Genetically encoded chemical probes in cells reveal the binding path of urocortin-I to CRF class B GPCR.

Molecular determinants regulating the activation of class B G-protein-coupled receptors (GPCRs) by native peptide agonists are largely unknown. We have investigated here the interaction between the corticotropin releasing factor receptor type 1 (CRF1R) and its native 40-mer peptide ligand Urocortin-I directly in mammalian cells. By incorporating unnatural amino acid photochemical and new click-chemical probes into the intact receptor expressed in the native membrane of live cells, 44 intermolecular spatial constraints have been derived for the ligand-receptor interaction. The data were analyzed in the context of the recently resolved crystal structure of CRF1R transmembrane domain and existing extracellular domain structures, yielding a complete conformational model for the peptide-receptor complex. Structural features of the receptor-ligand complex yield molecular insights on the mechanism of receptor activation and the basis for discrimination between agonist and antagonist function.

Molecular and cellular pruritus mechanisms in the host skin.

Pruritus, also known as itching, is a complex sensation that involves the activation of specific physiological and cellular receptors. The skin is innervated with sensory nerves as well as some receptors for various sensations, and its immune system has prominent neurological connections. Sensory neurons have a considerable impact on the sensation of itching. However, immune cells also play a role in this process, as they release pruritogens. Disruption of the dermal barrier activates an immune response, initiating a series of chemical, physical, and cellular reactions. These reactions involve various cell types, including keratinocytes, as well as immune cells involved in innate and adaptive immunity. Collective activation of these immune responses confers protection against potential pathogens. Thus, understanding the molecular and cellular mechanisms that contribute to pruritus in host skin is crucial for the advancement of effective treatment approaches. This review provides a comprehensive analysis of the present knowledge concerning the molecular and cellular mechanisms underlying itching signaling in the skin. Additionally, this review explored the integration of these mechanisms with the broader context of itch mediators and the expression of their receptors in the skin.

An imported malaria case with repeated episodes of neurological syndromes resulting from different Plasmodium species.

BACKGROUND: Imported cerebral malaria (CM) cases in non-endemic areas are often misdiagnosed, which delays treatment. Post-malaria neurological syndrome (PMNS) after recovery from severe malaria can also complicate diagnosis. CASE: We report an imported malaria case from West Africa with two sequential episodes with neurological syndromes within about a month. The first episode was diagnosed as CM with microscopy-positive Plasmodium falciparum infection. The second episode, occurring a month after the recovery from the first CM episode, was consistent with PMNS, since malaria parasites were not detected by microscopy in peripheral blood smears. However, this diagnosis was complicated by the detection of Plasmodium vivax in peripheral blood by PCR, suggesting a potential cause of the second episode by P. vivax. CONCLUSION: This study suggests that PMNS often occurs after severe falciparum malaria. Concurrent P. vivax infection with pathogenic biomass being predominantly extravascular further complicates accurate diagnosis.

The Diagnostic Value of Carnett's Test with Chronic Abdominal Pain: A Narrative Review.

PURPOSE OF REVIEW: Chronic abdominal wall pain is a poorly recognized cause of chronic abdominal pain, and patients frequently go misdiagnosed despite a battery of medical tests. The Carnett's test is a diagnostic tool used to distinguish between abdominal wall pain and visceral pain. This review synthesizes the current literature on the Carnett's test, merges the viewpoints of diverse writers, and evaluates and reports on the Carnett's test's applicability. RECENT FINDINGS: Several clinical investigations have established the usefulness of the Carnett's test in the diagnosis of chronic abdominal wall pain. Furthermore, the Carnett's test is quite useful in determining the depth of the mass and detecting psychogenic abdominal pain. However, its diagnostic use for acute abdominal pain is limited. The Carnett's test is a simple and safe point-of-care diagnostic technique, with several studies supporting its usefulness. Early detection of abdominal wall pain is critical for chronic abdominal wall pain therapy. Carnett's test is very useful in patients with chronic, unexplained local abdominal discomfort who are compliant and do not have a clear rationale for surgery.

Comparison of the Efficacy of Different Radiofrequency Techniques for the Treatment of Lumbar Facet Joint Pain: Combined with Anatomy.

PURPOSE OF REVIEW: Lumbar facet pain is generally considered to be one of the major causes of chronic low back pain. Each lumbar facet joint is innervated by the medial branch of the posterior spinal nerve from its own level and above. Radiofrequency (RF) of the medial branch of the posterior branch of the spinal nerve is an effective method for the treatment of lumbar facet pain. RF technology is diverse, including traditional radiofrequency (TRF), pulsed radiofrequency (PRF), cooled radiofrequency (CRF), low-temperature plasma radiofrequency ablation (CA), and other treatment methods. The purpose of this paper is to compare the efficacy of different radiofrequency techniques and to analyze the reasons for this in the context of anatomy. RECENT FINDINGS: There have been studies confirming the differences in efficacy of different RF techniques. However, most of the studies only compared two RF techniques, not four techniques, TRF, CRF, PRF, and CA, and did not analyze the reasons for the differences in efficacy. This article reviews the differences in the efficacy of the above four RF techniques, clarifies that the differences are mainly due to the inability to precisely localize the medial branch of the posterior branch of the spinal nerve, analyzes the reasons for the inability to precisely localize the posterior branch of the spinal nerve in conjunction with anatomy, and proposes that the development of RF technology for lumbar facet pain requires more in-depth anatomical, imaging, and clinical studies.

An Artificial Enzyme for Asymmetric Nitrocyclopropanation of α,ß-Unsaturated Aldehydes-Design and Evolution.

The introduction of an abiological catalytic group into the binding pocket of a protein host allows for the expansion of enzyme chemistries. Here, we report the generation of an artificial enzyme by genetic encoding of a non-canonical amino acid that contains a secondary amine side chain. The non-canonical amino acid and the binding pocket function synergistically to catalyze the asymmetric nitrocyclopropanation of α,ß-unsaturated aldehydes by the iminium activation mechanism. The designer enzyme was evolved to an optimal variant that catalyzes the reaction at high conversions with high diastereo- and enantioselectivity. This work demonstrates the application of genetic code expansion in enzyme design and expands the scope of enzyme-catalyzed abiological reactions.

Temporal and Gene Reassortment Analysis of Influenza C Virus Outbreaks in Hong Kong, SAR, China.

From 2014 to week 07/2020 the Centre for Health Protection in Hong Kong conducted screening for influenza C virus (ICV). A retrospective analysis of ICV detections to week 26/2019 revealed persistent low-level circulation with outbreaks occurring biennially in the winters of 2015 to 2016 and 2017 to 2018 (R. S. Daniels et al., J Virol 94:e01051-20, 2020, https://doi.org/10.1128/JVI.01051-20). Here, we report on an outbreak occurring in 2019 to 2020, reinforcing the observation of biennial seasonality in Hong Kong. All three outbreaks occurred in similar time frames, were subsequently dwarfed by seasonal epidemics of influenza types A and B, and were caused by similar proportions of C/Kanagawa/1/76 (K)-lineage and C/São Paulo/378/82 S1- and S2-sublineage viruses. Ongoing genetic drift was observed in all genes, with some evidence of amino acid substitution in the hemagglutinin-esterase-fusion (HEF) glycoprotein possibly associated with antigenic drift. A total of 61 ICV genomes covering the three outbreaks were analyzed for reassortment, and 9 different reassortant constellations were identified, 1 K-lineage, 4 S1-sublineage, and 4 S2-sublineage, with 6 of these being identified first in the 2019-1920 outbreak (2 S2-lineage and 4 S1-lineage). The roles that virus interference/enhancement, ICV persistent infection, genome evolution, and reassortment might play in the observed seasonality of ICV in Hong Kong are discussed. IMPORTANCE Influenza C virus (ICV) infection of humans is common, with the great majority of people being infected during childhood, though reinfection can occur throughout life. While infection normally results in "cold-like" symptoms, severe disease cases have been reported in recent years. However, knowledge of ICV is limited due to poor systematic surveillance and an inability to propagate the virus in large amounts in the laboratory. Following recent systematic surveillance in Hong Kong SAR, China, and direct ICV gene sequencing from clinical specimens, a 2-year cycle of disease outbreaks (epidemics) has been identified, with gene mixing playing a significant role in ICV evolution. Studies like those reported here are key to developing an understanding of the impact of influenza C virus infection in humans, notably where comorbidities exist and severe respiratory disease can develop.

A dual-targeting near-infrared biomimetic drug delivery system for HBV treatment.

Hepatitis B virus (HBV) infection is a serious global public health threat. It remains elusive to achieve a functional HBV cure with currently available antivirals. Herein, a photo-responsive delivery vehicle composed of Nd3+ -sensitized core-shell upconversion nanoparticle (UCNP), mesoporous silica nanoparticle (MSN), antisense oligonucleotides (ASOs), and capsid-binding inhibitor C39 was established, which was named UMAC according to the initials of its components. Subsequently, the as-synthesized delivery vehicle was encapsulated by ß- D-galactopyranoside (Gal) modified red blood cell (RBC) membrane vesicles, which enabled precise targeting of the liver cells (UMAC-M-Gal). Both in vitro and in vivo experiments demonstrated that this biomimetic system could successfully achieve controlled drug release under light conditions at 808 nm, leading to effective suppression of HBV replication in this dual-targeted therapeutic approach. Together, these results substantiate the system has huge prospects for application to achieve functional HBV cure, and provides a promising novel strategy for drug delivery.

Chemoenzymatic synthesis of (+)-isoagatholactone, (+)-spongian-16-one, and 3-deoxychavalone A via biocatalytic polyene cyclization.

The stereoselective cyclization of geranylgeraniol catalysed by squalene-hopene cyclase (SHC) was investigated. By use of this transformation, spongiane diterpenoids (+)-isoagatholactone and (+)-spongian-16-one, and meroterpenoid 3-deoxychavalone A were synthesized in a concise and redox-economic manner. This work showcases the application of SHC-catalysed cyclization as a key step in terpenoid synthesis.

Enantioselective conjugate addition of malonates to α,ß-unsaturated aldehydes catalysed by 4-oxalocrotonate tautomerase.

The enantioselective conjugate addition of malonates to α,ß-unsaturated aldehydes catalysed by 4-oxalocrotonate tautomerase is described. High conversions, high enantioselectivities, and good isolation yields were achieved for a range of substrates. We further completed a four-step synthesis of the antidepressant (+)-femoxetine by utilizing this reaction and an enzymatic reductive amination reaction.

Opposite atom dependence of isotope engineering of thermal conductivity in bulk and 2D GaN.

Isotope engineering has been shown to be an effective means of regulating thermal conductivity. In this work, we studied the isotope engineering of thermal conductivity in bulk and 2D GaN, and diametrically opposite atom isotope dependence is found. That is, Ga isotope has a large effect (77%) on bulk GaN, while the effect of N isotope on the thermal conductivity is negligible. In 2D GaN, however, N isotope effect (20%) is more significant than that of Ga. Understanding of the different isotope dependence is achieved by deeper insight. Due to the relative magnitude of scattering rate, isotopic scattering influences the thermal conductivity of bulk and 2D GaN in different frequency regions, leading to the opposite atom dependence.

Performance and mechanism of a novel S-scheme heterojunction sonocatalyst CuS/BaWO4 for degradation of bisphenol A by ultrasonic activation.

A novel CuS/BaWO4 heterojunction catalyst was prepared and characterized. Taking bisphenol A as the target pollutant for catalytic degradation, the sonocatalytic activity of CuS/BaWO4 composite was evaluated, and the combination with persulfate improved the sonocatalytic degradation of bisphenol A. The results showed that CuS/BaWO4 composite had good sonocatalytic degradation activity for bisphenol A, and the degradation rate was 70.99% ± 1.46%. After combined with persulfate, the degradation rate was further increased to 95.34% ± 0.10%, and the reaction time was relatively shortened. The results of the trapping experiment and calculated energy band positions showed that the formation of S-scheme heterojunction and the formation of hydroxyl radicals and holes were the key to the catalytic degradation of bisphenol A by CuS/BaWO4 composite. In this study, a new CuS/BaWO4 heterojunction sonocatalyst was synthesized. The catalyst can efficiently remove bisphenol A from the water environment and can be used as a potential solution for endocrine disruptor pollution in the water environment.

A novel polymer enabled by polymerized small molecule strategy for tumor photothermal and photodynamic therapy.

Photothermal therapy (PTT) and photodynamic therapy (PDT) are effective method for tumor treatment. However, the limited variety and quantity of photothermal agents (PTAs) and photosensitizer (PSs) are still major challenges. Moreover, the cell apoptosis mechanism induced by PDT and PTT is still elusive. A fused-ring small molecule acceptor-donor acceptor' donor-acceptor (A-DA'D-A) type of Y5 (Scheme 1) has a narrow band-gap and strong light absorption. Herein, we used Y5 to polymerize with thiophene unit to obtain polymer PYT based on polymerized small molecule strategy, and PYT nanoparticles (PYT NPs) was prepared via one-step nanoprecipitation strategy with DSPE-PEG2000. PYT NPs had excellent biocompatibility, good photostability, high photothermal conversion efficiency (67%) and reactive oxygen species (ROS) production capacity under 808 nm laser irradiation (PYT NPs + NIR). In vitro and in vivo experiments revealed that PYT NPs + NIR had the ability to completely ablate tumor cells. It was demonstrated that cell apoptosis induced by PYT NPs + NIR was closely related to mitochondrial damage. This study provides valuable guidance for constructing high-performance organic PTAs and PSs for tumor treatment. Scheme 1 PYT enabled by polymerized small molecule strategy for tumor photothermal and photodynamic therapy.

Manganese-induced apoptosis through the ROS-activated JNK/FOXO3a signaling pathway in CTX cells, a model of rat astrocytes.

Manganese (Mn) is an essential trace element that maintains many normal physiological functions. However, multi-system disorders would occur once overexposure to Mn, especially neurotoxicity. Despite evidence demonstrating the critical role of ROS-activated JNK/FOXO3a signaling pathway in neuronal survival, the specific mechanisms by which it contributes to Mn-induced neurotoxicity are still unclear. The objectives of this study was to examine the modulation of the JNK/FOXO3a signaling pathway, which is activated by ROS, in Mn-induced apoptosis, using a rat brain astrocyte cell line (CTX cells). This study found that a dose-dependent decrease in cell viability of CTX cells was observed with 150, 200, 250, 300 µmol/L Mn. The results of apoptosis-related protein assay showed that Mn decreased the expression of anti-apoptotic protein Bcl-2 and enhanced the expression of apoptosis-related proteins like Bax and Cleaved-Caspase3. In addition, treatment with Mn resulted in elevated ROS levels and increased phosphorylation levels of JNK. Conversely, phosphorylation of nuclear transcription factors FOXO3a, which regulates expression of transcription factors including Bim and PUMA, was decreased. Depletion of ROS by N-acetyl-L-cysteine (NAC) and inhibition of the JNK pathway by SP600125 prevented Mn-induced JNK/FOXO3a pathway activation and, more importantly, the level of apoptosis was also significantly reduced. Confirmation of Mn-induced apoptosis in CTX cells through ROS generation and activation of the JNK/FOXO3a signaling pathway was the outcome of this study. These findings offer fresh insights into the neurotoxic mechanisms of Mn and therapeutic targets following Mn exposure.

Assessing lead curtains' impact on radiation protection in coronary interventions.

The objective of this investigation is to assess the impact of supplementary lead curtains on the reduction of radiation dose exposure to operators during coronary interventional procedures. Seven standard positions during coronary angiography (foot, right foot, head, left foot, left lateral, left head, and right lateral) were simulated on a standard anthropomorphic phantom with radial artery access. Measurements were taken at two different heights, 125 cm and 155 cm, and dosimeters were used to measured surface incident dose rates for the first and second operators, both with and without additional lead curtains at various positions. Each position was measured 20 times, and arithmetic means were computed. At-test was utilised to compare dose rates with and without supplementary lead curtains, as well as dose rates with additional lead curtains at varying heights. The finding indicate that the dose rates of the first operator with supplementary lead curtains were not significantly lower compared to those without, except for the 125 cm head and left foot positions and the 155 cm head position with the additional lead curtain edge 10 cm below the umbilical level (tumbilical= 0.9, 0.4, 0.5,P> 0.05). The dose rates of the second operator with additional lead curtains were significantly lower than those without, with statistically significant differences (P< 0.05). The arithmetic mean dose rates for the first and second operators at each position were lowest when the upper edge of the additional lead curtain was situated 10 cm above the umbilical level. Employing supplementary lead curtains during coronary interventions effectively reduces radiation doses received by operators. The protective effect is enhanced when the additional lead curtain is closer to the irradiation field. Hence, it is recommended that additional curtains be employed judiciously, while ensuring that clinical procedures are not impeded, in order to effectively mitigate the radiation exposure of operators.

Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D.

Incorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional-group interconversions, the use of enzymatic C-C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel-Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure-activity relationship studies of [7.7]paracyclophane natural products.

METTL3-mediated m6A modification promotes processing and maturation of pri-miRNA-19a to facilitate nasopharyngeal carcinoma cell proliferation and invasion.

The interplay between N6-methyladenosine (m6A) modification and microRNAs (miRs) participates in cancer progression. This study is conducted to explore the role of miR-19a-3p in nasopharyngeal carcinoma (NPC) cell proliferation and invasion. Reverse transcription quantitative polymerase chain reaction and Western blot showed that miR-19a-3p was upregulated in NPC tissues and cells and related to poor prognosis, methyltransferase-like 3 (METTL3) was highly expressed, whereas BMP and activin membrane-bound inhibitor (BAMBI) was weakly expressed in NPC tissues and cells. miR-19a-3p downregulation inhibited cell proliferation and invasion, whereas miR-19a-3p overexpression played the opposite role. m6A quantification and m6A RNA immunoprecipitation assays showed that METTL3-mediated m6A modification promoted the processing and maturation of pri-miR-19a via DiGeorge syndrome critical region gene 8 (DGCR8). Dual-luciferase assay showed that BAMBI was a target of miR-19a-3p. The rescue experiments showed that BAMBI downregulation reversed the role of miR-19a-3p inhibition in NPC cells. A xenograft tumor model showed that METTL3 downregulation inhibited tumor growth via the miR-19a-3p/BAMBI in vivo. Overall, our findings elicited that METTL3-mediated m6A modification facilitated the processing and maturation of pri-miR-19a via DGCR8 to upregulate miR-19a-3p, and miR-19a-3p inhibited BAMBI expression to promote NPC cell proliferation and invasion, thus driving NPC progression.

Clinical implications of exosome-derived noncoding RNAs in liver.

Exosomes, one of three main types of extracellular vesicles, are ~30-100 nm in diameter and have a lipid bilayer membrane. They are widely distributed in almost all body fluids. Exosomes have the potential to regulate unknown cellular and molecular mechanisms in intercellular communication, organ homeostasis, and diseases. They are critical signal carriers that transfer nucleic acids, proteins, lipids, and other substances into recipient cells, participating in cellular signal transduction and material exchange. ncRNAs are non-protein-coding genes that account for over 90% of the genome and include microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). ncRNAs are crucial for physiological and pathological activities in the liver by participating in gene transcription, posttranscriptional epigenetic regulation, and cellular processes through interacting with DNA, RNA, or proteins. Recent evidence from both clinical and preclinical studies indicates that exosome-derived noncoding RNAs (ncRNAs) are highly involved in the progression of acute and chronic liver diseases by regulating hepatic lipid metabolism, innate immunity, viral infection, fibrosis, and cancer. Therefore, exosome-derived ncRNAs have promising potential and clinical implications for the early diagnosis, targeted therapy, and prognosis of liver diseases.

Design, synthesis and structure-activity relationship optimization of phenanthridine derivatives as new anti-vitiligo compounds.

Humans have been suffering from vitiligo for a long time. Target vitiligo drugs have yet been approved. Activation of Wnt/ß-catenin signalling has potential in the therapeutic use of vitiligo, so exploring new drugs that specifically directly activate Wnt is worthwhile to obtain new anti-vitiligo agents. In this work, two portions design and synthesis were put into effect. firstly, 17 phenanthridine derivatives with C-4 substitutes were designed and synthesized, which compounds 4, 6, 12, 13 served as H-acceptor with protein showed enhance melanogenesis activity; Secondly, 7 hybrid new scaffolds of compounds were designed and synthesized, scaffold hopping compound 36 that aromatic benzene was replaced pyrazole on ring C showed enhance melanogenesis and tyrosinase activity; The last and most important, a comprehensive optimization and SARs of compound 36 were carried out, compounds 41 and 43 shared phenolic hydroxyl or 3-methyl-pyridine substitutes at C-7 position remarkably improved the capacity of melanogenesis and tyrosinase activity. Compound 43 were identified as new anti-vitiligo agents that specifically activate the Wnt/ß-catenin signalling pathway by targeting Axin. Structure-activity relationship analysis implied that H-acceptor substitutions at the C-4 position and phenolic hydroxyl or pyridine substitutions at the C-7 position would improve the activities of the compounds. These findings reveal a new therapeutic strategy for vitiligo, and compounds 41 and 43 may represent potential compounds for vitiligo treatment.

Potential biomarkers for inherited thrombocytopenia 2 identified by plasma proteomics.

Inherited thrombocytopenia 2 (THC2) is difficult to diagnose due to the lack of specific clinical characteristics and diagnostic methods. To identify potential plasma protein biomarkers for THC2, we collected the plasma samples from a THC2 family (9 THC2 and 15 non-THC2 members), enriched the medium and low abundant proteins using Proteominer and analyzed the protein profiles using the liquid chromatography-mass spectrometry in data independent acquisition mode. Initially, we detected 784 proteins in the plasma samples of this family and identified 27 up-regulated and 36 down-regulated in the THC2 group compared to the non-THC2 group (|log2 ratio| >1 and p-value <0.05). To improve the predictive power, top eight dysregulated proteins (B7Z2B4, LTF, HP, ERN1, IGHV1-8, A0A0X9V9C4, VH6DJ, and D3JV41) were selected by an area under the curve-based random forest process to construct a clinical model. Multivariate analysis with random forest and support vector machine showed that the prediction model provided high discrimination ability for THC2 diagnosis (AUC: 1.000 and 0.967, respectively). The potential plasma protein biomarkers will be tested in more THC2 patients and other thrombocytopenia patients to further validate their specificity and sensitivity.