Abstract Protein phosphatase 1B (PPM1B), a member of metal‐dependent protein serine/threonine phosphatase family, is involved in the regulation of several signalling pathways. However, our understanding of its substrate interaction and physiological functions is still largely limited. There is no reported PPM1B inhibitor to date. In this study, we identified HN252, a p‐terphenyl derivative, as a potent PPM1B inhibitor ( K i = 0.52 ± 0.06 µM). HN252 binding to PPM1B displayed remarkable and specific inhibition of PPM1B in both in vitro and ex vivo. With the aid of this small molecular inhibitor, we identified 30 proteins’ serine/threonine phosphorylation as potential substrates of PPM1B, 5 of which were demonstrated by immunoprecipitation, including one known (CDK2) and 4 novel ones (AKT1, HSP90B, β‐catenin and BRCA1). Furthermore, GO and KEGG analysis of dramatically phosphorylated proteins by PPM1B inhibition indicated that PPM1B plays roles in the regulation of multiple cellular processes and signalling pathways, such as gene transcription, inflammatory regulation, ageing and tumorigenesis. Our work provides novel insights into further investigation of molecular mechanisms of PPM1B.
Edwardsiella tarda is an important Gram-negative enteric pathogen affecting both animals and humans. It possesses a type III secretion system (T3SS) essential for pathogenesis. EseB, EseC and EseD have been shown to form a translocon complex after secretion, while EscC functions as a T3SS chaperone for EseB and EseD. In this paper we identify EscA, a protein required for accumulation and proper secretion of another translocon component, EseC. The escA gene is located upstream of eseC and the EscA protein has the characteristics of T3SS chaperones. Cell fractionation experiments indicated that EscA is located in the cytoplasm and on the cytoplasmic membrane. Mutation with in-frame deletion of escA greatly decreased the secretion of EseC, while complementation of escA restored the wild-type secretion phenotype. The stabilization and accumulation of EseC in the cytoplasm were also affected in the absence of EscA. Mutation of escA did not affect the transcription of eseC but reduced the accumulation level of EseC as measured by using an EseC-LacZ fusion protein in Ed. tarda . Co-purification and co-immunoprecipitation studies demonstrated a specific interaction between EscA and EseC. Further analysis showed that residues 31–137 of EseC are required for EseC-EscA interaction. Mutation of EseC residues 31–137 reduced the secretion and accumulation of EseC in Ed. tarda . Finally, infection experiments showed that mutations of EscA and residues 31–137 of EseC increased the LD 50 by approximately 10-fold in blue gourami fish. These results indicated that EscA functions as a specific chaperone for EseC and contributes to the virulence of Ed. tarda .
Field experiments were conducted to study the effects of different proportions of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer on the yield and nitrogen utilization efficiency of direct-seeding rapeseed. Using a conventional nitrogen application rate of 180 kg ha-1 as a control, a total of 5 types of available nitrogen fertilizers and different proportions of controlled-release nitrogen fertilizers were mixed for fertilizer treatment. The proportion of available nitrogen fertilizer used was 135 kg ha-1, and the addition ratios of the five types of controlled-release nitrogen fertilizers were 0%, 30%, 50%, 70%, and 100%, respectively (i.e., the proportion of controlled-release nitrogen to the total nitrogen application amount). These ratios were represented as N135R0, N135R1, N135R2, N135R3, and N135R4, respectively. The results showed that there was no significant difference in the number of pods per plant, the number of seeds per pod, or the grain yield under the treatment of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer for proportions of 30-50% (N135R1~R3) when compared with the control, and a stable yield was achieved. Mixing controlled-release nitrogen fertilizer under reduced nitrogen application can significantly improve the apparent utilization rate of rapeseed nitrogen fertilizer, but it first increases and then decreases with the increase of the controlled-release nitrogen mixing ratio, reaching its highest under the N135R2 treatment. The agronomic utilization efficiency and partial productivity of nitrogen fertilizer first increased and then decreased with the increased proportion of controlled-release nitrogen, and both reached their highest utilization with the N135R2 treatment. The mixed treatment of controlled-release nitrogen did not affect soil urease activity, but significantly increased soil sucrase activity. The mixed treatment of controlled-release nitrogen also increased soil microbial biomass nitrogen and carbon content. Especially in the flowering stage, the soil microbial biomass nitrogen and carbon content was significantly higher under a controlled-release nitrogen mixing ratio of 30-50%. At the same time, it had a similar effect on soil inorganic nitrogen content. Therefore, a controlled-release nitrogen mixing treatment provided sufficient nitrogen for the key growth period of rapeseed. Under the condition of reducing the amount of nitrogen fertilizer by 25% based on the amount of nitrogen fertilizer applied to conventional rapeseed, the application of controlled-release urea mixed with common nitrogen fertilizer mixed at a ratio of 30-50% can be an effective way to maintain grain yield levels and improve nitrogen utilization efficiency.
This study aims to evaluate whether miR-22 could be used as a potential biomarker to screen breast cancer patients from healthy controls. This has never been explored.Real time PCR analysis was carried out to explore the expression of serum miR-22 in breast cancer patients. Chi-square test was used for counting data. Log rank test was used for comparing survival curves. CoX regression model was used for univariate and multivariate prognosis analysis. In addition, we also evaluated the role of miR-22 on the migration capacity of MCF-7 cells using a wound healing assay.We found that low expression of miR-22 was significantly associated with late TNM stage, lymph node metastasis, local recurrence, and distant metastasis. Meanwhile, low expression of miR-22 was significantly associated with short survival and poor prognosis in all patients and lymph node subgroups. Analysis of CoX univariate and multivariate models demonstrated that miR-22 is an independent prognostic marker of breast cancer. In ad-dition, overexpression of miR-22 significantly decreased the migration of MCF-7 cells, validating the tumor suppressor role of miR-22 in breast cancer cells.In summary, low miR-22 expression may be a potential biomarker to screen breast cancer patients from healthy control.
Rural living space represents the physical environment where rural residents carry out their daily activities, encompassing various aspects such as housing, employment, consumption, and leisure. It serves as a spatial conglomeration that integrates the spatial form, content, and significance within a specific rural region. Within the contemporary context, the notion of rural living space assumes a paramount perspective in understanding the intricate relationship between individuals and their rural surroundings. The primary objective of this paper is to conduct a comprehensive review of recent domestic and international research on rural living space. Based on geographical simulation and optimization system (GeoSOS) and future land use simulation (FLUS), we aim to propose a theoretical analysis framework for understanding rural living space and its associated facets. The endeavor provides valuable insights to facilitate future research endeavors on rural living space.
The induced EPCs were transfected by Ad-BMP-2-IRES-HIF-1αmu, and then transplanted into femoral head necrotic zone, the effect on osteogenesis and agiogenesis of necrosis zone was detected. The Ad-BMP-2-IRES-HIF-1α was transfected into induced EPCs and then transplanted into avascular necrotic parts of the femoral head (ANFH).Afterwards, the promotion effect on angiogenic and osteogenic capabilities of the necrosis parts from Ad-BMP-2-IRES-HIF-1α was detected. Rabbit bone marrow MNCs were obtained by density gradient centrifugation method, and were induced into EPCs by M199 medium; EPCs were identified in accordance with the cell morphology, specific surface markers and uptake abilities. The Ad-BMP-2-IRES-HIF-1α was transfected to EPCs and then transplanted into parts of ANFH. The models were euthanized 2 and 4 weeks after operation and then the angiogenic and osteogenic indexes of necrotic parts were detected. The results showed that more blood vessels generated in group A than that in group B and C (P<0.05), and the statistical differences were found between group B and C (P<0.05). The detection of histology and BMP-2 immunohistochemistry showed that there were statistically significant differences between group A and B, group A and C (P<0.05). There was no significant difference between group B and C (P<0.05). To sum up, this experiment shows that the EPCs transfected by Ad-BMP-2-IRES-HIF-1α have stronger angiogenic and osteogenic capabilities.
Abstract Slingshot proteins form a small group of dual‐specific phosphatases that modulate cytoskeleton dynamics through dephosphorylation of cofilin and Lim kinases (LIMK). Small chemical compounds with Slingshot‐inhibiting activities have therapeutic potential against cancers or infectious diseases. However, only a few Slingshot inhibitors have been investigated and reported, and their cellular activities have not been examined. In this study, we identified two rhodanine‐scaffold‐based para ‐substituted benzoic acid derivatives as competitive Slingshot inhibitors. The top compound, ( Z )‐4‐((4‐((4‐oxo‐2‐thioxo‐3‐( o ‐tolyl)thiazolidin‐5‐ylidene)methyl)phenoxy)methyl)benzoic acid ( D3 ) had an inhibition constant ( K i ) of around 4 μ m and displayed selectivity over a panel of other phosphatases. Moreover, compound D3 inhibited cell migration and cofilin dephosphorylation after nerve growth factor (NGF) or angiotensin II stimulation. Therefore, our newly identified Slingshot inhibitors provide a starting point for developing Slingshot‐targeted therapies.
The high-pathogenicity island (HPI) was initially identified in Yersinia and can be horizontally transferred to Escherichia coli to produce yersiniabactin (Ybt), which enhances the pathogenicity of E. coli by competing with the host for Fe3+. Pyroptosis is gasdermin-induced necrotic cell death. It involves the permeabilization of the cell membrane and is accompanied by an inflammatory response. It is still unclear whether Ybt HPI can cause intestinal epithelial cells to undergo pyroptosis and contribute to gut inflammation during E. coli infection. In this study, we infected intestinal epithelial cells of mice with E. coli ZB-1 and the Ybt-deficient strain ZB-1Δirp2. Our findings demonstrate that Ybt-producing E. coli is more toxic and exacerbates gut inflammation during systemic infection. Mechanistically, our results suggest the involvement of the NLRP3/caspase-1/GSDMD pathway in E. coli infection. Ybt promotes the assembly and activation of the NLRP3 inflammasome, leading to GSDMD cleavage into GSDMD-N and promoting the pyroptosis of intestinal epithelial cells, ultimately aggravating gut inflammation. Notably, NLRP3 knockdown alleviated these phenomena, and the binding of free Ybt to NLRP3 may be the trigger. Overall, our results show that Ybt HPI enhances the pathogenicity of E. coli and induces pyroptosis via the NLRP3 pathway, which is a new mechanism through which E. coli promotes gut inflammation. Furthermore, we screened drugs targeting NLRP3 from an existing drug library, providing a list of potential drug candidates for the treatment of gut injury caused by E. coli.
Transverse myelitis (TM) is a relatively infrequent but severe complication in systemic lupus erythematosus (SLE). Owing to its rarity and unfavorable outcome, we investigated its general features on MRI and incidence in the context of lupus activity, to facilitate early recognition and treatment.We report a case of a young man with clinically inactive lupus nephritis but who presented with a sudden attack of myelitis. We performed systematic literature search in Medline to study the clinical features of SLE-related TM.From 1960 to April 2013, a total of 72 articles containing 194 cases of lupus myelitis were found. Among acquired articles, 93 patients fulfilled the inclusion criteria. The majority of the cases (88.8%) were female. Longitudinal myelitis was the predominant imaging finding on MRI (71.4%, 45/63). Nearly two-thirds (61/94) of lupus myelitis occurred in association with active lupus, and one-third (33/94) occurred in low disease activity.Upon literature review, we found myelitis in SLE more frequently manifested as longitudinal on MRI. Although lupus myelitis often presented at an active phase of SLE, one-third of events happened in the presence of low disease activity. Early initiation of effective immunosuppressive therapy facilitated recovery.