Targeting senescent HDF with the USP7 inhibitor P5091 to enhance DFU wound healing through the p53 pathway

OBJECTIVE

The objective of this study was to examine the potential of USP7 as a target for senolytic therapy and to investigate the molecular mechanism by which its inhibitor selectively induced apoptosis in senescent HDF and enhanced DFU wound healing.

METHODS

Clinical samples of DFU were collected to detect the expression of USP7 and aging-related proteins using immunohistochemistry and Western blot. In addition, β-galactosidase staining, qPCR, flow cytometry, ROS and MMP kits, and Western blot were used to analyze the biological functions of P5091 on senescence, cycle, and apoptosis. RNAseq was employed to further analyze the molecular mechanism of P5091. Finally, the DFU rat model was established to evaluate the effect of P5091 on wound healing.

RESULTS

The expression of USP7 and p21 were increased in DFU clinical samples. After treatment with d-glucose (30 mM, 7 days), β-galactosidase staining was deepened, proliferation rate decreased. USP7 inhibitors (P5091) could reduce the release of SASP factors, activate the production of ROS, and reduce MMP. In addition, it induced apoptosis and selectively clears senescent cells through the p53 signaling pathway. Finally, P5091 can improve diabetic wound healing in rats.

CONCLUSION

This study clarified the molecular mechanism of USP7 inhibitor (P5091) selectively inducing apoptosis of high glucose senescent HDF cells. This provides a new senolytics target and experimental basis for promoting DFU wound healing.

Prognostic value of plasma diquat concentration in patients with acute oral diquat poisoning: a retrospective study

Objectives

Diquat poisoning is an important public health and social security agency. This study aimed to develop a prognostic model and evaluate the prognostic value of plasma diquat concentration in patients with acute oral diquat poisoning, focusing on how its impact changes over time after poisoning.

Methods

This was a retrospective cohort study using electronic healthcare reports from the Second Hospital of Hebei Medical University. The study sample included 80 patients with acute oral Diquat poisoning who were admitted to the hospital between January 2019 and May 2022. Time-to-event analyses were performed to assess the risk of all-cause mortality (30 days and 90 days), controlling for demographics, comorbidities, vital signs, and other laboratory measurements. The prognostic value of plasma DQ concentration on admission was assessed by computing the area under a time-dependent receiver operating characteristic curve (ROC).

Results

Among the 80 patients, 29 (36.25%) patients died, and 51 (63.75%) patients survived in the hospital. Non-survivors had a median survival time (IQR) of 1.3(1.0) days and the longest survival time of 4.5 days after DQ poisoning. Compared with non-survivors, survivors had significantly lower amounts of ingestion, plasma DQ concentration on admission, lungs injury within 24 h after admission, liver injury within 24 h after admission, kidney injury within 24 h after admission, and CNS injury within 36 h after admission, higher APACHE II score and PSS within 24 h after admission (all p < 0.05). Plasma Diquat concentration at admission (HR = Exp (0.032-0.059 × ln (t))) and PSS within 24 h after admission (HR: 4.470, 95%CI: 1.604 ~ 12.452, p = 0.004) were independent prognostic factors in the time-dependent Cox regression model.

Conclusion

Plasma DQ concentration at admission and PSS within 24 h after admission are independent prognostic factors for the in-hospital case fatality rate in patients with acute oral DQ poisoning. The prognostic value of plasma DQ concentration decreased with time.

Antimicrobial and Antiviral Nanofibers Halt Co-Infection Spread via Nuclease-Mimicry and Photocatalysis

The escalating spread of drug-resistant bacteria and viruses is a grave concern for global health. Nucleic acids dominate the drug-resistance and transmission of pathogenic microbes. Here, imidazolium-type poly(ionic liquid)/porphyrin (PIL-P) based electrospun nanofibrous membrane and its cerium (IV) ion complex (PIL-P-Ce) are developed. The obtained PIL-P-Ce membrane exhibits high and stable efficiency in eradicating various microorganisms (bacteria, fungi, and viruses) and decomposing microbial antibiotic resistance genes and viral nucleic acids under light. The nuclease-mimetic and photocatalytic mechanisms of the PIL-P-Ce are elucidated. Co-infection wound models in mice with methicillin-resistant S. aureus and hepatitis B virus demonstrate that PIL-P-Ce integrate the triple effects of cationic polymer, photocatalysis, and nuclease-mimetic activities. As revealed by proteomic analysis, PIL-P-Ce shows minimal phototoxicity to normal tissues. Hence, PIL-P-Ce has potential as a "green" wound dressing to curb the spread of drug-resistant bacteria and viruses in clinical settings.

Enhanced physiochemical, antibacterial, and hemostatic performance of collagen-quaternized chitosan-graphene oxide sponges for promoting infectious wound healing

Bacteria-infected wound healing has attracted widespread attention in biomedical engineering. Wound dressing is a potential strategy for repairing infectious wounds. However, the development of wound dressing with appropriate physiochemical, antibacterial, and hemostatic properties, remains challenging. Hence, there is a motivation to develop new synthetic dressings to improve bacteria-infected wound healing. Here, we fabricate a biocompatible sponge through the covalent crosslinking of collagen (Col), quaternized chitosan (QCS), and graphene oxide (GO). The resulting Col-QCS-GO sponge shows an elastic modulus of 1.93-fold higher than Col sponge due to enhanced crosslinking degree by GO incorporation. Moreover, the fabricated Col-QCS-GO sponge shows favorable porosity (84.30 ± 3.12 %), water absorption / retention (2658.0 ± 113.4 % / 1114.0 ± 65.7 %), and hemostasis capacities (blood loss <50.0 mg). Furthermore, the antibacterial property of the Col-QCS-GO sponge under near-infrared (NIR) irradiation is significantly enhanced (the inhibition rates are 99.9 % for S. aureus and 99.9 % for E. coli) due to the inherent antibacterial properties of QCS and the photothermal antibacterial capabilities of GO. Finally, the Col-QCS-GO+NIR sponge exhibits the lowest percentage of wound area (9.05 ± 1.42 %) at day 14 compared to the control group (31.61 ± 1.76 %). This study provides new insights for developing innovative sponges for bacteria-infected wound healing.

Ultrathin High-Entropy Fe-Based Spinel Oxide Nanosheets with Metalloid Band Structures for Efficient Nitrate Reduction toward Ammonia

Spinel oxides with tunable chemical compositions have emerged as versatile electrocatalysts, however their performance is greatly limited by small surface area and low electron conductivity. Here, ultrathin high-entropy Fe-based spinel oxides nanosheets are rationally designed (i.e., (Co0.2Ni0.2Zn0.2Mg0.2Cu0.2)Fe2O4; denotes A5Fe2O4) in thickness of ≈4.3 nm with large surface area and highly exposed active sites via a modified sol-gel method. Theoretic and experimental results confirm that the bandgap of A5Fe2O4 nanosheets is significantly smaller than that of ordinary Fe-based spinel oxides, realizing the transformation of binary spinel oxide from semiconductors to metalloids. As a result, such A5Fe2O4 nanosheets manifest excellent performance for the nitrate reduction reaction (NO3 -RR) to ammonia (NH3), with a NH3 yield rate of ≈2.1 mmol h-1 cm-2 at -0.5 V versus Reversible hydrogen electrode, outperforming other spinel-based electrocatalysts. Systematic mechanism investigations reveal that the NO3 -RR is mainly occurred on Fe sites, and introducing high-entropy compositions in tetrahedral sites regulates the adsorption strength of N and O-related intermediates on Fe for boosting the NO3 -RR. The above findings offer a high-entropy platform to regulate the bandgap and enhance the electrocatalytic performance of spinel oxides.

Tailored gelatin methacryloyl-based hydrogel with near-infrared responsive delivery of Qiai essential oils boosting reactive oxygen species scavenging, antimicrobial, and anti-inflammatory activities for diabetic wound healing

The management of diabetic wounds poses a substantial economic and medical burden for diabetic patients. Oxidative stress and persistent bacterial infections are considered to be the primary factors. Qiai essential oil (QEO) exhibits various pharmacological characteristics, including inflammatory-reducing, antibacterial, and antioxidant properties. Nevertheless, the hydrophobic nature and propensity for explosive release of this substance present constraints on its potential for future applications. Here, we developed a stimulus-responsive hydrogel to overcome the multiple limitations of QEO-based wound dressings. The QEO was encapsulated within graphene oxide (GO) through repeated extrusion using an extruder. Subsequently, QEO@GO nanoparticles were incorporated into a Gelatin-methacryloyl (GelMA) hydrogel. The QEO@GO-GelMA hydrogel demonstrated controlled release ablation, photothermal antibacterial effects, and contact ablation against two representative bacterial strains. It effectively reduced reactive oxygen species (ROS) generation, promoted angiogenesis, and decreased levels of the pro-inflammatory cytokine interleukin-6 (IL-6), thereby accelerating the healing process of diabetic wounds. In addition, in vitro and in vivo tests provided further evidence of the favorable biocompatibility of this multifunctional hydrogel dressing. Overall, the QEO@GO-GelMA hydrogel provides numerous benefits, encompassing antimicrobial properties, ROS-scavenging abilities, anti-inflammatory effects, and the capacity to expedite diabetic wound healing. These attributes make it an optimal choice for diabetic wound management.

Suboptimal status of tummy time for infants in early childhood education institutions in urban China: A cross-sectional study

Background

Although tummy time is recommended as a form of physical activity for non-movable infants worldwide, little is known regarding the current status of tummy time practices among Chinese infants. Early childhood education (ECE) institutions provide children with rich learning experiences; however, tummy time practices among infants in these ECE institutions were unclear. This study aimed to investigate the status of tummy time among infants within the context of ECE institutions.

Methods

We conducted a cross-sectional survey with primary caregivers of infants aged 0-11 months across 31 provinces of China from 1 March to 30 April 2023. To recruit participants, we collaborated with Gymboree Play & Music, an ECE institution with over 500 centres in nearly 200 cities in urban China. Our survey instrument was developed based on the World Health Organization (WHO) guidelines and literature to collect data on infants' tummy time practices, caregivers' tummy time knowledge and information sources. We used self-administered questionnaires through WeChat, in which participants scanned a quick response (QR) code to complete the questionnaire.

Results

We included 1040 infants and their primary caregivers, with 504 infants aged 0-5 and 536 infants aged 6-11 months old. Less than half of infants (48.2%) started tummy time in the neonatal period, with 20.5% starting within two weeks after birth. Only 27.2% of infants engaged in at least 30 minutes of tummy time during the last 24 hours, with infants aged 0-5 months significantly lower than those aged 6-11 months (21.6 vs 32.5%, P < 0.0001). No significant difference was found between attending ECE class and non-attending ECE class groups for the proportion of infants with tummy time ≥30 minutes per day (28.9 vs 23.4%, P = 0.0625); however, infants aged 0-5 months in the attending group engaged in longer duration of tummy time than those in the non-attending group (P = 0.0005). The compliance with the tummy time guidelines in infants receiving long-nurturing care was significantly higher than those receiving short-nurturing care (30.4 vs 22.1%, P = 0.0036). Only 42.7% of caregivers knew that at least 30 minutes daily tummy time was necessary for infant, and more primary caregivers in the attending group knew that, compared to the non-attending group (45.3 vs 36.8%, P = 0.0098).

Conclusions

The current status of infants' tummy time practices and caregivers' knowledge are generally suboptimal within the context of ECE institutions in urban China. Longer nurturing time contributes to higher compliance with tummy time guidelines. Effectively promoting tummy time practices through multiple channels in China is crucial.

Complementary feeding practices for children aged 6-23 months in early childhood education institutions in urban China: A cross-sectional study

Background

Appropriate infant and young child feeding (IYCF) plays a crucial role in promoting the healthy growth of children. Currently, many Chinese urban parents are seeking care of children from the early childhood education (ECE) institutions, however, little is known about the feeding practices of infants and young children in ECE institutions. This study aims to investigate the complementary feeding practices for Chinese urban children aged 6-23 months in ECE institutions and explore potential factors influencing their feeding practices.

Methods

This cross-sectional study was conducted among primary caregivers of children aged 6-23 months in ECE institutions across 31 provinces in China from 1 March to 30 April 2023. Convenience sampling was used to recruit caregivers from centres of Gymboree Play & Music (an ECE institution). Self-administered questionnaires were designed using the online survey tool Sojump and distributed through WeChat platform, which collected information on 1) children's complementary feeding practices; 2) food frequency of seven food groups; 3) caregivers' feeding knowledge and practices; 4) frequency of children attended ECE classes and the primary caregivers' daily nurturing care time; 5) source of information on complementary feeding.

Results

A total of 2731 children and their caregivers were surveyed, with 416 children aged 6-11 months and 2315 children aged 12-23 months. The prevalence of minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum acceptable diet (MAD) was 59.4, 60.6, and 39.2%, respectively. Only 17.3% caregivers believed that continued breastfeeding should be at two years or above, and 29.5% children were continuously breastfed at 12-23 months (CBF). The proportion of non-responsive feeding practices among caregivers ranged from 28 to 64%. Except for CBF, the prevalence of other key complementary feeding practices was higher among children who attending ECE classes than those not attending ECE classes (all P < 0.05). Moreover, children aged 12-23 months who received long-nursing care time (≥4h/d) had significantly higher MMF and MAD prevalence than those in short-nursing care time group (MMF = 66.2 vs. 58.8%, P = 0.0003; MAD = 44.2 vs. 38.3%, P = 0.0047).

Conclusions

The complementary feeding practices of children aged 6-23 months in ECE institutions in urban China remained suboptimal, and non-responsive feeding practices among caregivers were common. The attendance of ECE classes and the caregivers' daily nurturing care time could be beneficial in ensuring children to comply with complementary feeding recommendations.

Diphylleia Grayi-Inspired Intelligent Temperature-Responsive Transparent Nanofiber Membranes

Nanofiber membranes (NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a great challenge due to the enormous reflection and incredibly poor transmission generated by the nanofiber-air interface. In this research, we report a general strategy for the preparation of flexible temperature-responsive transparent (TRT) membranes, which achieves a rapid transformation of NFMs from opaque to highly transparent under a narrow temperature window. In this process, the phase change material eicosane is coated on the surface of the polyurethane nanofibers by electrospray technology. When the temperature rises to 37 °C, eicosane rapidly completes the phase transition and establishes the light transmission path between the nanofibers, preventing light loss from reflection at the nanofiber-air interface. The resulting TRT membrane exhibits high transmittance (> 90%), and fast response (5 s). This study achieves the first TRT transition of NFMs, offering a general strategy for building highly transparent nanofiber materials, shaping the future of next-generation intelligent temperature monitoring, anti-counterfeiting measures, and other high-performance devices.

[Study on clearance of chlorfenapyr via blood purification (a case analysis)]

This paper analyzed the clinical data of a patient with acute oral emamectin·chlorfenapyr poisoning, and discussed the effect of blood purification therapy on chlorfenapyr poisoning. Chlorfenapyr was detected in the blood, urine, ultrafiltrate and plasma exchange fluid of the patient, and the concentrations of chlorfenapyr poison gradually decreased with time. Blood purification has a certain effect on chlorfenapyr, and early blood purification may be an effective measure to treat chlorfenapyr poisoning.

Silk fibroin/polyvinyl alcohol composite film loaded with antibacterial AgNP/polydopamine-modified montmorillonite; characterization and antibacterial properties

In this study, a kind of nanocomposite film was fabricated via combining silk fibroin, polyvinyl alcohol (SF/PVA) and AgNP/polydopamine-modified Montmorillonite (AgNP/PDA-Mt). The structural characteristics and properties of the SF/PVA/AgNP/PDA-Mt nanocomposites films were identified using X-ray diffraction (XRD), Thermal gravimetric analyzer (TGA), Fourier transform infrared spectroscopy (FTIR), EDS-mapping analyses and Scanning electron microscope (SEM). The results indicated enhanced thermal performance of SF/PVA/AgNP/PDA-Mt nanocomposites with increased AgNP/PDA-Mt weight. The nanocomposite film exhibited excellent antibacterial activity against E. coli and S. aureus. The 2 % SF/PVA/AgNP/PDA-Mt film showed the highest zone of inhibition with an average inhibition circle diameter of 26.1 mm against E. coli and 20.61 mm against S. aureus. Cytotoxicity test results indicated that the nanocomposites films were biocompatible with L929 cells with a 100 % survival rate, which can be considered as one of the advantages of new nanocomposites films. These findings suggest that SF/PVA/AgNP/PDA-Mt films have potential clinical applications in wound dressing and antibacterial biomedical applications.

Suboptimal movement behaviours among children under two years old in early childhood education institutions in urban China: A cross-sectional study

Background

Healthy movement behaviours in early life promote better physical health and facilitate psychological development. Early childhood education (ECE) institutions provide opportunities for caregivers to improve children's movement behaviour practices, but little is known about the current status of movement behaviours among infants and young children in urban China in this context. We aimed to investigate the movement behaviour status of children under two years of age via ECE institutions and compare movement behaviour practices and knowledge between children attending ECE classes and those not attending.

Methods

We conducted the cross-sectional survey from 1 March to 30 April 2023 in Gymboree Play&Music, an ECE institution covering 31 provinces in China. We developed our survey instrument based on World Health Organization (WHO) guidelines to measure children's movement behaviour practices and caregivers' movement behaviour knowledge. We carried out the online questionnaire survey through Sojump, the largest professional online survey platform in China. We sent a quick response (QR) code to Gymboree Play&Music centres; the QR code was linked to a questionnaire intended for caregiver members and non-members coming for experience classes and activities.

Results

We surveyed 3355 primary caregivers, encompassing 504, 536, and 2315 children aged 0-5 months, 6-11 months, and 12-23 months, respectively. Overall, less than half of the children met recommendations in physical activity time (PAT) (19.2%), physical restraint (PR) (45.8%), and screen time (ST) (46.4%) during the last 24 hours. PAT, outdoor time (OT), and sleep duration (SD) in children aged 0-5 months were significantly lower than in the other two age groups, while ST was significantly higher than in the other two age groups during the last 24 hours (all P < 0.001). For children attending ECE classes, PAT, OT, and SD were significantly higher than those not attending ECE during the last 24 hours and the last two weeks (all P < 0.05). All indicators in the long-nursing care time (NCT) group were significantly higher than those in the short-NCT group, while there was no statistical difference in SD between the two groups (66.6% vs 65.6%; P = 0.558).

Conclusions

The status of movement behaviours for children under two years old in urban China is not optimistic, especially for PAT, PR, and ST. Additionally, attending early childhood education classes and primary caregivers' daily nurturing care time are important for infants and young children to adhere to movement guidelines. Consequently, more ECE institution-specific practical strategies and educational materials are needed to promote compliance with movement behaviour guidelines.

Exploration of the SIRT1-mediated BDNF-TrkB signaling pathway in the mechanism of brain damage and learning and memory effects of fluorosis

Introduction

Fluoride is considered an environmental pollutant that seriously affects organisms and ecosystems, and its harmfulness is a perpetual public health concern. The toxic effects of fluoride include organelle damage, oxidative stress, cell cycle destruction, inflammatory factor secretion, apoptosis induction, and synaptic nerve transmission destruction. To reveal the mechanism of fluorosis-induced brain damage, we analyzed the molecular mechanism and learning and memory function of the SIRT1-mediated BDNF-TrkB signaling pathway cascade reaction in fluorosis-induced brain damage through in vivo experiments.

Methods

This study constructed rat models of drinking water fluorosis using 50 mg/L, 100 mg/L, and 150 mg/L fluoride, and observed the occurrence of dental fluorosis in the rats. Subsequently, we measured the fluoride content in rat blood, urine, and bones, and measured the rat learning and memory abilities. Furthermore, oxidative stress products, inflammatory factor levels, and acetylcholinesterase (AchE) and choline acetyltransferase (ChAT) activity were detected. The pathological structural changes to the rat bones and brain tissue were observed. The SIRT1, BDNF, TrkB, and apoptotic protein levels were determined using western blotting.

Results

All rats in the fluoride exposure groups exhibited dental fluorosis; decreased learning and memory abilities; and higher urinary fluoride, bone fluoride, blood fluoride, oxidative stress product, and inflammatory factor levels compared to the control group. The fluoride-exposed rat brain tissue had abnormal AchE and ChAT activity, sparsely arranged hippocampal neurons, blurred cell boundaries, significantly fewer astrocytes, and swollen cells. Furthermore, the nucleoli were absent from the fluoride-exposed rat brain tissue, which also contained folded neuron membranes, deformed mitochondria, absent cristae, vacuole formation, and pyknotic and hyperchromatic chromatin. The fluoride exposure groups had lower SIRT1, BDNF, and TrkB protein levels and higher apoptotic protein levels than the control group, which were closely related to the fluoride dose. The findings demonstrated that excessive fluoride caused brain damage and affected learning and memory abilities.

Discussion

Currently, there is no effective treatment method for the tissue damage caused by fluorosis. Therefore, the effective method for preventing and treating fluorosis damage is to control fluoride intake.

Effect of microserum environment stimulation on extraction and biological function of colorectal cancer stem cells

BACKGROUND

3D cancer stem cell (CSC) cultures are widely used as in vitro tumor models. In this study, we determined the effects of enriching HCT116 tumor spheres initially cultured in serum-free medium with different concentrations of serum, focusing on the effect of microserum environment stimulation on extraction and biological function of colorectal cancer stem cells (CCSCs).

METHODS

CCSCs were enriched in standard serum-free medium and serum-free medium with different concentrations of serum for 1 week. The expression of CSC-associated markers in CCSCs, and the presence and relative proportion of CSCs (CD133/CD44 cell sorting) were then determined to elucidate the effect of the microserum environment on the preservation of CSC-related features. Further, the tumorigenic capacity of CCSCs was evaluated in an immunodeficiency mouse model.

RESULTS

Our data indicated that a significantly greater number of spheres with a greater size range and high viability without drastic alteration in biological and structural features, which maintained self-renewal potential after sequential passages were formed after serum supplementation. Real-time analysis showed that both serum spheres and serum-free spheres displayed similar expression patterns for key stemness genes. Serum spheres showed higher expression of the CSC surface markers CD133 and CD44 than did CSCs spheres cultured in serum-free medium. Adherent cultures in complete medium could adapt to the serum-containing microenvironment faster and showed higher proliferation ability. The addition of serum induced EMT and promoted the migration and invasion of serum globular cells. Compared with serum-free cells and adherent cells, serum spheres showed higher tumor initiation ability.

CONCLUSIONS

Microserum environment stimulation could be an effective strategy for reliable enrichment of intact CCSCs, and a more efficient CSC enrichment method.

Antimicrobial resistance and virulence profiles of staphylococci isolated from clinical bovine mastitis

Staphylococci, mainly including Staphylococcus aureus and coagulase-negative staphylococci (CNS), are one of the most common pathogens causing bovine mastitis worldwide. In this study, we investigated the antimicrobial resistance and virulence profiles of staphylococci from clinical bovine mastitis in Ningxia Hui Autonomous Region of China. Antimicrobial resistance was determined by disc diffusion combined with E-test method. Genes of antimicrobial resistance and virulence factors were determined by PCR. A total of 332 staphylococcal isolates were confirmed from 1,519 mastitic milk samples, including 172 S. aureus and 160 CNS isolates. Fifteen CNS species were identified, with S. chromogenes being the most frequent found (49.4%), followed by S. equorum (13.8%). Noticeably, 2 S. agnetis isolates were found among the CNS isolates. To our knowledge, this is the first report documenting the presence of S. agnetis from bovine mastitis in China. The S. aureus and CNS isolates showed high resistance against penicillin, followed by erythromycin and tetracycline. Multidrug resistance was found in 11.6 and 16.3% of the S. aureus and CNS isolates, respectively. Resistance to penicillin was attributed to the presence of blaZ, erythromycin resistance to ermC (alone or combined with ermB) and tetracycline resistance to tetK (alone or combined with tetM). Notably, one S. equorum isolate and one S. saprophyticus isolate were both methicillin-resistant and mecA positive. Additionally, all S. aureus isolates carried the adhesin genes fnbpA, clfA, clfB, and sdrC, and most of them contained cna and sdrE. Conversely, only a few of the CNS isolates carried clfA, cna, and fnbA. Regarding toxin genes, all S. aureus isolates harbored hlb, and most of them were hlg positive. The lukE-lukD, lukM, sec, sed, sei, sen, seo, tst, seg, seh, and sej were also detected with low frequencies. However, no toxin genes were observed in CNS isolates. This study reveals high species diversity of staphylococci from clinical bovine mastitis in Ningxia Hui Autonomous Region of China. The findings for the genetic determinants of antimicrobial resistance and virulence factor provide valuable information for control and prevention of staphylococcal bovine mastitis.

Basement membrane regeneration and TGF-β1 expression in rabbits with corneal perforating injury

Purpose

To evaluate the relationship between basement membrane (BM) regeneration and the spatiotemporal expression of TGF-β1 during wound healing in rabbits with corneal perforating injury.

Methods

Forty-two rabbits were randomly allocated into 7 experimental groups, with 6 rabbits per group at each time point. The central cornea of the left eye was injured with 2.0 mm trephine to establish the perforating injury model. Six rabbits that received no treatment were used as controls. The cornea was evaluated at 3 days, 1-3 weeks, and 1-3 months after injury with a slit lamp for haze levels. Real-time quantitative polymerase chain reaction (qRT-PCR) was performed to quantify the relative expression of TGF-β1 and α-SMA mRNA. Immunofluorescence (IF) was used to assess TGF-β1 and alpha-smooth actin (α-SMA) expression and localization. BM regeneration was assessed using transmission electron microscopy (TEM).

Results

After injury, dense haze appeared at 1 month and then gradually faded. The relative expression of TGF-β1 mRNA peaked at 1 week and then decreased until 2 months. The relative α-SMA mRNA expression reached its peak at 1 week, then reached a small peak again at 1 month. IF results showed that TGF-β1 was initially detected in the fibrin clot at 3 days and then in the entire repairing stroma at 1 week. TGF-β1 localization gradually diminished from the anterior region to the posterior region at 2 weeks to 1 month, and it was nearly absent at 2 months. The myofibroblast marker α-SMA was observed in the entire healing stroma at 2 weeks. Localization of α-SMA gradually disappeared from the anterior region at 3 weeks to 1 month, remaining only in the posterior region at 2 months and disappearing at 3 months. Defective epithelial basement membrane (EBM) was first detected at 3 weeks after injury, then gradually repaired, and was nearly regenerated at 3 months. A thin and uneven Descemet's membrane (DM) was initially detected at 2 months after injury, then gradually regenerated to some extent, but remained abnormal at 3 months.

Conclusions

In the rabbit corneal perforating injury model, EBM regeneration was observed earlier than DM. At 3 months, complete EBM regeneration was observed, while the regenerated DM was still defective. TGF-β1 was distributed throughout the entire wound area in the early stages and then decreased from the anterior to the posterior region. α-SMA exhibited a similar temporospatial expression to TGF-β1. EBM regeneration may play a key role in low expression of TGF-β1 and α-SMA in the anterior stroma. Meanwhile, incomplete DM regeneration may contribute to the sustained expression of TGF-β1 and α-SMA in the posterior stroma.

[Honokiol reduces oxidative stress by activating the SIRT3-MnSOD2 pathway to alleviate hypertriglyceridemia-induced acute pancreatitis in rats]

OBJECTIVE

To determine how honokiol affects the sirtuin-3 (SIRT3)-MnSOD2 pathway and oxidative stress in rats with hypertriglyceridemia-induced acute pancreatitis (HTGP).

METHODS

Thirty 4-week-old male SD rats were randomly divided into two groups for normal feeding and high-fat feeding for 4 weeks, after which the rats with normal feeding were randomized into control group and acute pancreatitis (AP) group (n=6), and those with high-fat feeding were divided into hypertriglyceridemia group, HTGP group, and honokiol treatment group (n=6). In AP, HTGP, and honokiol groups, AP models were established by intraperitoneal injection of cerulean; in honokiol group, the rats received an intraperitoneal injection of 5 mg/kg honokiol 15 min after cerulean injection. Serum TG, IL-6, and TNF-α levels were measured 24 h after the treatments, and pathological changes in the pancreas were observed with HE staining; The levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione peroxidase (GSH) were measured, and SIRT3 and manganese superoxide dismutase (MnSOD2) expressions were detected using Western blotting and immunohistochemistry. Transmission electron microscopy was used to examine the ultrastructure of pancreatic acinar cells and mitochondria.

RESULTS

Compared with the those with normal feeding, the rats with high-fat feeding had significantly elevated serum TG level (P < 0.05). The rat models of AP showed significantly increased serum levels of IL-6, TNF-α, and MDA and decreased GSH level and expressions of SIRT3 and MnSOD2, with obvious edema and inflammatory cell infiltration and enhanced ROS fluorescence intensity in the pancreas and ultrastructural damages of the acinar cells and mitochondria. In rats with HTGP, honokiol treatment significantly decreased serum levels of IL-6, TNF-α, and MDA, increased GSH level and SIRT3 and MnSOD2 expressions, reduced ROS production, and alleviated ultrastructural damage of the acinar cells and mitochondria in the pancreas.

CONCLUSION

Honokiol reduce oxidative stress and alleviates pancreatic injuries in HTGP rats possibly by activating the SIRT3-MnSOD2 pathway.

The molecular mechanism of γ-aminobutyric acid against AD: the role of CEBPα/circAPLP2/miR-671-5p in regulating CNTN1/2 expression

The expression levels of the synaptic-related proteins contactin 1/2 (CNTN1/2) are down-regulated in the brain of Alzheimer's disease (AD), but the mechanism has not been clarified. γ-Aminobutyric acid (GABA) is considered a biologically active ingredient in food. Our previous research revealed that GABA can regulate CEBPα expression in Aβ-treated U251 cells. However, it is uncertain whether GABA can antagonize the pathogenesis of AD. Whether GABA can inhibit the reduction in CNTN1/2 expression by regulating CEBPα/circAPLP2/miR-671-5p in the AD brain remains unclear yet. Here, we demonstrate that GABA could attenuate the deposition of Aβ in the brain and ameliorate cognitive impairments in AD model mice. The expressions of CEBPα, circAPLP2, and CNTN1/2 were decreased and that of miR-671-5p was increased in AD model mouse brains and Aβ-induced SH-SY5Y cells. These alterations were partly reversed by GABA. The CNTN1/2 expression was down-regulated and up-regulated in SH-SY5Y cells treated with miR-671-5p mimics and miR-671-5p inhibitors, respectively. The results from the luciferase reporter assay revealed that miR-671-5p could bind to the 3'-untranslated region of circAPLP2. The silencing of circAPLP2 with the siRNA duplex caused an up-regulation of miR-671-5p and a down-regulation of CNTN1/2 in SH-SY5Y cells. The silencing of CEBPα with the siRNA duplex caused a down-regulation of circAPLP2 or CNTN1/2 and an up-regulation of miR-671-5p. In conclusion, GABA may decrease the deposition of Aβ in the brain, inhibit the down-regulation of CNTN1/2 expression, and ameliorate the cognitive deficits of AD model mice. The CEBPα/circAPLP2/miR-671-5p pathway plays a role in regulating CNTN1/2 expression by GABA in AD.

Enhancing the Performance of PVDF/GO Ultrafiltration Membrane via Improving the Dispersion of GO with Homogeniser

In this study, PVDF/GO-h composite membranes were synthesised using a homogeniser to improve the dispersion of GO nanosheets within the composite membrane's structure, and then characterised and contrasted to PVDF/GO-s control samples, which were synthesised via traditional blending method-implementing a magnetic stirrer. By characterizing membrane via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), water contact angle (WCA) and membrane performance. SEM results showed that the number of the finger-like structure channels and pores in the sponge like structure of PVDF/GO-h composite membranes become more compared with PVDF/GO-s membranes. Water contact angle tests showed that the PVDF/GO-h composite membranes have lower contact angle than PVDF/GO-s control, which indicated the PVDF/GO-h composite membranes are more hydrophilic. Results also showed that composite membranes blended using homogeniser exhibited both improved water flux and rejection of target pollutants. In summary, it was shown that the performance of composite membranes could be improved significantly via homogenisation during synthesis, thus outlining the importance of further research into proper mixing.

Study on Spacing Regulation and Separation Performance of Nanofiltration Membranes of GO

Graphene oxide (GO) membranes have attracted significant attention in the field of water processing in recent years due to their unique characteristics. However, few reports focus on both membrane stability and the “trade-off” effect. In this study, a series of aliphatic diamines (1, 2-ethylenediamine, 1, 4-butanediamine, and 1, 6-hexamethylenediamine) of covalent crosslinked GO were used to prepare diamine-modified nanofiltration membranes, BPPO/AX-GO, with adjustable layer spacing using the vacuum extraction−filtration method. Moreover, Ax-GO-modified nanofiltration membranes modified with adipose diamine had higher layer spacing, lower mass-transfer resistance, and better stability. When the number of carbon atoms was 5, the best layer spacing was reached, and when the number of carbon atoms was greater than 4, the modified membrane nanosheets more easily accumulated. With the increase in layer spacing, the water flux of the composite film increased to 26.27 L/m2·h·bar. Meanwhile, adipose diamine crosslinking significantly improved the stability of GO films. The interception sequence of different valence salts in the composite membrane was NaCl > Na2SO4 > MgSO4, and the rejection rate of bivalent salts was higher than that of monovalent salts. The results can provide some experimental basis and research ideas for overcoming the “trade-off” effect of a lamellar GO membrane.

A Trilayered Composite Fabric with Directional Water Transport and Resistance to Blood Penetration for Medical Protective Clothing

Functional textiles with enhanced moisture management can facilitate sweat transport away from the skin to improve personal comfort. However, porous materials exhibit low capability of preventing the intrusion of external liquids, becoming a bottleneck in the design of medical protective clothing. Herein, a trilayered composite fabric based on a gradient wettability structure is demonstrated for directional water transport and resistance to blood penetration. The proposed fabric shows distinct advantages, including a high water breakthrough pressure of 2.43 kPa from the external side, an outstanding positive water transport index (1522%), and an antiblood penetration resistance of 2.71 kPa. Moreover, the fabric shows improved comfort with a high moisture transmission (320 g m^-2 h^-1) and desired water evaporation rate (0.36 g h^-1). This work addressed the concern of directional water transport and resistance to blood penetration while providing a comfortable wearing microenvironment, leading to a promising research direction for multifunctional medical textiles.