[Analysis of the types and functions of CD34+ cells in full-thickness skin defect wounds of normal mice and diabetic mice by single-cell RNA sequencing]

Objective: To analyze the types and functions of CD34+ cells in full-thickness skin defect wounds of normal mice and diabetic mice by single-cell RNA sequencing. Methods: This study was an experimental study. The CD34+ cell lineage tracing mouse was produced, and the visualization of CD34+ cells under the fluorescent condition was realized. Six male CD34+ cell lineage tracing mice aged 7-8 weeks (designated as diabetic group) were intraperitoneally injected with streptozotocin to establish a diabetic model, and full-thickness skin defect wounds were prepared on their backs when they reached 13 weeks old. Another 6 male CD34+ cell lineage tracing mice aged 13 weeks (designated as control group) were also subjected to full-thickness skin defect wounds on their backs. On post-injury day (PID) 4, wound tissue was collected from 3 mice in control group and 2 mice in diabetic group, and digested to prepare single-cell suspensions. CD34+ cells were screened using fluorescence-activated cell sorting, followed by single-cell RNA sequencing. The Seurat 4.0.2 program in the R programming language was utilized for dimensionality reduction, visualization, and cell clustering analysis of CD34+ cell types, and to screen and annotate the marker genes for each CD34+ cell subpopulation. Kyoto encyclopedia of genes and genomes (KEGG) and gene ontology (GO) enrichment analysis was performed to analyze the differentially expressed genes (DEGs) of CD34+ fibroblasts (Fbs), smooth muscle cells (SMCs), keratinocytes (KCs), and chondrocyte-like cells (CLCs) in the wound tissue of two groups of mice for exploring cellular functions. Results: On PID 4, CD34+ cells in the wound tissue of both groups of mice were consisted of 7 cell types, specifically endothelial cells, Fbs, KCs, macrophages, T cells, SMCs, and CLCs. Among these, Fbs were further classified into 5 subpopulations. Compared with those in control group, the proportions of CD34+ endothelial cells, Fbs subpopulation 1, Fbs subpopulation 4, KCs, and CLCs in the wound tissue of mice were increased in diabetic group, while the proportions of CD34+ Fbs subpopulation 2, Fbs subpopulation 3, and SMCs were decreased. The marker genes for annotating CD34+ CLCs, endothelial cells, Fbs subpopulation 1, Fbs subpopulation 2, Fbs subpopulation 3, Fbs subpopulation 4, Fbs subpopulation 5, KCs, macrophages, SMCs, and T cells were respectively metastasis-associated lung adenocarcinoma transcript 1, fatty acid binding protein 4, Gremlin 1, complement component 4B, H19 imprinted maternally expressed transcript, Dickkopf Wnt signaling pathway inhibitor 2, fibromodulin, keratin 5, CD74 molecule, regulator of G protein signaling 5, and inducible T-cell co-stimulator molecule. KEGG and GO enrichment analysis revealed that, compared with those in control group, DEGs with significant differential expression (SDE) in CD34+ Fbs from the wound tissue of mice in diabetic group on PID 4 were significantly enriched in terms related to inflammatory response, extracellular matrix (ECM) organization, regulation of cell proliferation, and aging (with Pvalues all <0.05), DEGs with SDE in CD34+ SMCs were significantly enriched in terms related to cell migration, apoptotic process, positive regulation of transcription, and phagosome (with P values all <0.05), DEGs with SDE in CD34+ KCs were significantly enriched in terms related to mitochondrial function, transcription, and neurodegenerative diseases (with P values all <0.05), and DEGs with SDE in CD34+ CLCs were significantly enriched in terms related to rhythm regulation, ECM, and viral infection (with P values all <0.05). Conclusions: CD34+ cells display high heterogeneity in the healing process of full-thickness skin defect wounds in both normal mice and diabetic mice. The significantly enriched functions of DEGs with SDE in CD34+ cell subpopulations in the wound tissue of the two mouse groups are closely related to the wound healing process.

Fruit Intake and Alzheimer's Disease: Results from Mendelian Randomization

Alzheimer's disease (AD) is the leading cause of dementia in old age, recognized as a global health priority. To explore causal effects of fresh fruit intake and dried fruit intake on AD liability, this study utilized GWAS from the UK Biobank and FinnGen to conduct Mendelian randomization (MR) analysis, and used inverse variance weighted (IVW), MR-Egger, and weighted median approaches for MR estimates, and visual inspections judged result stability. Results suggested little evidence of a potential causal relationship between fresh fruit intake and AD (OR=0.97, 95%CI=0.50-1.91, P=0.939), while significant, robust causality was indicated between dried fruit intake and AD (OR=4.09, 95%CI=2.07-8.10, P<0.001). Stability evaluations showed no heterogeneity or pleiotropy affecting interpretability and credibility of primary analyses. In conclusion, we strengthened evidence for positive causality from dried fruit intake to AD liability, with causality from fresh fruit intake on AD risk was not demonstrated.

Bevacizumab for recurrent glioblastoma: a systematic review and meta-analysis

OBJECTIVE

The phenomenon is that few randomized control trials (RCTs) directly compared the effects of bevacizumab with other types of standard treatments for recurrent glioblastoma (GBM). We conducted a systematic review and meta-analysis to assess the efficacy of bevacizumab in recurrent GBM patients.

MATERIALS AND METHODS

We searched electronic databases (Medline, Embase, and Web of Science) contrasting the bevacizumab with standard treatments up to May 2021. For the continuous outcomes of median progression-free survival (PFS) and median overall survival (OS), we summarized the mean difference (MD) as the effective index. We used relative risk (RR) to estimate the data with a random-effects model to get the outcomes of objective response rate (ORR), 12-month OS, 6-month PFS, and any mentioned adverse events.

RESULTS

A total of 807 patients in 5 RCTs included into our systematic review and meta-analysis. The results showed bevacizumab could provide benefits of the ORR (RR, 2.67; 95% CI: 1.14-6.26, p = 0.02), median PFS (MD, 1.12 months; 95% CI: 0.35-1.90 months, p = 0.005), but not the median OS (MD, -0.19 months; 95% CI: -1.37-0.99 months, p = 0.75). Whereas the rates of the secondary outcomes of interest were similar between the bevacizumab group and control group, including 6 month-PFS (RR, 1.23; 95% CI, 0.82-1.84, p = 0.32) and 12 month-OS (RR, 0.93; 95% CI, 0.79-1.09, p = 0.36). As for adverse events, patients with bevacizumab showed higher rates of grade 3/4 and any grade hypertension compared with those with standard treatments (RR, 3.71; 95% CI: 1.17-11.76, p = 0.03; RR, 2.68; 95% CI: 1.26-5.76, p = 0.01, respectively).

CONCLUSIONS

This study provides clear proof of the beneficial effects of bevacizumab treatment in recurrent GBM patients. The only observed adverse event was grade 3/4 or any grade hypertension.

Correction to: CDK5 Regulates PD-L1 Expression and Cell Maturation in Dendritic Cells of CRSwNP

The article CDK5 Regulates PD-L1 Expression and Cell Maturation in Dendritic Cells of CRSwNP, written by C. C. Liu, H. L. Zhang, L. L. Zhi, P. Jin, L. Zhao, T. Li, X. M. Zhou, D. S. Sun, G. H. Cheng, Q. Xin, L. Shi, and M. Xia was originally published electronically on the publisher's internet.

Engineering the porosity and acidity of H-Beta zeolite by dealumination for the production of 2-ethylanthraquinone via 2-(4′-ethylbenzoyl)benzoic acid dehydration

Environmentally-friendly zeolites have been used commercially to replace concentrated sulfuric acid and oleum in the alkylation reactions and dehydration of alcohols. However, moderate activity, associated with access and diffusion limitations, low intramolecular dehydration selectivity, associated with unsatisfactory acidity, and unknown reusability have hampered their industrial implementation in the dehydration of bulky 2-(4′-ethylbenzoyl)benzoic acid (E-BBA) to 2-ethylanthraquinone (2-EAQ). Herein, we have discovered that after being treated with mild HNO₃, nano-sized H-Beta zeolite showed outstanding catalytic activity, selectivity and reusability, compared with a commercial oleum catalyst. A number of techniques, such as XRD, XPS, XRF, ²⁹Si MAS NMR, ²⁷Al MQ MAS NMR, FTIR, NH₃-TPD, argon physisorption and HR-TEM, have been employed to decouple the interdependence between acidity, porosity and catalytic performance. It was found that mild HNO₃ treatment could clean out the extra-framework aluminium deposits and selectively extract the aluminium species on the outer surface of Beta zeolites, which strengthened the acidity of the Brønsted acid sites (Si(OH)Al) inside the H-Beta micropores, thus increasing the possibility of intramolecular dehydration of E-BBA. Moreover, this mild HNO₃ treatment also dredged the network of intercrystalline mesopores, alleviating the diffusion constraints. Therefore, through the dual adjustment of acidity and porosity, dealuminated H-Beta zeolite has a promising future in the green synthesis of 2-EAQ.

Mild HNO₃ treated nano-sized H-Beta zeolite showed outstanding catalytic activity, selectivity and reusability, compared with a commercial oleum catalyst.

Gene-gene interactions of IRF5, STAT4, IKZF1 and ETS1 in systemic lupus erythematosus

Interferon (IFN) activation signaling and T helper 17 (Th17)-cell/B-cell regulation play a critical role in the pathogenesis of systemic lupus erythematosus (SLE). Several studies have provided convincing evidence that polymorphisms in IRF5, STAT4, IKZF1 and ETS1 from these pathways may be involved in SLE by affecting gene expression or epistasis. We analyzed the genetic interaction in known SLE susceptibility loci from the four genes in northern Han Chinese. A total of 946 northern Han Chinese participated in this study (370 unrelated SLE patients and 576 healthy controls). Subjects underwent genotyping for the single-nucleotide polymorphisms (SNPs) rs2004640 in IRF5, rs7574865 in STAT4, rs4917014 in IKZF1 and rs1128334 in ETS1 by use of a TaqMan SNP genotyping assay and direct sequencing. Gene-gene interaction analysis involved direct counting, multifactor dimensionality reduction (MDR) and linear regression analysis. SLE patients and controls differed in allele frequencies of rs7574865, rs1128334 (P < 0.001) and rs4917014 (P < 0.01). Direct counting revealed that the frequency of risk homozygote combinations was higher for SLE patients than controls (P < 0.01). Furthermore, 2-, 3- and 4-way gene-gene epistasis in SLE was confirmed by parametric methods and MDR analysis. Gene expression analysis partially supported the findings. Our study confirmed the association of the IFN pathway or Th17/B-cells and the pathogenesis of SLE, and gene-gene interaction in this pathway may increase the risk of SLE.

Perinatal exposure to low doses of tributyltin chloride advances puberty and affects patterns of estrous cyclicity in female mice

Tributyltin (TBT), a proven endocrine-disrupting chemical, is well known to induce imposex in female gastropods. Herein we demonstrate the effects of low doses of tributyltin chloride (TBTCl) on the female offspring of KM mice. Pregnant mice were administered by gavage with 0, 1, 10, or 100 μg TBTCl/kg body weight/day from day 6 of pregnancy through the period of lactation. TBTCl dramatically advanced the age of onset of vaginal opening (VO) and first vaginal estrus, and reduced body weights at VO and first estrus. Furthermore, perinatal treatment with TBTCl significantly reduced the number of days between VO and first estrus. In addition, female offspring from dams exposed to 10 and 100 μg kg(-1) TBTCl exhibited altered patterns of estrous cyclicity in adulthood. In conclusion, perinatal exposure to low doses TBTCl result in early puberty and impaired estrous cyclicity in female mice, which suggest that TBTCl might act as an estrogen agonist or/and a disruptor on hypothalamic-pituitary function in the present study.

Effects of perinatal exposure to low doses of tributyltin chloride on pregnancy outcome and postnatal development in mouse offspring

Tributyltin (TBT), an endocrine-disrupting chemical, is well known to induce imposex in female gastropods. In this study, we assessed the effects of low doses of tributyltin chloride (TBTCl) on dams and their offspring. Pregnant mice were administered by gavage with 0, 1, 10, or 100 μg TBTCl/kg body weight/day from day 6 of pregnancy through the period of lactation. There were no TBT treatment-related deaths or clinical signs of toxicity for dams, and no treatment-related effects on body weight, litter sizes, gestational length of dams, and sex ratio, lactational body weight, postnatal survival, age at eruption of incisors, and eye opening of pups. However, at 100 μg/kg, TBTCl retarded the testes descent of male offspring. Behavioral tests showed a significant delay in cliff-drop aversion response in offspring of 10 and 100 μg/kg groups, but no significant difference in the righting reflex between control and TBT-exposed offspring was detectable. These results indicate that neurobehavioral toxicity seems to be one sensitive indicator to assess the risk of low doses of TBT.

An intronic variant associated with systemic lupus erythematosus changes the binding affinity of Yinyang1 to downregulate WDFY4

Two recent genome-wide association studies of East Asian populations revealed three genetic variants in WDFY4/LRRC18 associated with systemic lupus erythematosus (SLE). To identify the gene contributing to this disease susceptibility, we examined the mRNA expression of WDFY4 and LRRC18 in patients with SLE and healthy controls. WDFY4 was significantly downregulated in SLE patients as compared with controls. We used allelic expression and dual-luciferase assays to identify the functional variant. Transcriptional activity was lower for the rs877819A than -G allele. Electrophoretic mobility shift and supershift assays revealed that the transcription factor Yinyang1 (YY1) binds to rs877819, with lower affinity to the A allele, which explained the reduced transcriptional activity. This effect was further confirmed by YY1 small interfering RNA knockdown, overexpression and chromatin immunoprecipitation experiments. rs877819 in WDFY4 might be the functional site associated with SLE by reduced binding of YY1 and downregulating WDFY4 expression.

Adipogenesis in ducks interfered by small interfering ribonucleic acids of peroxisome proliferator-activated receptor gamma gene

Peroxisome proliferator-activated receptor γ (PPARγ) participates in adipocyte differentiation and maintenance, including the promotion of lipid storage in mammals. In the present study, 3 duck PPARγ small interfering RNA (siRNA) expression plasmids were constructed to investigate the effect of downregulating the expression of PPARγ on adipogenesis and fat accumulation in ducks. The results indicate that the 3 siRNA specific for conserved regions of PPARγ can effectively inhibit expression of PPARγ. It was demonstrated that the expression of lipoprotein lipase and adipocyte fatty acid-binding protein in duck adipose tissue is repressed when the expression of PPARγ is downregulated by siRNA. At the same time, the weight of abdominal fat at 21 and 35 d of age is decreased significantly (P < 0.05) compared with the control. However, the triglyceride levels in serum and muscle are not affected when the mRNA of PPARγ is repressed. The current study indicates that the suppression of PPARγ reduces abdominal fat deposition and regulates adipogenesis in ducks.

Adsorption and oxidation of ethanol on colloid-based Pt/C, PtRu/C and Pt3Sn/C catalysts: In situ FTIR spectroscopy and on-line DEMS studies

The interaction of colloid-based, carbon supported Pt/C (40 wt%), PtRu/C (45 wt%) and Pt3Sn/C (24 wt%) catalysts with ethanol and their performance for ethanol electrooxidation were investigated in model studies by electrochemical, in situ infrared spectroscopy and on-line differential electrochemical mass spectrometry measurements. The combined application of in situ spectroscopic techniques on realistic catalysts and under realistic reaction (DEMS, IR) and transport conditions (DEMS) yields new insight on mechanistic details of the reaction on these catalysts under the above reaction and transport conditions. Based on these results, the addition of Sn or Ru, though beneficial for the overall activity for ethanol oxidation, does not enhance the activity for C-C bond breaking. Dissociative adsorption of ethanol to form CO2 is more facile on the Pt/C catalyst than on PtRu/C and Pt3Sn/C catalysts within the potential range of technical interests (<0.6 V), but Pt/C is rapidly blocked by an inhibiting CO adlayer. In all cases acetaldehyde and acetic acid are dominant products, CO2 formation contributes less than 2% to the total current. The higher ethanol oxidation current density on the Pt3Sn/C catalyst at these potentials results from higher yields of C2 products, not from an improved complete ethanol oxidation to CO2.

Simultaneous detection of catecholamine exocytosis and Ca2+ release from single bovine chromaffin cells using a dual microsensor

A dual microsensor with a 5 microns radius was fabricated to detect simultaneously Ca2+ and catecholamines following their secretion from individual biological cells. Detection of Ca2+ was based on changes in fluorescence as a result of its binding with a surface-attached dye, and catecholamines were detected by amperometry. The fluorescent dye employed, calcium green-1 dextran, is a selective chelator for Ca2+. It was attached to the tip of a carbon fiber electrode by cross-linking with 5% glutaraldehyde. The dual microsensor has a subsecond response time for both Ca2+ and catecholamine concentration changes. Ca2+ concentrations of 100 nM can be detected, while the detection limit for catecholamine is in the micromolar range. The utility of the dual microsensor was evaluated at the surface of bovine adrenal medullary cells. Release of catecholamines by exocytosis was evoked by transient application of histamine. This was detected by amperometry, and it was found to be accompanied by Ca2+ release, as measured by fluorescence from the same sensor.

Transport of choline in rat brain slices

Enzyme-modified amperometric microsensors have been utilized in the investigation of acetylcholine and choline diffusion in solution and choline uptake and diffusion in rat brains. A small amount of the substance of interest was introduced by pressure injection and transport to the sensor was monitored. The apparent diffusion coefficients for acetylcholine and choline in agarose gel perfused with physiological solutions were determined to be 5.2 +/- 0.7 x 10(-6) cm2/s and 6.1 +/- 0.8 x 10(-6) cm2/s, respectively. Choline transport was monitored in two brain regions: the caudate and anterior hypothalamus. The transport time of choline in the caudate was concentration dependent, but was unaffected by the presence of a competitive, high-affinity uptake inhibitor, hemicholinium-3. The apparent diffusion coefficient (D) and uptake rate (k) for choline in the caudate and anterior hypothalamus were calculated using a model for point source diffusion coupled with first-order uptake kinetics. The effect of the sensors' response time on the measurements was removed by deconvolution. The D and k were 1.8 +/- 0.1 x 10(-6) cm2/s and 2.0 +/- 0.1 x 10(-2) s-1 in the caudate and 1.9 +/- 0.1 x 10(-6) cm2/s and 3.2 +/- 0.6 x 10(-2) s-1 in the anterior hypothalamus. The reduced diffusion coefficient determined in brain tissue compared to agar gel is consistent with the increased tortuosity of the brain microenvironment. A substance in brain tissue, presumably acetylcholinesterase, prevents the use of differential measurements of acetylcholine because choline sensors became sensitive to acetylcholine.

[Clinical characteristics of silent myocardial ischemia and the effect of nifedipine treatment]

The characteristics of ischemic episodes in exercise test and daily activities were observed in a silent myocardial ischemia (SMI) group and an anginal group (23 patients each). 15 patients in the SMI group were treated with nifedipine. In exercise test, the time of onset of ischemia was earlier and the ischemic threshold was lower in SMI group. During daily activities, the frequency of SMI was high. The heart rate just before onset of SMI was lower than the mean heart rate in 24-hour Holter monitoring. The highest frequency of SMI was found between 5 AM and 12 noon. Postinfarction patients had a higher frequency and a longer duration of SMI than noninfarction patients. The frequency and duration of SMI decreased in the 15 patients treated with nifedipine in SMI group. It is concluded that silent ischemic episodes were frequent and occurred easily. They might be associated with poor prognosis in CAD patients. Nifedipine was effective in reducing the frequency and duration of SMI in our patients.