic Acid/pharmacology* ; Chlorophyll A/pharmacology* ; Spectroscopy, Fourier Transform Infrared ; Chlorophyll/pharmacology* ; Ascorbic Acid ; Superoxide Dismutase/metabolism* ; Photosynthesis ; Glutathione ; Plant Leaves ; Stress, Physiological ; Seedlings