Phase Separation of a PKA Regulatory Subunit Controls cAMP Compartmentation and Oncogenic Signaling.

The fidelity of intracellular signaling hinges on the organization of dynamic activity architectures. Spatial compartmentation was first proposed over 30 years ago to explain how diverse G protein-coupled receptors achieve specificity despite converging on a ubiquitous messenger, cyclic adenosine monophosphate (cAMP). However, the mechanisms responsible for spatially constraining this diffusible messenger remain elusive. Here, we reveal that the type I regulatory subunit of cAMP-dependent protein kinase (PKA), RIα, undergoes liquid-liquid phase separation (LLPS) as a function of cAMP signaling to form biomolecular condensates enriched in cAMP and PKA activity, critical for effective cAMP compartmentation. We further show that a PKA fusion oncoprotein associated with an atypical liver cancer potently blocks RIα LLPS and induces aberrant cAMP signaling. Loss of RIα LLPS in normal cells increases cell proliferation and induces cell transformation. Our work reveals LLPS as a principal organizer of signaling compartments and highlights the pathological consequences of dysregulating this activity architecture.

Endosome positioning coordinates spatially selective GPCR signaling.

G-protein-coupled receptors (GPCRs) can initiate unique functional responses depending on the subcellular site of activation. Efforts to uncover the mechanistic basis of compartmentalized GPCR signaling have concentrated on the biochemical aspect of this regulation. Here we assess the biophysical positioning of receptor-containing endosomes as an alternative salient mechanism. We devise a strategy to rapidly and selectively redistribute receptor-containing endosomes 'on command' in intact cells without perturbing their biochemical composition. Next, we present two complementary optical readouts that enable robust measurements of bulk- and gene-specific GPCR/cyclic AMP (cAMP)-dependent transcriptional signaling with single-cell resolution. With these, we establish that disruption of native endosome positioning inhibits the initiation of the endosome-dependent transcriptional responses. Finally, we demonstrate a prominent mechanistic role of PDE-mediated cAMP hydrolysis and local protein kinase A activity in this process. Our study, therefore, illuminates a new mechanism regulating GPCR function by identifying endosome positioning as the principal mediator of spatially selective receptor signaling.

Signaling Microdomains in the Spotlight: Visualizing Compartmentalized Signaling Using Genetically Encoded Fluorescent Biosensors.

How cells muster a network of interlinking signaling pathways to faithfully convert diverse external cues to specific functional outcomes remains a central question in biology. Through their ability to convert dynamic biochemical activities to rapid and precise optical readouts, genetically encoded fluorescent biosensors have become instrumental in unraveling the molecular logic controlling the specificity of intracellular signaling. In this review, we discuss how the use of genetically encoded fluorescent biosensors to visualize dynamic signaling events within their native cellular context is elucidating the different strategies employed by cells to organize signaling activities into discrete compartments, or signaling microdomains, to ensure functional specificity.

High pyroptosis activity in pancreatic adenocarcinoma: poor prognosis and oxaliplatin resistance.

BACKGROUND: Pyroptosis, as a type of inflammatory programmed cell death, has been studied in inflammatory diseases and numerous cancers but its role in pancreatic ductal adenocarcinoma (PDAC) remains further exploration. METHODS: A TCGA-PDAC cohort was enrolled for bioinformatics analysis to investigate the effect of pyroptosis on the prognosis and drug sensitivity of patients. PA-TU-8988T and CFPAC-1 cells were selected for investigating the role of GSDMC in PDAC. RESULTS: A distinct classification pattern of PDAC mediated by 21 pyroptosis-related genes (PRGs) was identified. It was suggested that higher pyroptosis activity was associated with poor prognosis of patients and higher tumor proliferation rates. We further established a prognostic model based on three PRGs (GSDMC, CASP4 and NLRP1) and the TCGA-PDAC cohort was classified into low and high-risk subgroups. It is noteworthy that the high-risk group showed significantly higher tumor proliferation rates and was proved to be highly correlated with oxaliplatin resistance. Further experiments suggested that overexpression of GSDMC promoted the proliferation and oxaliplatin resistance of PA-TU-8988T cells in vitro and vivo, while downregulation of GSDMC showed opposite effects in CFPAC-1 cells. Finally, we found that the activation of pentose phosphate pathway (PPP) was the mechanism by which GSDMC overexpression promoted the proliferation and oxaliplatin resistance of pancreatic cancer cells. CONCLUSIONS: In this study, we found that higher pyroptosis activity is associated with worse prognosis and oxaliplatin resistance of PDAC patients. In addition, as a core effector of pyroptosis, GSDMC promoted proliferation and oxaliplatin resistance of pancreatic cancer cells, which will provide new therapeutic target for PDAC patients.

Alteration of prefrontal cortex and its associations with emotional and cognitive dysfunctions in adolescent borderline personality disorder.

The neurobiological mechanism of borderline personality disorder (BPD) in adolescents remains unclear. The study aimed to assess the alterations in neural activity within prefrontal cortex in adolescents with BPD and investigate the relationship of prefrontal activity with emotional regulation and cognitive function. This study enrolled 50 adolescents aged 12-17 years with BPD and 21 gender and age-matched healthy control (HC) participants. Study assessment for each participant included a brain resting-state functional MRI (rs-fMRI), clinical assessment questionnaires such as Borderline Personality Features Scale (BPFS), Difficulties in Emotion Regulation Scale (DERS), Ottawa Self-Injury Inventory and Childhood Trauma Questionnaire (CTQ) and cognitive testing with Stroop Color-Word Test (SCWT). Fractional amplitude of low-frequency fluctuations (fALFF) and seed-based functional connectivity (FC) were obtained from rs-fMRI analysis. Correlation analysis was also performed to evaluate the associations of the neuroimaging metrics such as fALFF and FC with clinical assessment questionnaire and cognitive testing scores. Adolescents with BPD showed increased fALFF values in the right inferior frontal gyrus and decreased activity in the left middle frontal gyrus as compared to the HC group (p < 0.05, cluster size ≥ 100, FWE correction). In adolescents with BPD, increased fALFF in the right inferior frontal gyrus was related to the BPFS (emotional dysregulation), DERS-F (lacking of emotional regulation strategies) and Ottawa Self-Injury Inventory-4 C scores (internal emotional regulation function of self-injurious behavior). The reduced fALFF in the left middle frontal gyrus was associated with the SCWT-A (reading characters) and the SCWT-B (reading color) scores. Additionally, the fALFF values in the left middle frontal gyrus and the right inferior frontal gyrus were related to the CTQ-D (emotional neglect) (p < 0.05). The left middle frontal gyrus exhibited increased FC with the right hippocampus, left inferior temporal gyrus and right inferior frontal gyrus (voxel p < 0.001, cluster p < 0.05, FWE correction). The increased FC between the left middle frontal gyrus and the right hippocampus was related to the SCWT-C (cognitive flexibility) score. We observed diverging changes in intrinsic brain activity in prefrontal cortex, and neural compensatory changes to maintain function in adolescents with BPD. In addition, decreased neural function was closely associated with emotional dysregulation, while increased neural function as indicated by brain activity and FC was associated with cognitive dysfunction. These results indicated that alterations of intrinsic brain activity may be one of the underlying neurobiological markers for clinical symptoms in adolescents with BPD.

Clinical Study on the Thoracodorsal Artery Perforator Flap in Breast-Conserving Reconstruction of T2 Breast Cancer.

BACKGROUND: Breast-conserving surgery combined with oncoplastic breast surgery has become the standard surgical treatment for early breast cancer. OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of the thoracodorsal artery perforator flap (TDAPF) in breast-conserving reconstruction of T2 breast cancer. METHODS: Thirty patients with T2 breast cancer admitted to our hospital from January 2019 to December 2020 were enrolled to receive pedicled TDAPF for repairing breast defects after breast-conserving surgery. Intraoperative conditions, postoperative complications, and shape satisfaction after breast reconstruction were recorded. RESULTS: The operation was successfully completed in all 30 patients, with an operation time of 177.77 ± 24.39 min, bleeding of 44.17 ± 7.67 mL, and length of hospital stay of 5.23 ± .97 d. There was no deformity or seroma at the donor site. Breast shape recovered well after operation. After operation, one patient had fat liquefaction in the recipient site, which healed well after wound treatment. The incidence of postoperative complications was 3.33%. Postoperative follow-up lasted 16-28 months, with a median of 22 months. The Breast-Q score for breast satisfaction was 61.83 ± 12.87 at 6 months after operation, compared to 62.07 ± 11.78 before operation (P > .05). CONCLUSIONS: TDAPF, featuring a high survival rate, moderate flap area, fewer postoperative complications, and high satisfaction with breast shape after operation. For east asian women with moderate breast size, TDAPF is a safe, effective choice for repairing defects in breast-conserving surgery for T2 breast cancer.

An ultrasensitive biosensor for high-resolution kinase activity imaging in awake mice.

Protein kinases control nearly every facet of cellular function. These key signaling nodes integrate diverse pathway inputs to regulate complex physiological processes, and aberrant kinase signaling is linked to numerous pathologies. While fluorescent protein-based biosensors have revolutionized the study of kinase signaling by allowing direct, spatiotemporally precise kinase activity measurements in living cells, powerful new molecular tools capable of robustly tracking kinase activity dynamics across diverse experimental contexts are needed to fully dissect the role of kinase signaling in physiology and disease. Here, we report the development of an ultrasensitive, second-generation excitation-ratiometric protein kinase A (PKA) activity reporter (ExRai-AKAR2), obtained via high-throughput linker library screening, that enables sensitive and rapid monitoring of live-cell PKA activity across multiple fluorescence detection modalities, including plate reading, cell sorting and one- or two-photon imaging. Notably, in vivo visual cortex imaging in awake mice reveals highly dynamic neuronal PKA activity rapidly recruited by forced locomotion.

TGF-ß/Alk5 signaling prevents osteoarthritis initiation via regulating the senescence of articular cartilage stem cells.

Osteoarthritis (OA) is the most common joint disease. The surface of joint cartilage is a defensive and first affected structure of articular cartilage (AC) during the pathogenesis of OA. Alk5 signaling is critical for maintaining AC homeostasis, however, the role and underlying mechanism for the involvement of Alk5 signaling in the phenotypes of articular cartilage stem cells (ACSCs) at the surface of AC is still unclear. The role of Alk5 in OA development was explored using an ACSCs-specific Alk5-deficient (cKO) mouse model. Alterations in cartilage structure were evaluated histologically. Senescence was detected by SA-ß-gal, while reactive oxygen species (ROS), MitoTracker, and LysoTracker staining were used to detect changes related to senescence. In addition, mice were injected intra-articularly with ganciclovir to limit the detrimental roles of senescent cells (SnCs). Alk5 cKO mice showed a decreased number of the slow-cell cycle cells and less lubricant secretion at the surface accompanied with drastically accelerated cartilage degeneration under ageing and surgically induced OA conditions. Further studies showed that Alk5 deficient ACSCs exhibited senescence-like manifestations including decreased proliferation and differentiation, more SA-ß-gal-positive cells and ROS production, as well as significantly swollen mitochondria and lysosome breakdown. We further found that local limitation of the detrimental roles of SnCs can attenuate the development of posttraumatic OA. Taken together, our findings suggest that Alk5 signaling acts as an important regulator of the SnCs in the superficial layer during AC maintenance and OA initiation.

Cell migration inducing hyaluronidase 1 (CEMIP) activates STAT3 pathway to facilitate cell proliferation and migration in breast cancer.

PURPOSE: This paper aims to assess the role of CEMIP in human breast cancer, and explore the potential mechanisms of CEMIP in the progression of breast cancer. METHODS: We examined the expression levels of CEMIP in breast cancer tissues and cell lines by quantitative PCR and immunohistochemical assays. The effects of CEMIP on the proliferation, migration and invasion of breast cancer cells were determined through colony formation assay, flow cytometry (FCM) assay, wound healing assay and transwell assay, respectively. Additionally, the downstream targets of CEMIP were examined by Immunoblot assays. RESULTS: CEMIP expression was upregulated in both breast cancer tissues and cell lines. Patients with higher CEMIP expression displayed shorter survival time than those with lower expression. In addition, CEMIP knockdown inhibited breast cancer cell proliferation, migration, and invasion in vitro. Our data further confirmed that CEMIP promoted the proliferation and migration of breast cancer cells via GRP78-STAT3 axis. CONCLUSION: Our data demonstrated the role of CEMIP in breast cancer was associated with STAT3 signaling pathway. Therefore, CEMIP might act as a possible therapeutic target for breast cancer.

Treatment of idiopathic granulomatous mastitis using ultrasound-guided microwave ablation: a report of 50 cases.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of ultrasound-guided microwave ablation combined with glucocorticoid therapy for treating idiopathic granulomatous mastitis (IGM). METHODS: From June 2017 to March 2020, 50 consecutive patients diagnosed with IGM using puncture histology were included. All patients received prednisone and ultrasound-guided microwave ablation and were closely monitored for 12-15 months. RESULTS: A total of 222 lesions in 50 patients were ablated. The results indicated that 78% of cases were cured within 12 months and an additional 20% were cured within 15 months; the recurrence rate was 2%. The clinical and pathological remission rate of the entire group was 98%. The main postoperative complications were local pain, skin ulcerations and sinus formation, skin and areola heat damage, subcutaneous congestion, and fat liquefaction, all of which were conservatively treated. CONCLUSION: Microwave ablation combined with glucocorticoid therapy was safe and effective for the treatment of IGM, with a low recurrence rate. In addition, the cosmetic appearance of the affected breast was preserved with little trauma. Therefore, microwave ablation is a viable method that can be successfully applied in clinical practice.

Ultrasound-guided microwave ablation for multiple benign breast lesions: A prospective study.

AIM: To provide medical evidence for the feasibility and clinical efficacy of microwave ablation (MWA) in the treatment of benign breast lesions, especially multiple benign breast lesions. METHODS: We included patients with multiple benign breast lesions who were seen at our hospital during the period from June 2016 to December 2017. After signed informed consent had been obtained and core breast biopsy, all included patients who underwent MWA at 2450 MHz with 30 W power adjustment. Postoperative follow-up was performed for 1 year, at 3-month intervals. Ablation time, complications, volume-reduction ratio (VRR), and lesion residuals after ablation were analyzed. RESULTS: We ultimately included 1274 lesions from 164 cases in the study with a median follow-up time of 13.6 months. For a single lesion, the median ablation time was 36 s. Pain, fat liquefaction, and skin scalding were the most common complications. The overall complete disappearance rate was 92.1% (1173/1274), with the highest complete disappearance rate observed among those patients with lesions <10 mm in diameter (942/968, 97.3%). For lesions that persisted at 12 months after MWA, the average the volume-reduction ratio (VRR) was 87.5%. CONCLUSIONS: For multiple benign lesions of the breast, especially lesions with the longest diameter <10 mm, ultrasound guided MWA is a minimally invasive, relatively quick therapeutic strategy associated with accuracy in treatment and few complications.

WHSC1 promotes wnt/ß-catenin signaling in a FoxM1-dependent manner facilitating proliferation, invasion and epithelial-mesenchymal transition in breast cancer.

Objectives: Wolf-Hirschhorn syndrome candidate gene-1 (WHSC1) is highly expressed in various malignant tumors. We investigated the correlation and regulatory pathway of WHSC1 in the progression of breast cancer (BC).Methods: The expression and distribution of WHSC1 in the BC tissues and cell lines were determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical staining. Spearman correlation analysis demonstrated the correlation between WHSC1 high expression level and the clinical characteristics of BC patients. The effects of WHSC1 on the proliferation, apoptosis, migration and invasion of BC cells were analyzed by cell transfection, MTT, colony formation, scratch assay, and transwell. Furthermore, the expression of Forkhead box M1 (FoxM1) and the location of ß-catenin were detected by qRT-PCR and western blot.Results: Firstly, WHSC1 expression was up-regulated in BC tissues and cell lines. The high expression of WHSC1 in BC is associated with the tumor size (p = 0.027), metastasis (p = 0.018) and pathological stages (p = 0.025) of the BC patients. The knockdown of WHSC1 inhibited the growth, proliferation migration, invasion and EMT of BC cell lines. Furthermore, WHSC1 could promote the expression of FoxM1 in BC cells and tissues. WHSC1 enhanced the expression of FoxM1, and promoted the nuclear localization of ß-catenin, and thus activated the downstream genes expression of Wnt/ß-catenin signaling pathway to regulate the development of BC.Conclusion: In summary, our study elucidates the correlation and specific regulatory mechanism between WHSC1 and the progression of BC, thus implying that WHSC1 may function as molecular diagnosis, prognosis and molecular targeted therapy of BC.

[Incidence of neonatal asphyxia and contributing factors for the develpment of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture: a multicenter study].

OBJECTIVE: To investigate the incidence of neonatal asphyxia and possible contributing factors for the development of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture, China. METHODS: A total of 16 hospitals in Hubei Enshi Tujia and Miao Autonomous Prefecture were selected as research centers. A retrospective analysis was performed for the clinical data of 22 294 live births in these 16 hospitals from January to December, 2016 to investigate the incidence rate of neonatal asphyxia and possible contributing factors for the development of severe asphyxia. RESULTS: Of the 22 294 neonates born alive, 733 (3.29%) were diagnosed with neonatal asphyxia, among whom 627 had mild asphyxia and 106 had severe asphyxia. The neonates with low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight had a higher incidence of severe asphyxia (P<0.05). CONCLUSIONS: The incidence rate of neonatal asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture is higher. Low maternal education level, maternal anemia during pregnancy, chorioamnionitis, abnormal amniotic fluid, abnormal umbilical cord, placenta previa, placental abruption, Tujia Minority, preterm birth, and low birth weight may be related to the development of severe neonatal asphyxia.

Sadness and happiness are amplified in solitary listening to music.

Previous studies have shown that music is a powerful means to convey affective states, but it remains unclear whether and how social context shape the intensity and quality of emotions perceived in music. Using a within-subject design, we studied this question in two experimental settings, i.e. when subjects were alone versus in company of others without direct social interaction or feedback. Non-vocal musical excerpts of the emotional qualities happiness or sadness were rated on arousal and valence dimensions. We found evidence for an amplification of perceived emotion in the solitary listening condition, i.e. happy music was rated as happier and more arousing when nobody else was around and, in an analogous manner, sad music was perceived as sadder. This difference might be explained by a shift of attention in the presence of others. The observed interaction of perceived emotion and social context did not differ for stimuli of different cultural origin.

Sensitive Fluorescent Biosensor Reveals Differential Subcellular Regulation of PKC.

The protein kinase C (PKC) family of serine/threonine kinases, which consist of three distinctly regulated subfamilies, have long been established as critical for a variety of cellular functions. However, how PKC enzymes are regulated at different subcellular locations, particularly at emerging signaling hubs such as the ER, lysosome, and Par signaling complexes, is unclear. Here, we present a sensitive Excitation Ratiometric (ExRai) C Kinase Activity Reporter (ExRai-CKAR2) that enables the detection of minute changes in subcellular PKC activity. Using ExRai-CKAR2 in conjunction with an enhanced diacylglycerol (DAG) biosensor capable of detecting intracellular DAG dynamics, we uncover the differential regulation of PKC isoforms at distinct subcellular locations. We find that G-protein coupled receptor (GPCR) stimulation triggers sustained PKC activity at the ER and lysosomes, primarily mediated by Ca2+ sensitive conventional PKC (cPKC) and novel PKC (nPKC), respectively, with nPKC showing high basal activity due to elevated basal DAG levels on lysosome membranes. The high sensitivity of ExRai-CKAR2, targeted to either the cytosol or Par-complexes, further enabled us to detect previously inaccessible endogenous atypical PKC (aPKC) activity in 3D organoids. Taken together, ExRai-CKAR2 is a powerful tool for interrogating PKC regulation in response to physiological stimuli.

Insights into copper(I) phenylacetylide with in-situ transformation of oxygen and enhanced visible-light response for water decontamination: Cu-O bond promotes exciton dissociation and charge transfer.

The widespread contamination of hexavalent chromium (Cr(VI)), pharmaceuticals and personal care products (PPCPs), and dyes is a growing concern. necessitating the development of convenient and effective technologies for their removal. Copper(I) phenylacetylide (PhC2Cu) has emerged as a promising photocatalyst for environmental remediation. In this study, we introduced a functional Cu-O bond into PhC2Cu (referred to as OrPhC2Cu) by creatively converting the adsorbed oxygen on the surface of PhC2Cu into a Cu-O bond to enhance the efficiency of Cr(VI) photoreduction, PPCPs photodegradation, and dyes photodegradation through a facile vacuum activating method. The incorporation of the Cu-O bond optimized the electron structure of OrPhC2Cu, facilitating exciton dissociation and charge transfer. The exciton dissociation behavior and charge transfer mechanism were systematically investigated for the first time in the OrPhC2Cu system by photoelectrochemical tests, fluorescence and phosphorescence (PH) techniques, and density functional theory (DFT) calculations. Remarkably, the enhanced visible-light response of OrPhC2Cu improved photon utilization and significantly promoted the generation of reactive species (RSs), leading to the highly efficient Cr(VI) photoreduction (98.52% within 25 min) and sulfamethazine photodegradation (94.65% within 60 min), with 3.91 and 5.23 times higher activity compared to PhC2Cu. Additionally, the photocatalytic efficiency of OrPhC2Cu in degrading anionic dyes surpassed that of cationic dyes. The performance of the OrPhC2Cu system in treating electroplating effluent or natural water bodies suggests its potential for practical applications.

Midterm follow-up results of a novel technique: Contralateral breast overlapped reconstruction after mastectomy for unilateral breast cancer.

BACKGROUND: The breasts of Oriental women are characterized by an obvious scar constitution and a relatively small mammary gland volume. Thus, plastic surgery, which is now popular in the West, is not suitable for most patients in China, and Chinese surgeons are searching for symmetrical plastic surgery options that are suitable for patients with breast tumors, unilateral breast implants and an obvious scar constitution. METHODS: Between January 2016 and December 2019, 15 patients underwent contralateral breast overlapped reconstruction (COBOR) at the Affiliated Hospital of Putian University. We assessed their clinicopathological data, complications, cosmetic satisfaction and quality of life. RESULTS: The mean age was 41.6 years (range, 31-54 years), the average BMI was 24.36 kg/m2 (range, 20.3-28.4 kg/m2), the most common tumor location was the upper outer quadrant (n = 9), the mean preoperative tumor size was 21.11 mm (range, 7-42 mm), and 4 patients underwent neoadjuvant chemotherapy. The cancer grades and histological types were as follows: G3 nonspecial type (NST), 3 cases; G2 NST, 6 cases; G2 lobular carcinoma, 1 case; and ductal carcinoma in situ (DCIS), 5 cases. The nipple margin was negative in all of these cases. Among them, there was 1 case of poor wound healing caused by subcutaneous fat liquefaction around the incision. In another case, partial nipple necrosis occurred on the affected side due to an insufficient nipple blood supply after the operation and healed after debridement and dressing changes. There were no cases of tumor recurrence during the mean follow-up of 22.53 months (range, 11-47 months). The BREAST-Q scores showed that COBOR provided good patient satisfaction. CONCLUSION: For Oriental patients with small breasts, COBOR, which results in fewer scars, good symmetry and good satisfaction, is an effective and safe surgical method. However, larger studies with longer follow-up periods are needed to obtain more reliable postoperative results.

Carbon nitride nanotubes anchored with Cu(I) triggers peracetic acid activation with visible light for removal of antibiotic contaminants: Probing mechanisms of non-radical pathways and identifying active sites.

The peracetic acid (PAA)-activation process has attracted much attention in wastewater treatment. However, the low electron efficiency at the interface between heterogeneous catalysts and PAA has affected its practical application. For this study, we developed a carbon nitride hollow-nanotube catalysts with dispersed Cu(I) sites (Cu(I)-TCN) for the photocatalytic activation of PAA for antibiotics degradation. The obtained Cu(I)-TCN catalyst demonstrated an enhanced capacity for visible light harvesting along with increased charge transfer rates. Specifically, the developed Cu(I)-TCN/visible light/PAA system was able to completely remove antibiotics within 20 min, with a kinetic constant that was 25 times higher than a Cu(I)-TCN/visible light system, and 83 times higher than Cu(I)-TCN/PAA systems. Scavenging experiment and electron paramagnetic resonance (EPR) indicated that singlet oxygen was dominant reactive specie for sulfisoxazole (SIZ) removal. Besides, electrochemical tests and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy verified that the electron transfer efficiency of PAA activation was promoted due to the formation of inner-sphere interactions between PAA and Cu(I)-TCN, resulting in the quick removal of antibiotics. Further, after exposure to visible light, the Cu(I)-TCN excited photogenerated electrons which supplemented the electrons consumed in the reaction and drove the valence cycle of Cu ions. Overall, this research offered novel insights into the non-radical pathway for heterogeneous visible light-driven advanced oxidation processes and their potential for practical wastewater remediation.

Strategy for improvement of molecular oxygen activation capacity of PPECu by chlorine doping for water decontamination.

The activation of molecular oxygen and generation of reactive oxygen species (ROS) play important roles in the efficient removal of contaminants from aqueous ecosystems. Herein, using a simple and rapid solvothermal process, we developed a chlorine-doped phenylethynylcopper (Cl/PPECu) photocatalyst and applied it to visible light degradation of sulfamethazine (SMT) in aqueous media. The Cl/PPECu was optimized to have a 2.52 times higher steady-state concentration of O2•- (3.62 × 10-5 M) and a 28.87 times higher degradation rate constant (0.2252 min-1) for SMT compared to pure PPECu. Further, the effectiveness of Cl/PPECu in treating sulfonamide antibiotics (SAs) in real water systems was verified through an investigation involving natural water bodies, SAs, and ambient sunlight. The energy band structure, DFT calculation and correlation heat map indicated that the addition of chlorine modulated the local electronic structure of PPECu, leading to an improvement in the electron-hole separation, enhanced the O2 activation, and promoted the generation of ROSs. This study not only puts forward innovative ideas for the eco-compatible remediation of environmental pollution using PPECu, but also sheds new light on the activation of oxygen through elemental doping.

m6A eraser FTO impairs gemcitabine resistance in pancreatic cancer through influencing NEDD4 mRNA stability by regulating the PTEN/PI3K/AKT pathway.

BACKGROUND: Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant regulatory role in chemosensitivity; however, it is not apparent whether gemcitabine resistance can be regulated by fat mass and obesity-associated protein (FTO). METHODS: Cells with established gemcitabine resistance and tissues from pancreatic cancer patients were used to evaluate FTO expression. The biological mechanisms of the effects of FTO on gemcitabine resistant cells were investigated using CCK-8, colony formation assay, flow cytometry, and inhibitory concentration 50. Immunoprecipitation/mass spectrometry, MeRIP-seq, RNA sequencing and RIP assays, RNA stability, luciferase reporter, and RNA pull down assays were employed to examine the mechanism of FTO affecting gemcitabine resistant pancreatic cancer cells. RESULTS: The results revealed that FTO was substantially expressed in cells and tissues that were resistant to gemcitabine. Functionally, the gemcitabine resistance of pancreatic cancer could be enhanced by FTO, while its depletion inhibited the growth of gemcitabine resistant tumor cells in vivo. Immunoprecipitation/mass spectrometry showed that the FTO protein can be bound to USP7 and deubiquitinated by USP7, leading to the upregulation of FTO. At the same time, FTO knockdown significantly decreased the expression level of NEDD4 in an m6A-dependent manner. RNA pull down and RNA immunoprecipitation verified YTHDF2 as the reader of NEDD4, which promoted the chemoresistance of gemcitabine resistant cells. FTO knockdown markedly increased the PTEN expression level in an NEDD4-dependent manner and influenced the chemosensitivity to gemcitabine through the PI3K/AKT pathway in pancreatic cancer cells. CONCLUSION: In conclusion, we found that gemcitabine resistance in pancreatic cancer can be influenced by FTO that demethylates NEDD4 RNA in a m6A-dependent manner, which then influences the PTEN expression level and thereby affects the PI3K/AKT pathway. We also identified that the FTO level can be upregulated by USP7.