Structural characterization of four <i>Rhododendron</i> spp. chloroplast genomes and comparative analyses with other azaleas

Azalea is a general designation of Rhododendron in the Ericaceae family. Rhododendron not only has high ornamental value but also has application value in ecological protection, medicine, and scientific research. In this study, we used Illumina and PacBio sequencing to assemble and annotate the entire chloroplast genomes (cp genomes) of four Rhododendron species. The chloroplast genomes of R. concinnum, R. henanense subsp. lingbaoense, R. micranthum, and R. simsii were assembled into 207,236, 208,015, 207,233, and 206,912 bp, respectively. All chloroplast genomes contain eight rRNA genes, with either 88 or 89 protein-coding genes. The four cp genomes were compared and analyzed by bioinformatics, and the phylogenetic analysis based on chloroplast genomes of 26 species of Ericaceae, Actinidiaceae, and Primulaceae under Ericales was conducted. A comparison of the linear structure of cp genomes of four Rhododendron showed that there were substantial sequence similarities in coding regions, but high differences in non-coding regions. A phylogenetic analysis, based on chloroplast whole genome sequences, showed that all Rhododendron species are in the clade Ericaceae. This study provides valuable genetic information for the study of population genetics and evolutionary relationships in Rhododendron and other azalea species.     

Targeting the “undruggable” cancer driver genes: <i>Ras</i>, <i>myc</i>, and <i>tp53</i>

The term “undruggable” is to describe molecules that are not targetable or at least hard to target pharmacologically. Unfortunately, some targets with potent oncogenic activity fall into this category, and currently little is known about how to solve this problem, which largely hampered drug research on human cancers. Ras, as one of the most common oncogenes, was previously considered “undruggable”, but in recent years, a few small molecules like Sotorasib (AMG-510) have emerged and proved their targeted anti-cancer effects. Further, myc, as one of the most studied oncogenes, and tp53, being the most common tumor suppressor genes, are both considered “undruggable”. Many attempts have been made to target these “undruggable” targets, but little progress has been made yet. This article summarizes the current progress of direct and indirect targeting approaches for ras, myc, two oncogenes, and tp53, a tumor suppressor gene. These are potential therapeutic targets but are considered “undruggable”. We conclude with some emerging research approaches like proteolysis targeting chimeras (PROTACs), cancer vaccines, and artificial intelligence (AI)-based drug discovery, which might provide new cues for cancer intervention. Therefore, this review sets out to clarify the current status of targeted anti-cancer drug research, and the insights gained from this review may be of assistance to learn from experience and find new ideas in developing new chemicals that directly target such “undruggable” molecules.     

LncRNA <i>ZFAS1</i> regulates cardiomyocyte differentiation of human embryonic stem cells

Background: Cardiomyocytes derived from human embryonic stem cells (hESCs) are regulated by complex and stringent gene networks during differentiation. Long non-coding RNAs (lncRNAs) exert critical epigenetic regulatory functions in multiple differentiation processes. However, the involvement of lncRNAs in the differentiation of hESCs into cardiomyocytes has not yet been fully elucidated. Here, we identified the key roles of ZFAS1 (lncRNA zinc finger antisense 1) in the differentiation of cardiomyocytes from hESCs. Methods: A model of cardiomyocyte differentiation from stem cells was established using the monolayer differentiation method, and the number of beating hESCs-derived cardiomyocytes was calculated. Gene expression was analyzed by quantitative real-time PCR (qRT-PCR). Immunofluorescence assays were performed to assess the expression of cardiac troponin T (cTnT) and α-actinin protein in cardiomyocytes. Results: qRT-PCR showed that ZFAS1 expression in the mesoderm was significantly higher than that in embryonic stem cells, cardiac progenitor cells, and cardiomyocytes. Knockdown of ZFAS1 inhibited cardiomyocyte differentiation from hESCs, which was characterized by reduced expression of the cardiac-specific markers cTnT, α-actinin, myosin heavy chain 6 (MYH6), and myosin heavy chain 7 (MYH7). In contrast, ZFAS1 overexpression remarkably increased the percentage of spontaneously beating cardiomyocytes. In terms of the mechanism, we found that ZFAS1 is an antisense lncRNA at the 5′ end of the protein-coding gene ZNFX1. Knockdown of ZFAS1 could increase the mRNA expression level of ZNFX1. Furthermore, qRT-PCR demonstrated that the silencing of ZNFX1 led to an increase in cardiac-specific markers that predicted the promotion of cardiomyocyte differentiation. Conclusion: Altogether, these data suggest that lncRNA-ZFAS1 is required for cardiac differentiation by functionally inhibiting the expression of ZNFX1, which may provide a reference for the treatment of heart disease to a certain extent.     

Response of <i>MaHMA2</i> gene expression and stress tolerance to zinc stress in mulberry (<i>Morus alba</i> L.)

HMA2 (heavy metal ATPase 2) plays a crucial role in extracellular and intracellular Zn²⁺ transport across biomembranes, maintaining ion homeostasis, and playing an important role in the normal physiological metabolism, growth, and development of plants. In our study, a novel HMA2 gene, named MaHMA2, was isolated and cloned from white mulberry (Morus alba L.). The gene sequence obtained was 1,342 bp long, with an open reading frame of 1,194 bp, encoding a protein of 397 amino acids, with a predicted molecular mass of 42.852 kD and an isoelectric point of 7.53. This protein belonged to the PIB-type ATPase transport protein family. We analyzed the expression of the MaHMA2 gene by quantitative real-time PCR. The results showed that the level of MaHMA2 gene expression decreased to a Zn concentration of 800 mg/kg. Malondialdehyde and proline levels increased and responded to increasing Zn when the MaHMA2 gene was silenced, whereas the activities of peroxidase and superoxide dismutase tended to increase in response to increasing Zn²⁺ ion stress concentrations but were lower in the gene-silenced plants. These findings suggested that the MaHMA2 gene played an active role in the tolerance response of mulberry to Zn stress.     

Genome-wide identification of <i>U-box</i> gene family and expression analysis under abiotic stresses in <i>Salvia miltiorrhiza</i>

Plant U-box (PUB) E3 ubiquitin ligases play important roles in hormone signaling pathways and in response to different abiotic stresses, but little is known about U-box genes in Danshen (root of Salvia miltiorrhiza Bunge). Here, we identified and characterized 70 SmPUB genes based on its genome sequence. Phylogenetic analysis of U-box genes from S. miltiorrhiza and Arabidopsis suggested that they can be clustered into seven subgroups (I–VII). Typical U-box domains were found in all identified SmPUB genes through the analysis of conserved motifs. Moreover, qRT-PCR was applied to analyze the relative expression levels of U-box genes in S. miltiorrhiza roots and leaves under PEG-induced water deficit and salt stresses. Results revealed that the SmPUB genes exhibited stronger response to drought than to salt stress. To the best of our knowledge, this report is the first to perform genome-wide identification and analysis of the U-box gene family in S. miltiorrhiza, and the results provide valuable information for better understanding of the function of U-box in S. miltiorrhiza.     

Tanshinone IIA protects intestinal epithelial cells from ferroptosis through the upregulation of <i>GPX4</i> and <i>SLC7A11</i>

Background: Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD pathology. Growing evidence indicated that epithelial cell ferroptosis is linked to IBD and is considered a target process. Methods: RAS-selective lethal 3 (RSL3) was used to induce ferroptosis in intestinal epithelial cell line No. 6 (IEC-6) cells, and cell ferroptosis and the effects of tanshinone IIA (Tan IIA) were determined by cell counting kit-8 (CCK-8), reactive oxygen species (ROS) staining, Giemsa staining and transmission electron microscope (TEM). The cell viability of natural product library compounds was determined by CCK-8. The expression of ferroptosis-related genes were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Results: Treatment of IEC-6 cells results in the accumulation of ROS and typical morphological characteristics of ferroptosis. RSL3 treatment caused rapid cellular cytotoxicity which could be reversed by ferrostatin-1 (Fer-1) in IEC-6 cells. Natural product library screening revealed that Tan IIA is a potent inhibitor of IEC-6 cell ferroptosis. Tan IIA could significantly protect the RSL3-induced ferroptosis of IEC-6 cells. Furthermore, the ferroptosis suppressors, glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and miR-17-92 were found to be early response genes in RSL3-treated cells. Treatment of IEC-6 cells with Tan IIA resulted in upregulation of GPX4, SLC7A11, and miR-17-92. Conclusion: Our study demonstrated that Tan IIA protects IEC-6 cells from ferroptosis through the upregulation of GPX4, SLC7A11, and miR-17-92. The findings might provide a theoretical grounding for the future application of Tan IIA to treat or prevent IBD.     

Ultrastructural analysis of sperm from the genus <i>Idarnes</i> (Hymenoptera: Chalcidoidea,Sycophaginae)

In this study, the sperm ultrastructure of three species of Idarnes genus was investigated using light and transmission electron microscopy. Spermatozoon morphology of the three species was similar to that of most Chalcidoidea, with helicoidally twisted nucleus and flagellum. The head region consists of an acrosome and a nucleus; the nucleus-flagellum transition region characterized by the presence of mitochondrial derivatives and the centriolar adjunct; a flagellum region, which includes the axoneme with microtubular arrangement 9 + 9 + 2 and two mitochondrial derivatives. However, the sperm of these three species exhibit features that discriminate one species from each other: (1) only one species, Idarnes sp. 2 (carme group) exhibited an extracellular sheath surrounding the anterior portion of the nucleus, which extends to the anterior region of the flagellum, but it did not present filaments; (2) the acrosome in the three species was quite different, Idarnes sp. 1 and Idarnes sp. 2 (carme group) has two compartments (acrosomal and subacrosomal vesicles) while Idarnes sp. 3 (flavicollis group) has a third compartment (perforatorium); (3) the centriolar adjunct elongated and its location among the mitochondrial derivatives is similar for the three species analyzed; (4) mitochondrial derivatives differ between the species, with triangular (Idarnes sp. 1 and sp. 3) and elongated or flat shaped (Idarnes sp. 2) appearance. These data shows that sperm structure may differ within the same genus and confirms the potential of these cells in phylogenetic and taxonomic analyses in the Chalcidoidea superfamily, as well as in Hymenoptera in general.     

Expression analysis of <i>OsSERK</i>, <i>OsLEC1</i> and <i>OsWOX4</i> genes in rice (<i>Oryza</i> sativa L.) callus during somatic embryo development

Somatic embryogenesis is an asexual reproduction process that occurs in many plant species, including rice. This process contains several totipotency markers such as Somatic Embryogenesis Receptor-like Kinase (SERK), Leafy Cotyledon1 (LEC1) and WUSCHEL-Related Homeobox4 (WOX4) and also a helpful model for embryo development and clones and transformations. Here, we report the gene expression during somatic embryo development correlates with regeneration frequency in 14 Javanica rice (pigmented and non-pigmented) using modifified N6 media supplemented with Kinetin (2.0 mg/L) and NAA (1.0 mg/L). Although there have been advances in understanding the genetic basis of somatic embryogenesis in other varieties, rice is still unexplored, especially during somatic embryo development. Moreover, for the formation of callus induction from immature embryos, 2,4-D (2.0 mg/L, 3.0 mg/L) was used. This study analysed the gene expression of OsSERK, OsWOX4 and OsLEC1 genes through RT-PCR analysis. Higher expression of the OsLEC1 gene indicates that their function may correlate in the in vitro with the high response of rice after transfer to regeneration media. This study found that rice varieties of pigmented rice (MS Pendek and Gogoniti II) and non-pigmented rice (Pandan Ungu) showed high regeneration frequency, showing higher OsLEC1 expression than other varieties because OsLEC1 promotes the maturation of somatic embryos in plant regeneration on day 14. However, the contrast with Genjah nganjuk may be effective because of other regulatory genes. RT-PCR analysis showed OsSERK had less expression level than OsLEC1 and OsWOX4 in the varieties, which correlate with the percentage of plant regeneration, but not for Gogoniti II. In conclusion, the higher percentage of plant regeneration correlates with the higher expression level of OsLEC1 at day 14 of media regeneration of rice.     

Development of polymorphic SSR markers and their applicability in genetic diversity evaluation in <i>Euptelea pleiosperma</i>

Euptelea pleiosperma is a characteristic species of East Asian flora with both ornamental and scientific values. Based on the reduced-representation sequencing (RRS) technology of RAD-Seq, this study conducted high-throughput Illumina paired-end sequencing to find SSR marker information in the genome of E. pleiosperma, and to screen and verify polymorphism of SSR markers. We obtained 5.5G of high-quality data using RAD-Seq. The total number of contigs of the RAD tags was 299,376, with the maximum contig length of 2,062 bp and the average length of 445 bp. From these sequences, we identified 20,718 SSR loci, with a distribution density of one SSR per 6.45 kb (1/6.45 kb). Among all SSRs, dinucleotides (52.00%) were the most detected SSRs, followed by mononucleotides (21.63%). AG/CT was the dominant motif in the SSR loci, accounting for 34.8%. Primers were successfully designed for 14,593 loci, and 100 pairs of these primers were randomly selected for chemical synthesis and validated by SSR-PCR amplification in 20 individuals of E. pleiosperma. Seventy-nine primers were able to amplify the target bands. Cervus 3.0 software was used to analyze the selected 20 SSR loci with good polymorphism. For the 20 SSR markers, the number of alleles ranged from 4 to 9, and the observed heterozygosity and expected heterozygosity were from 0.35 to 0.75 and 0.541 to 0.875, respectively. The information content of polymorphic loci ranged from 0.463 to 0.848, with an average value of 0.638. Among them, there were 18 highly polymorphic loci, and 20 SSR loci did not deviate from the HardyWeinberg equilibrium. Furthermore, the 20 pairs of SSR primers were used to conduct PCoA analysis based on Nei’s genetic distance of 51 individuals from three populations. The results showed that these SSR markers could distinguish genetic differences based on different geographical locations.     

Genome-wide identification,characterization, and expression analysis of aluminum-activated malate transporter genes (ALMTs) in <i>Gossypium hirsutum</i> L.

Aluminum-activated malate transporters (ALMT) are widely involved in plant growth and metabolic processes, including adaptation to acid soils, guard cell regulation, anion homeostasis, and seed development. Although ALMT genes have been identified in Arabidopsis, wheat, barley, and Lotus japonicus, little is known about its presence in Gossypium hirsutum L. In this study, ALMT gene recognition in diploid and tetraploid cotton were done using bioinformatics analysis that examined correlation between homology and evolution. Differentially regulated ALMT genetic profile in G. hirsutum was examined, using RNA sequencing and qRT-PCR, during six fiber developmental time-points, namely 5 d, 7 d, 10 d, 15 d, 20 d, and 25 d. We detected 36 ALMT genes in G. hirsutum, which were subsequently annotated and divided into seven sub-categories. Among these ALMT genes, 34 had uneven distribution across 14/26 chromosomes. Conserved domains and gene structure analysis indicated that ALMT genes were highly conserved and composed of exons and introns. The GhALMT gene expression profile at different DPA (days post anthesis) in different varieties of G. hirsutum is indicative of a crucial role of ALMT genes in fiber development in G. hirsutum. This study provides basis for advancements in the cloning and functional enhancements of ALMT genes in enhancing fiber development and augmenting high quality crop production.     

Increased <i>MAD2L2</i> expression predicts poor clinical outcome in Colon Adenocarcinoma

Background: Colon adenocarcinoma (COAD) is the second leading cause of cancer death worldwide thus, identification of COAD biomarkers is critical. Mitotic Arrest Deficient 2 Like 2 (MAD2L2) is a key factor in mammalian DNA damage repair and is highly expressed in many malignant tumors. This is a comprehensive study of MAD2L2 expression, its diagnostic value, prognostic analysis, potential biological function, and impact on the immune system of patients with COAD. Methods: Gene expression, clinical relevance, prognostic analysis, diagnostic value, GO/KEGG cluster analysis, data obtained from TCGA, and bioinformatics statistical analysis were performed using the R package. Immune responses to MAD2L2 expression in COAD were analyzed using TIMER. The expression of MAD2L2 in HCT116 cells induced by the inflammatory factor TNF-α was detected using Western blot. Results: Our results underscore the clinical diagnostic value and potential biological significance of MAD2L2 in patients with COAD. A high level of MAD2L2 expression has been found in COAD and correlated with tumor status and colon polyps. ROC curve analysis showed that MAD2L2 expression has high diagnostic value in COAD. Analysis of immune infiltration results showed that MAD2L2 expression was positively correlated with neutrophil levels. The western blot results demonstrated that MAD2L2 was dose-dependently present with TNF-α. GO/KEGG revealed that MAD2L2 overexpressed and coexpressed genes were mostly involved in biological functions, including hypoxia response, response to reduced oxygen levels, mitochondrial translation elongation, and other processes. Conclusion: MAD2L2 as a new COAD biomarker contributes to our understanding of how alterations in gene expression and the immunological environment contribute to the development of colon cancer. Following further investigation, MAD2L2 may prove to be a viable target factor for clinical diagnosis and therapy of COAD.