Arginine methyltransferases PRMT2 and PRMT3 are essential for biosynthesis of plant-polysaccharide-degrading enzymes in Penicillium oxalicum.

Many filamentous fungi produce plant-polysaccharide-degrading enzymes (PPDE); however, the regulatory mechanism of this process is poorly understood. A Gal4-like transcription factor, CxrA, is essential for mycelial growth and PPDE production in Penicillium oxalicum. Its N-terminal region, CxrAΔ207-733 is required for the regulatory functions of whole CxrA, and contains a DNA-binding domain (CxrAΔ1-16&Δ59-733) and a methylated arginine (R) 94. Methylation of R94 is mediated by an arginine N-methyltransferase, PRMT2 and appears to induce dimerization of CxrAΔ1-60. Overexpression of prmt2 in P. oxalicum increases PPDE production by 41.4-95.1% during growth on Avicel, compared with the background strain Δku70;hphR+. Another arginine N-methyltransferase, PRMT3, appears to assist entry of CxrA into the nucleus, and interacts with CxrAΔ1-60 in vitro under Avicel induction. Deletion of prmt3 resulted in 67.0-149.7% enhanced PPDE production by P. oxalicum. These findings provide novel insights into the regulatory mechanism of fungal PPDE production.

Kinase POGSK-3ß modulates fungal plant polysaccharide-degrading enzyme production and development.

The filamentous fungus Penicillium oxalicum secretes integrative plant polysaccharide-degrading enzymes (PPDEs) applicable to biotechnology. Glycogen synthase kinase-3ß (GSK-3ß) mediates various cellular processes in eukaryotic cells, but the regulatory mechanisms of PPDE biosynthesis in filamentous fungi remain poorly understood. In this study, POGSK-3ß (POX_c04478), a homolog of GSK-3ß in P. oxalicum, was characterised using biochemical, microbiological and omics approaches. Knockdown of POGSK-3ß in P. oxalicum using a copper-responsive promoter replacement system led to 53.5 - 63.6%, 79.0 - 92.8% and 76.8 - 94.7% decreases in the production of filter paper cellulase, soluble starch-degrading enzyme and raw starch-degrading enzyme, respectively, compared with the parental strain ΔKu70. POGSK-3ß promoted mycelial growth and conidiation. Transcriptomic profiling and real-time quantitative reverse transcription PCR analyses revealed that POGSK-3ß dynamically regulated the expression of genes encoding major PPDEs, as well as fungal development-associated genes. The results broadened our understanding of the regulatory functions of GKS-3ß and provided a promising target for genetic engineering to improve PPDE production in filamentous fungi. KEY POINTS: • The roles of glycogen synthase kinase-3ß were investigated in P. oxalicum. • POGSK-3ß regulated PPDE production, mycelial growth and conidiation. • POGSK-3ß controlled the expression of major PPDE genes and regulatory genes.

Effect of minimally invasive versus conventional aortic root replacement on transfusion and postoperative wound complications in patients: A meta-analysis.

We examined whether small incision aortic root replacement could reduce the amount of blood transfusion during operation and the risk of postoperative complications. An extensive e-review of the 4 main databases (PubMed, Cochrane, Web of Science and EMBASE) was carried out to determine all the published trials by July 2023. The search terms used were associated with partial versus full sternotomy and aortic root. This analysis only included the study articles that compared partial and full sternotomy. After excluding articles based on titles or abstracts, selected full-text articles had reference lists searched for any potential further articles. We analysed a total of 2167 subjects from 10 comparable trials. The minimally invasive aortic root graft in breastbone decreased the duration of hospitalization (MD, -2.58; 95% CI, -3.15, -2.01, p < 0.0001) and intraoperative red blood cell transfusion (MD, -1.27; 95% CI, -2.34, -0.19, p = 0.02). However, there were no significant differences in wound infection (OR, 0.88; 95% CI, 0.16, 4.93, p = 0.88), re-exploration for bleeding (OR, 0.96; 95% CI, 0.60, 1.53, p = 0.86), intraoperative blood loss (MD, -259.19; 95% CI, -615.11, 96.73, p = 0.15) and operative time (MD, -7.39; 95% CI, -19.10, 4.32, p = 0.22); the results showed that the microsternotomy did not differ significantly from that of the routine approach. Small sternotomy may be an effective and safe substitute for the treatment of the aorta root. Nevertheless, the wide variety of data indicates that larger, well-designed studies are required to back up the current limited literature evidence showing a benefit in terms of complications like postoperative wound infections or the volume of intraoperative red blood cell transfusion.

The role of ferroptosis in the development of acute and chronic kidney diseases.

Ferroptosis, a novel form of regulated cell death, is characterized by imbalance of intracellular iron and redox systems, resulting from overgeneration of toxic lipid peroxidation products. In recent years, the verified crucial role of ferroptosis has been widely concerned in rudimentary pathogenesis and development of various acute and chronic kidney disease (CKD), comprehending the potential patterns of cell death can afford more reliable bases and principles for treatment and prevention of renal disease. In this review, the regulatory mechanisms of ferroptosis were introduced and the important roles of ferroptosis in diverse renal diseases such as acute kidney injury, CKD, and renal fibrosis were outlined to illuminate the potential of restraining ferroptosis in treatment and prevention of kidney disease.

Death-Associated Protein Kinase 1 Regulates Oxidative Stress in Cardiac Ischemia Reperfusion Injury.

To investigate the role of death-associated protein kinase 1 (DAPK1) in cardiac ischemia reperfusion (I/R) in vivo, and to determine whether the process is regulated by nuclear factor E2-associated factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (keap1). Western blot analysis was used to analyze the expression level of DAPK1 at different time points. The hemodynamic parameters and apoptosis of cardiac I/R injury in vivo were observed using DAPK1 knockdown lentivirus. The oxidative stress of I/R in vivo was observed. Nrf2-IN-1 was applied to determine whether the role of DAPK was regulated by Nrf2/keap1. Results show that the DAPK1 expression increased to a peak after 12 h of I/R. Moreover, the level of DAPK1 expression decreased, as determined by Western blot, after DAPK1 knockdown lentivirus administration. In addition, the hemodynamic parameters of the DAPK1-shRNA group were improved. The apoptosis level (Bax, Bcl-2, cleaved caspase-3, and TUNEL staining) increased in the I/R group, and the DAPK1 knockdown lentivirus could reverse the injury. The oxidative stress indices (CK, cTn-1, CAT, LDH, GSH-PX, MDA, and SOD) also improved in the DAPK1-shRNA group. Finally, Nrf2-IN-1 inhibited tNrf2, nNrf2, and Bcl-2 expression and boosted keap1, Bax, and cleaved caspase-3 expression after DAPK1 lentivirus administration. These findings suggest that DAPK1 may regulate the oxidative stress in cardiac I/R, and Nrf2/keap1 may be the downstream target factor of DAPK1.

Resveratrol against Cardiac Fibrosis: Research Progress in Experimental Animal Models.

Cardiac fibrosis is a heterogeneous disease, which is characterized by abundant proliferation of interstitial collagen, disordered arrangement, collagen network reconstruction, increased cardiac stiffness, and decreased systolic and diastolic functions, consequently developing into cardiac insufficiency. With several factors participating in and regulating the occurrence and development of cardiac fibrosis, a complex molecular mechanism underlies the disease. Moreover, cardiac fibrosis is closely related to hypertension, myocardial infarction, viral myocarditis, atherosclerosis, and diabetes, which can lead to serious complications such as heart failure, arrhythmia, and sudden cardiac death, thus seriously threatening human life and health. Resveratrol, with the chemical name 3,5,4'-trihydroxy-trans-stilbene, is a polyphenol abundantly present in grapes and red wine. It is known to prevent the occurrence and development of cardiovascular diseases. In addition, it may resist cardiac fibrosis through a variety of growth factors, cytokines, and several cell signaling pathways, thus exerting a protective effect on the heart.

Acetaminophen sensitizing erastin-induced ferroptosis via modulation of Nrf2/heme oxygenase-1 signaling pathway in non-small-cell lung cancer.

Growing evidence confirms that ferroptosis plays an important role in tumor growth inhibition. However, some non-small-cell lung cancer (NSCLC) cell lines are less sensitive to erastin-induced ferroptotic cell death. Elucidating the mechanism of resistance of cancer cells to erastin-induced ferroptosis and increasing the sensitivity of cancer cells to erastin need to be addressed. In our experiment, erastin and acetaminophen (APAP) cotreatment inhibited NSCLC cell viability and promoted ferroptosis and apoptosis, accompanied with attenuation of glutathione and ectopic increases in lipid peroxides. Erastin and APAP promoted NSCLC cell death by regulating nucleus translocation of nuclear factor erythroid 2-related factor 2 (Nrf2); and the ferroptosis induced by erastin and APAP was abrogated by bardoxolone methyl (BM) with less generation of reactive oxygen species and malondialdehyde. As a downstream gene of Nrf2, heme oxygenase-1 expression decreased significantly with the cotreatment of erastin and APAP, which could be rescued by BM. In vivo experiment showed that the combination of erastin and APAP had a synergic therapeutic effect on xenograft of lung cancer. In short, the present study develops a new effective treatment for NSCLC by synergizing erastin and APAP to induce ferroptosis.

Molecular cloning of SLC35D3 and analysis of its role during porcine intramuscular preadipocyte differentiation.

BACKGROUND: Solute carrier family 35 (SLC35) is one of a large number of membrane transporter protein families. Member D3 of this family is thought to be involved in adipose deposition and metabolic control. RESULTS: We obtained 2238 bp cDNA of porcine SLC35D3, it contains a 1272 bp ORF, encoding a 423 amino acid polypeptide, and a 966 bp 3' UTR. BLAST results revealed that the amino acid sequence of porcine SLC35D3 had the closest phylogenetic relationship with members of the genus Ovis aries. Further bioinformatics analysis showed that the SLC35D3 protein contains 8 transmembrane domains, and that there is no signal peptide structure. The secondary structure of the protein mainly contains 37.12% α-helixes, 7.8% in ß-folds, and 33.57% random coils. mRNA expression analysis showed that SLC35D3 is expressed in lung, liver, heart, spleen, kidney, longissimus dorsi muscle (LDM), leaf fat (LF), and subcutaneous adipose tissue (SAT). To examine the effects of SLC35D3 expression on fat synthesis and catabolism, SLC35D3-siRNA was transfected into cultured intramuscular adipocytes. SLC35D3 silenced cells showed increased expression of genes related to fat synthesis, and increased deposition of intramuscular fat (IMF), abundance of lipid droplets, and the level of free fatty acid (FFA) in the culture medium. In contrast, the siRNA decreased the expression genes involved in fat catabolism. CONCLUSIONS: Our results demonstrate that silenced SLC35D3 results in increased adipogenic processes in pig intramuscular adipocytes. These data represent the first exploration of SLC35D3 expression in swine, and provide valuable insights into the functions of SLC35D3 in adipocyte differentiation.

Regulation of GSK3ß/Nrf2 signaling pathway modulated erastin-induced ferroptosis in breast cancer.

Ferroptosis is a newly discovered form of regulated cell death and characterized by an iron-dependent accumulation of lethal lipid reactive oxygen species (ROS), ferroptosis may exhibit a novel spectrum of clinical activity for cancer therapy. However, the significance of ferroptosis in the context of carcinoma biology is still emerging. Glycogen synthase kinase-3ß (GSK-3ß) has been found to be a fundamental element in weaking antioxidant cell defense by adjusting the nuclear factor erythroid 2-related factor 2 (Nrf2). In our study, decreased expression of GSK-3ß was observed in the cancer tissues of breast cancer patients, results of immunohistochemistry indicated that Nrf2 was highly expressed in low-GSK-3ß-expressed breast cancer tissues. The contributions of aberrant expression of GSK-3ß and Nrf2 to the erastin-induced ferroptosis in breast cancer were further assessed, silence of GSK-3ß blocked erastin-induced ferroptosis with less production of ROS and malondialdehyde (MDA) via upregulation of GPX4 and downregulation of arachidonate 15-lipoxygenase (Alox15), overexpression of GSK-3ß enhanced erastin-triggered ferroptosis with elevated ROS and MDA. Enhanced erastin-induced ferroptosis by overexpression of GSK-3ß was blocked by activating Nrf2. We further confirmed that overexpression of GSK-3ß strengthened erastin-induced tumor growth inhibition in breast cancer xenograft models in vivo. In summary, our findings conclude that modulation the balance between GSK-3ß/Nrf2 is a promising therapeutic approach and probably will be important targets to enhance the effect of erastin-induced ferroptosis in breast cancer.

Multi-Scale Feature Integrated Attention-Based Rotation Network for Object Detection in VHR Aerial Images.

Accurate and robust detection of multi-class objects in very high resolution (VHR) aerial images has been playing a significant role in many real-world applications. The traditional detection methods have made remarkable progresses with horizontal bounding boxes (HBBs) due to CNNs. However, HBB detection methods still exhibit limitations including the missed detection and the redundant detection regions, especially for densely-distributed and strip-like objects. Besides, large scale variations and diverse background also bring in many challenges. Aiming to address these problems, an effective region-based object detection framework named Multi-scale Feature Integration Attention Rotation Network (MFIAR-Net) is proposed for aerial images with oriented bounding boxes (OBBs), which promotes the integration of the inherent multi-scale pyramid features to generate a discriminative feature map. Meanwhile, the double-path feature attention network supervised by the mask information of ground truth is introduced to guide the network to focus on object regions and suppress the irrelevant noise. To boost the rotation regression and classification performance, we present a robust Rotation Detection Network, which can generate efficient OBB representation. Extensive experiments and comprehensive evaluations on two publicly available datasets demonstrate the effectiveness of the proposed framework.

Wnt7a, frequently silenced by CpG methylation, inhibits tumor growth and metastasis via suppressing epithelial-mesenchymal transition in gastric cancer.

Wnt7a is a member of the Wnt family and has been reported to be involved in the carcinogenesis and progression of many types of human cancer. However, little is known about Wnt7a expression and function in gastric cancer (GC). In the present study, Wnt7a expression in GC tissues and cells was investigated, the correlation between Wnt7a expression and the prognosis was also examined. The effects of Wnt7a on proliferation, invasion, and metastasis were evaluated in vitro and in vivo. Furthermore, the expression of epithelial-mesenchymal transition (EMT) markers and hypermethylation of the Wnt7a promoter were both detected. Wnt7a was downregulated in GC and its expression was associated with poor prognosis of patients with GC. Moreover, upregulation of Wnt7a significantly suppressed the growth, invasion, and metastasis abilities of GC cells in vitro and in vivo. Mechanistically, Wnt7a was found to inhibit EMT process of GC cells. In addition, the reducing expression of Wnt7a was due to methylation of 5'-CpG island within the promoter. Furthermore, the tumor suppressor role of Wnt7a is independent of canonical Wnt/ß-catenin signaling in GC cells. In conclusion, our findings demonstrated that Wnt7a could be used as a potential diagnostic marker and target for GC management.

Targeted exosome-encapsulated erastin induced ferroptosis in triple negative breast cancer cells.

Ferroptosis is an iron-dependent, lipid peroxide-driven cell death caused by inhibition of the cystine/glutamate transporter, which is of importance for the survival of triple-negative breast cancer (TNBC) cells. Erastin is a low molecular weight chemotherapy drug that induces ferroptosis; however, poor water solubility and renal toxicity have limited its application. Exosomes, as drug delivery vehicles with low immunogenicity, high biocompatibility and high efficiency, have attracted increasing attention in recent years. Herein, we developed a formulation of erastin-loaded exosomes labeled with folate (FA) to form FA-vectorized exosomes loaded with erastin (erastin@FA-exo) to target TNBC cells with overexpression of FA receptors. The characterization, drug release, internalization and anti-tumor effect in vitro of erastin@FA-exo were determined. Erastin@FA-exo could increase the uptake efficiency of erastin into MDA-MB-231 cells; compared with erastin@exo and free erastin, erastin@FA-exo has a better inhibitory effect on the proliferation and migration of MDA-MB-231 cells. Furthermore, erastin@FA-exo promoted ferroptosis with intracellular depletion of glutathione and reactive oxygen species overgeneration. Western blot analyses revealed that erastin@FA-exo suppressed expression of glutathione peroxidase 4 (GPX4) and upregulated expression of cysteine dioxygenase (CDO1). We conclude that targeting and biocompatibility of exosome-based erastin preparations provide an innovative and powerful delivery platform for anti-cancer therapy.

NRDR inhibits estradiol synthesis and is associated with changes in reproductive traits in pigs.

Cumulus cells secreting steroid hormones have important functions in oocyte development. Several members of the short-chain dehydrogenase/reductase (SDR) family are critical to the biosynthesis of steroid hormones. NADPH-dependent retinol dehydrogenase/reductase ( NRDR), a member of the SDR superfamily, is overexpressed in pig breeds that also show high levels of androstenone. However, the potential functions and regulatory mechanisms of NRDR in pig ovaries have not been reported to date. The present study demonstrated that NRDR is highly expressed in pig ovaries and is specifically located in cumulus granulosa cells. Functional studies showed that NRDR inhibition increased estradiol synthesis. Both pregnant mare serum gonadotropin and human chorionic gonadotropin downregulated the expression of NRDR in pig cumulus granulosa cells. When the relationship between reproductive traits and single-nucleotide polymorphisms (SNPs) of the NRDR gene was examined, we found that two SNPs affected reproductive traits. SNP rs701332503 was significantly associated with a decrease in the total number of piglets born during multiparity, and rs326982309 was significantly associated with an increase in the average birth weight during primiparity. Thus, NRDR has an important role in steroid hormone biosynthesis in cumulus granulosa cells, and NRDR SNPs are associated with changes in porcine reproduction traits.

Effects of melatonin on the synthesis of estradiol and gene expression in pig granulosa cells.

The interaction of granulosa cells (GCs) with oocytes is important to regulate follicle development. The exogenous melatonin promoting the maturation of oocytes by GCs has been approved in pig, however, the transcriptome profile and the functions of the genes regulated by melatonin in GCs have not yet to be fully characterized. In this study, we found melatonin could stimulate the synthesis of estradiol in pig GCs. The RNA-seq was used to explore the effects of melatonin on gene expression, a total of 89 differentially expressed genes (DEGs) were identified. Gene ontology analysis showed DEGs which associated with regulation of cell proliferation, cell cycle, and anti-apoptosis were significantly enriched. The functions of two DEGs, NOTCH2 and FILIP1L, were studied in pig GCs. The results showed that NOTCH2 inhibited the synthesis of estradiol, but FILIP1L promoted the synthesis of estradiol. Furthermore, inhibiting NOTCH2 in granulosa cells cocultured with cumulus-oocyte-complexes had no obvious effect on the maturation of pig oocyte, but could upregulate the cleavage rate of oocyte. We proved that FILIP1L had no effect on the maturation and cleavage of pig oocytes. Our work deepens the understanding of melatonin's effects on GCs and oocyte. The DEGs we found will be beneficial to reveal mechanisms of melatonin acting on GCs and oocytes and design the pharmacological interventions.

Generation and immunity effect evaluation of biotechnology-derived Aeromonas veronii ghost by PhiX174 gene E-mediated inactivation in koi (Cyprinus carprio koi).

Aeromonas veronii is a conditional pathogen causing high mortality in many freshwater fish species worldwide. Bacterial ghosts are nonliving Gram-negative bacteria devoid of cytoplasmic contents, which induce protective immunity against microbial pathogens. The aims of this study were: a) to produce A. veronii ghost (AVG) constructed by PhiX174 gene E; b) to evaluate the specific, non-specific immune effects and protective immunity of AVG against A. veronii in koi. The lysis plasmid pBBR-E was constructed by cloning PhiX174 gene E into the broad-host-range vector pBBR1MCS2, and then transformed into A. veronii 7231. AVG was generated by increasing the incubation temperature up to 42 °C. Lysis of A. veronii occurred 3 h after temperature induction and completed in 12 h. The efficiency of ghost induction was 99.9998 ±â€¯0.0002%. Koi were immunized intraperitoneally with AVG, formalin-killed bacteria (FKC) or phosphate buffered saline (PBS) respectively, and then respiratory burst (RB), myeloperoxidase (MPO), lysozyme (LZM), malondialdehyde (MDA), complement 3 (C3) and antibody activities were examined in serum. Compared with negative control of PBS, the RB, MPO, LZM activities were significantly higher in koi immunized with AVG (P < 0.05). Nevertheless, the MDA activities of AVG treatment were significantly lower than those of PBS treatment (P < 0.05). The serum agglutination titers and IgM antibody titers in AVG group were significantly higher than those in FKC or PBS groups. After challenged with the parent strain A. veronii 7231, the average mortality of AVG group was significantly lower than that of FKC and PBS groups (P < 0.05) and the relative percent survival (RPS) of AVG group (73.92%) was higher than that of FKC group (43.48%). Therefore, AVG have the potential to induce protective immunity and they may be ideal vaccine candidates against A. veronii in koi.

HSPC159 promotes proliferation and metastasis by inducing epithelial-mesenchymal transition and activating the PI3K/Akt pathway in breast cancer.

HSPC159 is a novel human galectin-related protein that has been shown to be involved in carcinogenesis. Little is known about HSPC159 expression and function in breast cancer. Herein we showed that HSPC159 was aberrantly expressed in both breast cancer cell lines and tumor tissues and that its expression was associated with poor prognosis of breast cancer patients. Using gain- and loss-of-function methods we found that HSPC159 enhanced breast cancer cell proliferation and metastasis in vitro and in vivo. Mechanistically, HSPC159 was found to induce epithelial-mesenchymal transition (EMT) and the F-actin polymerization process of breast cancer cells. Moreover, HSPC159 promoted proliferation, migration and invasion through activating the PI3K/Akt signaling pathway in breast cancer. In conclusion, our findings showed that HSPC159 contributed to breast cancer progression through the PI3K/Akt pathway and might serve as a potential therapeutic target for the treatment of breast cancer.

miR-199a-5p regulates ß1 integrin through Ets-1 to suppress invasion in breast cancer.

Increasing evidence has revealed that miR-199a-5p is actively involved in tumor invasion and metastasis as well as in the decline of breast cancer tissues. In this research, overexpression of miR-199a-5p weakened motility and invasion of breast cancer cells MCF-7 and MDA-MB-231. Upregulation of Ets-1 increased breast cancer cell invasion, but the mechanism by which miR-199a-5p modulates activation of Ets-1 in breast cancer was not clarified. We investigated the relationship between miR-199a-5p and Ets-1 on the basis of 158 primary breast cancer case specimens, and the results showed that Ets-1 expression was inversely correlated with endogenous miR-199a-5p. Overexpression of miR-199a-5p reduced the mRNA and protein levels of Ets-1 in MCF-7 and MDA-MB-231 cells, whereas anti-miR-199a-5p elevated Ets-1. siRNA-mediated Ets-1 knockdown phenocopied the inhibition invasion of miR-199a-5p in vitro. Moreover, luciferase reporter assay revealed that miR-199a-5p directly targeted 3'-UTR of Ets-1 mRNA. This research revealed that miR-199a-5p could descend the levels of ß1 integrin by targeting 3'-UTR of Ets-1 to alleviate the invasion of breast cancer via FAK/Src/Akt/mTOR signaling pathway. Our results provide insight into the regulation of ß1 integrin through miR-199a-5p-mediated Ets-1 silence and will help in designing new therapeutic strategies to inhibit signal pathways induced by miR-199a-5p in breast cancer invasion.

miR-143 suppresses epithelial-mesenchymal transition and inhibits tumor growth of breast cancer through down-regulation of ERK5.

Epithelial-mesenchymal transition (EMT) plays a pivotal role in the development of cancer invasion and metastasis. Many studies have significantly enhanced the knowledge on EMT through the characterization of microRNAs (miRNAs) influencing the signaling pathways and downstream events that define EMT on a molecular level. In this study, we found that miR-143 suppressed EMT. Up-regulating miR-143 enhanced E-cadherin-mediated cell-cell adhesion ability, reduced mesenchymal markers, and decreased cell proliferation, migration, and invasion in vitro. In vivo, the xenograft mouse model also unveiled the suppressive effects of miR-143 on tumor growth. Additionally, we demonstrated that up-regulating extracellular signal regulated kinase 5 (ERK5) was associated with poor prognosis of breast cancer patients. Moreover, we observed an inverse correlation between miR-143 and ERK5 in breast cancer tissues. miR-143 directly targeted seed sequences in the 3'-untranslated regions of ERK5. Furthermore, we revealed that the downstream molecules of glycogen synthase kinase 3 beta (GSK-3ß)/Snail signaling were involved in EMT and modulated by ERK5. In summary, our findings demonstrated that miR-143 down-regulated its target ERK5, leading to the suppression of EMT induced by GSK-3ß/Snail signaling of breast cancer. © 2015 Wiley Periodicals, Inc.

Klf10 regulates odontoblast differentiation and mineralization via promoting expression of dentin matrix protein 1 and dentin sialophosphoprotein genes.

Klf10, a member of the Krüppel-like family of transcription factors, is critical for osteoblast differentiation, bone formation and mineralization. However, whether Klf10 is involved in odontoblastic differentiation and tooth development has not been determined. In this study, we investigate the expression patterns of Klf10 during murine tooth development in vivo and its role in odontoblastic differentiation in vitro. Klf10 protein was expressed in the enamel organ and the underlying mesenchyme, ameloblasts and odontoblasts at early and later stages of murine molar formation. Furthermore, the expression of Klf10, Dmp1, Dspp and Runx2 was significantly elevated during the process of mouse dental papilla mesenchymal differentiation and mineralization. The overexpression of Klf10 induced dental papilla mesenchymal cell differentiation and mineralization as detected by alkaline phosphatase staining and alizarin red S assay. Klf10 additionally up-regulated the expression of odontoblastic differentiation marker genes Dmp1, Dspp and Runx2 in mouse dental papilla mesenchymal cells. The molecular mechanism of Klf10 in controlling Dmp1 and Dspp expression is thus to activate their regulatory regions in a dosage-dependent manner. Our results suggest that Klf10 is involved in tooth development and promotes odontoblastic differentiation via the up-regulation of Dmp1 and Dspp transcription.

Bmp2 deletion causes an amelogenesis imperfecta phenotype via regulating enamel gene expression.

Although Bmp2 is essential for tooth formation, the role of Bmp2 during enamel formation remains unknown in vivo. In this study, the role of Bmp2 in regulation of enamel formation was investigated by the Bmp2 conditional knock out (Bmp2 cKO) mice. Teeth of Bmp2 cKO mice displayed severe and profound phenotypes with asymmetric and misshaped incisors as well as abrasion of incisors and molars. Scanning electron microscopy analysis showed that the enamel layer was hypoplastic and enamel lacked a typical prismatic pattern. Teeth from null mice were much more brittle as tested by shear and compressive moduli. Expression of enamel matrix protein genes, amelogenin, enamelin, and enamel-processing proteases, Mmp-20 and Klk4 was reduced in the Bmp2 cKO teeth as reflected in a reduced enamel formation. Exogenous Bmp2 up-regulated those gene expressions in mouse enamel organ epithelial cells. This result for the first time indicates Bmp2 signaling is essential for proper enamel development and mineralization in vivo.