E3 ubiquitin ligase NEDD4L negatively regulates inflammation by promoting ubiquitination of MEKK2.

Aberrant activation of inflammation signaling triggered by tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), and interleukin-17 (IL-17) is associated with immunopathology. Here, we identify neural precursor cells expressed developmentally down-regulated gene 4-like (NEDD4L), a HECT type E3 ligase, as a common negative regulator of signaling induced by TNF-α, IL-1, and IL-17. NEDD4L modulates the degradation of mitogen-activated protein kinase kinase kinase 2 (MEKK2) via constitutively and directly binding to MEKK2 and promotes its poly-ubiquitination. In interleukin-17 receptor (IL-17R) signaling, Nedd4l knockdown or deficiency enhances IL-17-induced p38 and NF-κB activation and the production of proinflammatory cytokines and chemokines in a MEKK2-dependent manner. We further show that IL-17-induced MEKK2 Ser520 phosphorylation is required not only for downstream p38 and NF-κB activation but also for NEDD4L-mediated MEKK2 degradation and the subsequent shutdown of IL-17R signaling. Importantly, Nedd4l-deficient mice show increased susceptibility to IL-17-induced inflammation and aggravated symptoms of experimental autoimmune encephalomyelitis (EAE) in IL-17R signaling-dependent manner. These data suggest that NEDD4L acts as an inhibitor of IL-17R signaling, which ameliorates the pathogenesis of IL-17-mediated autoimmune diseases.

PDE9 Inhibitor PF-04447943 Attenuates DSS-Induced Colitis by Suppressing Oxidative Stress, Inflammation, and Regulating T-Cell Polarization.

Ulcerative colitis (UC) is a form of inflammatory bowel disease, which manifests as irritation or swelling and sores in the large intestine in a relapsing and remitting manner. In a dextran sulfate sodium sulfate (DSS)-induced UC model in female mice, we found that the levels of cyclic guanosine monophosphate (cGMP) are reduced, while the expression of phosphodiesterase 9A (PDE9A) is highest among all phosphodiesterase (PDEs). Since PDE9 has the highest affinity toward cGMP, we evaluated the selective PDE9 inhibitor PF-04447943 (PF) as a potential candidate for UC treatment. PF has been extensively studies in cognitive function and in sickle cell disease, but not in models for inflammatory bowel disease (IBD). Therefore, we used female C57BL/6 mice treated with 3% DSS alone or co-treated with PF or sulfasalazine (SASP) to study the body weight, colon length, histopathology, and measure superoxide dismutase (SOD), malondialdehyde (MDA), and cGMP level, as well as cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-12/23 (IL-12/23), interleukin-10 (IL-10), and pathways including nuclear factor kappa B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and inflammasome activation. In addition, the number of dendritic cells (DC) and regulatory T cells (Treg cell) was assessed in the spleen, lymph node, and colon using flow cytometry. DSS reduced the number of goblet cells, decreased colon lengths and body weights, all of them were attenuated by PF treatment. It also suppressed the elevated level of inflammatory cytokines and increased level the anti-inflammatory cytokine, IL-10. PF treatment also reduced the DSS-induced inflammation by suppressing oxidative stress, NF-κB, STAT3, and inflammasome activation, by upregulating nuclear factor erythroid 2-related factor 2 (Nrf-2) and its downstream proteins via extracellular signal-regulated kinase (ERK) phosphorylation. Importantly, PF reversed imbalance in Treg/T helper 17 cells (Th17) cells ratio, possibly by regulating dendritic cells and Treg developmental process. In summary, this study shows the protective effect of a PDE9A inhibitor in ulcerative colitis by suppressing oxidative stress and inflammation as well as reversing the Treg/Th17 cells imbalance.

Research progress of phosphodiesterase inhibitors in inflammatory bowel disease treatment.

Inflammatory bowel disease is a recurrent chronic intestinal inflammatory disease with unknown etiology and no effective treatment. Phosphodiesterase (PDE) regulates a variety of physiological and pathophysiological processes by mediating the hydrolysis of intracellular second messengers cyclic adenosine monophosphate and cyclic guanosine monophosphate. In recent years, a series of researches suggest that PDE inhibitors such as several PDE4 inhibitors, PDE5 inhibitors (sildenafil, tadalafil and vardenafil), PDE3 inhibitors (cilostazol), PDE9 inhibitor (PF-04447943) and PDE3/PDE4 double inhibitor (pumafentrine) have ameliorating effect on experimental colitis in animals. In clinical trials, PDE4 inhibitor apremilast showed more therapeutic advantage than tetomilast. This article reviews the recent research progress of PDE inhibitors in treatment of inflammatory bowel disease.

Epidemiologic features of children with Epstein-Barr virus associated diseases in Hangzhou, China.

Epstein-Barr virus (EBV) infection is the causative agent of multiple diseases. EBV DNA in blood is a useful diagnostic marker of primary EBV infection and reactivation. This study aimed to provide epidemiological information on children with EBV-associated diseases identified by positive EBV DNA in Hangzhou, a city in East China. All children admitted to the Children's Hospital of Zhejiang University School of Medicine from 2010 to 2015 with suspected EBV-related diseases and serum EBV DNA tested by quantitative real-time polymerase chain reaction were included. Of the 10 470 children, 1205 were determined to have positive EBV DNA, and the positive rate was 11.5%. 15.8% (973 of 6162) of the illnesses of patients aged 1 to 7 years were caused by EBV as compared to that of 6.6% (179 of 2708) of children older than 7 years (P < .01) and 3.3% (53 of 1600) of of that of infants <1 year of age (P < .01). Among positive EBV DNA patients, 80.7% of EBV infections occurred in children at the age stage of 1 to 7 years. IM was the most common EBV-related disease, accounting for 75.7% of 581 hospitalized patients. Children aged 1 to 3 years were the age group most commonly hospitalized with EBV-IM (32.7% of the cohort) and EBV-hemophagocytic lymphohistiocytosis (HLH) (52.6%), while EBV-lymphoma was more common in children over 9-year old (58.3% of the cohort). The serum EBV-DNA load was much higher in patients with EBV-HLH than in patients with IM (P < .05). This is a large sample study, which revealed the epidemiological characteristics of children with EBV-associated diseases, including age, monthly and disease distribution.

Association between allergic conditions and colorectal cancer risk/mortality: a meta-analysis of prospective studies.

We aimed to assess the association between allergic conditions and risk/mortality of colorectal cancer (CRC). A systematic literature search was conducted using Pubmed and Embase to identify relevant studies. Prospective studies assessing the association between allergic conditions and risk/mortality of CRC were included. Risk ratios (RRs) were pooled with either a fixed- or a random-effects model according to heterogeneity. A total of 515379 participants and 10345 CRC cases from 12 studies were included in the analysis of CRC risk, while four studies with 1484741 individuals and 30040 CRC deaths were included in the analysis of CRC mortality. The pooled RR for the association between allergic conditions and CRC risk was 0.88 (95% CI 0.83-0.92). The inverse association was observed both in colon cancer (pooled RR = 0.83, 95% CI 0.72-0.97) and rectal cancer (pooled RR = 0.83, 95% CI 0.74-0.93). Moreover, no gender difference was observed in the analysis of CRC risk (for males, pooled RR = 0.88, 95% CI 0.81-0.96; for females, pooled RR = 0.88, 95% CI 0.82-0.95). And allergic conditions were also found to be inversely associated with CRC mortality (pooled RR = 0.88, 95% CI 0.83-0.92). In conclusion, the current meta-analysis provides further evidence that allergic conditions were inversely associated with CRC risk and mortality.

Promyelocytic leukemia protein enhances apoptosis of gastric cancer cells through Yes-associated protein.

It has been shown that Yes-associated protein (YAP) acts as a transcriptional co-activator to regulate p73-dependent apoptosis in response to DNA damage in some cell types, and promyelocytic leukemia (PML) protein is involved in the regulation loop through stabilization of YAP through sumoylation. Although YAP has been shown to be significantly upregulated in gastric cancer, whether the YAP/PML/p73 regulation loop also functions in gastric cancer is unknown. Here, we show significantly higher levels of YAP and significantly lower levels of PML in the gastric cancer specimen. Overexpression of YAP in gastric cancer cells significantly increased cell growth, but did not affect apoptosis. However, overexpression of PML in gastric cancer cells significantly increased cell apoptosis, resulting in decreases in cell growth, which seemed to require the presence of YAP. The effect of PML on apoptosis appeared to be conducted through p73-mediated modulation of apoptosis-associated genes, Bcl-2, Bak, and caspase9. Thus, our study suggests the presence of a YAP/PML/p73 regulatory loop in gastric cancer, and highlights PML as a promising tumor suppressor in gastric cancer through YAP-coordinated cancer cell apoptosis.

Multiple chronic non-specific ulcer of small intestine characterized by anemia and hypoalbuminemia.

A female patient with anemia and hypoalbuminemia was admitted to our hospital due to an over 20-year history of recurrent dizziness, fatigue and ankle edema. She was diagnosed as multiple chronic non-specific ulcer of the small intestine characterized by non-specific histology and persistent gastrointestinal bleeding.