Case report: A severe clinical phenotype of pontocerebellar hypoplasia type 7 with compound heterozygous variants of TOE1.

Pontocerebellar Hypoplasia (PCH) is a rare autosomal recessive hereditary neurological degenerative disease. To elaborate upon the clinical phenotypes of PCH and explore the correlation between TOE1 gene mutations and clinical phenotype, we analyze the clinical and genetic features of a Chinese infant afflicted with pontocerebellar dysplasia accompanied by gender reversal with bioinformatics methods. The main clinical features of this infant with TOE1 gene mutation included progressive lateral ventricle widening, hydrocephalus, severe postnatal growth retardation, and hypotonia, and simultaneously being accompanied by 46, XY female sex reversal. Whole exome sequencing revealed a compound heterozygous mutation in the TOE1 gene (c.299T > G, c.1414T > G), with the protein homology modeling-generated structure predicting a pathogenic variation, which is closely related to the clinical manifestations in the patient. The new mutation sites, c.299T > G and c.1414T > G, in the TOE1 gene are pathogenic variants of pontocerebellar hypoplasia type 7.

Genetic algorithm-based semisupervised convolutional neural network for real-time monitoring of Escherichia coli fermentation of recombinant protein production using a Raman sensor.

As a non-destructive sensing technique, Raman spectroscopy is often combined with regression models for real-time detection of key components in microbial cultivation processes. However, achieving accurate model predictions often requires a large amount of offline measurement data for training, which is both time-consuming and labor-intensive. In order to overcome the limitations of traditional models that rely on large datasets and complex spectral preprocessing, in addition to the difficulty of training models with limited samples, we have explored a genetic algorithm-based semi-supervised convolutional neural network (GA-SCNN). GA-SCNN integrates unsupervised process spectral labeling, feature extraction, regression prediction, and transfer learning. Using only an extremely small number of offline samples of the target protein, this framework can accurately predict protein concentration, which represents a significant challenge for other models. The effectiveness of the framework has been validated in a system of Escherichia coli expressing recombinant ProA5M protein. By utilizing the labeling technique of this framework, the available dataset for glucose, lactate, ammonium ions, and optical density at 600 nm (OD600) has been expanded from 52 samples to 1302 samples. Furthermore, by introducing a small component of offline detection data for recombinant proteins into the OD600 model through transfer learning, a model for target protein detection has been retrained, providing a new direction for the development of associated models. Comparative analysis with traditional algorithms demonstrates that the GA-SCNN framework exhibits good adaptability when there is no complex spectral preprocessing. Cross-validation results confirm the robustness and high accuracy of the framework, with the predicted values of the model highly consistent with the offline measurement results.

Bioorthogonal Functionalization of Material Surfaces with Bioactive Molecules.

The functionalization of material surfaces with biologically active molecules is crucial for enabling technologies in life sciences, biotechnology, and medicine. However, achieving biocompatibility and bioorthogonality with current synthetic methods remains a challenge. We report herein a novel surface functionalization method that proceeds chemoselectively and without a free transition metal catalyst. In this method, a coating is first formed via the tyrosinase-catalyzed putative polymerization of a tetrazine-containing catecholamine (DOPA-Tet). One or more types of molecule of interest containing trans-cyclooctene are then grafted onto the coating via tetrazine ligation. The entire process proceeds under physiological conditions and is suitable for grafting bioactive molecules with diverse functions and structural complexities. Utilizing this method, we functionalized material surfaces with enzymes (alkaline phosphatase, glucose oxidase, and horseradish peroxidase), a cyclic peptide (cyclo[Arg-Gly-Asp-D-Phe-Lys], or c(RGDfK)), and an antibiotic (vancomycin). Colorimetric assays confirmed the maintenance of the biocatalytic activities of the grafted enzymes on the surface. We established the mammalian cytocompatibility of the functionalized materials with fibroblasts. Surface functionalization with c(RGDfK) showed improved fibroblast cell morphology and cytoskeletal organization. Microbiological studies with Staphylococcus aureus indicated that surfaces coated using DOPA-Tet inhibit the formation of biofilms. Vancomycin-grafted surfaces additionally display significant inhibition of planktonic S. aureus growth.

Non-coding RNA in cancer drug resistance: Underlying mechanisms and clinical applications.

Cancer is one of the most frequently diagnosed malignant diseases worldwide, posing a serious, long-term threat to patients' health and life. Systemic chemotherapy remains the first-line therapeutic approach for recurrent or metastatic cancer patients after surgery, with the potential to effectively extend patient survival. However, the development of drug resistance seriously limits the clinical efficiency of chemotherapy and ultimately results in treatment failure and patient death. A large number of studies have shown that non-coding RNAs (ncRNAs), particularly microRNAs, long non-coding RNAs, and circular RNAs, are widely involved in the regulation of cancer drug resistance. Their dysregulation contributes to the development of cancer drug resistance by modulating the expression of specific target genes involved in cellular apoptosis, autophagy, drug efflux, epithelial-to-mesenchymal transition (EMT), and cancer stem cells (CSCs). Moreover, some ncRNAs also possess great potential as efficient, specific biomarkers in diagnosis and prognosis as well as therapeutic targets in cancer patients. In this review, we summarize the recent findings on the emerging role and underlying mechanisms of ncRNAs involved in cancer drug resistance and focus on their clinical applications as biomarkers and therapeutic targets in cancer treatment. This information will be of great benefit to early diagnosis and prognostic assessments of cancer as well as the development of ncRNA-based therapeutic strategies for cancer patients.

SUMOylation of SYNJ2BP-COX16 promotes breast cancer progression through DRP1-mediated mitochondrial fission.

Treatments targeting oncogenic fusion proteins are notable examples of successful drug development. Abnormal splicing of genes resulting in fusion proteins is a critical driver of various tumors, but the underlying mechanism remains poorly understood. Here, we show that SUMOylation of the fusion protein Synaptojanin 2 binding protein-Cytochrome-c oxidase 16 (SYNJ2BP-COX16) at K107 induces mitochondrial fission in breast cancer and that the K107 site regulates SYNJ2BP-COX16 mitochondrial subcellular localization. Compared with a non-SUMOylated K107R mutant, wild-type SYNJ2BP-COX16 contributed to breast cancer cell proliferation and metastasis in vivo and in vitro by increasing adenosine triphosphate (ATP) production and cytochrome-c oxidase (COX) activity. SUMOylated SYNJ2BP-COX16 recruits dynamin-related protein 1 (DRP1) to the mitochondria to promote ubiquitin-conjugating enzyme 9 (UBC9) binding to DRP1, enhance SUMOylation of DRP1 and phosphorylation of DRP1 at S616, and then induce mitochondrial fission. Moreover, Mdivi-1, an inhibitor of DRP1 phosphorylation, decreased the localization of DRP1 in mitochondria, and prevents SYNJ2BP-COX16 induced mitochondrial fission, cell proliferation and metastasis. Based on these data, SYNJ2BP-COX16 promotes breast cancer progression through the phosphorylation of DRP1 and subsequent induction of mitochondrial fission, indicating that SUMOylation at the K107 residue of SYNJ2BP-COX16 is a novel potential treatment target for breast cancer.

pH Stimuli-Responsive, Rapidly Self-healable Coatings Enhanced the Corrosion Resistance and Osteogenic Differentiation of Mg-1Ca Osteoimplant.

Mg-Ca alloys have emerged as a promising research direction for biomedical implants in the orthopedic field. However, their clinical use is deterred by their fast corrosion rate. In this work, a pH stimuli-responsive silk-halloysite (HNT)/phytic acid (PA) self-healing coating (Silk-HNT/PA) is constructed to slow down the corrosion rate of Mg-1Ca alloy and its cell viability and osteogenic differentiation ability are enhanced. The Silk-HNT/PA coating exhibits appealing active corrosion protection, by eliciting pH-triggerable self-healing effects, while simultaneously affording superior biocompatibility and osteogenic differentiation ability. Moreover, in vivo studies by histological analysis also demonstrate better osseointegration for the Silk-HNT/PA coated Mg-1Ca alloy. In summary, the Silk-HNT/PA coating in the present study has great potential in enhancing the biomedical utility of Mg alloys.

Mussel bioinspired morphosynthesis of substrate anchored core-shell silver self-assemblies with multifunctionality for bioapplications.

Core-shell nanoparticles (CSNs) have numerous intriguing properties for advanced device applications, while it remains challenging to directly grow them from a solid substrate. Here, we report a simple mussel-bioinspired solid chemistry strategy for in-situ synthesis of CSNs that are substrate anchored and morphologically tunable for wide-ranging biotechnological applications. Briefly, silver titanate was hydrothermally grown on template titanium and subjected to reaction with mussel-derived dopamine. The synergistic reactivity between silver titanate and dopamine prompted nanosilver/polydopamine (nAg/PD) CSNs to spontaneously assemble and grow on substrate. These CSNs possessed reaction time-dependent dimensions and morphologies, which were related to differing physiochemical properties and biological behaviors. Specifically, the CSNs-modified substrates demonstrated enhanced protein affinity and durable radical scavenging properties. In addition, they manifested remarkable yet robust release-killing and anti-biofilm activities against pathogenic Staphylococcus aureus bacteria. More delightedly, the surface-engineered substrates guaranteed the victory of the anti-infective battle of osteoblastic cells during cell/bacteria coculture, promising applications in implantable medical devices. The adaptability of this strategy was demonstrated by modifying complicated 3D-printed macroporous tissue engineering scaffolds. Intriguingly, the CSNs-modified scaffolds exhibited photothermal performances that bode well for phototherapy. To sum, our strategy combines the simplicity of synthesis modality, the controllability of core-shell silver structures, and the versatility of material functions. The resulting assemblies can enrich the library of nAg-based core-shell engineered nanomaterials.

Catecholamine-Copper Redox as a Basis for Site-Specific Single-Step Functionalization of Material Surfaces.

Realization of robust and facile surface functionalization processes is critical to biomaterials and biotechnology yet remains a challenge. Here, we report a new chemical approach that enables operationally simple and site-specific surface functionalization. The mechanism involves a catechol-copper redox chemistry, where the oxidative polymerization of an alkynyl catecholamine reduces Cu(II) to Cu(I), which in situ catalyzes a click reaction with azide-containing molecules of interest (MOIs). This process enables drop-coating and grafting of two- and three-dimensional solid surfaces in a single operation using as small as sub-microliter volumes. Generalizability of the method is shown for immobilizing MOIs of diverse structure and chemical or biological activity. Biological applications in anti-biofouling, cellular adhesion, scaffold seeding, and tissue regeneration are demonstrated, in which the activities or fates of cells are site-specifically manipulated. This work advances surface chemistry by integrating simplicity and precision with multipurpose surface functionalization.

Controllable biodegradation and enhanced osseointegration of ZrO2-nanofilm coated Zn-Li alloy: In vitro and in vivo studies.

Zinc and its alloys have emerged as a new research direction of biodegradable metals (BMs) due to the significant physiological functions of Zn2+ ions in human body. However, low inhibitory concentration threshold value to cause cytotoxicity by Zn2+ ions during in vitro study and delayed osseointegration in vivo are two key flaws for the bulk Zn-based BMs. To combat these issues, we constructed a barrier layer of ZrO2 nanofilm on the surface of Zn-0.1(wt.%) Li alloy via atomic layer deposition (ALD). A decreased release of Zn2+ ions accompanied with accelerated release of Li+ ions was observed on account of galvanic coupling between the coating compositions and Zn-0.1Li alloy substrate. Cytocompatibility assay reflected that ZrO2 nanofilm coated Zn-0.1Li alloy exhibited improved cell adhesion and viability. Histological analysis also demonstrated better in vivo osseointegration for the ZrO2 nanofilm coated Zn-0.1Li alloy. Hence, the present study elucidated that the ALD of ZrO2 nanofilm on Zn-based BMs can effectively promote osseointegration and control their biodegradation behavior. STATEMENT OF SIGNIFICANCE: Zn-Li binary alloy was reported recently to be the promising biodegradable metals with ultimate tensile strength over 500 MPa, yet the low inhibitory concentration threshold value to cause cytotoxicity by Zn2+ ions is the obstacle needed to be overcome. As a pilot study, a systematic investigation on the ZrO2 nanofilm coated Zn-Li alloy, prepared by atomic layer deposition (ALD) technique, was conducted in the present study, which involved in the formation process, in vitro and in vivo degradation behavior as well as biocompatibility evaluation. We found a controllable corrosion rate and better in vivo osseointegration can be achieved by ZrO2 nanofilm coating on Zn-Li alloy, which provides new insight into the surface modification on biodegradable Zn alloys for usage within bone.

Osteogenic and pH stimuli-responsive self-healing coating on biomedical Mg-1Ca alloy.

Various coatings have been used to slow down the corrosion rate of biomedical magnesium alloys. However, these coatings usually act only as passive barriers. It is much more desirable to endow such coatings with active, biocorrosion-responsive self-repairing capacity. In the present work, a self-healing coating system (denoted as "silk-PA") was constructed in the form of a sandwich architecture of fluoride precoating (bottom), silk-phytic acid (PA) coating (middle), and silk fibroin coating (top). Here, PA was loaded in the middle coating as a corrosion inhibitor by harnessing its strong chelating ability toward dissolving Mg2+ and Ca2+ ions. The self-healing property was evaluated by scratch and SVET tests, and the corrosion resistance was evaluated by in vitro immersion and electrochemical measurements. The results showed that the silk-PA manifested intriguing self-healing capacity with pH responsiveness, hence profiting the corrosion resistance of the Mg-1Ca alloy. The biocompatibility and osteogenic activity of the coating system were further evaluated using MC3T3-E1 cells, and it demonstrated favorable responses in multiple cellular behaviors, i.e., adherence, spreading, proliferation, and differentiation. These findings open new opportunities in the study of self-healing coatings for protection against corrosion in biomedical Mg alloys. STATEMENT OF SIGNIFICANCE: In the present study, a self-healing coating system with pH stimuli-responsiveness and osteogenic activity was fabricated on Mg-1Ca alloy by integrating a silk fibroin barrier coating, a silk fibrin/phytic acid composite coating, and a fluoride precoating. This coating system demonstrated interesting self-healing ability as compared to traditional surface modification layers. Furthermore, the self-healing ability enhanced the corrosion resistance of biomedical magnesium alloys, while effective compositions of the coating system endowed the substrate with osteogenic activity. This work provides some new insights into smart surface modification for biomedical Mg alloys.

A pH-sensitive self-healing coating for biodegradable magnesium implants.

Self-healing coatings have attracted attention on surface modification of magnesium alloys, as it can recover the barrier ability of the coatings from corrosion attack. Nevertheless, previous works on this aspect are not suitable for biomedical magnesium alloys owing to the lack of biocompatibility. In this study, we fabricated a self-healing coating on biomedical Mg-1Ca alloy by compositing silk fibroin and K3PO4. PO43- ions act as corrosion inhibitor, while K3+ ions help to regulate the secondary structures of silk fibroin. The scratch test, scanning vibrating electrode technique (SVET), and electrochemical impedance spectroscopy (EIS) provide comprehensive results, confirming the pH-sensitive self-healing capacity of the composite coating. Moreover, cells' (MC3T3-E1) multiple responses including spreading, adhesion, proliferation, and differentiation illustrate the preferable biocompatibility as well as the osteogenic activity of the coating. These primary findings might open new opportunities in the exploration of self-healing coatings on biomedical magnesium alloys. STATEMENT OF SIGNIFICANCE: Biomedical magnesium alloys surface modifications have been studied for years, which however the biomedical self-healing coatings were rarely involved. In this work, silk fibroin and phosphate (K3PO4) were composited to fabricate coating on biomedical magnesium alloys. The coating not only owned the self-healing ability with pH sensitivity, but also endowed the substrate preferable corrosion resistance as well as osteogenic activity. This work gives a new insight into surface modification for biomedical Mg alloys.

Triple-Bioinspired Burying/Crosslinking Interfacial Coassembly Strategy for Layer-by-Layer Construction of Robust Functional Bioceramic Self-Coatings for Osteointegration Applications.

Coating bioceramics of inherent bioactivity onto biometallic implants is a straightforward yet promising solution to address poor osteointegration of the latter. One step further, it would be a nontrivial accomplishment to develop a mild, cheap, and universal route to firmly stabilizing, in principle, any ceramics onto any implant substrate, while imparting expectedly versatile biofunctional performances. Herein, we describe a triple-bioinspired burying/cross-linking interfacial coassembly strategy for enabling such ceramic coatings, which ingeniously fuses bioinspiration from sea rocks (burying assisted particle immobilization), marine mussels (universal adhesion and versatile chemical reactivity), and reef-building oysters (cross-linking rendered cohesion). Specifically, surface functionalized, aqueous dispersed ceramic particles were buried within an substrate-anchored organic matrix of polyelectrolyte multilayers (i.e., (poly(ether imide) (PEI)/poly(sodium-p-styrenesulfonate) (PSS)) n), through a new inorganic-organic hybrid layer-by-layer (LBL) coassembly scheme wherein mussel (oyster) inspired adhesive (cohesive) chemistries were exquisitely orchestrated. As a conceptual demonstration, bioactive baghdadite (Ca3ZrSi2O9) was synthesized as model ceramics, with which we constructed on medical titanium robust, biomimetic, and cross-linkable LBL self-assemblies harnessing the said strategy. Intimate substrate contacts and well-defined buried inorganic-organic interfaces were evidently seen, together with good structural and chemical stabilities, especially after cross-linking. Sustained bioactive ion releasing and appreciable biomineralization activity were confirmed in vitro. Subsequently, biological performances of the assemblies were systematically investigated with respect to surface hydrophilicity, protein adsorption, and osteoblast functions. Additionally, nanosilver deposition, which imparted the surfaces with added antibacterial potencies, was used to exemplify the strategy's versatility in allowing multifunctionality. What's more, the flexibility of our approach was testified through modifying clinically relevant complicated 3D porous scaffolds. Overall, our strategy basically met the design expectations, boding well for future medical adoption. This study offers the promise of an alternative broadly useful avenue to bioactive and functional surface design of bone implants. It may also provide insights into other multiple-bioinspired materials/interfaces for biological and other applications.

Constructing Multilayer Silk Protein/Nanosilver Biofunctionalized Hierarchically Structured 3D Printed Ti6Al4 V Scaffold for Repair of Infective Bone Defects.

Biomaterials-enabled regenerative medicine in orthopedics is challenged with infective bone defects that do not heal normally. Three-dimensional (3D) scaffold biomaterials simultaneously emulating skeletal hierarchy and eliciting sustainable osteogenetic and antibacterial functionalities represent a potent solution holding increasing fascination. Here we describe a simple combinatorial strategy for constructing such scaffolds. Fully porous titanium was first tailor-made by metallic powder 3D printing and subjected to in situ hydrothermal growth of a micro/nanostructured titanate layer, to which nanosilver encapsulated, physically cross-linked silk fibrin multilayer films were anchored through polydopamine-assisted, silk-on-silk self-assembly. The hydrophilicity, protein adsorption, and surface bioactivity of the scaffolds were investigated. Employing clinically relevant pathogenic Staphylococcus aureus bacteria, we tested that the silver immobilized scaffolds not only reduced adherence of bacteria on the surface, they also actively killed those planktonic, and these performances were largely maintained over an extended period of 6 weeks. Additionally, our engineered scaffolds were amenable to 14 days' continuous, intense bacterial attacks showing little sign of biofilm colonization, and they were interestingly capable of eradicating bacteria in already formed biofilms. High cargo loading, durable topical Ag+ release, and overwhelming oxidative stress were shown to contribute to this sustainable antibacterial system. Irrespective of certain degree of cellular stress at early stages, our scaffolds elicited generally enhanced cell proliferation, alkaline phosphatase enzyme production, and matrix calcification of osteoblastic MC3T3-E1. These multifunctionalities, coupled with the design freedom, shape flexibility, and cost-effectiveness offered by 3D printing, make our scaffold biomaterials a promising option for customized restoration of complicated infective bone defects.

Endowing polyetheretherketone with synergistic bactericidal effects and improved osteogenic ability.

Biomedical associated infections (BAI) are difficult to treat and may even lead to amputation and death, especially after the emergence of drug-resistant bacteria. The aim of this study was to harness the potential synergistic effects of multiple bactericidal agents to endow polyetheretherketone (PEEK) with the ability of achieving full eradication of planktonic and adherent bacteria while maintaining acceptable biocompatibility. In this work, a mussel inspired, silver nanoparticles (AgNPs) incorporated silk fibroin (SF)/gentamicin sulfate (GS) coating was constructed upon porous PEEK surface. The obtained coating greatly enhanced the bactericidal efficiency to Gram-positive bacteria and Gram-negative bacteria. The number of bacteria survived in the culture medium after treated with this coating was 106 fold lower than that survived after treated with PEEK sample, while the number of viable bacteria adhered to this coating was 105 lower than that adhered to PEEK sample. Furthermore, release of Ag+ and GS increased with decreasing pH, indicating great potential of this coating to be a "smart" bacteria-triggered self-defensive coating. Meanwhile, this functional coating shows favorable cytocompatibility and osteogenic ability. The mechanism behind this dual function is also partially revealed. Expectedly, this "smart" dual function coating can give a promise for PEEK to become a solution to increasingly deteriorated BAI. STATEMENT OF SIGNIFICANCE: In this study, a mussel inspired, silver nanoparticles (AgNPs) incorporated silk fibroin (SF)/gentamicin sulfate (GS) coating was constructed upon porous polyetheretherketone (PEEK) surface. This design was aimed to provide a solution to the increasingly deteriorated biomedical associated infections (BAI). Actually, this design endowed PEEK with dual function: bacteria-triggered synergistic bactericidal effect and improved osteogenic ability. The combination of silver and GS exhibited synergistic bacteria killing effect on both Gram-positive and Gram-negative bacteria, which showed 106 times higher in releasing-killing and 105 times higher in anti-adhesion than that of untreated PEEK. Furthermore, release of bactericidal agents increased with decreasing pH, indicating great potential of this coating to be a bacteria-triggered self-defensive coating. More interestingly, this study revealed the mechanism of synergistic effect between silver and GS.

Novel pH-responsive tobramycin-embedded micelles in nanostructured multilayer-coatings of chitosan/heparin with efficient and sustained antibacterial properties.

To endow orthopaedic implants with satisfactory antibacterial properties, the design and development of antibiotic coating on the surface of implants is highly desired. In this work a novel and facile strategy was developed to form pH-responsive layer-by-layer (LbL) films implanted with polymeric micelles as nano-vehicles loaded with charge-weak antibiotic drugs, enabling high drug loading efficiency. Negatively charged tobramycin (Tob)-embeded heparin miscells (HET) and positively charged chitosan (CHT) were exploited as a pH-responsive LBL multilayer building block, respectively. The formation mechanism and pH-stimulated release behavior of the Tob-contained heparin micelles were studied. The characterization on the morphologies, chemical compositions and hydrophilicity of the modified surface confirmed the successuful deposition of the Tob-loaded CHT/HET multilayers coatings on the polydopamine-modified Ti surface. The drug release profiles displayed fast release at pH 7.4 and slow release after exposure to weakly acidic environments. Antibacterial tests indicated that the Tob-embed CHT/HET nanostructured multilayers not only strongly inhibited initial bacterial adhesion, but also disruptted biofilm formation. Particularly, this functional coatings showed "long-term antibacterial" pattern in acid condition. Meanwhile, MC3T3 cells showed acceptable adhesion, spread and proliferation on the multilayer coatings in cytocompatible studies. In a word, these multilayer coatings incorporated with a wide variety of antibiotics show promisiong applications in preventing postoperative infection and resolving unmet clinical need.

Effect of vanadium released from micro-arc oxidized porous Ti6Al4V on biocompatibility in orthopedic applications.

MAO-treated porous Ti6Al4V holds enormous potential for use in orthopedic implants due to their excellent biocompatibility and favourable mechanical strength. However, the effects on the V ion accumulation and release following the MAO-treated Ti6Al4V remain undetermined. The aim of the present study was to assess the effects of Vanadium on biocompatibility. In this study, the surface features and chemical compositions were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The ion release of Ti, Al and V was quantitatively measured by inductively-coupled plasma mass spectroscopy (ICP-MS) after immersion in Hanks' solution. To probe the mechanism of V release, the corrosion resistance of porous Ti6Al4V before and after the MAO process was evaluated by electrochemical tests. Thereafter, the effects on the biocompatibility were tested in vitro by cell culture assays and then in vivo by subcutaneous embedment. Finally, the bone tissue response and in vivo release profile of V ions were characterized by intra-osseous implantation. Therefore, this study suggests that the effect of V released from MAO-treated porous Ti6Al4V on biocompatibility and application safety is small and preventable.

U-box ubiquitin ligase PPIL2 suppresses breast cancer invasion and metastasis by altering cell morphology and promoting SNAI1 ubiquitination and degradation.

Metastasis is the leading cause of breast cancer fatalities. To develop new therapeutic strategies, the mechanisms underlying breast cancer invasion and metastasis need to be further investigated. Peptidylprolyl isomerase (cyclophilin)-like 2 (PPIL2) is a U-box-type E3 ubiquitin ligase belonging to the cyclophilin family. Proteins within this family are the major cytosolic binding proteins of the immunosuppressant drug cyclosporine A (CsA). Although PPIL2 has been reported to potentially be involved in cell migration, its role in breast cancer is still unclear. Herein, we demonstrate that PPIL2 suppressed metastasis in a breast cancer model by altering cell morphology and suppressing the epithelial-mesenchymal transition (EMT) process. Moreover, elevated PPIL2 inhibited EMT and breast cancer invasion by interacting with the classical EMT transcription factor, SNAI1, to enhance its ubiquitin-dependent degradation. Furthermore, PPIL2 protein level and stability was upregulated after CsA treatment, indicating that PPIL2 might be involved in CsA-mediated repression of EMT in breast cancer. Analysis of tissue samples taken from breast cancer patients showed a significant correlation between the expression of PPIL2 and the degree of cancer invasion and metastasis. In summary, these results would shed light on a potential clinical use of CsA in breast cancer patients.

Unraveling the osteogenesis of magnesium by the activity of osteoblasts in vitro.

Magnesium (Mg) alloys, having a unique combination of strength and degradation, are being explored for various craniofacial and orthopedic applications. Nevertheless, the underlying mechanism of Mg2+ to stimulate bone formation needs further investigation. In this in vitro study, the degradation behavior of pure Mg and the effect of Mg2+ on the activity of osteoblasts were elucidated. From the corrosion test, it was determined that the degradation of pure Mg was able to create an alkaline microenvironment. It was further determined that Mg2+ promoted the proliferation and differentiation of osteoblasts. By western blotting analysis, it was noted that Mg2+ increased the phosphorylation of ERK (enhanced the c-fos level) and induced GSK3ß phosphorylation (enhanced the ß-catenin levels). These results demonstrated that the degradation of Mg was able to promote the proliferation and differentiation of osteoblasts, which may be related to the newly created alkaline microenvironment and the osteogenesis potential of released Mg2+ through the MAPK/ERK signaling pathway.

Biomimetic Ca, Sr/P-Doped Silk Fibroin Films on Mg-1Ca Alloy with Dramatic Corrosion Resistance and Osteogenic Activities.

Magnesium and its alloys have emerged as some of the most promising biodegradable metals for temporary bone implants, but challenges remain in controlling their corrosion and biocompatibility and endowing them with bioactivity and osteogenic functionality. Herein, we presented newly developed bioactive Ca, Sr/P-containing silk fibroin films (the Ca, Sr/P silk) on top of Mg-1Ca alloy to simultaneously improve the corrosion resistance, osteocompatibility, and osteogenic activities important in maintaining mechanical integrity and stimulating bone formation, respectively. Briefly, extracellular matrix (ECM) mimicking Ca, Sr/P silk fibroin films were constructed layer upon layer on fluoridized Mg-1Ca alloy via simple spinning assembly. The corrosion resistance property of different samples was studied in vitro by immersion experiments and electrochemistry measurements in Hanks' solution, with the silk-coated ones showing over 1 order of magnitude increase in corrosion resistance compared to the uncoated. Particularly, the Ca, Sr/P silk had the best anticorrosion performance, presumably because of better retaining of the ß-sheet silk conformation and ion-induced structural conversion from random coils to silk I and α-helices. Furthermore, the preliminary study of the corrosion behavior of the Ca, Sr/P silk was confirmed the availability of the films for corrosion resistance improvement. The osteocompatibility and osteogenic activities were evaluated by the multiple osteoblast (MC3T3-E1) responses, i.e., proliferation, adherence, spreading, and differentiation in vitro. The Ca, Sr/P silk exhibited the optimal osteogenic activity among all experimental groups. These preliminary results comprehensively confirmed the validity of the coating strategy and they implicated the great potential of the modified Mg alloys as degradable bone implants.