Topography of histone H3-H4 interaction with the Hat1-Hat2 acetyltransferase complex.

Chaperones influence histone conformation and intermolecular interaction in multiprotein complexes, and the structures obtained with full-length histones often provide more accurate and comprehensive views. Here, our structure of the Hat1-Hat2 acetyltransferase complex bound to Asf1-H3-H4 shows that the core domains of H3 and H4 are involved in binding Hat1 and Hat2, and the N-terminal tail of H3 makes extensive interaction with Hat2. These findings expand the knowledge about histone-protein interaction and implicate a function of Hat2/RbAp46/48, which is a versatile histone chaperone found in many chromatin-associated complexes, in the passing of histones between chaperones.

Reproducible Reporting of the Collection and Evaluation of Annotations for Artificial Intelligence Models.

This work puts forth and demonstrates the utility of a reporting framework for collecting and evaluating annotations of medical images used for training and testing artificial intelligence (AI) models in assisting detection and diagnosis. AI has unique reporting requirements, as shown by the AI extensions to the Consolidated Standards of Reporting Trials (CONSORT) and Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklists and the proposed AI extensions to the Standards for Reporting Diagnostic Accuracy (STARD) and Transparent Reporting of a Multivariable Prediction model for Individual Prognosis or Diagnosis (TRIPOD) checklists. AI for detection and/or diagnostic image analysis requires complete, reproducible, and transparent reporting of the annotations and metadata used in training and testing data sets. In an earlier work by other researchers, an annotation workflow and quality checklist for computational pathology annotations were proposed. In this manuscript, we operationalize this workflow into an evaluable quality checklist that applies to any reader-interpreted medical images, and we demonstrate its use for an annotation effort in digital pathology. We refer to this quality framework as the Collection and Evaluation of Annotations for Reproducible Reporting of Artificial Intelligence (CLEARR-AI).

Association between weight-adjusted-waist index and gallstones: an analysis of the National Health and Nutrition Examination Survey.

BACKGROUND: The weight-adjusted-waist index (WWI) is a novel obesity index, and gallstones are associated with obesity. This study aimed to investigate the possible relationship between WWI and gallstones. METHODS: The datasets from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 were used in a cross-sectional investigation. Multivariate linear regression models were used to examine the linear connection between WWI and gallstones incidence. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship. RESULTS: The study comprised 8004 participants over the age of 20, including 833 reported with gallstones. Participants in the higher WWI tertile tended to have a higher gallstones prevalence. In the final adjusted model, a positive association between WWI and gallstones prevalence was observed (OR = 1.34, 95% CI: 1.20‒1.49). Participants in the highest WWI tertile had a significantly 71% higher risk of gallstones than those in the lowest WWI tertile (OR = 1.71, 95% CI: 1.35‒2.17). A nonlinear correlation was found between the WWI and gallstones prevalence, with an inflection point of 12.7. CONCLUSIONS: Our study found that higher WWI levels connected with increased prevalence of gallstones. However, more prospective studies are needed to validate our findings.

Proteomics analysis of histone deacetylase inhibitor-resistant solid tumors reveals resistant signatures and potential drug combinations.

Histone deacetylase inhibitors (HDACis) are important drugs for cancer therapy, but the indistinct resistant mechanisms of solid tumor therapy greatly limit their clinical application. In this study we conducted HDACi-perturbated proteomics and phosphoproteomics analyses in HDACi-sensitive and -resistant cell lines using a tandem mass tag (TMT)-based quantitative proteomic strategy. We found that the ribosome biogenesis proteins MRTO4, PES1, WDR74 and NOP16 vital to tumorigenesis might regulate the tumor sensitivity to HDACi. By integrating HDACi-perturbated protein signature with previously reported proteomics and drug sensitivity data, we predicted and validated a series of drug combination pairs potentially to enhance the sensitivity of HDACi in diverse solid tumor. Functional phosphoproteomic analysis further identified the kinase PDK1 and ROCK as potential HDACi-resistant signatures. Overall, this study reveals the potential HDACi-resistant signatures and may provide promising drug combination strategies to attenuate the resistance of solid tumor to HDACi.

A comparison of Bayesian and score methods for interval estimates of positive/negative likelihood ratios in support of diagnostic device performance evaluation.

BACKGROUND: Positive and negative likelihood ratios (PLR and NLR) are important metrics of accuracy for diagnostic devices with a binary output. However, the properties of Bayesian and frequentist interval estimators of PLR/NLR have not been extensively studied and compared. In this study, we explore the potential use of the Bayesian method for interval estimation of PLR/NLR, and, more broadly, for interval estimation of the ratio of two independent proportions. METHODS: We develop a Bayesian-based approach for interval estimation of PLR/NLR for use as a part of a diagnostic device performance evaluation. Our approach is applicable to a broader setting for interval estimation of any ratio of two independent proportions. We compare score and Bayesian interval estimators for the ratio of two proportions in terms of the coverage probability (CP) and expected interval width (EW) via extensive experiments and applications to two case studies. A supplementary experiment was also conducted to assess the performance of the proposed exact Bayesian method under different priors. RESULTS: Our experimental results show that the overall mean CP for Bayesian interval estimation is consistent with that for the score method (0.950 vs. 0.952), and the overall mean EW for Bayesian is shorter than that for score method (15.929 vs. 19.724). Application to two case studies showed that the intervals estimated using the Bayesian and frequentist approaches are very similar. DISCUSSION: Our numerical results indicate that the proposed Bayesian approach has a comparable CP performance with the score method while yielding higher precision (i.e. a shorter EW).

Surface characteristics and in vitro biocompatibility of titanium preserved in a vitamin C-containing saline storage solution.

The purpose of this study is to explore a storage solution for titanium implants and investigate its osteogenic properties. The commercial pure titanium (cp-Ti) surface and double-etched (SLA) titanium surface specimens were preserved in air, saline, 10 mM Vitamin C (VitC)-containing saline and 100 mM VitC-containing saline storage solutions for 2 weeks. The surface microtopography of titanium was observed by scanning electron microscopy (SEM), the surface elemental compositions of the specimens were analyzed by Raman and X-ray photoelectron spectroscopy (XPS), and water contact angle and surface roughness of the specimens were tested. The protein adsorption capacity of two titanium surfaces after storage in different media was examined by BCA kit. The MC3T3-E1 osteoblasts were cultured on two titanium surfaces after storage in different media, and the proliferation, adhesion and osteogenic differentiation activity of osteoblasts were detected by CCK-8, laser confocal microscope (CLSM) and Western blot. The SEM results indicated that the titanium surfaces of the air group were relatively clean while scattered sodium chloride or VitC crystals were seen on the titanium surfaces of the other three groups. There were no significant differences in the micromorphology of the titanium surfaces among the four groups. Raman spectroscopy detected VitC crystals on the titanium surfaces of two experimental groups. The XPS, water contact angle and surface roughness results suggested that cp-Ti and SLA-Ti stored in 0.9% NaCl and two VitC-containing saline storage solutions possessed less carbon contamination and higher surface hydrophilicity. Moreover, the protein adsorption potentials of cp-Ti and SLA-Ti surfaces were significantly improved under preservation in two VitC-containing saline storage solutions. The results of in vitro study showed that the preservation of two titanium surfaces in 100 mM VitC-containing saline storage solution upregulated the cell adhesion, proliferation, osteogenic related protein expressions of MC3T3-E1 osteoblasts. In conclusion, preservation of cp-Ti and SLA-Ti in 100 mM VitC-containing saline storage solution could effectively reduce carbon contamination and enhance surface hydrophilicity, which was conducive to osteogenic differentiation of osteoblasts.

Preventive and Therapeutic Benefits of Natural Ingredients in Photo-Induced Epidermal Dysfunction.

BACKGROUND: The skin, particularly the epidermis, is subjected to various external stresses, including ultraviolet (UV) irradiation. UV irradiation, mainly UVB at wavelength of 280-315 nm, can alter several epidermal functions, including cutaneous inflammation, epidermal hyperproliferation, DNA damage, disruption of epidermal permeability barrier and reduction in stratum corneum hydration levels. Because of the negative impacts of UVB irradiation on epidermal functions, great efforts have been made to develop regimens for the protection of alterations in epidermal function induced by UV irradiation. SUMMARY: While sunscreen can provide physical barrier to UV light, some natural ingredients can also effectively protect the skin from UVB irradiation-induced damages. Studies have demonstrated that either topical or oral administrations of some natural ingredients attenuate UVB irradiation-induced alterations in the epidermal function. The underlying mechanisms by which natural ingredients improve epidermal functions are attributable to antioxidation, stimulation of keratinocyte differentiation, increases in the content of epidermal natural moisturizers and inhibition of inflammation. KEY MESSAGE: Some natural ingredients exhibit protective and therapeutical benefits in photo-induced epidermal dysfunctions via divergent mechanisms.

Orexin recruits non-selective cationic conductance and endocannabinoid to dynamically modulate firing of caudal pontine reticular nuclear neurones.

The neuropeptide orexin is involved in motor circuit function. However, its modulation on neuronal activities of motor structures, integrating orexin's diverse downstream molecular cascades, remains elusive. By combining whole-cell patch-clamp recordings and neuropharmacological methods, we revealed that both non-selective cationic conductance (NSCC) and endocannabinoids (eCBs) are recruited by orexin signalling on reticulospinal neurones in the caudal pontine reticular nucleus (PnC). The orexin-NSCC cascade provides a depolarizing force that proportionally enhances the firing-responsive gain of these neurones. Meanwhile, the orexin-eCB cascade selectively attenuates excitatory synaptic strength in these neurones by activating presynaptic cannabinoid receptor type 1. This cascade restrains the firing response of the PnC reticulospinal neurones to excitatory inputs. Intriguingly, non-linear or linear interactions between orexin postsynaptic excitation and presynaptic inhibition can influence the firing responses of PnC reticulospinal neurones in different directions. When presynaptic inhibition is in the lead, non-linear interactions can prominently downregulate or even gate the firing response. Conversely, linear interactions occur to promote the firing response, and these linear interactions can be considered a proportional reduction in the contribution of depolarization to firing by presynaptic inhibition. Through the dynamic employment of these interactions, adaptive modulation may be achieved by orexin to restrain or even gate the firing output of the PnC to weak/irrelevant input signals and facilitate those to salient signals. KEY POINTS: This study investigated the effects of orexin on the firing activity of PnC reticulospinal neurones, a key element of central motor control. We found that orexin recruited both the non-selective cationic conductances (NSCCs) and endocannabinoid (eCB)-cannabinoid receptor type 1 (CB1R) system to pontine reticular nucleus (PnC) reticulospinal neurones. The orexin-NSCC cascade exerts a postsynaptic excitation that enhances the firing response, whereas the orexin-eCB-CB1R cascade selectively attenuates excitatory synaptic strength that restrains the firing response. The postsynaptic and presynaptic actions of orexins occur in an overlapping time window and interact to dynamically modulate firings in PnC reticulospinal neurones. Non-linear interactions occur when presynaptic inhibition of orexin is in the lead, and these interactions can prominently downregulate or even gate firing responses in PnC reticulospinal neurones. Linear interactions occur when postsynaptic excitation of orexin is in the lead, and these interactions can promote the firing response. These linear interactions can be considered a proportional reduction of the contribution of depolarization to firing by presynaptic inhibition.

Efficacy and safety of non-ergot dopamine-receptor agonists as an adjunct to levodopa in advanced Parkinson's disease: A network meta-analysis.

BACKGROUND AND PURPOSE: Non-ergot dopamine agonists (NEDAs) have been used as an adjunct therapy to levodopa in advanced Parkinson's disease (PD) for many years. However, there is no strong evidence that a given NEDA is more potent than another. To compare and rank the efficacy, tolerability, and safety of six commonly used NEDAs as an adjunct to levodopa in advanced PD, which includes long-acting and standard formulations, a network meta-analysis was performed. METHODS: The MEDLINE, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, and Wanfang databases were searched from January 1996 to June 2022 for eligible randomized controlled trials (RCTs). Six NEDAs, including rotigotine transdermal patch, ropinirole immediate-release (IR)/prolonged-release (PR), pramipexole IR/extended-release (ER), and piribedil, were investigated. RESULTS: A total of 34 RCTs (7868 patients) were included in the current study. The surface under the cumulative ranking curve indicated that ropinirole PR was associated with the best improvement in Unified Parkinson's Disease Rating Scale (UPDRS)-II, UPDRS-III, and UPDRS-II + III (0.811, 0.742, and 0.827). For OFF time reduction, pramipexole IR ranked first (0.979), and ropinirole PR ranked first in OFF time responder rate (0.927). Pramipexole ER ranked first in overall withdrawals, and rotigotine transdermal patch ranked first in the incidence of adverse events (≥1 AEs). CONCLUSIONS: This network meta-analysis suggests six commonly used NEDAs are effective as an adjunct to levodopa in advanced PD. In comprehensive consideration of better symptomatic management, ropinirole PR may be a better choice than other NEDAs in advanced PD. Six NEDAs showed different profiles of AEs.

Annulative Aminosulfonylation of Unactivated Alkenes for Accessing Pyrazolines via Multicomponent SO2 Insertion.

A direct arylsulfonylation of ß,γ-unsaturated hydrazones method, in which sulfonated pyrazolines are accessed by a three-component reaction of ß,γ-unsaturated hydrazones, DABSO, and aryldiazonium tetrafluoroborates, has been developed without external oxidants or catalysts. This transformation is triggered by the formation of arylsulfonyl radicals in situ from the reaction of aryldiazonium tetrafluoroborates and DABSO, and is enabled by controllable generation of C center radical, in which DABSO was utilized as the sulfone source and an oxidant in this radical-mediated cascaded reaction. A wide range of substrates can be applied in this process to afford pyrazolines in good yield, and it is amenable for gram-scale synthesis.

Repeated intravenous thrombolysis in recurrent ischemic stroke within 3 months: a systematic review.

BACKGROUND: Repeated intravenous thrombolysis (RIVT) within 3 months is an off-guideline therapy, however, may be an effective and safe way to treat early recurrent ischemic stroke. This study was conducted to assess the potential influencing factors on the efficacy and safety of RIVT in recurrent ischemic stroke within 3 months and to explore the strategy of RIVT within 3 months. METHODS: PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, and Wanfang Database were searched for cases of RIVT in recurrent ischemic stroke within 3 months up to February 1, 2023. Clinical characteristics were compared and analyzed between the good-outcome and poor-outcome groups and between the symptomatic intracranial hemorrhage (sICH) and non-sICH groups respectively. RESULTS: A total of 16 studies including 24 cases of RIVT within 3 months were retrospectively analyzed in the present study. The patients' ages ranged from 42 to 87 years (median 73.5 years) and the intervals between thrombolysis were from 0.25 to 90 days (median 9.5 days). Comparing the clinical characteristics between the good-outcome group and the poor-outcome group, no statistically significant differences were found (P > 0.05), but the differences in baseline National Institutes of Health stroke scale (NIHSS) score of the recurrent stroke (P = 0.056) and good outcome after the previous IVT (P = 0.054) nearly reached statistical significance. Comparing the data between the non-sICH group and the sICH group, statistically significant differences were found in terms of the proportion of cardiogenic embolism (P = 0.036), baseline NIHSS score in the recurrent stroke (P = 0.007) and the interval between thrombolysis (P = 0.041), but no significant difference was found by regression analysis. CONCLUSION: In patients with recurrent ischemic stroke within 3 months, those with a good outcome after the previous IVT and a low baseline NIHSS score in the recurrent stroke may be considered for RIVT, whereas those with a high baseline NIHSS score, a short interval between thrombolysis, and cardiogenic embolism may suffer a higher risk of sICH. Due to sample size and publication bias, more studies with larger sample sizes and more rigorous designs are needed to confirm this conclusion.

Synthesis of α-allenic aldehydes/ketones from homopropargylic alcohols using a visible-light irradiation system.

A visible-light irradiation tandem oxidative aryl migration/carbonyl formation reaction, mediated by K2S2O8 and visible-light photoredox catalysis, has been discovered. The presented transformation provides a straightforward access to important α-allenic aldehyde/ketone derivatives from readily available homopropargylic alcohol derivatives in a regioselective manner of 1,4-aryl shift concomitant with carbonyl formation. The operational simplicity and broad substrate scope demonstrate the great potential of this method for the synthesis of highly functional α-allenic aldehyde/ketone derivatives.

PhI(OAc)2-mediated aminoacyloxylation of ß,γ-unsaturated hydrazones using Togni reagent II as an acyloxyl precursor.

A metal-free protocol for the direct construction of C(sp2)-N and C-O bonds via a PhI(OAc)2-mediated dehydrogenative aminoacyloxylation of ß,γ-unsaturated hydrazones with Togni reagent II is reported. Initiated by the carboxyl-containing species generated in situ from Togni reagent II, this method offers a new solution for regioselective functionalization at a remote site on ß,γ-unsaturated hydrazones, thus providing a straightforward method for the synthesis of acyloxyl-substituted pyridazines. This reaction features a broad substrate scope and mild conditions.

Investigation of targets and anticancer mechanisms of covalently acting natural products by functional proteomics.

Eriocalyxin B (EB), 17-hydroxy-jolkinolide B (HJB), parthenolide (PN), xanthatin (XT) and andrographolide (AG) are terpenoid natural products with a variety of promising antitumor activities, which commonly bear electrophilic groups (α,ß-unsaturated carbonyl groups and/or epoxides) capable of covalently modifying protein cysteine residues. However, their direct targets and underlying molecular mechanisms are still largely unclear, which limits the development of these compounds. In this study, we integrated activity-based protein profiling (ABPP) and quantitative proteomics approach to systematically characterize the covalent targets of these natural products and their involved cellular pathways. We first demonstrated the anti-proliferation activities of these five compounds in triple-negative breast cancer cell MDA-MB-231. Tandem mass tag (TMT)-based quantitative proteomics showed all five compounds commonly affected the ubiquitin mediated proteolysis pathways. ABPP platform identified the preferentially modified targets of EB and PN, two natural products with high anti-proliferation activity. Biochemical experiments showed that PN inhibited the cell proliferation through targeting ubiquitin carboxyl-terminal hydrolase 10 (USP10). Together, this study uncovered the covalently modified targets of these natural products and potential molecular mechanisms of their antitumor activities.

Trend of changes in epidermal biophysical properties in the Chinese aged 1 month to 17-year old.

BACKGROUND: Although it is known that epidermal biophysical properties vary with age and gender, the changes in epidermal biophysical properties over the time from baby to adolescence have not been elucidated yet. In the present study, we assessed the trend of changes in transepidermal water loss rates (TEWL), stratum corneum hydration, and skin surface pH in Chinese children. PARTICIPANTS AND METHODS: A total of 780 boys and 610 girls, aged 1 month to 17-year old, were enrolled in this study. TEWL and stratum corneum hydration on the forearm and the shin were measured with GPSkin Barrier, whereas skin surface pH was measured with portable skin pH meter. RESULTS: Overall, TEWL and stratum corneum hydration levels decreased, whereas skin surface pH increased in children from 1-month old to 17-year old. Significant decline in TEWL was observed on both the forearm and the shin of girls, and the shin of boys aged 13-17-year old. Similarly, marked decline in stratum corneum hydration levels started at ages of 6-12-year old. In contrast, decline in skin surface pH was observed in both girls and boys aged one to 12-month old except on the forearm of boys. Afterward, skin surface pH remained either stable or slight increase except on the shin of boys aged >12 months to 3-year old. CONCLUSIONS: These results demonstrate that both TEWL and stratum corneum hydration levels decrease, whereas skin surface pH increases in children aged 1 month to 17-year old. The changes in these biophysical properties vary with age, gender, and body site.

The association between admission serum albumin and preoperative deep venous thrombosis in geriatrics hip fracture: a retrospective study of 1819 patients with age ≥ 65 years.

OBJECTIVE: This study evaluated the association between serum albumin levels and preoperative deep vein thrombosis (DVT) in geriatric hip fractures. METHODS: Older adult patients with hip fractures were screened between January 2015 and September 2019. The demographic and clinical characteristics of the patients were collected. Multivariate binary logistic regression and generalized additive model were used to identify the linear and nonlinear association between albumin levels and preoperative DVT. Analyses were performed using EmpowerStats and the R software. RESULTS: A total of 1819 patients were included in this study. The average age was 79.37 ± 6.88 years. There were 550 males and 1269 females. The preoperative albumin was 38.19 ± 4.07 g/L. There were 580 (31.89%) preoperative DVTs. Multivariate binary logistic regression showed that albumin level was associated with preoperative DVT (odds ratio [OR] = 0.94, 95% confidence interval [CI]: 0.91-0.97, P = 0.0002) after adjusting for confounding factors. The fully adjusted model showed a DVT risk decrease of 6% when albumin concentration increased by one g/L after controlling for confounding factors. In addition, the trend test and propensity score matching also showed a stable linear correlation between albumin level and preoperative DVT. CONCLUSION: Serum albumin is associated with preoperative DVT in geriatric patients with hip fractures, and it could be considered a predictor for the risk of DVT. REGISTRATION ID: ChiCTR2200057323.

The role of stimulator of interferon genes-mediated AMPK/mTOR/P70S6K autophagy pathway in cyfluthrin-induced testicular injury.

Cyfluthrin is widely used in the field of sanitary pest control by its wide insecticidal spectrum, high efficiency and low toxicity, low residue, and good biodegradability. But, as a double-edged sword, a large amount of cyfluthrin remains are still in the environment. The residual cyfluthrin is absorbed into the food chain through vegetation and then poses a risk to soil organisms and human health. Several studies have suggested that cyfluthrin is one of the main factors causing testicular damage, but the mechanism remains unclear. In this study, we established in vivo and in vitro models of testicular injury in rats and GC-2 cells exposed to cyfluthrin to explore whether stimulator of interferon genes (STING) gene mediates the regulation of AMPK/mTOR/p70S6K autophagy pathway, which lays a foundation for further study of the mechanism of testicular injury induced by cyfluthrin. The results showed that the activity of super oxide dismutase in testis decreased and the activity of malonic dialdehyde increased with the increase of concentration in vivo and in vitro. At the same time, the levels of mitochondrial damage and inflammation in the testis also increased, which further activated autophagy. In this process, the increased level of inflammation is related to the increased expression of STING gene, and AMPK/mTOR/p70S6K autophagy pathway is also involved. To sum up, cyfluthrin has certain reproductive toxicity, and long-term exposure can induce testicular cell damage. STING gene can participate in cyfluthrin-induced testicular injury through AMPK/mTOR/P70S6K autophagy pathway.

Histone deacetylase AtSRT2 regulates salt tolerance during seed germination via repression of vesicle-associated membrane protein 714 (VAMP714) in Arabidopsis.

Salt tolerance during seed germination is essential for seedling establishment under salt stress. Sirtuin-like proteins, NAD+ -dependent histone deacetylases, are involved in plant responses to abiotic stresses; however, the regulatory mechanism remains unknown. We elucidated the mechanism underlying AtSRT2 (a sirtuin-like protein)-mediated regulation of salt tolerance during seed germination in Arabidopsis. The AtSRT2 mutant srt2 exhibited significantly reduced seed germination percentages under salt stress; its targets were identified via chromatin immunoprecipitation coupled with ultra-high-throughput parallel DNA sequencing (ChIP-Seq) assay. Epistasis analysis was performed to identify AtSRT2-related pathways. Overexpression of SRT2.7, an AtSRT2 splice variant, rescued the salt-sensitive phenotype of mutant srt2. AtSRT2 histone deacetylation activity was important for salt tolerance during seed germination. The acetylation level of histone H4K8 locus in srt2-1 increased significantly under salt treatment. Vesicle-associated membrane protein 714 (VAMP714), a negative regulator of hydrogen peroxide (H2 O2 )-containing vesicle trafficking in cells, was identified as a target of AtSRT2. AtSRT2 regulated histone acetylation in the promoter region of VAMP714 and inhibited VAMP714 transcription under salt treatment. Seed germination percentage of double-mutant srt2-1vamp714 was close to that of single-mutant vamp714, and higher than that of single-mutant srt2 under salt stress. Hydrogen peroxide content and DNA damage increased after salt treatment in srt2 during seed germination. AtSRT2 regulates salt tolerance during seed germination through VAMP714 in Arabidopsis.

Aged and young mice differentially respond to tape-stripping in epidermal gene expression.

Disruption of epidermal permeability barrier induces an increase in proinflammatory cytokine expression and release, stimulation of epidermal lipid and DNA synthesis, and expression of antimicrobial peptides. Although alterations in epidermal function in the aged skin are known, whether the epidermal transcriptomic responses to barrier disruption differ between aged and young mice remains unknown. Here, we performed RNA sequencing of the epidermis in 2-month- vs. 20-month-old mice following barrier disruption with repeated tape-stripping. At baseline condition, the epidermis of 20-month-old mice displayed an upregulation of inflammation-associated genes and down-regulation of epidermal structure- and development-related genes in comparison to 2-month-old mice. Barrier disruption upregulated expression levels of 327 genes and downregulated 209 genes in 2-month-old mice. In 20-month-old mice, the numbers of upregulated and down-regulated genes were 537 and 299, respectively. In comparison to young mice, the prominently upregulated genes in the 20-month-old mice were associated with the IL-17 signalling pathway, while downregulated genes were mainly involved in the cytokine-cytokine receptor interaction pathway. These results indicate that inflammation-associated signalling pathways are upregulated, while epidermal structure- and development-related genes are downregulated in the epidermis of aged mice, with further aggravation following barrier disruption, suggesting the importance of improving epidermal function in the elderly.

Gasdermin D is involved in switching from apoptosis to pyroptosis in TLR4-mediated renal tubular epithelial cells injury in diabetic kidney disease.

BACKGROUND: Toll-like receptor 4 (TLR4) mediated pathway plays a pivotal role in promoting tubulointerstitial inflammation and contributes to the progression in type 2 diabetic kidney disease (T2DKD). As the first identified key pyroptosis executor, gasdermin D (GSDMD) is activated by caspases and might be the key protein to switch apoptosis to pyroptosis. It remains unclear that role of TLR4 on canonical pyroptosis pathway, and whether GSDMD is involved in switching from apoptosis to pyroptosis in the TLR4-related tubular injury in T2DKD. METHODS: Immunohistochemistry staining was used to detect the expression of pyroptosis-related proteins in renal tissues of T2DKD patients. T2DKD models was induced in TLR4 knockout (TLR4-/-) mice through a high-fat diet combined with streptozotocin. Pyroptosis (caspase-1, GSDMD, interleukin 18(IL-18), interleukin 1ß(IL-1ß)) and apoptosis levels (caspase-3, Bax and Bcl-2) were detected by Western blot. HK-2 cells were cultured under high-glucose (HG) conditions as an in vitro model and then challenged with a TLR4-specific antagonist (TAK-242). GSDMD small interfering RNA (siRNA) and overexpression plasmid were transfected into HK-2 cells to down- or up-regulate GSDMD. The pyroptosis and apoptosis rates were determined by flow cytometry. RESULTS: The expression levels of caspase-1, GSDMD, IL-18 and IL-1ß were increased in renal biopsy tissues of T2DKD patients and GSDMD expression was positively correlated with tubular injury. Silencing GSDMD attenuated HG-induced IL-18, IL-1ß, FN and α-SMA, and reduced pyroptotic cells rate in HK-2 cells. Up-regulation of GSDMD inhibited HG-induced expression of Bax and cleaved caspase-3 and reduced apoptosis rate. TLR4 knockout alleviated tubular injury and interstitial macrophages infiltration, improved impaired renal dysfunction, and decreased the expressions of active N-terminal of GSDMD(GSDMD-N), cleaved caspase-1(cl-caspase-1) and cleaved caspase-3(cl-caspase-3) in T2DKD mice. TLR4 inhibition reduced HG-induced pyroptosis and apoptosis level in HK-2 cells, while GSDMD up-regulation increased pyroptosis rate and decreased apoptosis rate. CONCLUSIONS: TLR4 could exacerbate tubular injury and fibrosis via GSDMD-mediated canonical pyroptosis pathway in T2DKD. Activation of GSDMD could inhibit apoptosis and activate pyroptosis, which may involve the potential switch mechanism between TLR4-mediated pyroptosis and apoptosis in T2DKD.