Disruption of epithelium integrity by inflammation-associated fibroblasts through prostaglandin signaling

Inflammation-associated fibroblasts (IAFs) are associated with progression and drug resistance of chronic inflammatory diseases such as inflammatory bowel disease (IBD), but their direct impact on epithelial cells is unknown. Here, we developed an in vitro model whereby human colon fibroblasts are induced by specific cytokines and recapitulate key features of IAFs in vivo. When cocultured with patient-derived colon organoids (colonoids), IAFs induced rapid colonoid expansion and barrier disruption due to swelling and rupture of individual epithelial cells. Colonoids cocultured with IAFs also show increased DNA damage, mitotic errors, and proliferation arrest. These IAF-induced epithelial defects are mediated by a paracrine pathway involving prostaglandin E2 and its receptor EP4, leading to protein kinase A -dependent activation of the cystic fibrosis transmembrane conductance regulator. EP4-specific chemical inhibitors effectively prevented IAF-induced colonoid swelling and restored normal proliferation and genome stability. These findings reveal a mechanism by which IAFs could promote and perpetuate IBD and suggest a therapeutic avenue to mitigate inflammation-associated epithelial injury.

Disruption of Epithelium Integrity by Inflammation-Associated Fibroblasts through Prostaglandin Signaling: IAFs disrupt colon epithelium via PGE2-EP4

Inflammation-associated fibroblasts (IAFs) are associated with the progression and drug resistance of chronic inflammatory diseases such as inflammatory bowel disease (IBD), but their direct impact on epithelial function and architecture is unknown. In this study, we developed an in vitro model whereby human colon fibroblasts are induced to become IAFs by specific cytokines and recapitulate key features of IAFs in vivo. When co-cultured with patient-derived colon organoids (colonoids), IAFs induced rapid colonoid swelling and barrier disruption due to swelling and rupture of individual epithelial cells. Epithelial cells co-cultured with IAFs also exhibit increased DNA damage, mitotic errors, and proliferation arrest. These IAF-induced epithelial defects are mediated through a paracrine pathway involving prostaglandin E2 (PGE2) and the PGE2 receptor EP4, leading to PKA-dependent activation of the CFTR chloride channel. Importantly, EP4-specific chemical inhibitors effectively prevented colonoid swelling and restored normal proliferation and genome stability of IAF-exposed epithelial cells. These findings reveal a mechanism by which IAFs could promote and perpetuate IBD and suggest a potential treatment to mitigate inflammation-associated epithelial injury.

Differential effects of aneuploidy on growth and differentiation in human intestinal stem cells

Aneuploidy, a near ubiquitous genetic feature of tumors, is a context-dependent driver of cancer evolution; however, the mechanistic basis of this role remains unclear. Here, by inducing heterogeneous aneuploidy in non-transformed human colon organoids (colonoids), we investigate how the effects of aneuploidy on cell growth and differentiation may promote malignant transformation. Single-cell RNA sequencing reveals that the gene expression signature across over 100 unique aneuploid karyotypes is enriched with p53 responsive genes. The primary driver of p53 activation is karyotype complexity. Complex aneuploid cells with multiple unbalanced chromosomes activate p53 and undergo G1 cell-cycle arrest, independent of DNA damage and without evidence of senescence. By contrast, simple aneuploid cells with 1-3 chromosomes gained or lost continue to proliferate, demonstrated by single cell tracking in colonoids. Notably, simple aneuploid cells exhibit impaired differentiation when niche factors are withdrawn. These findings suggest that while complex aneuploid cells are eliminated from the normal epithelium due to p53 activation, simple aneuploid cells can escape this checkpoint and may contribute to niche factor-independent growth of cancer-initiating cells.

Asymmetric opening of HIV-1 Env bound to CD4 and a coreceptor-mimicking antibody

The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein, a (gp120-gp41)₃ trimer, mediates fusion of viral and host cell membranes after gp120 binding to host receptor CD4. Receptor binding triggers conformational changes allowing coreceptor (CCR5) recognition through CCR5's tyrosine-sulfated amino (N) terminus, release of the gp41 fusion peptide and fusion. We present 3.3 Å and 3.5 Å cryo-EM structures of E51, a tyrosine-sulfated coreceptor-mimicking antibody, complexed with a CD4-bound open HIV-1 native-like Env trimer. Two classes of asymmetric Env interact with E51, revealing tyrosine-sulfated interactions with gp120 mimicking CCR5 interactions, and two conformations of gp120-gp41 protomers (A and B protomers in AAB and ABB trimers) that differ in their degree of CD4-induced trimer opening and induction of changes to the fusion peptide. By integrating the new structural information with previous closed and open envelope trimer structures, we modeled the order of conformational changes on the path to coreceptor binding site exposure and subsequent viral-host cell membrane fusion.

[Clinical observation on specific immunotherapy of allergic rhinitis with artemisia pollen]

Objective:The aim of this study is to observe the clinical efficacy of pollen specific immunotherapy with Artemisia in allergic rhinitis. Method:A total of 139 patients with allergic rhinitis who were positive for Artemisia pollen were selected for allergen skin pricking. All of them were treated with Artemisia pollen-specific immunotherapy. The patients were followed-up for 3 months, respectively before treatment (N), after treatment start interval. 3 months (D1, D2, D3) followup fill in the total score of nasal symptoms (TNSS), visual analogue scale (VAS) score, olfactory function grading, ocular symptom score (TOSS) and rhinoconjunctivitis quality of life questionnaire (RQLQ) )score. Result:TNSS：N>D1，N>D2，N>D3，D1,D2,D3 two of the three compared to no difference.VAS：N>D1，N>D2，N>D3，among D1,D2,D3, two of the three compared to no difference. Olfactory function classification:N>D1，N>D2，N>D3，among D1,D2,D3, two of the three compared to no difference.TOSS：N>D1，N>D2，N>D3，among D1,D2,D3,D1>D2,the rest had no difference. RQLQ: N>D1, N>D2, N>D3, D1>D2, D3>D1, D3>D2. Conclusion:The specific pollen immunotherapy of artemisia is effective in the treatment of allergic rhinitis, and the symptoms are obviously improved.

Akt Kinase Activation Mechanisms Revealed Using Protein Semisynthesis

Akt is a critical protein kinase that drives cancer proliferation, modulates metabolism, and is activated by C-terminal phosphorylation. The current structural model for Akt activation by C-terminal phosphorylation has centered on intramolecular interactions between the C-terminal tail and the N lobe of the kinase domain. Here, we employ expressed protein ligation to produce site-specifically phosphorylated forms of purified Akt1 that are well suited for mechanistic analysis. Using biochemical, crystallographic, and cellular approaches, we determine that pSer473-Akt activation is driven by an intramolecular interaction between the C-tail and the pleckstrin homology (PH)-kinase domain linker that relieves PH domain-mediated Akt1 autoinhibition. Moreover, dual phosphorylation at Ser477/Thr479 activates Akt1 through a different allosteric mechanism via an apparent activation loop interaction that reduces autoinhibition by the PH domain and weakens PIP3 affinity. These results provide a new framework for understanding how Akt is controlled in cell signaling and suggest distinct functions for differentially modified Akt forms.

[Application of directed acyclic graphs in control of confounding]

Observational study is a method most commonly used in the etiology study of epidemiology, but confounders, always distort the true causality between exposure and outcome when local inferencing. In order to eliminate these confounding, the determining of variables which need to be adjusted become a key issue. Directed acyclic graph(DAG)could visualize complex causality, provide a simple and intuitive way to identify the confounding, and convert it into the finding of the minimal sufficient adjustment for the control of confounding. On the one hand, directed acyclic graph can choose less variables, which increase statistical efficiency of the analysis. On the other hand, it could help avoiding variables that is not measured or with missing values. In a word, the directed acyclic graph could facilitate the reveal of the real causality effectively.

[Influence of social support and coping style on chronic post-traumatic stress disorder after floods]

OBJECTIVE

To explore the long-term prognosis and influence of social support and coping style of patients with post-traumatic stress disorder (PTSD) after suffering from floods.

METHODS

Patients suffered PTSD due to Dongting lake flood in 1998 were selected through cluster random sampling. PTSD scale civilian version (PCL-C) was used to examine and diagnose the participants in this study. PTSD was then evaluated by the social support rating scale (SSRS) and the simple coping style questionnaire (SCSQ).

RESULTS

Among all the 120 subjects, 14(11.67%) of them were diagnosed as having PTSD. Compared with the rehabilitation group, scores on subjective support, objective support, total social support and positive coping, total of coping style from the non-rehabilitation group all appeared significant low (P<0.05). Data from the multivariate logistic regression showed that social support (OR=0.281, 95% CI: 0.117-0.678) and coping style (OR= 0.293, 95% CI: 0.128-0.672) were protective factors of the chronic PTSD after the floods while disaster experience (OR=1.626, 95%CI: 1.118-2.365) appeared as a risk factor.

CONCLUSION

Chronic PTSD developed after the floods called for attention. Better social support, positive coping style could significantly improve the long-term prognosis of patients with PTSD after the floods.

The effect of a disastrous flood on the quality of life in Dongting lake area in China

We carried out an epidemiological study to assess the impact of flood on the quality of life (QOL) of residents in the affected areas in China. We used a natural experiment approach, randomly selected 494 adults from 18 villages, which suffered from flooding as a result of embankments collapsing, 473 adults from 16 villages, which suffered from, soaked flood, and 773 adults from 11 villages without flood (control group). We used the Generic QOL Inventory-74 (GQOLI-74), social support scale, and questionnaires to assess the QOL of all study participants. The QOL was significantly poorer in soaked group (58.4) and (especially) in collapsed group (55.1) than in control group (59.5, p<0.001). Adjustment for potential confounding factors did not change the results. The impact of flood on QOL was stronger among farmers, seniors, persons with introvert personality, and residents with adverse life-events, whereas social support and extrovert personalities offset the negative impact of flood on QOL.

Nuclear transplantation in teleosts. Hybrid fish from the nucleus of crucian and the cytoplasm of carp

Hybrid fish are obtained from the combination of nucleus and cytoplasm from two genera of fresh-water teleosts using the technique of nuclear transplantation (i.e. the combination of the nucleus of crucian (Carassius auratus) and the cytoplasm of carp (Cyprinus carpio]. Morphological characteristics of these hybrid fish that have been examined so far indicate that some features such as barbs, pharyngeal teeth, the number of scales along the lateral line, and the number of vertebrae are similar to those of crucian. Some of the hybrid fish grow to normal adult fish.