Selective inhibition of overactive warmth-sensitive Ca2+-permeable TRPV3 channels by antispasmodic agent flopropione for alleviation of skin inflammation.

The temperature-sensitive Ca2+-permeable TRPV3 ion channel is robustly expressed in the skin keratinocytes, and its gain-of-function mutations are involved in the pathology of skin lesions. Here, we report the identification of an antispasmodic agent flopropione that alleviates skin inflammation by selective inhibition of TRPV3. In whole-cell patch clamp recordings, flopropione selectively inhibits macroscopic TRPV3 currents in a concentration-dependent manner with an IC50 value of 17.8 ± 3.5 µM. At the single-channel level, flopropione inhibits TRPV3 channel open probability without alteration of its unitary conductance. In an in vivo mouse model of skin inflammation induced by the skin sensitizer DNFB, flopropione also alleviates dorsal skin lesions and ear skin swelling. Further molecular docking combined with site-directed mutagenesis reveals that two residues E501 and I505 in the channel S2-helix are critical for flopropione-mediated inhibition of TRPV3. Taken together, our findings demonstrate that the spasmolytic drug flopropione as a selective inhibitor of TRPV3 channel not only provides a valuable tool molecule for understanding of TRPV3 channel pharmacology but also holds repurposing potential for therapy of skin disorders, such as dermatitis and pruritus.

Pan-cancer analysis of CDKN2A alterations identifies a subset of gastric cancer with a cold tumor immune microenvironment.

BACKGROUND: Although CDKN2A alteration has been explored as a favorable factor for tumorigenesis in pan-cancers, the association between CDKN2A point mutation (MUT) and intragenic deletion (DEL) and response to immune checkpoint inhibitors (ICIs) is still disputed. This study aims to determine the associations of CDKN2A MUT and DEL with overall survival (OS) and response to immune checkpoint inhibitors treatment (ICIs) among pan-cancers and the clinical features of CDKN2A-altered gastric cancer. METHODS: This study included 45,000 tumor patients that underwent tumor sequencing across 33 cancer types from four cohorts, the MSK-MetTropism, MSK-IMPACT, OrigiMed2020 and TCGA cohorts. Clinical outcomes and genomic factors associated with response to ICIs, including tumor mutational burden, copy number alteration, neoantigen load, microsatellite instability, tumor immune microenvironment and immune-related gene signatures, were collected in pan-cancer. Clinicopathologic features and outcomes were assessed in gastric cancer. Patients were grouped based on the presence of CDKN2A wild type (WT), CDKN2A MUT, CDKN2A DEL and CDKN2A other alteration (ALT). RESULTS: Our research showed that CDKN2A-MUT patients had shorter survival times than CDKN2A-WT patients in the MSK MetTropism and TCGA cohorts, but longer OS in the MSK-IMPACT cohort with ICIs treatment, particularly in patients having metastatic disease. Similar results were observed among pan-cancer patients with CDKN2A DEL and other ALT. Notably, CDKN2A ALT frequency was positively related to tumor-specific objective response rates to ICIs in MSK MetTropism and OrigiMed 2020. Additionally, individuals with esophageal carcinoma or stomach adenocarcinoma who had CDKN2A MUT had poorer OS than patients from the MSK-IMPACT group, but not those with adenocarcinoma. We also found reduced levels of activated NK cells, T cells CD8 and M2 macrophages in tumor tissue from CDKN2A-MUT or DEL pan-cancer patients compared to CDKN2A-WT patients in TCGA cohort. Gastric cancer scRNA-seq data also showed that CDKN2A-ALT cancer contained less CD8 T cells but more exhausted T cells than CDKN2A-WT cancer. A crucial finding of the pathway analysis was the inhibition of three immune-related pathways in the CDKN2A ALT gastric cancer patients, including the interferon alpha response, inflammatory response, and interferon gamma response. CONCLUSIONS: This study illustrates the CDKN2A MUT and DEL were associated with a poor outcome across cancers. CDKN2A ALT, on the other hand, have the potential to be used as a biomarker for choosing patients for ICI treatment, notably in esophageal carcinoma and stomach adenocarcinoma.

Ultrasound-Activated PROTAC Prodrugs Overcome Immunosuppression to Actuate Efficient Deep-Tissue Sono-Immunotherapy in Orthotopic Pancreatic Tumor Mouse Models.

The degradation of oncoproteins mediated by proteolysis-targeting chimera (PROTAC) has emerged as a potent strategy in cancer therapy. However, the clinical application of PROTACs is hampered by challenges such as poor water solubility and off-target adverse effects. Herein, we present an ultrasound (US)-activatable PROTAC prodrug termed NPCe6+PRO for actuating efficient sono-immunotherapy in a spatiotemporally controllable manner. Specifically, US irradiation, which exhibits deep-tissue penetration capability, results in Ce6-mediated generation of ROS, facilitating sonodynamic therapy (SDT) and inducing immunogenic cell death (ICD). Simultaneously, the generated ROS cleaves the thioketal (TK) linker through a ROS-responsive mechanism, realizing the on-demand activation of the PROTAC prodrug in deep tissues. This prodrug activation results in the degradation of the target protein BRD4, while simultaneously reversing the upregulation of PD-L1 expression associated with the SDT process. In the orthotopic mouse model of pancreatic tumors, NPCe6+PRO effectively suppressed tumor growth in conjunction with US stimulation.

Inhibition of Cardiac Kv4.3/KChIP2 Channels by Sulfonylurea Drug Gliquidone.

The Kv4.3 channel features fast N-type inactivation and also undergoes a slow C-type inactivation. The gain-of-function mutations of Kv4.3 channels cause an inherited disease called Brugada syndrome (BrS), characterized by a shortened duration of cardiac action potential repolarization and ventricular arrhythmia. The sulfonylurea drug gliquidone, an ATP-dependent K+ channel antagonist, is widely used for the treatment of type 2 diabetes. Here, we report a novel role of gliquidone in inhibiting Kv4.3 and Kv4.3/KChIP2 channels that encode the cardiac transient outward K+ currents responsible for the initial phase of action potential repolarization. Gliquidone results in concentration-dependent inhibition of both Kv4.3 and Kv4.3/KChIP2 fast or steady-state inactivation currents with an IC50 of approximately 8 µM. Gliquidone also accelerates Kv4.3 channel inactivation and shifts the steady-state activation to a more depolarizing direction. Site-directed mutagenesis and molecular docking reveal that the residues S301 in the S4 and Y312A and L321A in the S4-S5 linker are critical for gliquidone-mediated inhibition of Kv4.3 currents, as mutating those residues to alanine significantly reduces the potency for gliquidone-mediated inhibition. Furthermore, gliquidone also inhibits a gain-of-function Kv4.3 V392I mutant identified in BrS patients in voltage- and concentration-dependent manner. Taken together, our findings demonstrate that gliquidone inhibits Kv4.3 channels by acting on the residues in the S4 and the S4-S5 linker. Therefore, gliquidone may hold repurposing potential for the therapy of Brugada syndrome. SIGNIFICANCE STATEMENT: We describe a novel role of gliquidone in inhibiting cardiac Kv4.3 currents and the channel gain-of-function mutation identified from patients with Brugada syndrome, suggesting its repurposing potential for therapy for the heart disease.

Inhibition of cutaneous heat-sensitive Ca2+ -permeable transient receptor potential vanilloid 3 channels alleviates UVB-induced skin lesions in mice.

Ultraviolet B (UVB) radiation causes skin injury by trigging excessive calcium influx and signaling cascades in the skin keratinocytes. The heat-sensitive Ca2+ -permeable transient receptor potential vanilloid 3 (TRPV3) channels robustly expressed in the keratinocytes play an important role in skin barrier formation and wound healing. Here, we report that inhibition of cutaneous TRPV3 alleviates UVB radiation-induced skin lesions. In mouse models of ear swelling and dorsal skin injury induced by a single exposure of weak UVB radiation, TRPV3 genes and proteins were upregulated in quantitative real-time PCR and Western blot assays. In accompany with TRPV3 upregulations, the expressions of proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were also increased. Knockout of the TRPV3 gene alleviates UVB-induced ear swelling and dorsal skin inflammation. Furthermore, topical applications of two selective TRPV3 inhibitors, osthole and verbascoside, resulted in a dose-dependent attenuation of skin inflammation and lesions. Taken together, our findings demonstrate the causative role of overactive TRPV3 channel function in the development of UVB-induced skin injury. Therefore, topical inhibition of TRPV3 may hold potential therapy or prevention of UVB radiation-induced skin injury.

Robust Thiazole-Linked Covalent Organic Frameworks for Water Sensing with High Selectivity and Sensitivity.

The rational design of covalent organic frameworks (COFs) with hydrochromic properties is of significant value because of the facile and rapid detection of water in diverse fields. In this report, we present a thiazole-linked COF (TZ-COF-6) sensor with a large surface area, ultrahigh stability, and excellent crystallinity. The sensor was synthesized through a simple three-component reaction involving amine, aldehyde, and sulfur. The thiazole and methoxy groups confer strong basicity to TZ-COF-6 at the nitrogen sites, making them easily protonated reversibly by water. Therefore, TZ-COF-6 displayed color change visible to the naked eye from yellow to red when protonated, along with a red shift in absorption in the ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) when exposed to water. Importantly, the water-sensing process was not affected by polar organic solvents, demonstrating greater selectivity and sensitivity compared to other COF sensors. Therefore, TZ-COF-6 was used to detect trace amounts of water in organic solvents. In strong polar solvents, such as N,N-dimethyl formamide (DMF) and ethanol (EtOH), the limit of detection (LOD) for water was as low as 0.06% and 0.53%, respectively. Even after 8 months of storage and 15 cycles, TZ-COF-6 retained its original crystallinity and detection efficiency, displaying high stability and excellent cycle performance.

A Novel Role of Uricosuric Agent Benzbromarone in BK Channel Activation and Reduction of Airway Smooth Muscle Contraction.

The uricosuric drug benzbromarone, widely used for treatment of gout, hyperpolarizes the membrane potential of airway smooth muscle cells, but how it works remains unknown. Here we show a novel role of benzbromarone in activation of large conductance calcium-activated K+ channels. Benzbromarone results in dose-dependent activation of macroscopic big potassium (BK) currents about 1.7- to 14.5-fold with an EC50 of 111 µM and shifts the voltage-dependent channel activation to a more hyperpolarizing direction about 10 to 54 mV in whole-cell patch clamp recordings. In single-channel recordings, benzbromarone decreases single BKα channel closed dwell time and increases the channel open probability. Coexpressing ß1 subunit also enhances BK activation by benzbromarone with an EC50 of 67 µM and a leftward shift of conductance-voltage (G-V) curve about 44 to 138 mV. Site-directed mutagenesis reveals that a motif of three amino acids 329RKK331 in the cytoplasmic linker between S6 and C-terminal regulator of potassium conductance (RCK) gating ring mediates the pharmacological activation of BK channels by benzbromarone. Further ex vivo assay shows that benzbromarone causes reduction of tracheal strip contraction. Taken together, our findings demonstrate that uricosuric benzbromarone activates BK channels through molecular mechanism of action involving the channel RKK motif of S6-RCK linker. Pharmacological activation of BK channel by benzbromarone causes reduction of tracheal strip contraction, holding a repurposing potential for asthma and pulmonary arterial hypertension or BK channelopathies. SIGNIFICANCE STATEMENT: We describe a novel role of uricosuric agent benzbromarone in big potassium (BK) channel activation and relaxation of airway smooth muscle contraction. In this study, we find that benzbromarone is an activator of the large-conductance Ca2+- and voltage-activated K+ channel (BK channel), which serves numerous cellular functions, including control of smooth muscle contraction. Pharmacological activation of BK channel by the FDA-approved drug benzbromarone may hold repurposing potential for treatment of asthma and pulmonary arterial hypertension or BK channelopathies.

Molecular determinants for the chemical activation of the warmth-sensitive TRPV3 channel by the natural monoterpenoid carvacrol.

Transient receptor potential vanilloid 3 (TRPV3), robustly expressed in the skin, is a nonselective calcium-permeable cation channel activated by warm temperature, voltage, and certain chemicals. Natural monoterpenoid carvacrol from plant oregano is a known skin sensitizer or allergen that specifically activates TRPV3 channel. However, how carvacrol activates TRPV3 mechanistically remains to be understood. Here, we describe the molecular determinants for chemical activation of TRPV3 by the agonist carvacrol. Patch clamp recordings reveal that carvacrol activates TRPV3 in a concentration-dependent manner, with an EC50 of 0.2 mM, by increasing the probability of single-channel open conformation. Molecular docking of carvacrol into cryo-EM structure of TRPV3 combined with site-directed mutagenesis further identified a unique binding pocket formed by the channel S2-S3 linker important for mediating this interaction. Within the binding pocket consisting of four residues (Ile505, Leu508, Arg509, and Asp512), we report that Leu508 is the most critical residue for the activation of TRPV3 by carvacrol, but not 2-APB, a widely used nonspecific agonist and TRP channel modulator. Our findings demonstrate a direct binding of carvacrol to TRPV3 by targeting the channel S2-S3 linker that serves as a critical domain for chemical-mediated activation of TRPV3. We also propose that carvacrol can function as a molecular tool in the design of novel specific TRPV3 modulators for the further understanding of TRPV3 channel pharmacology.

Selective activation of TRPA1 ion channels by nitrobenzene skin sensitizers DNFB and DNCB.

2, 4-dinitrofluorobenzene (DNFB) and 2, 4-dinitrochlorobenzene (DNCB) are well known as skin sensitizers that can cause dermatitis. DNFB has shown to more potently sensitize skin; however, how DNFB and DNCB cause skin inflammation at a molecular level and why this difference in their sensitization ability is observed remain unknown. In this study, we aimed to identify the molecular targets and mechanisms on which DNFB and DNCB act. We used a fluorescent calcium imaging plate reader in an initial screening assay before patch-clamp recordings for validation. Molecular docking in combination with site-directed mutagenesis was then carried out to investigate DNFB and DNCB binding sites in the TRPA1 ion channel that may be selectively activated by these tow sensitizers. We found that DNFB and DNCB selectively activated TRPA1 channel with EC50 values of 2.3 ± 0.7 µM and 42.4 ± 20.9 µM, respectively. Single-channel recordings revealed that DNFB and DNCB increase the probability of channel opening and act on three residues (C621, E625, and Y658) critical for TRPA1 activation. Our findings may not only help explain the molecular mechanism underlying the dermatitis and pruritus caused by chemicals such as DNFB and DNCB, but also provide a molecular tool 7.5-fold more potent than the current TRPA1 activator allyl isothiocyanate (AITC) used for investigating TRPA1 channel pharmacology and pathology.

Attenuation of Epileptogenesis and Cognitive Deficits by a Selective and Potent Kv7 Channel Opener in Rodent Models of Seizures.

Targeting neuronal Kv7 channels by pharmacological activation has been proven to be an attractive therapeutic strategy for epilepsy. Here, we show that activation of Kv7 channels by an opener SCR2682 dose-dependently reduces seizure activity and severity in rodent models of epilepsy induced by a GABAa receptor antagonist pentylenetetrazole (PTZ), maximal electroshock, and a glutamate receptor agonist kainic acid (KA). Electroencephalographic recordings of rat cerebral cortex confirm that SCR2682 also decreases epileptiform discharges in KA-induced seizures. Nissl and neuronal nuclei staining further demonstrates that SCR2682 also protects neurons from injury induced by KA. In Morris water maze navigation and Y-maze tests, SCR2682 improves PTZ- and KA-induced cognitive impairment. Taken together, our findings demonstrate that pharmacological activation of Kv7 by novel opener SCR2682 may hold promise for therapy of epilepsy with cognitive impairment. SIGNIFICANCE STATEMENT: A neuronal Kv7 channel opener SCR2682 attenuates epileptogenesis and seizure-induced cognitive impairment in rodent models of seizures, thus possessing a developmental potential for effective therapy of epilepsy with cognitive impairment.

Phase microscopy using band-limited image and its Fourier transform constraints.

In this Letter, we present a new, to the best of our knowledge, form of single-exposure quantitative phase microscopy based on the phase retrieval method by recording the band-limited image and its Fourier image simultaneously. Applying the intrinsic physical constraints of microscopy systems in the phase retrieval algorithm, we remove the inherent ambiguities of the reconstruction and achieve a rapid iterative convergence. In particular, this system does not require tight support of the object and the oversampling needed in coherent diffraction imaging. We have demonstrated that, in both simulations and experiments, the phase can be rapidly retrieved from a single-exposure measurement using our algorithm. The presented phase microscopy provides a promising technique for real-time quantitative biological imaging.

Pan-cancer analysis of NFE2L2 mutations identifies a subset of lung cancers with distinct genomic and improved immunotherapy outcomes.

BACKGROUND: Mutations in the KEAP1-NFE2L2 signaling pathway were linked to increased tumorigenesis and aggressiveness. Interestingly, not all hotspot mutations on NFE2L2 were damaging; some even were activating. However, there was conflicting evidence about the association between NFE2L2 mutation and Nrf2-activating mutation and responsiveness to immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) and other multiple cancers. METHODS: The study with the largest sample size (n = 49,533) explored the landscape of NFE2L2 mutations and their impact response/resistance to ICIs using public cohorts. In addition, the in-house WXPH cohort was used to validate the efficacy of immunotherapy in the NFE2L2 mutated patients with NSCLC. RESULTS: In two pan-cancer cohorts, Nrf2-activating mutation was associated with higher TMB value compared to wild-type. We identified a significant association between Nrf2-activating mutation and shorter overall survival in pan-cancer patients and NSCLC patients but not in those undergoing ICIs treatment. Similar findings were obtained in cancer patients carrying the NFE2L2 mutation. Furthermore, in NSCLC and other cancer cohorts, patients with NFE2L2 mutation demonstrated more objective responses to ICIs than patients with wild type. Our in-house WXPH cohort further confirmed the efficacy of immunotherapy in the NFE2L2 mutated patients with NSCLC. Lastly, decreased inflammatory signaling pathways and immune-depleted immunological microenvironments were enriched in Nrf2-activating mutation patients with NSCLC. CONCLUSIONS: Our study found that patients with Nrf2-activating mutation had improved immunotherapy outcomes than patients with wild type in NSCLC and other tumor cohorts, implying that Nrf2-activating mutation defined a distinct subset of pan-cancers and might have implications as a biomarker for guiding ICI treatment, especially NSCLC.

ROS-Responsive Prodrug Micelle Co-Delivery System for Synergistic Antiatherosclerotic Therapy.

Tanshinone IIA (TS-IIA) and salvianic acid A (SAA) are the main pharmacological active constituents of Danshen, which exhibit potent effects on atherosclerosis. A combination of TS-IIA and SAA might exert a synergistic antiatherosclerotic effect. However, the opposite solubility profiles of TS-IIA and SAA might lead to difficulty in achieving a synergistic combined effect of the two active components. Therefore, in this work, we fabricated a ROS-responsive prodrug micelle for the codelivery of TS-IIA and SAA (TS-IIA-PM) by self-assembling amphiphilic block copolymer PEG5000-SAA/PLA10000-APBA. The amphiphilic polymer was characterized by 1H NMR, FTIR, and alizarin red S competition tests. The ROS responsiveness of TS-IIA-PM was evidenced by time-course monitoring of particle size and morphology changes and drug release behavior in the presence of 1 mM H2O2. We found TS-IIA-PM was stable according to its critical micelle concentration and the unchanged particle sizes in 10% FBS for 7 days. The results of in vitro and in vivo tests revealed that TS-IIA-PM was safe and biocompatible. Furthermore, it was observed that TS-IIA and prodrug micelle could produce synergistic antiatherosclerotic effect based on the results of the antioxidant study, which was further confirmed by a series of pharmocodynamics studies, such as in vitro DiI-oxLDL uptake study, oil red O staining, cholesterol efflux study, inflammatory cytokine analysis, in vivo CD68 immunostaining, and lipid disposition staining studies. Collectively, TS-IIA-PM holds great potential for the safe and efficient codelivery of TS-IIA and SAA for synergistic antiatherosclerosis.

Butyrate induces development-dependent necrotizing enterocolitis-like intestinal epithelial injury via necroptosis.

BACKGROUND: The accumulation of short-chain fatty acids (SCFAs) from bacterial fermentation may adversely affect the under-developed gut as observed in premature newborns at risk for necrotizing enterocolitis (NEC). This study explores the mechanism by which specific SCFA fermentation products may injure the premature newborn intestine mucosa leading to NEC-like intestinal cell injury. METHODS: Intraluminal injections of sodium butyrate were administered to 14- and 28-day-old mice, whose small intestine and stool were harvested for analysis. Human intestinal epithelial stem cells (hIESCs) and differentiated enterocytes from preterm and term infants were treated with sodium butyrate at varying concentrations. Necrosulfonamide (NSA) and necrostatin-1 (Nec-1) were used to determine the protective effects of necroptosis inhibitors on butyrate-induced cell injury. RESULTS: The more severe intestinal epithelial injury was observed in younger mice upon exposure to butyrate (p = 0.02). Enterocytes from preterm newborns demonstrated a significant increase in sensitivity to butyrate-induced cell injury compared to term newborn enterocytes (p = 0.068, hIESCs; p = 0.038, differentiated cells). NSA and Nec-1 significantly inhibited the cell death induced by butyrate. CONCLUSIONS: Butyrate induces developmental stage-dependent intestinal injury that resembles NEC. A primary mechanism of cell injury in NEC is necroptosis. Necroptosis inhibition may represent a potential preventive or therapeutic strategy for NEC. IMPACT: Butyrate induces developmental stage-dependent intestinal injury that resembles NEC. A primary mechanism of cell injury caused by butyrate in NEC is necroptosis. Necroptosis inhibitors proved effective at significantly ameliorating the enteral toxicity of butyrate and thereby suggest a novel mechanism and approach to the prevention and treatment of NEC in premature newborns.

Development of VER-50589 analogs as novel Hsp90 inhibitors.

As an important target for tumor therapy, heat shock protein 90 has attracted tremendous attention. Through structure analysis, we rationally designed three analogs of VER-50589 which is a known and potent Hsp90 inhibitor. Target inhibitory activity result showed that one compound dubbed as 12-1 exhibited strong inhibitory activity against Hsp90 with an IC50 value of 9 nM. In tumor cell viability experiment, compound 12-1 robustly repressed the proliferation against six human tumor cells with IC50 values all in nanomolar range scoring over VER-50589 and geldanamycin. 12-1 was able to induce apoptosis of tumor cells and arrest the tumor cell cycle in G0/G1 phase. Meanwhile, western blot results showed that 12-1 could significantly downregulated the expression of two Hsp90 client proteins CDK4 and HER2. Finally, molecular dynamic simulation showed that compound 12-1 could fit well with ATP binding site on N-terminal of Hsp90.

MPpredictor: An Artificial Intelligence-Driven Web Tool for Composition-Based Material Property Prediction.

The applications of artificial intelligence, machine learning, and deep learning techniques in the field of materials science are becoming increasingly common due to their promising abilities to extract and utilize data-driven information from available data and accelerate materials discovery and design for future applications. In an attempt to assist with this process, we deploy predictive models for multiple material properties, given the composition of the material. The deep learning models described here are built using a cross-property deep transfer learning technique, which leverages source models trained on large data sets to build target models on small data sets with different properties. We deploy these models in an online software tool that takes a number of material compositions as input, performs preprocessing to generate composition-based attributes for each material, and feeds them into the predictive models to obtain up to 41 different material property values. The material property predictor is available online at http://ai.eecs.northwestern.edu/MPpredictor.

Design, synthesis, and biological evaluation of acyl sulfonamide derivatives with spiro cycles as NaV1.7 inhibitors for antinociception.

Chronic pain, as an unmet medical need, severely impacts the quality of life. The voltage-gated sodium channel NaV1.7 preferentially expressed in sensory neurons of dorsal root ganglia (DRG) serves a promising target for pain therapy. Here, we report the design, synthesis, and evaluation of a series of acyl sulfonamide derivatives targeting Nav1.7 for their antinociceptive activities. Among the derivatives tested, the compound 36c was identified as a selective and potent NaV1.7 inhibitor in vitro and exhibited antinociceptive effects in vivo. The identification of 36c not only provides a new insight into the discovery of selective NaV1.7 inhibitors, but also may hold premise for pain therapy.

Design, synthesis and anticancer evaluation of novel oncolytic peptide-chlorambucil conjugates.

Nitrogen mustards (NMs) are an important class of chemotherapeutic drugs and have been widely employed for the treatment of various cancers. However, due to the high reactivity of nitrogen mustard, most NMs react with proteins and phospholipids within the cell membrane. Therefore, only a very small fraction of NMs can reach the reach nucleus, alkylating and cross-linking DNA. To efficiently penetrate the cell membrane barrier, the hybridization of NMs with a membranolytic agent may be an effective strategy. Herein, the chlorambucil (CLB, a kind of NM) hybrids were first designed by conjugation with membranolytic peptide LTX-315. However, although LTX-315 could help large amounts of CLB penetrate the cytomembrane and enter the cytoplasm, CLB still did not readily reach the nucleus. Our previous work demonstrated that the hybrid peptide NTP-385 obtained by covalent conjugation of rhodamine B with LTX-315 could accumulate in the nucleus. Hence, the NTP-385-CLB conjugate, named FXY-3, was then designed and systematically evaluated both in vitro and in vivo. FXY-3 displayed prominent localization in the cancer cell nucleus and induced severe DNA double-strand breaks (DSBs) to trigger cell apoptosis. Especially, compared with CLB and LTX-315, FXY-3 exhibited significantly increased in vitro cytotoxicity against a panel of cancer cell lines. Moreover, FXY-3 showed superior in vivo anticancer efficiency in the mouse cancer model. Collectively, this study established an effective strategy to increase the anticancer activity and the nuclear accumulation of NMs, which will provide a valuable reference for future nucleus-targeting modification of nitrogen mustards.

The hybrid oncolytic peptide NTP-385 potently inhibits adherent cancer cells by targeting the nucleus.

The use of oncolytic peptides with activity against a wide range of cancer entities as a new and promising cancer therapeutic strategy has drawn increasing attention. The oncolytic peptide LTX-315 derived from bovine lactoferricin (LfcinB) was found to be highly effective against suspension cancer cells, but not adherent cancer cells. In this study, we tactically fused LTX-315 with rhodamine B through a hybridization strategy to design and synthesize a series of nucleus-targeting hybrid peptides and evaluated their activity against adherent cancer cells. Thus, four hybrid peptides, NTP-212, NTP-217, NTP-223 and NTP-385, were synthesized. These hybrid peptides enhanced the anticancer activity of LTX-315 in a panel of adherent cancer cell lines by 2.4- to 37.5-fold. In model mice bearing B16-F10 melanoma xenografts, injection of NTP-385 (0.5 mg per mouse for 3 consecutive days) induced almost complete regression of melanoma, prolonged the median survival time and increased the overall survival. Notably, the administered dose of NTP-385 was only half the effective dose of LTX-315. We further revealed that unlike LTX-315, which targets the mitochondria, NTP-385 disrupted the nuclear membrane and accumulated in the nucleus, resulting in the transfer of a substantial amount of reactive oxygen species (ROS) from the cytoplasm to the nucleus through the fragmented nuclear membrane. This ultimately led to DNA double-strand break (DSB)-mediated intrinsic apoptosis. In conclusion, this study demonstrates that hybrid peptides obtained from the fusion of LTX-315 and rhodamine B enhance anti-adherent cancer cell activity by targeting the nucleus and triggering DNA DSB-mediated intrinsic apoptosis. This study also provides an advantageous reference for nucleus-targeting peptide modification.

The role of sleep quality and perceived stress on depressive symptoms among tertiary hospital nurses: a cross-sectional study.

BACKGROUND: Nurses in tertiary hospitals are at high risk for depression. Understanding sleep quality and perceived stress may contribute to nurses' mental health and health-related nursing productivity. The aim of this study was to investigate the role of sleep quality and perceived stress on depressive symptoms among nurses in tertiary hospitals. METHODS: A total of 2,780 nurses (overall response rate = 91.1%) were recruited through a cross-sectional survey in 23 tertiary hospitals in China. Questionnaires included the Self-Rating Depression Scale, the Pittsburgh Sleep Quality Index, and the Chinese Perceived Stress Scale. Variables that were significant in Chi-square tests were further entered into binary logistic stepwise regression. RESULTS: The prevalence of depressive symptoms was 60.3% (n = 1,676), of which 97.4% (n = 1,633) were female, and 77.8% were younger than 35 years (n = 1,304). Nurses who had moderate, poor, severe sleep quality and poor perceived pressure were more likely to be depressed. Master's degree, 6-10 years of work, and physical activity were protective factors, while the opposite was the case for shift work and high dissatisfaction. CONCLUSIONS: More than half of nurses working in tertiary care hospitals reported depressive symptoms, and lower sleep quality and higher perceived stress were more associated with this. Perceived stress is an interesting concept, which may provide a new entry point for the well-known idea that there is a relationship between poor sleep quality and depression. It is possible to reduce depressive symptoms among public hospital nurses by providing information on sleep health and stress relief.