ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.

ObjectiveTo investigate the novel post-translational modifications (PTMs) of SnRK2.6, a central component in the abscisic acid (ABA) signaling pathway, such as SUMOylation, and to establish a foundation for revealing the physiological functions and molecular mechanisms of SnRK2.6 regulated by these new modifications. MethodsThe interaction between SnRK2.6 and the SUMO E3 ligase SIZ1, as well as members of the SUMO protease family, was examined using yeast two-hybrid and in vitro pull-down assays. An in vitro SUMOylation system in Escherichia coli was utilized to determine whether SnRK2.6 undergoes SUMOylation. Mass spectrometry, combined with site-directed mutagenesis of candidate lysine residues, was employed to identify potential SUMOylation sites on SnRK2.6. In vitro de-SUMOylation assays were performed to assess whether SUMO proteases interacting with SnRK2.6 could catalyze the removal of SUMO moieties from modified SnRK2.6. The protein stability of SnRK2.6 was assessed in a cell-free degradation assay using bacterial-purified SnRK2.6 incubated with total protein extracts from Col and siz1 mutant seedlings. To dissect the genetic relationship between SnRK2.6 and SIZ1, stomatal aperture assays were performed under ABA treatment using snrk2.6, siz1, and snrk2.6 siz1 double mutant plants. ResultsSnRK2.6 physically interacts with SIZ1 and the SUMO protease ESD4, with the binding domains localized to the C-terminal region of SIZ1 and the N-terminal region of ESD4, respectively. SnRK2.6 was found to be SUMOylated, exhibiting two distinct high-molecular-mass bands ranging from 70 to 100 ku, indicative of modified forms. Bioinformatics analysis predicted four putative SUMOylation sites on lysine residues K57, K63, K142, and K190. Mass spectrometry identified three SUMOylation sites on K63, K142, and K174. However, individual or combinatorial point mutations on these sites had minimal impact on the pattern or intensity of SUMOylation signals, suggesting that these residues may not be responsible for the SUMOylation on SnRK2.6. Instead, such mutations only weaken the protein stability or accelerate the protein mobility of SnRK2.6. Therefore, the exact SUMOylation sites on SnRK2.6 remain unidentified. In de-SUMOylation experiments, incubation of GST-ESD4 with SUMOylated SnRK2.6 for 1-2 h led to the near-complete disappearance of both SUMOylated bands. In contrast, neither the GST control nor the catalytically inactive mutant GST-ESD4^C448S exhibited any de-SUMOylation activity. In protein turnover experiments, SnRK2.6 exhibited markedly enhanced half-life in siz1 compared with Col, indicating that SIZ1-dependent SUMOylation promotes SnRK2.6 turnover. Phenotypically, snrk2.6 mutants were completely insensitive to ABA-induced stomatal closure; siz1 mutants displayed pronounced hypersensitivity; and the snrk2.6 siz1 double mutant phenocopied snrk2.6—showing no significant response to ABA beyond that of the snrk2.6 mutant. These data indicate that SIZ1 acts as a negative regulator of ABA-triggered stomatal closure and SnRK2.6 functions as a positive regulator, and the inhibitory activity of SIZ1 is strictly dependent on SnRK2.6, placing SnRK2.6 genetically upstream of SIZ1 in the ABA signaling pathway. ConclusionSnRK2.6 undergoes SUMOylation, although the specific SUMOylation sites have not been defined. SnRK2.6 is dynamically regulated by reversible SUMOylation—catalyzed by SIZ1 and reversed by ESD4—which controls its protein stability. SUMOylation acts as a destabilizing signal for SnRK2.6, and SIZ1 exerts its negative effect on ABA-triggered stomatal closure probably through promoting SnRK2.6 degradation via SUMOylation. These findings uncover SUMOylation as a critical regulatory layer fine-tuning SnRK2.6 abundance in ABA signaling.

Alzheimer’s disease (AD) is a prevalent neurodegenerative condition characterized by progressive cognitive decline and memory loss. As the incidence of AD continues to rise annually, researchers have shown keen interest in the active components found in natural plants and their neuroprotective effects against AD. Quercetin, a flavonol widely present in fruits and vegetables, has multiple biological effects including anticancer, anti-inflammatory, and antioxidant. Oxidative stress plays a central role in the pathogenesis of AD, and the antioxidant properties of quercetin are essential for its neuroprotective function. Quercetin can modulate multiple signaling pathways related to AD, such as Nrf2-ARE, JNK, p38 MAPK, PON2, PI3K/Akt, and PKC, all of which are closely related to oxidative stress. Furthermore, quercetin is capable of inhibiting the aggregation of β‑amyloid protein (Aβ) and the phosphorylation of tau protein, as well as the activity of β‑secretase 1 and acetylcholinesterase, thus slowing down the progression of the disease.The review also provides insights into the pharmacokinetic properties of quercetin, including its absorption, metabolism, and excretion, as well as its bioavailability challenges and clinical applications. To improve the bioavailability and enhance the targeting of quercetin, the potential of quercetin nanomedicine delivery systems in the treatment of AD is also discussed. In summary, the multifaceted mechanisms of quercetin against AD provide a new perspective for drug development. However, translating these findings into clinical practice requires overcoming current limitations and ongoing research. In this way, its therapeutic potential in the treatment of AD can be fully utilized.

BACKGROUND:With the development of computer-aided design and computer-aided manufacturing technology,zirconia abutments with a titanium base are widely used in clinic due to its good application advantages,but there are still some problems and a lack of consensus design standards. OBJECTIVE:To review the fabrication methods of Ti-base zirconia abutment,and the effect of abutment connection,emergence design,abutment angle,and bonding on mechanical properties of Ti-base zirconia abutment. METHODS:Relevant literature published from 2010 to 2023 was searched in CNKI and PubMed databases with the search terms"zirconia abutment,titanium base"in Chinese and English,respectively.The search time limit was extended for some classical literature.The relevant literature was obtained through inclusion and exclusion criteria,and 57 eligible documents were included for review. RESULTS AND CONCLUSION:It is recommended that clinicians try to select antirotational titanium bases or rotational titanium bases with a Morse taper connection.Implants should be placed in the correct axial angulation of not more than 15° or with an inclination to the palatal side when using angled zirconia abutments.When a≥30° labial inclination is followed for implant placement,the bite force must be decreased effectively to reduce the risk of mechanical and biological complications of implants,abutments,and prostheses.Ti-base zirconia abutments with a higher gingival height should be selected,and its restorative angle should not exceed 40°.Multilink Hybrid Abutment could be the first choice for extraoral bonding of zirconia abutment to titanium bases.

This study aims to investigate the potential effect of the water extract of fresh Rehmanniae Radix on hypercholesterolemia in mice that was induced by a high-fat and high-cholesterol diet and explore its possible mechanism from bile acid reabsorption. Male C57BL/6 mice were randomly assigned into the following groups: control, model, low-and high-dose(4 and 8 g·kg~(-1), respectively) fresh Rehmanniae Radix, and positive drug(simvastatin, 0.05 g·kg~(-1)). Other groups except the control group were fed with a high-fat and high-cholesterol diet for 6 consecutive weeks to induce hypercholesterolemia. From the 6th week, mice were administrated with corresponding drugs daily via gavage for additional 6 weeks, while continuing to be fed with a high-fat and high-cholesterol diet. Serum levels of total cholesterol(TC), triglycerides(TG), low density lipoprotein-cholesterol(LDL-c), high density lipoprotein-cholesterol(HDL-c), and total bile acid(TBA), as well as liver TC and TG levels and fecal TBA level, were determined by commercial assay kits. Hematoxylin-eosin(HE) staining, oil red O staining, and transmission electron microscopy were performed to observe the pathological changes in the liver. Three livers samples were randomly selected from each of the control, model, and high-dose fresh Rehmanniae Radix groups for high-throughput transcriptome sequencing. Differentially expressed genes were mined and KEGG pathway enrichment analysis was performed to predict the key pathways and target genes of the water extract of fresh Rehmanniae Radix in the treatment of hypercholesterolemia. RT-qPCR was employed to measure the mRNA levels of cholesterol 7α-hydroxylase(CYP7A1) and cholesterol 27α-hydroxylase(CYP27A1) in the liver. Western blot was employed to determine the protein levels of CYP7A1 and CYP27A1 in the liver as well as farnesoid X receptor(FXR), apical sodium-dependent bile acid transporter(ASBT), and ileum bile acid-binding protein(I-BABP) in the ileum. The results showed that the water extract of fresh Rehmanniae Radix significantly lowered the levels of TC and TG in the serum and liver, as well as the level of LDL-c in the serum. Conversely, it elevated the level of HDL-c in the serum and TBA in feces. No significant difference was observed in the level of TBA in the serum among groups. HE staining, oil red O staining, and transmission electron microscopy showed that the water extract reduced the accumulation of lipid droplets in the liver. Further mechanism studies revealed that the water extract of fresh Rehmanniae Radix significantly down-regulated the protein levels of FXR and bile acid reabsorption-related proteins ASBT and I-BABP. Additionally, it enhanced CYP7A1 and CYP27A1, the key enzymes involved in bile acid synthesis. Therefore, it is hypothesized that the water extract of fresh Rehmanniae Radix may exert an anti-hypercholesterolemic effect by regulating FXR/ASBT/I-BABP signaling, inhibiting bile acid reabsorption, and increasing bile acid excretion, thus facilitating the conversion of cholesterol to bile acids.
Animals ; Male ; Bile Acids and Salts/metabolism* ; Mice, Inbred C57BL ; Mice ; Diet, High-Fat/adverse effects* ; Cholesterol/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Hypercholesterolemia/genetics* ; Receptors, Cytoplasmic and Nuclear/genetics* ; Rehmannia/chemistry* ; Liver/drug effects* ; Humans ; Cholesterol 7-alpha-Hydroxylase/genetics* ; Plant Extracts

N,N-Dimethylglycine (DMG) is a glycine derivative, and its sodium salt (DMG-Na) has been demonstrated to possess various biological activities, including immunomodulation, free radical scavenging, and antioxidation, collectively contributing to the stability of tissue and cellular functions. However, its direct effects and underlying mechanisms in wound healing remain unclear. In this study, a full-thickness excisional wound model was established on the dorsal skin of mice, and wounds were treated locally with DMG-Na. Wound healing progression was assessed by calculating wound closure rates. Histopathological analysis was conducted using hematoxylin-eosin (HE) staining, and keratinocyte proliferation, migration, and differentiation were evaluated using CCK-8 assays, scratch wound assays, and quantitative reverse transcription PCR (qRT-PCR). Inflammation-related cytokine expression in keratinocytes was analyzed via ELISA and qRT-PCR. Results revealed that DMG-Na treatment significantly accelerated wound healing in mice and improved overall wound closure quality. The wound healing rates on days 3, 6, and 9 were 49.18%, 68.87%, and 90.55%, respectively, with statistically significant differences compared to the control group ( P<0.05). DMG-Na treatment downregulated the mRNA levels of keratinocyte differentiation markers while enhancing cell proliferation and migration ( P<0.05). Furthermore, DMG-Na decreased the secretion of LPS-induced keratinocyte inflammatory cytokines, including IL-1β, IL-6, IL-8, TNF-α, and CXCL10 ( P<0.05). These findings indicate that DMG-Na regulates inflammatory responses and promotes keratinocyte proliferation and migration, thereby facilitating the healing of skin wounds.
Animals ; Wound Healing/drug effects* ; Mice ; Cell Proliferation/drug effects* ; Keratinocytes/drug effects* ; Cell Movement/drug effects* ; Cell Differentiation/drug effects* ; Glycine/pharmacology* ; Skin/injuries* ; Male

Direct electrical stimulation of the human cortex can produce subjective visual sensations, yet these sensations are unstable. The underlying mechanisms may stem from differences in electrophysiological activity within the distributed network outside the stimulated site. To address this problem, we recruited 69 patients who experienced visual sensations during invasive electrical stimulation while intracranial electroencephalography (iEEG) data were recorded. We found significantly flattened power spectral slopes in distributed regions involving different brain networks and decreased integrated information during elicited visual sensations compared with the non-sensation condition. Further analysis based on minimum information partitions revealed that the reconfigured network interactions primarily involved the inferior frontal cortex, posterior superior temporal sulcus, and temporoparietal junction. The flattened power spectral slope in the inferior frontal gyrus was also correlated with integrated information. Taken together, this study indicates that the altered electrophysiological signatures provide insights into the neural mechanisms underlying subjective visual sensations.
Humans ; Male ; Female ; Adult ; Visual Perception/physiology* ; Electric Stimulation ; Middle Aged ; Young Adult ; Electrocorticography ; Electroencephalography ; Brain Mapping

Objective:To study the influence of methyltransferases like 3(METTL3)on the radiosensitivity of oral squamous cell carcinoma cells(OSCCs).Methods:The apoptosis level of OSCCs CAL27,SCC9 and SCC15 treated with X-ray radiation doses of 2,4 and 8 Gy respectively was compared by flow cytometry,the expression of methylated gene RNA and protein in the cells were examined by qRT-PCR and Western blot.m6A in the cells was quantified by LC/LC-MS method.qRT-PCR and Western blot were used to investigate the expression of methylated gene RNA and protein in the cells.Flow cytometry was used to examine the cell apoptosis level of CAL27 and SCC15 cells treated with METTL3 overexpression and knockdown respectively.The clone forma-tion of CAL27 and SCC15 cells after knockdown and overexpression of target genes followed by radiation treatment was observed by clonogenic assays.Results:The apoptosis rate of all the cell lines increased with the increase dose of radiation at each dose,CAL27 cells showed the highest and SCC15 showed the lowerst apoptosis rate.The RNA and protein expression levels of METTL3 in CAL27 were significantly lower than those of SCC15.m6A quantification showed that the methylation modification in CAL27 cells was lower than that in SCC15.The expression of METTL3 was increased in CAL27 and SCC15 cells after radiation treatment.Knockdown of METTL3 increaced the apoptosis rate and decreased the clonogenesity,overession of METTL3 the decreaced the ap optosis rate and increased the clonogenecity of the cells.Conclusion:Regulation of METTL3 can affect the radiotherapy sensitivity of OSCCs,METTL3 may become a new target for radiosensitization of OSCCs.

OBJECTIVE To investigate the types of bacteria isolated from skin lesions in adolescent patients with ac-ne vulgaris and analyze their drug resistance to commonly used antibacterial drugs.METHODS A total of 80 ado-lescent patients with acne vulgaris admitted to the Seventh Medical Center of Chinese PLA General Hospital from Mar.2022 to Mar.2024 were enrolled.The contents of facial acne skin lesions were collected for bacterial identifi-cation and the E-test method was employed to evaluate the drug resistance rates of isolated bacteria to commonly used antibacterial drugs.RESULTS Among the collected skin lesion samples in this study,74 strains(92.50％)of Propionibacterium acnes,76 strains(95.00％)of Staphylococcus epidermidis and 12 strains(15.00％)of S.aureus were detected.No statistically significant differences were observed in the detection rates of P.acnes,S.epidermidis and S.aureus among patients of different genders,ages,disease courses or severity levels.P.ac-nes exhibited high sensitivity to tetracycline,doxycycline and minocycline(all＞95％)but was almost completely resistant to metronidazole.Its sensitivity rate to macrolides such as erythromycin,clarithromycin,clindamycin,roxithromycin and azithromycin were low(＜50％).S.epidermidis showed sensitivity rates of 67.11％,81.58％and 82.89％to tetracycline,doxycycline and minocycline,respectively,with high drug resistance to metronidazole(96.05％)and low sensitivity rate to erythromycin,clarithromycin,clindamycin,roxithromycin and azithromycin(＜60％).S.aureus demonstrated sensitivity rates of 58.33％,75.00％and 75.00％to tetracycline,doxycycline and minocycline,respectively,while its sensitivity rates to erythromycin,clarithromycin,clindamycin,roxithro-mycin and azithromycin were 33.33％,41.67％,50.00％,41.67％and 33.33％,respectively.CONCLUSIONS The predominant bacteria isolated from skin lesions in adolescent patients with acne vulgaris are S.epidermidis and P.acnes,with a lower detection rate of S.aureus.All three isolated bacteria exhibit high sensitivity to tetra-cycline antibacterial drugs but significant drug resistance to macrolides and near-complete drug resistance to met-ronidazole.

This study assessed the role and mechanism of the recombinant Bacillus Calmette-Gue?rin vaccine(rBCG)with c-di-AMP adjuvant in regulating metabolism and immunity in epididymal white adipose(eWAT)in mice.Male C57BL/6 mice were intravenously immunized with BCG and rBCG,and their body weights were monitored.eWAT was isolated from the mice,and the stromal vascular fractions(SVFs)cell number was counted with a hemocytometer.Sections of mouse adipose tissue were prepared,and the size,number,and morphology of eWAT adipocytes and crown-like structure(CLS)formation were compared under a microscope after HE staining.The transcription levels of lipid metabolism-associated factors,cytokines and aging-associated genes in each group were determined with qRT-PCR.The body weights of mice gradually increased after immunization with BCG and rBCG.The proportions of eWAT increased,and the SVFs cell number decreased,in rBCG immunized mice.HE staining indicated that BCG immunization promoted hyperplasia,whereas rBCG immunization promoted hypertrophy of eWAT adipocytes;moreover,both BCG and rBCG immunization induced CLS formation in eWAT.The qRT-PCR results indicated that rBCG immunization inhibited the expression of genes associated with lipolysis and energy expenditure in eWAT.BCG immunization had little effect on cytokine transcription,whereas rBCG significantly induced the transcription of IFN-γ and IL-1Ra,and inhibited that of IL-15 and IL-2,but did not induce the expression of aging-associated genes.Thus,rBCG immunization induced eWAT adipocyte hypertrophy,which was associated with the inhibition of eWAT lipolysis and the regulation of cytokine expression.