Design and synthesis of 1H-benzo[d]imidazole selective HDAC6 inhibitors with potential therapy for multiple myeloma.

Pan-HDAC inhibitors exhibit significant inhibitory activity against multiple myeloma, however, their clinical applications have been hampered by substantial toxic side effects. In contrast, selective HDAC6 inhibitors have demonstrated effectiveness in treating multiple myeloma. Compounds belonging to the class of 1H-benzo[d]imidazole hydroxamic acids have been identified as novel HDAC6 inhibitors, with the benzimidazole group serving as a specific linker for these inhibitors. Notably, compound 30 has exhibited outstanding HDAC6 inhibitory activity (IC50 = 4.63 nM) and superior antiproliferative effects against human multiple myeloma cells, specifically RPMI-8226. Moreover, it has been shown to induce cell cycle arrest in the G2 phase and promote apoptosis through the mitochondrial pathway. In a myeloma RPMI-8226 xenograft model, compound 30 has demonstrated significant in vivo antitumor efficacy (T/C = 34.8%) when administered as a standalone drug, with no observable cytotoxicity. These findings underscore the immense potential of compound 30 as a promising therapeutic agent for the treatment of multiple myeloma.

Anoikis-related gene signatures can aid prognosis of lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer, and while advancements in diagnosis, surgery, radiotherapy, and molecular therapy have improved clinical prognosis, the long-term survival rate and quality of life of patients remain unsatisfactory. Therefore, identifying new prognostic biomarkers and potential therapeutic targets is crucial. OBJECTIVES: This study aimed to analyze the role of anoikis-related gene characteristics in LUAD. MATERIAL AND METHODS: The anoikis-related genes were obtained from the GeneCards database. Genetic expression data and clinical characteristic information were collected from The Cancer Genome Atlas (TCGA)-LUAD, and the Gene Expression Omnibus (GEO) GSE31210, GSE37745, and GSE68465 datasets. Random survival forest and least absolute shrinkage and selection operator (LASSO) models were applied to construct the risk model. An analysis of immune cell infiltration and function was performed with the scores. RESULTS: Four prognosis-related genes (TLE1, GLI2, PLK1, and BAK1) were obtained and used to construct the anoikis score. We found that the patient survival rate was higher in the low-anoikis score (LAS) group. Moreover, both the stromal and immune scores were negatively correlated with the anoikis score. With the increase of the anoikis score, the levels of natural killer cells, regulatory T cells, CD4+ T cells, CD8+ T cells, B cells, and macrophages decreased. The anoikis score had a negative regulatory relationship with the immune response, natural killer cell activation and T cell activation. The TP53 mutation was significant in LUAD patients and was present in 56% of the high-anoikis score (HAS) group and in 40% of the LAS group. CONCLUSIONS: The anoikis score was associated with poor prognosis in LUAD patients. Anoikis-related genes were associated with tumor immune dysregulation and TP53 mutation in LUAD. This study opens a new perspective for LUAD therapy.

The impact of neighborhood mental health on the mental health of older adults.

BACKGROUND: In this article, we use cross-sectional data obtained from the 2018 China Health and Aging Tracking Survey (CHARLS) to examine the impact of neighborhood mental health at the community level on the mental health of older adults aged 60 years and older. METHODS: NMH is the average mental health of older adults in the same community, excluding the older adults themselves. The explained variable mental health in this paper was measured using the simple CES-D depression scale. The mediating variables were social connectedness, social participation and social inclusion, and the instrumental variables were physical exercise and amusement. regression analysis was conducted using OLS regression models, two-stage least squares (IV-2SLS) instrumental variables to address the two-way causality of NMH and MH, and KHB decomposition was used to investigate the effect mechanism. RESULTS: Baseline regressions showed that the neighborhood mental health effect positively influenced the mental health of older adults (Coef. = 0.356, 95% CI 0.315,0.397). The neighborhood mental health effect estimated by IV-2SLS (Coef. = 0.251, 95% CI 0.096,0.405) was higher than the OLS regression, indicating endogeneity. The mediated effects of KHB showed total (Coef. = 0.356, 95% CI 0.314,0.398), direct (Coef. = 0.281, 95% CI 0.232,0.330), and indirect effects (Coef. = 0.075, 95% CI 0.049,0.101). While the total effect was 1.266 times higher than the direct effect, 21.03% of the total effect came from mediating variables. CONCLUSIONS: First, the neighborhood mental health effect has a positive impact on the mental health of older adults, but there are heterogeneous differences based on gender, age, and place of residence. Second, the results of the IV-2SLS estimation showed that the effect of the neighborhood mental health effect was underestimated if endogenous problems were not controlled for. Third, the effect of neighborhood mental health on older adults' mental health was tested to be stable. Moreover, social connectedness, social participation, and social interaction are important mediating mechanisms for the effect of neighborhood mental health on older adults' mental health. This study provides new perspectives and ideas for an in-depth understanding of the mental health of older adults in the context of social transformation in China.

Filamin A is overexpressed in non-alcoholic steatohepatitis and contributes to the progression of inflammation and fibrosis.

Non-alcoholic steatohepatitis (NASH) is a chronic and progressive liver disease characterized by steatosis, inflammation, and fibrosis. Filamin A (FLNA), an actin-binding protein, is involved in various cell functions, including the regulation of immune cells and fibroblasts. However, its role in the development of NASH through inflammation and fibrogenesis is not fully understood. In this study, we found that FLNA expression was increased in liver tissues of patients with cirrhosis and mice with non-alcoholic fatty liver disease (NAFLD)/NASH and fibrosis. Immunofluorescence analysis showed that FLNA was primarily expressed in macrophages and hepatic stellate cells (HSCs). Knocking down of FLNA by specific shRNA in phorbol-12-myristate-13-acetate (PMA)-derived THP-1 macrophages reduced lipopolysaccharide (LPS)-stimulated inflammatory response. The decreased mRNA levels of inflammatory cytokines and chemokines and suppression of the STAT3 signaling were observed in FLNA-downregulated macrophages. In addition, knockdown of FLNA in immortalized human hepatic stellate cells (LX-2 cells) resulted in decreased mRNA levels of fibrotic cytokines and enzymes involved in collagen synthesis, as well as increased levels of metalloproteinases and pro-apoptotic proteins. Overall, these results suggest that FLNA may contribute to the pathogenesis of NASH through its role in the regulation of inflammatory and fibrotic mediators.

Effect of noise on hearing loss among workers in a fastener manufacturing enterprise / 预防医学

Objective @#To investigate the current status of hearing loss in a fastener manufacturing enterprise, and to analyze its influencing factors, so as to provide insights into occupational disease prevention and control. @*Methods@#The occupational health examination data of noise exposed workers and the workplace occupational disease hazard factors detection data in a fastener manufacturing enterprise in Jiaxing City in 2022 were collected through the Occupational Disease and Occupational Health Hazard Factors Detection System of China Disease Prevention and Control Information System, and factors affecting the development of high-frequency noise-induced hearing loss (HFNIHL) and speech-frequency noise-induced hearing loss (SFNIHL) were analyzed. @*Results@#Totally 625 workers were investigated, with a median age of 44.00 (interquartile range, 13.00) years and a median length of service of 8.00 (interquartile range, 9.00) years, and including 519 men (83.04%) and 106 women (16.96%). There were 309 workers with single noise exposure (49.44%) and 316 workers with joint noise exposure (50.56%), and 518 workers exposed to noise with the normalized continuous A-weighted sound pressure level equivalent to a 40 h working week (LEX,40 h) that exceeded the national standard (82.88%). The detection rates of HFNIHL and SFNIHL were 49.12% and 35.04%, respectively. Multivariable logistic regression analysis indicated that males (OR=10.528, 95%CI: 5.271-21.025), length of service of 10 years and longer (OR=2.451, 95%CI: 1.599-3.759), LEX,40 h of >85 dB (A) (OR=2.227, 95%CI: 1.318-3.764) and joint noise exposure (OR=3.002, 95%CI: 2.080-4.334) were associated with an increased risk of HFNIHL, and male (OR=9.400, 95%CI: 4.211-20.985), LEX,40 h of >85 dB (A) (OR=2.305, 95%CI: 1.345-3.951), and joint noise exposure (OR=3.880, 95%CI: 2.677-5.623) were associated with an increased risk of SFNIHL.@*Conclusion@#Gender, length of service, noise intensity and exposure mode are factors affecting the risk of HFNIHL, while gender, noise intensity and exposure mode are factors affecting the risk of SFNIHL.

Design and synthesis of highly TRAIL expression HDAC inhibitors based on ONC201 to promote apoptosis of colorectal cancer.

Activation of the TRAIL proapoptotic pathway can promote cancer cell apoptosis. Histone deacetylases (HDACs) also are promising drug targets for cancers, and their synergistic effect with TRAIL can improve the inhibitory effect on cancer cells. Therefore, the development of highly TRAIL-sensitive HDAC inhibitors might be a promising strategy for the treatment of cancers. We synthesized a series of HDAC inhibitors by introducing effective fragments sensitive to TRAIL. Compound IIc showed good inhibitory activity against HDAC1 and HCT116 cells and showed higher sensitivity to activating the expression of the TRAIL protein and promoting the apoptosis of HCT-116 cells compared with ONC201. The inhibitory activity of compound IIc (25 mg/kg) in the HCT-116 xenograft model was significantly greater than those of the positive control drugs (ONC201, chidamide). These findings suggested that development of highly TRAIL-sensitive HDAC inhibitors as colorectal tumor cancer drugs.

Design and synthesis of dual inhibitors targeting snail and histone deacetylase for the treatment of solid tumour cancer.

Snail and histone deacetylases (HDACs) have an important impact on cancer treatment, especially for their synergy. Therefore, the development of inhibitors targeting both Snail and HDAC might be a promising strategy for the treatment of cancers. In this work, we synthesized a series of Snail/HDAC dual inhibitors. Compound 9n displayed the most potent inhibitory activity against HDAC1 with an IC50 of 0.405 µM, potent inhibition against Snail with a Kd of 0.180 µM, and antiproliferative activity in HCT-116 cell lines with an IC50 of 0.0751 µM. Compound 9n showed a good inhibitory effect on NCI-H522 (GI50 = 0.0488 µM), MDA-MB-435 (GI50 = 0.0361 µM), and MCF7 (GI50 = 0.0518 µM). Docking studies showed that compound 9n can be well docked into the active binding sites of Snail and HDAC. Further studies showed that compound 9n increased histone H4 acetylation in HCT-116 cells and decreased the expression of Snail protein to induce cell apoptosis. These findings highlight the potential for the development of Snail/HDAC dual inhibitors as anti-solid tumour cancer drugs.

The Chromosome Microdissection and Microcloning Technique.

Chromosome microdissection followed by microcloning is an efficient tool combining cytogenetics and molecular genetics that can be used for the construction of the high density molecular marker linkage map and fine physical map, the generation of probes for chromosome painting, and the localization and cloning of important genes. Here, we describe a modified technique to microdissect a single chromosome, paint individual chromosomes, and construct single-chromosome DNA libraries.

Genes encoding Δ(8)-sphingolipid desaturase from various plants: identification, biochemical functions, and evolution.

∆(8)-sphingolipid desaturase catalyzes the C8 desaturation of a long chain base, which is the characteristic structure of various complex sphingolipids. The genes of 20 ∆(8)-sphingolipid desaturases from 12 plants were identified and functionally detected by using Saccharomyces cerevisiae system to elucidate the relationship between the biochemical function and evolution of this enzyme. Results showed that the 20 genes all can encode a functional ∆(8)-sphingolipid desaturase, which catalyzes different ratios of two products, namely, 8(Z) and 8(E)-C18-phytosphingenine. The coded enzymes could be divided into two groups on the basis of biochemical functions: ∆(8)-sphingolipid desaturase with a preference for an E-isomer product and ∆(8)-sphingolipid desaturase with a preference for a Z-isomer product. The conversion rate of the latter was generally lower than that of the former. Phylogenetic analysis revealed that the 20 desaturases could also be clustered into two groups, and this grouping is consistent with that of the biochemical functions. Thus, the biochemical function of ∆(8)-sphingolipid desaturase is correlated with its evolution. The two groups of ∆(8)-sphingolipid desaturases could arise from distinct ancestors in higher plants. However, they might have initially evolved from ∆(8)-sphingolipid desaturases in lower organisms, such as yeasts, which can produce E-isomer products only. Furthermore, almost all of the transgenic yeasts harboring ∆(8)-sphingolipid desaturase genes exhibit an improvement in aluminum tolerance. Our study provided new insights into the biochemical function and evolution of ∆(8)-sphingolipid desaturases in plants.

Identification of the substrate recognition region in the Δ6-fatty acid and Δ8-sphingolipid desaturase by fusion mutagenesis.

Δ8-sphingolipid desaturase and Δ6-fatty acid desaturase share high protein sequence identity. Thus, it has been hypothesized that Δ6-fatty acid desaturase is derived from Δ8-sphingolipid desaturase; however, there is no direct proof. The substrate recognition regions of Δ6-fatty acid desaturase and Δ8-sphingolipid desaturase, which aid in understanding the evolution of these two enzymes, have not been reported. A blackcurrant Δ6-fatty acid desaturase and a Δ8-sphingolipid desaturase gene, RnD6C and RnD8A, respectively, share more than 80 % identity in their coding protein sequences. In this study, a set of fusion genes of RnD6C and RnD8A were constructed and expressed in yeast. The Δ6- and Δ8-desaturase activities of the fusion proteins were characterized. Our results indicated that (1) the exchange of the C-terminal 172 amino acid residues can lead to a significant decrease in both desaturase activities; (2) amino acid residues 114-174, 206-257, and 258-276 played important roles in Δ6-substrate recognition, and the last two regions were crucial for Δ8-substrate recognition; and (3) amino acid residues 114-276 of Δ6-fatty acid desaturase contained the substrate recognition site(s) responsible for discrimination between ceramide (a substrate of Δ8-sphingolipid desaturase) and acyl-PC (a substrate of Δ6-fatty acid desaturase). Substituting the amino acid residues 114-276 of RnD8A with those of RnD6C resulted in a gain of Δ6-desaturase activity in the fusion protein but a loss in Δ8-sphingolipid desaturase activity. In conclusion, several regions important for the substrate recognition of Δ8-sphingolipid desaturase and Δ6-fatty acid desaturase were identified, which provide clues in understanding the relationship between the structure and function in desaturases.

A new strategy to produce a defensin: stable production of mutated NP-1 in nitrate reductase-deficient Chlorella ellipsoidea.

Defensins are small cationic peptides that could be used as the potential substitute for antibiotics. However, there is no efficient method for producing defensins. In this study, we developed a new strategy to produce defensin in nitrate reductase (NR)-deficient C. ellipsoidea (nrm-4). We constructed a plant expression vector carrying mutated NP-1 gene (mNP-1), a mature α-defensin NP-1 gene from rabbit with an additional initiator codon in the 5'-terminus, in which the selection markers were NptII and NR genes. We transferred mNP-1 into nrm-4 using electroporation and obtained many transgenic lines with high efficiency under selection chemicals G418 and NaNO(3). The mNP-1 was characterized using N-terminal sequencing after being isolated from transgenic lines. Excitingly, mNP-1 was produced at high levels (approximately 11.42 mg/l) even after 15 generations of continuous fermentation. In addition, mNP-1 had strong activity against Escherichia coli at 5 µg/ml. This research developed a new method for producing defensins using genetic engineering.

The role of C-terminal amino acid residues of a Δ6-fatty acid desaturase from blackcurrant.

Δ6-fatty acid desaturase is an important enzyme in the catalytic synthesis of polyunsaturated fatty acids. Using domain swapping and a site-directed mutagenesis strategy, we found that the region of the C-terminal 67 amino acid residues of Δ6-fatty acid desaturase RnD6C from blackcurrant was essential for its catalytic activity and that seven different residues between RnD6C and RnD8A in that region were involved in the desaturase activity. Compared with RnD6C, the activity of the following mutations, V394A, K395I, F411L, S436P, VK3945AI and IS4356VP, was significantly decreased, whereas the activity of I417T was significantly increased. The amino acids N, T and Y in the last four residues also play a certain role in the desaturase activity.

Isolation and functional characterisation of the genes encoding Δ(8)-sphingolipid desaturase from Brassica rapa.

Δ(8)-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding Δ(8)-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding Δ(8)-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups: BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse Δ(8)-sphingolipid desaturases that catalyse different ratios of the two products 8(Z)- and 8(E)-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8(Z):8(E)-C18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of Δ(8)-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8(Z)- and 8(E)-C18-phytosphingenine biosynthesis.

An ATP signalling pathway in plant cells: extracellular ATP triggers programmed cell death in Populus euphratica.

We elucidated the extracellular ATP (eATP) signalling cascade active in programmed cell death (PCD) using cell cultures of Populus euphratica. Millimolar amounts of eATP induced a dose- and time-dependent reduction in viability, and the agonist-treated cells displayed hallmark features of PCD. eATP caused an elevation of cytosolic Ca(2+) levels, resulting in Ca(2+) uptake by the mitochondria and subsequent H(2) O(2) accumulation. P. euphratica exhibited an increased mitochondrial transmembrane potential, and cytochrome c was released without opening of the permeability transition pore over the period of ATP stimulation. Moreover, the eATP-induced increase of intracellular ATP, essential for the activation of caspase-like proteases and subsequent PCD, was found to be related to increased mitochondrial transmembrane potential. NO is implicated as a downstream component of the cytosolic Ca(2+) concentration but plays a negligible role in eATP-stimulated cell death. We speculate that ATP binds purinoceptors in the plasma membrane, leading to the induction of downstream intermediate signals, as the proposed sequence of events in PCD signalling was terminated by the animal P2 receptor antagonist suramin.

Enhanced tolerance to NaCl and LiCl stresses by over-expressing Caragana korshinskii sodium/proton exchanger 1 (CkNHX1) and the hydrophilic C terminus is required for the activity of CkNHX1 in Atsos3-1 mutant and yeast.

Sodium/proton exchangers (NHX antiporters) play important roles in plant responses to salt stress. Previous research showed that hydrophilic C-terminal region of Arabidopsis AtNHX1 negatively regulates the Na(+)/H(+) transporting activity. In this study, CkNHX1 were isolated from Caragana korshinskii, a pea shrub with high tolerance to salt, drought, and cold stresses. Transcripts of CkNHX1 were detected predominantly in roots, and were significantly induced by NaCl stress in stems. Transgenic yeast and Arabidopsisthalianasos3-1 (Atsos3-1) mutant over-expressing CkNHX1 and its hydrophilic C terminus-truncated derivative, CkNHX1-ΔC, were generated and subjected to NaCl and LiCl stresses. Expression of CkNHX1 significantly enhanced the resistance to NaCl and LiCl stresses in yeast and Atsos3-1 mutant. Whereas, compared with expression of CkNHX1, the expression of CkNHX1-ΔC had much less effect on NaCl tolerance in Atsos3-1 and LiCl tolerance in yeast and Atsos3-1. All together, these results suggest that the predominant expression of CkNHX1 in roots might contribute to keep C. korshinskii adapting to the high salt condition in this plant's living environment; CkNHX1 could recover the phenotype of Atsos3-1 mutant; and the hydrophilic C-terminal region of CkNHX1 should be required for Na(+)/H(+) and Li(+)/H(+) exchanging activity of CkNHX1.

Newly identified essential amino acid residues affecting Δ8-sphingolipid desaturase activity revealed by site-directed mutagenesis.

In order to identify amino acid residues crucial for the enzymatic activity of Δ(8)-sphingolipid desaturases, a sequence comparison was performed among Δ(8)-sphingolipid desaturases and Δ(6)-fatty acid desaturases from various plants. In addition to the known conserved cytb(5) (cytochrome b(5)) HPGG motif and three conserved histidine boxes, they share additional 15 completely conserved residues. A series of site-directed mutants were generated using our previously isolated Δ(8)-sphingolipid desaturase gene from Brassica rapa to evaluate the importance of these residues to the enzyme function. The mutants were functionally characterized by heterologous expression in yeast, allowing the identification of the products of the enzymes. The results revealed that residues H63, N203, D208, D210, and G368 were obligatorily required for the enzymatic activity, and substitution of the residues F59, W190, W345, L369 and Q372 markedly decreased the enzyme activity. Among them, replacement of the residues W190, L369 and Q372 also has significant influence on the ratio of the two enzyme products. Information obtained in this work provides the molecular basis for the Δ(8)-sphingolipid desaturase activity and aids in our understanding of the structure-function relationships of the membrane-bound desaturases.

Genes encoding the biotin carboxylase subunit of acetyl-CoA carboxylase from Brassica napus and parental species: cloning, expression patterns, and evolution.

Comparative genomics is a useful tool to investigate gene and genome evolution. Biotin carboxylase (BC), an important subunit of heteromeric acetyl-CoA carboxylase (ACCase) that is a rate-limiting enzyme in fatty acid biosynthesis in dicots, catalyzes ATP, biotin carboxyl carrier protein, and CO2 to form carboxybiotin carboxyl carrier protein. In this study, we cloned four genes encoding BC from Brassica napus L. (namely BnaC.BC.a, BnaC.BC.b, BnaA.BC.a, and BnaA.BC.b), and two were cloned from each of the two parental species Brassica rapa L. (BraA.BC.a and BraA.BC.b) and Brassica oleracea L. (BolC.BC.a and BolC.BC.b). Sequence analyses revealed that in B. napus the genes BnaC.BC.a and BnaC.BC.b were from the C genome of B. oleracea, whereas BnaA.BC.a and BnaA.BC.b were from the A genome of B. rapa. Comparative and cluster analysis indicated that these genes were divided into two major groups, BnaC.BC.a, BnaA.BC.a, BraA.BC.a, and BolC.BC.a in group-1 and BnaC.BC.b, BnaA.BC.b, BraA.BC.b, and BolC.BC.b in group-2. The divergence of group-1 and group-2 genes occurred in their common ancestor 13-17 million years ago (MYA), soon after the divergence of Arabidopsis and Brassica (15-20 MYA). This time of divergence is identical to the previously reported triplicated time of paralogous subgenomes of diploid Brassica species and the divergence date of group-1 and group-2 genes of α-carboxyltransferase, another subunit of heteromeric ACCase, in Brassica. Reverse transcription PCR revealed that the expression level of group-1 and group-2 genes varied in different organs, and the expression patterns of the two groups of genes were similar in different organs, except in flower. However, two paralogs of group-2 BC genes from B. napus could express differently in mature plants tested by generating BnaA.BC.b and BnaC.BC.b promoter-ß-glucuronidase (GUS) fusions. The amino acid sequences of proteins encoded by these genes were highly conserved, except the sequence encoding predicted plastid transit peptides. The plastid transit peptides on the BC precursors of Brassica (71-72 amino acid residues) were predicted based on AtBC protein, compared, and confirmed by fusion with green fluorescent protein. Our results will be helpful in elucidating the evolution and the regulation of ACCase in the genus Brassica.