Diminishing Self-Discharge of High-Loading Li-S Batteries with Oxygen-Rich Biomass Carbon Interlayers.

Lithium-sulfur batteries (Li-S) have possessed gratifying development in the past decade due to their high theoretical energy density. However, the severe polysulfide shuttling provokes undesirable self-discharge effect, leading to low energy efficiency in Li-S batteries. Herein, an interlayer composed of oxygen-rich carbon nanosheets (OCN) derived from bagasse is elaborated to suppress the shuttle effect and reduce the resultant self-discharge effect. The OCN interlayer is able to physically block the shuttling behavior of polysulfides and its oxygen-rich functional groups can strongly interact with polysulfides via O-S bonds to chemically immobilize mobile polysulfides. The self-discharge test for seven days further shows that the self-discahrge rate is diminished by impressive 93 %. As a result, Li-S batteries with the OCN interlayer achieve an ultrahigh discharge specific capacity of 710 mAh g-1 at a high mass loading of 7.18 mg. The work provides a facile method for designing functional interlayers and opens a new avenue for realizing Li-S batteries with high energy efficiency.

A strategy for mechanically integrating robust hydrogel-tissue hybrid to promote the anti-calcification and endothelialization of bioprosthetic heart valve.

Bioprosthetic heart valve (BHV) replacement has been the predominant treatment for severe heart valve diseases over decades. Most clinically available BHVs are crosslinked by glutaraldehyde (GLUT), while the high toxicity of residual GLUT could initiate calcification, severe thrombosis, and delayed endothelialization. Here, we construed a mechanically integrating robust hydrogel-tissue hybrid to improve the performance of BHVs. In particular, recombinant humanized collagen type III (rhCOLIII), which was precisely customized with anti-coagulant and pro-endothelialization bioactivity, was first incorporated into the polyvinyl alcohol (PVA)-based hydrogel via hydrogen bond interactions. Then, tannic acid was introduced to enhance the mechanical performance of PVA-based hydrogel and interfacial bonding between the hydrogel layer and bio-derived tissue due to the strong affinity for a wide range of substrates. In vitro and in vivo experimental results confirmed that the GLUT-crosslinked BHVs modified by the robust PVA-based hydrogel embedded rhCOLIII and TA possessed long-term anti-coagulant, accelerated endothelialization, mild inflammatory response and anti-calcification properties. Therefore, our mechanically integrating robust hydrogel-tissue hybrid strategy showed the potential to enhance the service function and prolong the service life of the BHVs after implantation.

A drug-free cardiovascular stent functionalized with tailored collagen supports in-situ healing of vascular tissues.

Drug-eluting stent implantation suppresses the excessive proliferation of smooth muscle cells to reduce in-stent restenosis. However, the efficacy of drug-eluting stents remains limited due to delayed reendothelialization, impaired intimal remodeling, and potentially increased late restenosis. Here, we show that a drug-free coating formulation functionalized with tailored recombinant humanized type III collagen exerts one-produces-multi effects in response to injured tissue following stent implantation. We demonstrate that the one-produces-multi coating possesses anticoagulation, anti-inflammatory, and intimal hyperplasia suppression properties. We perform transcriptome analysis to indicate that the drug-free coating favors the endothelialization process and induces the conversion of smooth muscle cells to a contractile phenotype. We find that compared to drug-eluting stents, our drug-free stent reduces in-stent restenosis in rabbit and porcine models and improves vascular neointimal healing in a rabbit model. Collectively, the one-produces-multi drug-free system represents a promising strategy for the next-generation of stents.

The novel lactoferrin and DHA-codelivered liposomes with different membrane structures: Fabrication, in vitro infant digestion, and suckling pig intestinal organoid absorption.

Inspired by membrane structure of breast milk and infant formula fat globules, four liposomes with different particle size (large and small) and compositions (Single phospholipids contained phosphatidylcholine, complex phospholipids contained phosphatidylcholine, phosphatidylethanolamine and sphingomyelin) were fabricated to deliver lactoferrin and DHA. In vitro infant semi-dynamic digestive behavior and absorption in intestinal organoids of liposomes were investigated. Liposomal structures were negligible changed during semi-dynamic gastric digestion while damaged in intestine. Liposomal degradation rate was primarily influenced by particle size, and complex phospholipids accelerated DHA hydrolysis. The release rate of DHA (91.7 ± 1.3 %) in small-sized liposomes (0.181 ± 0.001 µm) was higher than free DHA (unencapsulated, 64.6 ± 3.4 %). Complex phospholipids liposomal digesta exhibited higher transport efficiency (3.4-fold for fatty acids and 2.0-fold for amino acids) and better organoid growth than digesta of bare nutrients. This study provided new insights into membrane structure-functionality relationship of liposomes and may aid in the development of novel infant nutrient carriers.

Polyphenol-mediated sandwich-like coating promotes endothelialization and vascular healing.

Drug-eluting stents have become one of the most effective methods to treat cardiovascular diseases. However, this therapeutic strategy may lead to thrombosis, stent restenosis, and intimal hyperplasia and prevent re-endothelialization. In this study, we selected 3-aminophenylboronic acid-modified hyaluronic acid and carboxylate chitosan as polyelectrolyte layers and embedded an epigallocatechin-3-gallate-tanshinone IIA sulfonic sodium (EGCG-TSS) complex to develop a sandwich-like layer-by-layer coating. The introduction of a functional molecular EGCG-TSS complex improved not only the biocompatibility of the coating but also its stability by enriching the interaction between the polyelectrolyte coatings through electrostatic interactions, hydrogen bonding, π-π stacking, and covalent bonding. We further elucidated the effectiveness of sandwich-like coatings in regulating the inflammatory response, smooth muscle cell growth behavior, stent thrombosis and restenosis suppression, and vessel re-endothelialization acceleration via in vivo and in vitro. Conclusively, we demonstrated that sandwich-like coating assisted by an EGCG-TSS complex may be an effective surface modification strategy for cardiovascular therapeutic applications.

Value Added Conversion of Ethanol on Morphologically Controlled and Defect-Engineered Titanium Dioxide Nanorods.

Developing an environmentally benign and highly effective strategy for the value-added conversion of biomass platform molecules such as ethanol has emerged as a significant challenge and opportunity. This challenge stems from the need to harness renewable solar energy and conduct thermodynamically unfavorable reactions at room temperature. To tackle this challenge, one-dimensional titanium dioxide photocatalysts have been designed and fabricated to achieve a remarkable photocatalytic selectivity of almost 100 % for transforming ethanol into value-added 1,1-diethoxyethane, contrasting the primary production of acetaldehyde in titanium dioxide nanoparticles. By incorporating a Pt co-catalyst and infusing oxygen vacancies into the one-dimensional catalyst, the ethanol transformation rate was doubled to 128.8 mmol g-1 h-1 with respect to that of its unmodified counterpart (about 66.7 mmol g-1 h-1 ). The underlying mechanism for this high conversion and selectivity resides in the narrowed bandgap of the catalyst and the prolonged lifetime of the photo-generated carriers. This is a promising strategy for the photocatalytic transformation of essential biomass platform molecules that intertwines morphological control and defect engineering.

Postfunctionalization of biological valve leaflets with a polyphenol network and anticoagulant recombinant humanized type III collagen for improved anticoagulation and endothelialization.

Almost all commercial bioprosthetic heart valves (BHVs) are crosslinked with glutaraldehyde (GLUT); however, issues such as immune responses, calcification, delayed endothelialization, and especially severe thrombosis threaten the service lifespan of BHVs. Surface modification is expected to impart GLUT-crosslinked BHVs with versatility to optimize service performance. Here, a postfunctionalization strategy was established for GLUT-crosslinked BHVs, which were firstly modified with metal-phenolic networks (MPNs) to shield the exposed calcification site, and then anticoagulant recombinant humanized type III collagen (rhCOLIII) was immobilized to endow them with long-term antithrombogenicity and enhanced endothelialization properties. The postfunctionalization coating exhibited promising mechanical properties and resistance to enzymatic degradation capability resembling that of GLUT-crosslinked porcine pericardium (GLUT-PP). With the introduction of meticulously tailored rhCOLIII, the anti-coagulation and re-endothelialization properties of TA/Fe-rhCOLIII were significantly improved. Furthermore, the mild inflammatory response and reduced calcification were evidenced in TA/Fe-rhCOLIII by subcutaneous implantation. In conclusion, the efficacy of the proposed strategy combining anti-inflammatory MPNs and multifunctional rhCOLIII to improve anticoagulation, reduce the inflammatory response, and ultimately achieve rapid reendothelialization was supported by both ex vivo and in vivo experiments. Altogether, the current findings may provide a simple strategy for enhancing the service function of BHVs after implantation and show great potential in clinical applications.

A bio-inspired nanoparticle coating for vascular healing and immunomodulatory by cGMP-PKG and NF-kappa B signaling pathways.

Drug-eluting stents (DESs) implantation is an effective method to tackle in-stent restenosis (ISR), which has been considered as an efficient treatment for coronary atherosclerosis. Although fruitful results have been achieved in treating coronary artery diseases (CAD), concern has arisen regarding the long-term safety and efficacy of DESs, primarily due to adverse events such as delayed re-endothelialization, persistent inflammatory response, and late stent thrombosis (LST). Taking inspiration from the immunomodulatory functions of camouflage strategies, this study designed a bio-inspired nanoparticle-coated stent. Briefly, the platelet membrane-coated poly (lactic-co-glycolic acid)/Rapamycin nanoparticles (PNP) were sprayed onto stents, forming a homogenous nanoparticle coating. The bilayer of poly (lactic-co-glycolic acid) (PLGA) and platelet membrane works synergistically to promote the sustained-release effect of rapamycin. In vitro studies revealed that the PNP-coated surfaces promoted the competitive adhesion of endothelia cells while inhibiting smooth muscle cells. Subsequent in vivo studies demonstrated that these surfaces expedite re-endothelialization and elicit immunomodulatory effects by regulating the cGMP-PKG and NF-kappa B signaling pathways, influencing the biosynthesis cofactors and immune system signaling. The study successfully deviced a novel and biomimetic drug-eluting stent system, unraveling its detailed functions and molecular mechanism of action for enhanced vascular healing.

Rapid Kinetic Interactions of Sugar and Sugar Alcohol with Sweet Taste Receptors on Live Cells Using Stopped-Flow Spectroscopy.

The subjective measurement of the dynamic perception of sweetness is a problem in food science. Herein, the rapid interactions of sugars and sugar alcohols with sweet taste receptors on living cells on a millisecond timescale were studied via stopped-flow fluorescence spectroscopy. According to the rapid-kinetic parameters, sweeteners were divided into two groups. Sweeteners in group I disrupted the hydrogen bond network structure of water, and the apparent rate constant (kobs) was in the range of 0.45-0.6 s-1. Sweeteners in group II promoted the hydrogen bond formation of water, and the kobs was mostly in the range of 0.6-0.75 s-1. For most sweeteners, the kobs of cell responses was negatively correlated with the apparent specific volume of sweeteners. The differences in the cellular responses may be attributed to the disturbance in the water structure. Experimental results showed that the kinetic parameters of sweet cell responses reflected the dynamic perception of sweetness. Rapid kinetics, solution thermodynamic analysis, and water structure analysis enriched the physicochemical study of the sweetness mechanism and can be used to objectively evaluate the dynamic perception of sweetness.

(Epi)catechin damage effects on the development of mouse intestinal epithelial structure through the PERK-eIF2α-ATF4-CHOP pathway.

As powerful bioactive compounds found in a variety of plant-based foods, (epi)catechins have been identified to be associated with an abundant array of health benefits. While their adverse impacts have also been gaining increasing attention, their intestinal impact is still unclear. In this study, intestinal organoids were used as an in vitro model to analyze the effects of four (epi)catechins on the development of the intestinal epithelial structure. Morphological characteristics, oxidative stress, and endoplasmic reticulum (ER) stress assays with (epi)catechins treatment showed that (epi)catechins promoted intestinal epithelial apoptosis and stress response. These effects had dose-dependent and structural differences (EGCG > EGC > ECG > EC). Furthermore, GSK2606414, a protein kinase RNA (PKR)-like ER kinase (PERK) pathway inhibitor, confirmed that the PERK-eukaryotic translation initiation factor 2α (eIF2α)-activating transcription factor 4 (ATF4)-C/EBP-homologous protein (CHOP) pathway is closely related to the damage. In addition, the results for the intestinal inflammatory mouse model further verified that (epi)catechins significantly delayed intestinal repair. Taken together, these findings revealed that overdosage of (epi)catechins has damage potential on the intestinal epithelium and may increase the risk of intestinal damage.

Crypt-like patterned electrospun nanofibrous membrane and probiotics promote intestinal epithelium models close to tissues.

In vitro intestinal epithelium models have drawn great attention to investigating intestinal biology in recent years. However, the difficulty to maintain the normal physiological status of primary intestinal epithelium in vitro limits the applications. Here, we designed patterned electrospun polylactic acid (PLA) nanofibrous membranes with crypt-like topography and mimic ECM fibrous network to support crypt culture and construct in vitro intestinal epithelium models. The patterned electrospun PLA nanofibrous membranes modified with Matrigels at 0 °C showed high biocompatibility and promoted cell growth and proliferation. The constructed duodenum epithelium models and colon epithelium models on the patterned electrospun PLA nanofibrous membranes expressed the typical differentiation markers of intestinal epithelia and the gene expression levels were close to the original tissues, especially with the help of probiotics. The constructed intestinal epithelium models could be used to assess probiotic adhesion and colonization, which were verified to show significant differences with the Caco-2 cell models due to the different cell types. These findings provide new insights and a better understanding of the roles of biophysical, biochemical, and biological signals in the construction of in vitro intestinal epithelium models as well as the potential applications of these models in the study of host-gut microbes interactions. KEY POINTS: • Patterned electrospun scaffold has crypt-like topography and ECM nanofibrous network. • Matrigels at 0°C modify scaffolds more effectively than at 37°C. • Synergy of biomimic scaffold and probiotics makes in vitro model close to tissue.

An extracellular matrix-mimetic coating with dual bionics for cardiovascular stents.

Anti-inflammation and anti-coagulation are the primary requirements for cardiovascular stents and also the widely accepted trajectory for multi-functional modification. In this work, we proposed an extracellular matrix (ECM)-mimetic coating for cardiovascular stents with the amplified functionalization of recombinant humanized collagen type III (rhCOL III), where the biomimetics were driven by structure mimicry and component/function mimicry. Briefly, the structure-mimic was constructed by the formation of a nanofiber (NF) structure via the polymerization of polysiloxane with a further introduction of amine groups as the nanofibrous layer. The fiber network could function as a three-dimensional reservoir to support the amplified immobilization of rhCoL III. The rhCOL III was tailored for anti-coagulant, anti-inflammatory and endothelialization promotion properties, which endows the ECM-mimetic coating with desired surface functionalities. Stent implantation in the abdominal aorta of rabbits was conducted to validate the in vivo re-endothelialization of the ECM-mimetic coating. The mild inflammatory responses, anti-thrombotic property, promotion of endothelialization and suppression of excessive neointimal hyperplasia confirmed that the ECM-mimetic coating provided a promising approach for the modification of vascular implants.

[Analysis of teicoplanin impurities by two-dimensional ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry].

A two-dimensional ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry （2D-UPLC-Q/TOF-MS） method was established for the separation and structural analysis of the components in teicoplanin. This method effectively solved the problems associated with chromatographic systems， such as liquid chromatography-mass spectrometry （LC-MS）， which used a non-volatile phosphate buffer as the mobile phase and were not suitable for the rapid identification of impurities. Moreover， this method circumvented the complexities associated with locating and identifying impurities using the original method by re-establishing a chromatographic system suitable for LC-MS. In this study， for one-dimensional （1D） chromatography， the chromatographic separation was performed on an Octadecyl silica （ODS） hypersil column （250 mm×4.6 mm， 5 µm） with gradient elution using 3.0 g/L sodium dihydrogen phosphate buffer （pH 6.0）/acetonitrile=9/1 （v/v） as mobile phase A and 3.0 g/L sodium dihydrogen phosphate buffer （pH 6.0）/acetonitrile=3/7 （v/v） as mobile phase B. The column temperature was maintained at 30 ℃ and an ultraviolet detector was used at 254 nm for analysis. For 2D chromatography， desalting was performed on a Waters ACQUITY UPLC BEH C18 column （50 mm×2.1 mm， 1.7 µm） with gradient elution using ammonium formate buffer （pH 6.0） and acetonitrile as the mobile phases. The column temperature was maintained at 45 ℃. The MS data for the components and impurities were collected by positive ion electrospray ionization （ESI） using the full-information tandem MS mode （MSE）. The cone and nebulizer gas flow rates were set at 50 and 900 L/h， respectively. The ion source and nebulizer gas temperatures were set at 120 ℃ and 500 ℃， respectively. The ESI and cone needle voltages were set at 2500 and 60 V， respectively. The collision energy was set at 20-50 eV. The molecular formulas of the components and impurities were determined using their exact masses and isotope distributions， and the structural components and impurities of teicoplanin were deduced from their fragment ions according to the fragmentation pathway of the TA2-2 component. Moreover， the 10 components reported in the European Pharmacopoeia 10.0 were analyzed and 22 impurities of teicoplanin were identified by 2D-UPLC-Q/TOF-MS. Three new impurities and two characteristic fragment ions of the teicoplanin parent nucleus were detected， and the fragmentation pathway of TA2-2 was deduced. Using this method， 1D-UPLC is applicable for the accurate qualification of components based on relative retention times， and 2D-UPLC-Q/TOF-MS is suitable for the rapid identification of the structure of components based on their fragment ions. The results indicate that 2D-UPLC-Q/TOF-MS may be used to analyze the structure of impurities in teicoplanin based on their exact masses， isotope distributions， and fragment ions. The method is rapid， simple， and sensitive， which provides a novel strategy for the quality control and process optimization of teicoplanin.

Significantly enhanced photothermal catalytic CO2 reduction over TiO2/g-C3N4 composite with full spectrum solar light.

Using solar energy to drive catalytic conversion of CO2 into value-added chemicals has great potential to alleviate the global energy shortage and anthropogenic climate change. Herein, a "hitting three birds with one stone" strategy was reported to prepared boron-doped g-C3N4/TiO2-x composite (BCT) by a one-step thermal reduction process. A series of characterizations showed that the composite catalyst has extended full-spectrum absorption, rapid photogenerated charge separation, and outstanding CO2 photoreduction performance (265.2 µmol g-1h-1), which is 7.5 and 9.2 times higher than that of pure TiO2 and g-C3N4, respectively. In addition, the CO2 conversion rate can be further increased to 345.1 µmol g-1h-1 at 70 °C due to its excellent photothermal conversion. Mechanistic studies reveal that synergistic effects alter the charge density distribution, thereby lowering the energy barrier for CO2 conversion by adsorbing and activating CO2 molecules. This work provides a novel three-in-one integrated strategy for fabricating high-efficiency catalysts.

Type II taste cells participate in mucosal immune surveillance.

The oral microbiome is second only to its intestinal counterpart in diversity and abundance, but its effects on taste cells remains largely unexplored. Using single-cell RNASeq, we found that mouse taste cells, in particular, sweet and umami receptor cells that express taste 1 receptor member 3 (Tas1r3), have a gene expression signature reminiscent of Microfold (M) cells, a central player in immune surveillance in the mucosa-associated lymphoid tissue (MALT) such as those in the Peyer's patch and tonsils. Administration of tumor necrosis factor ligand superfamily member 11 (TNFSF11; also known as RANKL), a growth factor required for differentiation of M cells, dramatically increased M cell proliferation and marker gene expression in the taste papillae and in cultured taste organoids from wild-type (WT) mice. Taste papillae and organoids from knockout mice lacking Spib (SpibKO), a RANKL-regulated transcription factor required for M cell development and regeneration on the other hand, failed to respond to RANKL. Taste papillae from SpibKO mice also showed reduced expression of NF-κB signaling pathway components and proinflammatory cytokines and attracted fewer immune cells. However, lipopolysaccharide-induced expression of cytokines was strongly up-regulated in SpibKO mice compared to their WT counterparts. Like M cells, taste cells from WT but not SpibKO mice readily took up fluorescently labeled microbeads, a proxy for microbial transcytosis. The proportion of taste cell subtypes are unaltered in SpibKO mice; however, they displayed increased attraction to sweet and umami taste stimuli. We propose that taste cells are involved in immune surveillance and may tune their taste responses to microbial signaling and infection.

Chlorogenic acid improves intestinal morphology by enhancing intestinal stem-cell activity.

BACKGROUND: Chlorogenic acid (CGA), as one of the most abundant naturally occurring phenolic acids, has been documented to be beneficial for intestinal health. However, the underlying mechanism is still not fully understood. The adult intestinal stem cell is the critical driver of epithelial homeostasis and regeneration. RESULTS: This study hypothesized that CGA exerted intestinal health effects by modulating intestinal stem-cell functions. Lgr5-EGFP mice were treated for 14 days, and intestinal organoids derived from these mice were treated for 3 days, using CGA solution. In comparison with the control group, CGA treatment increased intestinal villous height and crypt depth in mice and augmented the area expansion and the number of budding intestinal organoids. Quantitative polymerase chain reaction (qPCR) analysis revealed that CGA treatment significantly increased the expression of genes coding intestinal stem-cell markers in intestinal tissue and organoids, and upregulated the expression of genes coding secretory cell lineages and enterocytes, although not statistically significantly. Fluorescence-activated cell-sorting analysis further confirmed that CGA augmented the number of stem cells. 5-Ethynyl-2'-deoxyuridine (EdU) incorporation and Ki67 immunostaining results also demonstrated that CGA treatment enhanced intestinal stem-cell proliferation. CONCLUSION: Altogether, our findings indicate that CGA could activate intestinal stem-cell and epithelial regeneration, which could contribute to the improvement of intestinal morphology or organoid growth of mice. This highlights a promising mechanism for CGA as an excellent candidate for the formulation of dietary supplements and functional foods for intestinal protection. © 2023 Society of Chemical Industry.

Intestinal models based on biomimetic scaffolds with an ECM micro-architecture and intestinal macro-elasticity: close to intestinal tissue and immune response analysis.

The synergetic biological effect of scaffolds with biomimetic properties including the ECM micro-architecture and intestinal macro-mechanical properties on intestinal models in vitro remains unclear. Here, we investigate the profitable role of biomimetic scaffolds on 3D intestinal epithelium models. Gelatin/bacterial cellulose nanofiber composite scaffolds crosslinked by the Maillard reaction are tuned to mimic the chemical component, nanofibrous network, and crypt architecture of intestinal ECM collagen and the stability and mechanical properties of intestinal tissue. In particular, scaffolds with comparable elasticity and viscoelasticity of intestinal tissue possess the highest biocompatibility and best cell proliferation and differentiation ability, which makes the intestinal epithelium models closest to their counterpart intestinal tissues. The constructed duodenal epithelium models and colon epithelium models are utilized to assess the immunobiotics-host interactions, and both of them can sensitively respond to foreign microorganisms, but the secretion levels of cytokines are intestinal cell specific. The results demonstrate that probiotics alleviate the inflammation and cell apoptosis induced by Escherichia coli, indicating that probiotics can protect the intestinal epithelium from damage by inhibiting the adhesion and invasion of E. coli to intestinal cells. The designed biomimetic scaffolds can serve as powerful tools to construct in vitro intestinal epithelium models, providing a convenient platform to screen intestinal anti-inflammatory components and even to assess other physiological functions of the intestine.

Correlation between copper speciation and transport pathway in Caco-2 cells.

BACKGROUND: Previous studies have demonstrated that, in contrast to the properties of food-derived copper, water-derived copper exerts neurotoxic effects and exhibits different speciation during digestion. The cellular uptake efficiencies of different speciation of copper are distinct. However, it is unclear whether these different speciation share the same transport pathway in intestinal epithelial cells. In the present study, the intracellular accumulation of copper derived from copper ion and copper complex solutions was investigated in Caco-2 cells. RESULTS: The cellular accumulation of copper derived from copper ions was higher than that of copper derived from the copper complex. Treatment with carboplatin and Ag+ , which are copper transporter receptor 1 (Ctr1, LC31A1) inhibitors, did not inhibit copper accumulation in Caco-2 cells, but inhibited copper accumulation in HepG2 cells. Zinc ion significantly decreased the intracellular copper content from 114 ± 7 µg g-1 protein to 88 ± 4 µg g-1 protein in the copper ion-treated Caco-2 cells, but not in the copper complex-treated Caco-2 cells (84.6 ± 14 µg g-1 protein versus 87.7 ± 20 µg g-1 protein, P > 0.05). Additionally, copper accumulation in Caco-2 and HepG2 cells significantly differed depending on different solvents (Hanks' balanced salt solution and NaNO3 , P < 0.05). CONCLUSION: These results indicate that the intracellular accumulation of copper derived from copper ion and copper complex is mediated by distinct copper transport pathways. Copper speciation may be an important factor that affects copper absorption and toxicity. © 2022 Society of Chemical Industry.

Genetic mutation analysis of hereditary spherocytosis in Guangxi Zhuang Autonomous Region.

Hereditary spherocytosis (HS) is a common, hereditary hemolytic anemia (HHA) that is attributed to the disturbance of five erythrocyte membrane proteins. HS is also common in Guangxi, China. Target region capture high-throughput sequencing technology was used to analyze genetic mutations found in HS patients. Pedigree analysis was also performed, in some cases, to provide an optimized approach for the etiological diagnosis of complex, hereditary hemolytic anemia. Blood samples from the probands and their families were assessed by laboratory tests, target region capture high-throughput sequencing technology, and Sanger sequencing. We detected 79 HS patients from 37 unrelated families. The mutations observed in these patients were found mainly in four HS-related genes. These included SLC4A1, which was mutated in 31.65% of patients (25/79), SPTA1 (30.78% (24/79)), EPB42 (6.33% (5/79)), and SPTB (5.06% (4/79)). Composite genotype was observed in 26.58% (21/79) of patients and included mutations in two or more HS-related genes or mutations in HS-related genes combined with thalassemia or G6PD deficiency. No significant differences in clinical symptoms were found among patients of various genotypes except total bilirubin. Mean reticulocyte volume (MRV) and mean sphered cell volume (MSCV) of the composite genotype were significantly different from other groups. A total of 28 mutation types were found in HS-related genes. Using high-throughput sequencing technology, we also found some cases that had been misdiagnosed. MRV and MSCV are more significant in compound mutations as sensitive determinants of HS. High-throughput sequencing technology can be used to provide a more effective etiological diagnostic method for HS, with high efficiency and specificity.

Sweet taste perception in mice is blunted by PTBP1-regulated skipping of Tas1r2 exon 4.

Taste perception, initiated by activation of taste receptors in taste bud cells, is crucial for regulating nutrient intake. Genetic polymorphisms in taste receptor genes cannot fully explain the wide individual variations of taste sensitivity. Alternative splicing (AS) is a ubiquitous posttranscriptional mode of gene regulation that enriches the functional diversity of proteins. Here, we report the identification of a novel splicing variant of sweet taste receptor gene Tas1r2 (Tas1r2_∆e4) in mouse taste buds and the mechanism by which it diminishes sweet taste responses in vitro and in vivo. Skipping of Tas1r2 exon 4 in Tas1r2_∆e4 led to loss of amino acids in the extracellular Venus flytrap domain, and the truncated isoform reduced the response of sweet taste receptors (STRs) to all sweet compounds tested by generating nonfunctional T1R2/T1R3 STR heterodimers. The splicing factor PTBP1 (polypyrimidine tract-binding protein 1) promoted Tas1r2_∆e4 generation through binding to a polypyrimidine-rich splicing silencer in Tas1r2 exon 4, thus decreasing STR function and sweet taste perception in mice. Taken together, these data reveal the existence of a regulated AS event in Tas1r2 expression and its effect on sweet taste perception, providing a novel mechanism for modulating taste sensitivity at the posttranscriptional level.