Radiata pine bark is a widely available organic waste, requiring alternative uses due to its environmental impact on soil, fauna, and forest fires. Pine bark waxes could be used as cosmetic ...substitutes, but their toxicity requires evaluation since pine bark may contain toxic substances or xenobiotics, depending on the extraction process. This study evaluates the toxicity of radiata pine bark waxes obtained through various extraction methods on human skin cells grown in vitro. The assessment includes using XTT to evaluate mitochondrial activity, violet crystal dye to assess cell membrane integrity, and ApoTox-Glo triple assay to measure cytotoxicity, viability, and apoptosis signals. Pine bark waxes extracted via T3 (acid hydrolysis and petroleum ether incubation) and T9 (saturated steam cycle, alkaline hydrolysis, and petroleum ether incubation) exhibit non-toxicity up to 2% concentration, making them a potential substitute for petroleum-based cosmetic materials. Integrating the forestry and cosmetic industries through pine bark wax production under circular economy principles could promote development while replacing petroleum-based materials. Extraction methodology affects pine bark wax toxicity in human skin cells due to the retention of xenobiotic compounds including methyl 4-ketohex-5-enoate; 1-naphthalenol; dioctyl adipate; eicosanebioic acid dimethyl ester; among others. Future research will investigate whether the extraction methodology alters the molecular structure of the bark, affecting the release of toxic compounds in the wax mixture.
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SALL2 is a poorly characterized transcription factor that belongs to the Spalt‐like family involved in development. Mutations on SALL2 have been associated with ocular coloboma and cancer. In ...cancers, SALL2 is deregulated and is proposed as a tumor suppressor in ovarian cancer. SALL2 has been implicated in stemness, cell death, proliferation, and quiescence. However, mechanisms underlying roles of SALL2 related to cancer remain largely unknown. Here, we investigated the role of SALL2 in cell proliferation using mouse embryo fibroblasts (MEFs) derived from Sall2−/− mice. Compared to Sall2+/+ MEFs, Sall2−/− MEFs exhibit enhanced cell proliferation and faster postmitotic progression through G1 and S phases. Accordingly, Sall2−/− MEFs exhibit higher mRNA and protein levels of cyclins D1 and E1. Chromatin immunoprecipitation and promoter reporter assays showed that SALL2 binds and represses CCND1 and CCNE1 promoters, identifying a novel mechanism by which SALL2 may control cell cycle. In addition, the analysis of tissues from Sall2+/+ and Sall2−/− mice confirmed the inverse correlation between expression of SALL2 and G1‐S cyclins. Consistent with an antiproliferative function of SALL2, immortalized Sall2−/− MEFs showed enhanced growth rate, foci formation, and anchorage‐independent growth, confirming tumor suppressor properties for SALL2. Finally, cancer data analyses show negative correlations between SALL2 and G1‐S cyclins’ mRNA levels in several cancers. Altogether, our results demonstrated that SALL2 is a negative regulator of cell proliferation, an effect mediated in part by repression of G1‐S cyclins’ expression. Our results have implications for the understanding and significance of SALL2 role under physiological and pathological conditions.
SALL2 inhibits cell proliferation by repressing G1‐to S‐phase cell cycle transition. This effect of SALL2 is associated with the transcriptional repression of cyclins D1 and E1.
SALL2/Sall2 is a transcription factor associated with development, neuronal differentiation, and cancer. Interestingly,
SALL2/Sall2
deficiency leads to failure of the optic fissure closure and ...neurite outgrowth, suggesting a positive role for SALL2/Sall2 in cell migration. However, in some cancer cells,
SALL2
deficiency is associated with increased cell migration. To further investigate the role of Sall2 in the cell migration process, we used immortalized
Sall2
knockout (
Sall2
−/−
) and
Sall2
wild-type (
Sall2
+/+
) mouse embryonic fibroblasts (iMEFs). Our results indicated that Sall2 positively regulates cell migration, promoting cell detachment and focal adhesions turnover.
Sall2
deficiency decreased cell motility and altered focal adhesion dynamics. Accordingly, restoring Sall2 expression in the
Sall2
−/−
iMEFs by using a doxycycline-inducible Tet-On system recovered cell migratory capabilities and focal adhesion dynamics. In addition, Sall2 promoted the autophosphorylation of Focal Adhesion Kinase (FAK) at Y397 and increased integrin β1 mRNA and its protein expression at the cell surface. We demonstrated that SALL2 increases
ITGB1
promoter activity and binds to conserved SALL2-binding sites at the proximal region of the
ITGB1
promoter, validated by ChIP experiments. Furthermore, the overexpression of integrin β1 or its blockade generates a cell migration phenotype similar to that of
Sall2
+/+
or
Sall2
−/−
cells, respectively. Altogether, our data showed that Sall2 promotes cell migration by modulating focal adhesion dynamics, and this phenotype is associated with SALL2/Sall2-transcriptional regulation of integrin β1 expression and FAK autophosphorylation. Since deregulation of cell migration promotes congenital abnormalities, tumor formation, and spread to other tissues, our findings suggest that the SALL2/Sall2-integrin β1 axis could be relevant for those processes.
SALL2 is a transcription factor involved in development and disease. Deregulation of SALL2 has been associated with cancer, suggesting that it plays a role in the disease. However, how SALL2 is ...regulated and why is deregulated in cancer remain poorly understood. We previously showed that the p53 tumor suppressor represses SALL2 under acute genotoxic stress. Here, we investigated the effect of Histone Deacetylase Inhibitor (HDACi) Trichostatin A (TSA), and involvement of Sp1 on expression and function of SALL2 in Jurkat T cells. We show that SALL2 mRNA and protein levels were enhanced under TSA treatment. Both, TSA and ectopic expression of Sp1 transactivated the SALL2 P2 promoter. This transactivation effect was blocked by the Sp1-binding inhibitor mithramycin A. Sp1 bound in vitro and in vivo to the proximal region of the P2 promoter. TSA induced Sp1 binding to the P2 promoter, which correlated with dynamic changes on H4 acetylation and concomitant recruitment of p300 or HDAC1 in a mutually exclusive manner. Our results suggest that TSA-induced Sp1-Lys703 acetylation contributes to the transcriptional activation of the P2 promoter. Finally, using a CRISPR/Cas9 SALL2-KO Jurkat-T cell model and gain of function experiments, we demonstrated that SALL2 upregulation is required for TSA-mediated cell death. Thus, our study identified Sp1 as a novel transcriptional regulator of SALL2, and proposes a novel epigenetic mechanism for SALL2 regulation in Jurkat-T cells. Altogether, our data support SALL2 function as a tumor suppressor, and SALL2 involvement in cell death response to HDACi.
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•In Jurkat T cells, SALL2 gene is regulated by an epigenetic mechanism that involves p300, HDAC1 and Sp1.•Sp1 directly binds to proximal regions of SALL2-P2 promoter, and its binding increased by Trichostatin A treatment.•TSA and other FDA-approved HDACi upregulate SALL2 expression in Jurkat T cells.•SALL2 is required for the cell death response to TSA treatment in Jurkat T cells.
Diverse factors play roles in chromatin dynamics, including linker proteins. Among them are high mobility group (HMG) box family proteins and linker histones. In the yeast Saccharomyces cerevisiae, ...Hmo1 has been identified as an HMG-box protein. This protein displays properties that are in agreement with this allocation. However, a number of studies have postulated that Hmo1 functions as a linker histone in yeast. On the other hand, when discovered, the Hho1 protein was identified as a linker histone. While multiple studies support this classification, some findings point to characteristics of Hho1 that are dissimilar to those commonly assigned to linker histones. In order to better understand the roles played by Hmo1 and Hho1 in chromatin dynamics and transcriptional regulation, we performed several analyses directly comparing these two proteins. Our analyses of genome-wide binding profiles support the belonging of Hmo1 to the HMGB family and Hho1 to the linker histones family. Interestingly, by performing protein-protein interaction analyses we found that both Hmo1 and Hho1 display physical interaction with the ATP-dependent chromatin remodeling complexes RSC, ISW1a and SWI/SNF. Moreover, by carrying out nucleosome remodeling assays, we found that both proteins stimulate the activity of the ISW1a complex. However, in the case of RSC, Hmo1 and Hho1 displayed differential properties, with Hho1 mainly showing an inhibitory effect. Our results are in agreement with the opposite roles played by RSC and ISW1a in chromatin dynamics and transcriptional regulation, and expand the view for the roles played by Hho1 and linker histones.
•New properties found for Hmo1 are consistent with those present in HMG proteins.•Hho1 physically interacts with the nucleosome remodeling complexes RSC and ISW1a.•Hho1 stimulates ATP-dependent nucleosome remodeling activity of the ISW1a complex.•Hho1 exerts a differential effect on RSC and ISW1a remodeling activities.•The properties displayed by Hmo1 and Hho1 point to opposite or different roles.
•Were tested different conditions of extraction of lipophilic fractions from the bark of Pinus radiata D. Don.•The extracts were physicochemically characterized by standardized protocols, gas ...chromatography and infrared spectrometry.•The results revealed that the use of different solvents and process, influence extractive yield.•Physicochemical characteristics are like mineral oil, proposing a potential replacement for this hydrocarbon from a renewable source.
The bark of Pinus radiata D. Don is a bioresource of great worldwide abundance. While various forms of use have been studied, it is still a little-used bioresource. Due to its great accumulation, significant solid emissions of this residue generate environmental problems such as changes in soil chemistry, ecological problems such as the alteration of arthropod communities and fire risk. The opportunity to take advantage of this bioresource could be in its wax content, which could be a replacement for the main raw materials used in the production of cosmetics. These currently correspond to petroleum-derived substances, such as petroleum jelly, paraffin, or mineral oil. The importance of replacing these raw materials is that several studies report that they are the main causes of human skin diseases, such as chemical hypersensitivity syndrome and allergic contact dermatitis. This study seeks to prove that lipophilic extracts (waxes) from pine bark can replace petroleum-derived raw materials used in cosmetics. To achieve this, pine bark at drying conditions was characterized, and the performance of wax extraction by various treatments was studied. The density, viscosity, melting point, and solubility in culture media of the obtained waxes were determined. The waxes were chemically characterized by FT-IR and GCMS analysis. The results reveal that the maximum moisture of the bark is 14.54 %, the best extraction yields are obtained by using water at 120 °C and 1.2 atm, and petroleum ether (3.12 %), alkaline hydrolysis 1 mol L−1 (NaOH) and petroleum ether (3.53 %) ethyl acetate (3.23 %). Values were close to the reference study using the rapid lipid extraction method. The density of the wax is 0.845 g mL−1 and its viscosity of 530 cP (24 °C), and the melting point varied according to the extractive treatment at between 25 and 40 °C. Solubility tests made it possible to determine that the 10/50/1000 μL ratio of modified Eagle Dulbecco wax/dimethylsulfoxide/medium allows homogeneous solubilization of the wax without the presence of precipitates. Chemical characterization identified typical functional groups of plant-based waxes such as long-chain alkanes, alkyls, methyl groups, esters, and carbonyls, with the most abundant fatty acids being C:22 and C:24.
SALL2, also known as Spalt-like transcription factor 2, is a member of the SALL family of transcription factors involved in development and conserved through evolution. Since its identification in ...1996, findings indicate that SALL2 plays a role in neurogenesis, neuronal differentiation and eye development. Consistently, SALL2 deficiency associates with neural tube defects and coloboma, a congenital eye disease. Relevant to cancer, clinical studies indicate that SALL2 is deregulated in various cancers and is a specific biomarker for Synovial Sarcoma. However, the significance of SALL2 deregulation in this disease is controversial. Here, we present and discuss all available information about SALL2 since its discovery, including isoforms, regulation, targets and functions. We specifically discuss the role of SALL2 in the regulation of cell proliferation and survival within the context of the identified target genes, its interaction with viral oncogenes, and its association with the TP53 tumor suppressor and MYC oncogene. Special attention is given to p53-independent SALL2 regulation of pro-apoptotic genes BAX and PMAIP1, and the implication of these findings on the apoptotic response of cancer cells to therapy. Understanding SALL2 function and the molecular mechanisms governing its expression and activity is critical to comprehend why and how SALL2 could contribute to disease. This knowledge will open new perspectives for the development of molecular targeted approaches in disease.
The SALL2 transcription factor, an evolutionarily conserved gene through vertebrates, is involved in normal development and neuronal differentiation. In disease, SALL2 is associated with eye, kidney, ...and brain disorders, but mainly is related to cancer. Some studies support a tumor suppressor role and others an oncogenic role for SALL2, which seems to depend on the cancer type. An additional consideration is tissue-dependent expression of different SALL2 isoforms. Human and mouse
gene loci contain two promoters, each controlling the expression of a different protein isoform (E1 and E1A). Also, several improvements on the human genome assembly and gene annotation through next-generation sequencing technologies reveal correction and annotation of additional isoforms, obscuring dissection of SALL2 isoform-specific transcriptional targets and functions. We here integrated current data of normal/tumor gene expression databases along with ChIP-seq binding profiles to analyze SALL2 isoforms expression distribution and infer isoform-specific SALL2 targets. We found that the canonical SALL2 E1 isoform is one of the lowest expressed, while the E1A isoform is highly predominant across cell types. To dissect SALL2 isoform-specific targets, we analyzed publicly available ChIP-seq data from Glioblastoma tumor-propagating cells and in-house ChIP-seq datasets performed in SALL2 wild-type and E1A isoform knockout HEK293 cells. Another available ChIP-seq data in HEK293 cells (ENCODE Consortium Phase III) overexpressing a non-canonical SALL2 isoform (short_E1A) was also analyzed. Regardless of cell type, our analysis indicates that the SALL2 long E1 and E1A isoforms, but not short_E1A, are mostly contributing to transcriptional control, and reveals a highly conserved network of brain-specific transcription factors (i.e., SALL3, POU3F2, and NPAS3). Our data integration identified a conserved molecular network in which SALL2 regulates genes associated with neural function, cell differentiation, development, and cell adhesion between others. Also, we identified
as a gene that is likely regulated by SALL2 across tissues. Our study encourages the validation of publicly available ChIP-seq datasets to assess a specific gene/isoform's transcriptional targets. The knowledge of SALL2 isoforms expression and function in different tissue contexts is relevant to understanding its role in disease.
The regulation of gene expression at the level of transcription involves the concerted action of several proteins and protein complexes committed to dynamically alter the surrounding chromatin ...environment of a gene being activated or repressed. ATP-dependent chromatin remodeling complexes are key factors in chromatin remodeling, and the SWI/SNF complex is the founding member. While many studies have linked the action of these complexes to specific transcriptional regulation of a large number of genes and much is known about their catalytic activity, less is known about the nuclear elements that can enhance or modulate their activity. A number of studies have found that certain High Mobility Group (HMG) proteins are able to stimulate ATP-dependent chromatin remodeling activity, but their influence on the different biochemical outcomes of this activity is still unknown. In this work we studied the influence of the yeast Nhp6A, Nhp6B and Hmo1 proteins (HMGB family members) on different biochemical outcomes of yeast SWI/SNF remodeling activity. We found that all these HMG proteins stimulate the sliding activity of ySWI/SNF, while transient exposure of nucleosomal DNA and octamer transfer catalyzed by this complex are only stimulated by Hmo1. Consistently, only Hmo1 stimulates SWI/SNF binding to the nucleosome. Additionally, the sliding activity of another chromatin remodeling complex, ISW1a, is only stimulated by Hmo1. Further analyses show that these differential stimulatory effects of Hmo1 are dependent on the presence of its C-terminal tail, which contains a stretch of acidic and basic residues.
•Nhp6A, Nhp6B and Hmo1 stimulate the sliding activity of the yeast SWI/SNF complex.•Hmo1 differentially stimulates SWI/SNF and ISW1a activity, as compared to Nhp6A/B.•The C-terminal tail of Hmo1 is required for its stimulatory effect on SWI/SNF action.•Hmo1 C-terminal tail does not endow Nhp6 with the stimulatory properties of Hmo1.
Diverse chromatin modifiers are involved in regulation of gene expression at the level of transcriptional regulation. Among these modifiers are ATP-dependent chromatin remodelers, where the SWI/SNF ...complex is the founding member. It has been observed that High Mobility Group (HMG) proteins can influence the activity of a number of these chromatin remodelers. In this context, we have previously demonstrated that the yeast HMG proteins Nhp6 and Hmo1 can stimulate SWI/SNF activity. Here, we studied the genome-wide binding patterns of Nhp6, Hmo1 and the SWI/SNF complex, finding that most of gene promoters presenting high occupancy of this complex also display high enrichment of these HMG proteins. Using deletion mutant strains we demonstrate that binding of SWI/SNF is significantly reduced at numerous genomic locations by deletion of NHP6 and/or deletion of HMO1. Moreover, alterations in the nucleosome landscape take place at gene promoters undergoing reduced SWI/SNF binding. Additional analyses show that these effects also correlate with alterations in transcriptional activity. Our results suggest that, besides the ability to stimulate SWI/SNF activity, these HMG proteins are able to assist the loading of this complex onto gene regulatory regions.
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•The genome-wide binding profiles of SWI/SNF, Nhp6 and Hmo1 are highly correlated.•SWI/SNF binding to numerous gene promoters is reduced by deletion of NHP6A/B or HMO1.•Reduced SWI/SNF binding is accompanied by alterations in transcriptional activity.•Chromatin landscape is altered at promoters undergoing reduction of SWI/SNF binding.
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