4-(Triethoxysilyl)butanoic acid as a self-assembled monolayer for surface modification of titanium dioxide.

In this study, the carboxy silane 4-(triethoxysilyl)butanoic acid (TESBA) was used to modify titanium dioxide (TiO2) to create a self-assembled monolayer (SAM) and then directionally immobilize a capture antibody using protein A. We selected the amino silane (3-aminopropyl)triethoxysilane (APTES) to perform a comparative analysis with TESBA, and employed glutaraldehyde (GA) as the control. The modification and detection effects and the limit of detection (LOD) were evaluated by detecting human immunoglobulin G (IgG). The average normalized sensitivity of the dual-grating coupler waveguide biosensor was 49.63 ± 0.27 RIU-1 and the optimum resolution was 1.30 × 10-6 RIU. When the SAM was prepared using TESBA and APTES followed by GA, the LOD was 4.59 × 10-7 g mL-1 and 5.29 × 10-7 g mL-1, respectively. We analyzed the modification and detection effects by the t-test and concluded that the differences in the modification effects using TESBA and APTES followed by GA were significant and the differences in the detection effects using TESBA and APTES followed by GA were insignificant. The use of TESBA as the SAM led to the modification effect being superior to that obtained using APTES followed by GA. The detection effect using TESBA was as outstanding as that using APTES followed by GA. Our findings demonstrate the feasibility and effectiveness of using TESBA as the SAM to carboxylate the surface of TiO2, thereby enabling immobilization of biomolecules for human IgG detection.

Impaired gut barrier integrity and reduced colonic expression of free fatty acid receptors in patients with Parkinson's disease.

BACKGROUND: Altered gut metabolites, especially short-chain fatty acids (SCFAs), in feces and plasma are observed in patients with Parkinson's disease (PD). OBJECTIVE: We aimed to investigate the colonic expression of two SCFA receptors, free fatty acid receptor (FFAR)2 and FFAR3, and gut barrier integrity in patients with PD and correlations with clinical severity. METHODS: In this retrospective study, colonic biopsy specimens were collected from 37 PD patients and 34 unaffected controls. Of this cohort, 31 participants (14 PD, 17 controls) underwent a series of colon biopsies. Colonic expression of FFAR2, FFAR3, and the tight junction marker ZO-1 were assayed by immunofluorescence staining. The You Only Look Once (version 8, YOLOv8) algorithm was used for automated detection and segmentation of immunostaining signal. PD motor function was assessed with the Movement Disorder Society (MDS)-Unified Parkinson's Disease Rating Scale (UPDRS), and constipation was assessed using Rome-IV criteria. RESULTS: Compared with controls, PD patients had significantly lower colonic expression of ZO-1 (p < 0.01) and FFAR2 (p = 0.01). On serial biopsy, colonic expression of FFAR2 and FFAR3 was reduced in the pre-motor stage before PD diagnosis (both p < 0.01). MDS-UPDRS motor scores did not correlate with colonic marker levels. Constipation severity negatively correlated with colonic ZO-1 levels (r = -0.49, p = 0.02). CONCLUSIONS: Colonic expression of ZO-1 and FFAR2 is lower in PD patients compared with unaffected controls, and FFAR2 and FFAR3 levels decline in the pre-motor stage of PD. Our findings implicate a leaky gut phenomenon in PD and reinforce that gut metabolites may contribute to the process of PD.

The HSP40 family chaperone isoform DNAJB6b prevents neuronal cells from tau aggregation.

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disorder with clinical presentations of progressive cognitive and memory deterioration. The pathologic hallmarks of AD include tau neurofibrillary tangles and amyloid plaque depositions in the hippocampus and associated neocortex. The neuronal aggregated tau observed in AD cells suggests that the protein folding problem is a major cause of AD. J-domain-containing proteins (JDPs) are the largest family of cochaperones, which play a vital role in specifying and directing HSP70 chaperone functions. JDPs bind substrates and deliver them to HSP70. The association of JDP and HSP70 opens the substrate-binding domain of HSP70 to help the loading of the clients. However, in the initial HSP70 cycle, which JDP delivers tau to the HSP70 system in neuronal cells remains unclear. RESULTS: We screened the requirement of a diverse panel of JDPs for preventing tau aggregation in the human neuroblastoma cell line SH-SY5Y by a filter retardation method. Interestingly, knockdown of DNAJB6, one of the JDPs, displayed tau aggregation and overexpression of DNAJB6b, one of the isoforms generated from the DNAJB6 gene by alternative splicing, reduced tau aggregation. Further, the tau bimolecular fluorescence complementation assay confirmed the DNAJB6b-dependent tau clearance. The co-immunoprecipitation and the proximity ligation assay demonstrated the protein-protein interaction between tau and the chaperone-cochaperone complex. The J-domain of DNAJB6b was critical for preventing tau aggregation. Moreover, reduced DNAJB6 expression and increased tau aggregation were detected in an age-dependent manner in immunohistochemical analysis of the hippocampus tissues of a mouse model of tau pathology. CONCLUSIONS: In summary, downregulation of DNAJB6b increases the insoluble form of tau, while overexpression of DNAJB6b reduces tau aggregation. Moreover, DNAJB6b associates with tau. Therefore, this study reveals that DNAJB6b is a direct sensor for its client tau in the HSP70 folding system in neuronal cells, thus helping to prevent AD.

Phenotypic Heterogeneity in Patients with Mutations in the Mitochondrial Complex I Assembly Gene NDUFAF5.

BACKGROUND: Rare mutations in NADH:ubiquinone oxidoreductase complex assembly factor 5 (NDUFAF5) are linked to Leigh syndrome. OBJECTIVE: We aimed to describe clinical characteristics and functional findings in a patient cohort with NDUFAF5 mutations. METHODS: Patients with biallelic NDUFAF5 mutations were recruited from multi-centers in Taiwan. Clinical, laboratory, radiological, and follow-up features were recorded and mitochondrial assays were performed in patients' skin fibroblasts. RESULTS: Nine patients from seven unrelated pedigrees were enrolled, eight homozygous for c.836 T > G (p.Met279Arg) in NDUFAF5 and one compound heterozygous for p.Met279Arg. Onset age had a bimodal distribution. The early-onset group (age <3 years) presented with psychomotor delay, seizure, respiratory failure, and hyponatremia. The late-onset group (age ≥5 years) presented with normal development, but slowly progressive dystonia. Combing 25 previously described patients, the p.Met279Arg variant was exclusively identified in Chinese ancestry. Compared with other groups, patients with late-onset homozygous p.Met279Arg were older at onset (P = 0.008), had less developmental delay (P = 0.01), less hyponatremia (P = 0.01), and better prognosis with preserved ambulatory function into early adulthood (P = 0.01). Bilateral basal ganglia necrosis was a common radiological feature, but brainstem and spinal cord involvement was more common with early-onset patients (P = 0.02). A modifier gene analysis showed higher concomitant mutation burden in early-versus late-onset p.Met279Arg homozygous cases (P = 0.04), consistent with more impaired mitochondrial function in fibroblasts from an early-onset case than a late-onset patient. CONCLUSIONS: The p.Met279Arg variant is a common mutation in our population with phenotypic heterogeneity and divergent prognosis based on age at onset. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Sediment pollutant exposures caused hepatotoxicity and disturbed glycogenesis.

Liver metabolic syndrome, which involves impaired hepatic glycogen synthesis, is persistently increased by exposure to environmental pollutants. Most studies have investigated the pathogenesis of liver damage caused by single metal species or pure organics. However, under normal circumstances, the pollutants that we are exposed to are usually chemical mixtures that accumulate over time. Sediments are long-term repositories for environmental pollutants due to their environmental cycles, which make them good samples for evaluating the effect of environmental pollutants on the liver via bioaccumulation. This study aimed to clarify the effects of sediment pollutants on liver damage. Our results indicate that industrial wastewater sediment (downstream) is more cytotoxic than sediments from other zones. Downstream sediment extract (DSE) causes hepatotoxicity, stimulates reactive oxygen species (ROS) generation, triggers mitochondrial dysfunction, induces cell apoptosis, and results in the release of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) proteins. Additionally, to elucidate the underlying mechanism by which sediment pollutants disturb hepatic glycogen synthesis, we investigated the effects of different sediment samples from different pollution situations on glycogen synthesis in liver cell lines. It was found that DSE induced multiple severe impairments in liver cells, and disturbed glycogen synthesis more than under other conditions. These impairments include decreased hepatic glycogen synthesis via inhibition and insulin receptor substrate 1 (IRS-1) /AKT /glycogen synthase kinase3ß (GSK3ß)-mediated glycogen synthase (GYS) inactivation. To our knowledge, this study provides the first detailed evidence of in vitro sediment-accumulated toxicity that interferes with liver glycogen synthesis, leading to hepatic cell damage through apoptosis.

Proteomic and microbial assessments on the effect of Antrodia cinnamomea in C57BL/6 mice.

Antrodia cinnamomea (AC) is a nutraceutical fungus and studies have suggested that AC has the potential to prevent or alleviate diseases. However, little is known about the AC-induced phenotypes on the intestine-liver axis and gut microbial alterations. Here, we performed two-dimensional difference gel electrophoresis (2D-DIGE) and MALDI-Biotyper to elaborate the AC-induced phenotypes on the intestine-liver axis and gut microbial distribution of C57BL/6 mice. The experimental outcomes showed that the hepatic density may increase by elevating hepatic redox regulation, lipid degradation and glycolysis-related proteins and alleviating cholesterol biosynthesis and transport-related proteins in C57BL/6 mice with AC treatment. Moreover, AC facilitates intestinal glycolysis, TCA cycle, redox and cytoskeleton regulation-related proteins, but also reduces intestinal vesicle transport-related proteins in C57BL/6 mice. However, the body weight, GTT, daily food/water intake, and fecal/urine weight were unaffected by AC supplementation in C57BL/6 mice. Notably, the C57BL/6-AC mice had a higher gut microbial abundance of Alistipes shahii (AS) than C57BL/6-Ctrl mice. In summary, the AC treatment affects intestinal permeability by regulating redox and cytoskeleton-related proteins and elevates the gut microbial abundance of AS in C57BL/6 mice that might be associated with increasing hepatic density and metabolism-related proteins of the liver in C57BL/6 mice. Our study provides an insight into the mechanisms of AC-induced phenotypes and a comprehensive assessment of AC's nutraceutical effect in C57BL/6 mice.

Biomarker discovery in highly invasive lung cancer cell through proteomics approaches.

Lung cancer is one of the leading causes of cancer-related death worldwide. The most common type of lung cancer is non-small cell lung cancer (NSCLC). When NSCLC is detected, patients are typically already in a metastatic stage. Metastasized cancer is a major obstacle of effective treatment and understanding the mechanisms underlying metastasis is critical to treat cancer. Herein, we selected an invasive subpopulation from the human lung cancer cell line A549 using the transwell system and named it as A549-I5. Invasive and migratory activities of this cell line were analysed using wound healing, invasion, and migration assays. In addition, epithelial-mesenchymal transition (EMT) markers, such as Snail 1, Twist, Vimentin, N-cadherin and E-cadherin, were assessed through immunoblotting. In comparison to A549 cells, the invasive A549-I5 lung cancer cells had enhanced invasiveness, motility and EMT marker expression. Proteomic analysis identified 83 significantly differentially expressed proteins in A549-I5 cells. These identified proteins were classified according to their cellular functions and most were involved in cytoskeleton, redox regulation, protein degradation and protein folding. In summary, our results provide potential diagnostic markers and therapeutic candidates for the treatment of NSCLC metastasis. SIGNIFICANCE OF THE STUDY: When NSCLC is detected, most patients are already in a metastatic stage. Herein, we selected an invasive subpopulation from a human lung cancer cell line which had increased EMT markers as well as high wound healing, invasion and migration abilities. Proteomic analysis identified numerous proteins associated with functions in cytoskeleton, redox regulation, protein degradation and protein folding that were differentially expressed in these cells. These results may provide potential diagnostic markers and therapeutic candidates for the treatment of NSCLC metastasis.

Targeting UDP-glucose dehydrogenase inhibits ovarian cancer growth and metastasis.

More than 70% of patients with ovarian cancer are diagnosed in advanced stages. Therefore, it is urgent to identify a promising prognostic marker and understand the mechanism of ovarian cancer metastasis development. By using proteomics approaches, we found that UDP-glucose dehydrogenase (UGDH) was up-regulated in highly metastatic ovarian cancer TOV21G cells, characterized by high invasiveness (TOV21GHI ), in comparison to its parental control. Previous reports demonstrated that UGDH is involved in cell migration, but its specific role in cancer metastasis remains unclear. By performing immunohistochemical staining with tissue microarray, we found overexpression of UGDH in ovarian cancer tissue, but not in normal adjacent tissue. Silencing using RNA interference (RNAi) was utilized to knockdown UGDH, which resulted in a significant decrease in metastatic ability in transwell migration, transwell invasion and wound healing assays. The knockdown of UGDH caused cell cycle arrest in the G0 /G1 phase and induced a massive decrease of tumour formation rate in vivo. Our data showed that UGDH-depletion led to the down-regulation of epithelial-mesenchymal transition (EMT)-related markers as well as MMP2, and inactivation of the ERK/MAPK pathway. In conclusion, we found that the up-regulation of UGDH is related to ovarian cancer metastasis and the deficiency of UGDH leads to the decrease of cell migration, cell invasion, wound healing and cell proliferation ability. Our findings reveal that UGDH can serve as a prognostic marker and that the inhibition of UGDH is a promising strategy for ovarian cancer treatment.

Progesterone receptor membrane component 1 is involved in oral cancer cell metastasis.

Cancer metastasis is a common cause of failure in cancer therapy. However, over 60% of oral cancer patients present with advanced stage disease, and the five-year survival rates of these patients decrease from 72.6% to 20% as the stage becomes more advanced. In order to manage oral cancer, identification of metastasis biomarker and mechanism is critical. In this study, we use a pair of oral squamous cell carcinoma lines, OC3, and invasive OC3-I5 as a model system to examine invasive mechanism and to identify potential therapeutic targets. We used two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to examine the global protein expression changes between OC3 and invasive OC3-I5. A proteomic study reveals that invasive properties alter the expression of 101 proteins in OC3-I5 cells comparing to OC3 cells. Further studies have used RNA interference technique to monitor the influence of progesterone receptor membrane component 1 (PGRMC1) protein in invasion and evaluate their potency in regulating invasion and the mechanism it involved. The results demonstrated that expression of epithelial-mesenchymal transition (EMT) markers including Twist, p-Src, Snail1, SIP1, JAM-A, vimentin and vinculin was increased in OC3-I5 compared to OC3 cells, whereas E-cadherin expression was decreased in the OC3-I5 cells. Moreover, in mouse model, PGRMC1 is shown to affect not only migration and invasion but also metastasis in vivo. Taken together, the proteomic approach allows us to identify numerous proteins, including PGRMC1, involved in invasion mechanism. Our results provide useful diagnostic markers and therapeutic candidates for the treatment of oral cancer invasion.

The Role of Transforming Growth Factor-Beta in Retinal Ganglion Cells with Hyperglycemia and Oxidative Stress.

A characteristic of diabetes mellitus is hyperglycemia, which is considered with an emphasis on the diabetic retinopathy of progressive neurodegenerative disease. Retinal ganglion cells (RGCs) are believed to be important cells affected in the pathogenesis of diabetic retinopathy. Transforming growth factor-beta (TGF-ß) is a neuroprotective protein that helps to withstand various neuronal injuries. To investigate the potential roles and regulatory mechanisms of TGF-ß in hyperglycemia-triggered damage of RGCs in vitro, we established RGCs in 5.5, 25, 50, and 100 mM D-glucose supplemented media and focused on the TGF-ß-related oxidative stress pathway in combination with hydrogen peroxide (H2O2). Functional experiments showed that TGF-ß1/2 protein expression was upregulated in RGCs with hyperglycemia. The knockdown of TGF-ß enhanced the accumulation of reactive oxygen species (ROS), inhibited the cell proliferation rate, and reduced glutathione content in hyperglycemia. Furthermore, the results showed that the TGF-ß-mediated enhancement of antioxidant signaling was correlated with the activation of stress response proteins and the antioxidant pathway, such as aldehyde dehydrogenase 3A1 (ALDH3A1), heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor (Nrf2), and hypoxia-inducible factor (HIF-1α). Summarizing, our results demonstrated that TGF-ß keeps RGCs from hyperglycemia-triggered harm by promoting the activation of the antioxidant pathway, suggesting a potential anti-diabetic therapy for the treatment of diabetic retinopathy.

Neural stem cells promote nerve regeneration through IL12-induced Schwann cell differentiation.

Regeneration of injured peripheral nerves is a slow, complicated process that could be improved by implantation of neural stem cells (NSCs) or nerve conduit. Implantation of NSCs along with conduits promotes the regeneration of damaged nerve, likely because (i) conduit supports and guides axonal growth from one nerve stump to the other, while preventing fibrous tissue ingrowth and retaining neurotrophic factors; and (ii) implanted NSCs differentiate into Schwann cells and maintain a growth factor enriched microenvironment, which promotes nerve regeneration. In this study, we identified IL12p80 (homodimer of IL12p40) in the cell extracts of implanted nerve conduit combined with NSCs by using protein antibody array and Western blotting. Levels of IL12p80 in these conduits are 1.6-fold higher than those in conduits without NSCs. In the sciatic nerve injury mouse model, implantation of NSCs combined with nerve conduit and IL12p80 improves motor recovery and increases the diameter up to 4.5-fold, at the medial site of the regenerated nerve. In vitro study further revealed that IL12p80 stimulates the Schwann cell differentiation of mouse NSCs through the phosphorylation of signal transducer and activator of transcription 3 (Stat3). These results suggest that IL12p80 can trigger Schwann cell differentiation of mouse NSCs through Stat3 phosphorylation and enhance the functional recovery and the diameter of regenerated nerves in a mouse sciatic nerve injury model.

Proteomic Analysis of Various Rat Ocular Tissues after Ischemia-Reperfusion Injury and Possible Relevance to Acute Glaucoma.

Glaucoma is a group of eye diseases that can cause vision loss and optical nerve damage. To investigate the protein expression alterations in various intraocular tissues (i.e., the cornea, conjunctiva, uvea, retina, and sclera) during ischemia-reperfusion (IR) injury, this study performed a proteomic analysis to qualitatively investigate such alterations resulting from acute glaucoma. The IR injury model combined with the proteomic analysis approach of two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to monitor the protein expression alterations in two groups of specimens (an IR injury group and a control group). The analysis results revealed 221 unique differentially expressed proteins of a total of 1481 proteins in the cornea between the two groups. In addition, 97 of 1206 conjunctival proteins, 90 of 1354 uveal proteins, 61 of 1180 scleral proteins, and 37 of 1204 retinal proteins were differentially expressed. These findings imply that different ocular tissues have different tolerances against IR injury. To sum up, this study utilized the acute glaucoma model combined with 2D-DIGE and MALDI-TOF MS to investigate the IR injury affected protein expression on various ocular tissues, and based on the ratio of protein expression alterations, the alterations in the ocular tissues were in the following order: the cornea, conjunctiva, uvea, sclera, and retina.

Enhanced sensitivity in injection-molded guided-mode-resonance sensors via low-index cavity layers.

We present an investigation on the use of low-index cavity layers to enhance the sensitivity of injection-molded guided-mode resonance (GMR) sensors. By adjusting the sputtering parameters, a low-index cavity layer is created at the interface between the waveguide layer and the substrate. Refractive index measurements show that a sensitivity enhancement of up to 220% is achieved with a cavity layer, in comparison to a reference GMR sensor without a cavity layer. Finite-element-method simulations were performed, and the results indicate that the cavities significantly redistribute the resonance mode profile and thus enhances the sensitivity. The present investigation demonstrates a new method for enhancing the sensitivity of injection-molded GMR sensors for high-sensitivity label-free biosensing.

Differential adhesion and actomyosin cable collaborate to drive Echinoid-mediated cell sorting.

Cell sorting involves the segregation of two cell populations into `immiscible' adjacent tissues with smooth borders. Echinoid (Ed), a nectin ortholog, is an adherens junction protein in Drosophila, and cells mutant for ed sort out from the surrounding wild-type cells. However, it remains unknown which factors trigger cell sorting. Here, we dissect the sequence of this process and find that cell sorting occurs when differential expression of Ed triggers the assembly of actomyosin cable. Conversely, Ed-mediated cell sorting can be rescued by recruitment of Ed, via homophilic or heterophilic interactions, to the wild-type cell side of the clonal interface, even when differential Ed expression persists. We found, unexpectedly, that when actomyosin cable was largely absent, differential adhesion was sufficient to cause limited cell segregation but with a jagged tissue border (imperfect sorting). We propose that Ed-mediated cell sorting is driven both by differential Ed adhesion that induces cell segregation with a jagged border and by actomyosin cable assembly at the interface that smoothens this border.

Activated PAR-2 regulates pancreatic cancer progression through ILK/HIF-α-induced TGF-α expression and MEK/VEGF-A-mediated angiogenesis.

Tissue factor initiates the process of thrombosis and activates cell signaling through protease-activated receptor-2 (PAR-2). The aim of this study was to investigate the pathological role of PAR-2 signaling in pancreatic cancer. We first demonstrated that activated PAR-2 up-regulated the protein expression of both hypoxia-inducible factor-1α (HIF-1α) and HIF-2α, resulting in enhanced transcription of transforming growth factor-α (TGF-α). Down-regulation of HIFs-α by siRNA or YC-1, an HIF inhibitor, resulted in depleted levels of TGF-α protein. Furthermore, PAR-2, through integrin-linked kinase (ILK) signaling, including the p-AKT, promoted HIF protein expression. Diminishing ILK by siRNA decreased the levels of PAR-2-induced p-AKT, HIFs-α, and TGF-α; our results suggest that ILK is involved in the PAR-2-mediated TGF-α via an HIF-α-dependent pathway. Furthermore, the culture medium from PAR-2-treated pancreatic cancer cells enhanced human umbilical vein endothelial cell proliferation and tube formation, which was blocked by the MEK inhibitor, PD98059. We also found that activated PAR-2 enhanced tumor angiogenesis through the release of vascular endothelial growth factor-A (VEGF-A) from cancer cells, independent of the ILK/HIFs-α pathways. Consistent with microarray analysis, activated PAR-2 induced TGF-A and VEGF-A gene expression. In conclusion, the activation of PAR-2 signaling induced human pancreatic cancer progression through the induction of TGF-α expression by ILK/HIFs-α, as well as through MEK/VEGF-A-mediated angiogenesis, and it plays a role in the interaction between cancer progression and cancer-related thrombosis.

Biomarker discovery for neuroendocrine cervical cancer.

Neuroendocrine cervical cancer is an aggressive but rare form of cervical cancer. The majority of neuroendocrine cervical cancer patients present with advanced-stage diseases. However, the limited numbers of neuroendocrine tumor markers are insufficient for clinical purposes. Thus, we used a proteomic approach combining lysine labeling 2D-DIGE and MALDI-TOF MS to investigate the biomarkers for neuroendocrine cervical cancer. By analyzing the global proteome alteration between the neuroendocrine cervical cancer line (HM-1) and non-neuroendocrine cervical cancer lines (CaSki cells, ME-180 cells, and Hela cells), we identified 82 proteins exhibiting marked changes between HM-1 and CaSki cells, and between ME-180 and Hela cells. Several proteins involved in protein folding, cytoskeleton, transcription control, signal transduction, glycolysis, and redox regulation exhibited significant changes in abundance. Proteomic and immunoblot analyses indicated respective 49.88-fold and 25-fold increased levels of transgelin in HM-1 cells compared with that in other non-neuroendocrine cervical cancer cell lines, implying that transgelin is a biomarker for neuroendocrine cervical cancer. In summary, we used a comprehensive neuroendocrine/non-neuroendocrine cervical cancer model based proteomic approach for identifying neuroendocrine cervical cancer markers, which might contribute to the prognosis and diagnosis of neuroendocrine cervical cancer.

Identification of up- and down-regulated proteins in doxorubicin-resistant uterine cancer cells: reticulocalbin-1 plays a key role in the development of doxorubicin-associated resistance.

Drug resistance is a frequent cause of failure in cancer chemotherapy treatments. In this study, a pair of uterine sarcoma cancer lines, MES-SA, and doxorubicin-resistant partners, MES-SA/DxR-2µM cells and MES-SA/DxR-8µM cells, as a model system to investigate resistance-dependent proteome alterations and to identify potential therapeutic targets. We used two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to perform this research and the results revealed that doxorubicin-resistance altered the expression of 208 proteins in which 129 identified proteins showed dose-dependent manners in response to the levels of resistance. Further studies have used RNA interference, H2A.X phosphorylation assay, cell viability analysis, and analysis of apoptosis against reticulocalbin-1 (RCN1) proteins, to prove its potency on the formation of doxorubicin resistance as well as the attenuation of doxorubicin-associated DNA double strand breakage. To sum up, our results provide useful diagnostic markers and therapeutic candidates such as RCN1 for the treatment of doxorubicin-resistant uterine cancer.

Depletion of 4E-BP1 and regulation of autophagy lead to YXM110-induced anticancer effects.

Natural products have always been a profuse database for developing new chemotherapeutics. YXM110 is a newly synthesized phenanthroquinolizidines that exhibits excellent anticancer activity in numerous cancer cells. In this study, we examined the anticancer mechanisms of YXM110 both in vitro and in vivo. Protein level of 4E-binding protein 1, which is crucial in cap-independent translation, was decreased significantly after YXM110 treatment via c-Jun N-terminal kinases-mediated proteasomal degradation. Moreover, the effects of YXM110 were associated with several characteristics of autophagy, including accumulation of autophagic vacuoles, elevation of Atg12-Atg5 and light chain 3 (LC3)-II, and levels of GFP-LC3 puncta. The results suggested that depletion of Mcl-1 contributes to YXM110-triggered autophagy, whereas downregulation of lysosomal-related genes could cause autophagy impairment. Furthermore, YXM110-induced cell death was prevented by autophagy inhibitor 3-methyladenine and Atg5 silencing, indicating that YXM110-mediated autophagy impairment leads to cancer cell death. These data reveal key mechanisms that support the further development of YXM110 as a promising anticancer agent.

Echinoid regulates Flamingo endocytosis to control ommatidial rotation in the Drosophila eye.

Planar cell polarity (PCP) refers to a second polarity axis orthogonal to the apicobasal axis in the plane of the epithelium. The molecular link between apicobasal polarity and PCP is largely unknown. During Drosophila eye development, differentiated photoreceptors form clusters that rotate independently of the surrounding interommatidial cells (ICs). Here, we demonstrate that both Echinoid (Ed), an adherens junction-associated cell adhesion molecule, and Flamingo (Fmi), a PCP determinant, are endocytosed via a clathrin-mediated pathway in ICs. Interestingly, we found that Ed binds the AP-2 adaptor and is required for the internalization of Fmi into ICs. Loss of ed led to increased amounts of Fmi on the cell membrane of non-rotating ICs and also to the misrotation of photoreceptor clusters. Importantly, overexpression of fmi in ICs alone was sufficient to cause misrotation of the adjacent photoreceptor clusters. Together, we propose that Ed, when internalized by AP-2, undergoes co-endocytosis with, and thereby decreases, Fmi levels on non-rotating ICs to permit correct rotation of ommatidial clusters. Thus, co-endocytosis of Ed and Fmi provides a link between apicobasal polarity and PCP.

Palladium-catalyzed regioselective synthesis of 2(2'-biphenyl)benzimidazoles through C-H activation.

An efficient palladium-catalyzed strategy through C-H bond activation for the synthesis of 2(2[Formula: see text]-biphenyl)-benzimidazoles is reported herein. The regioselective C-C bond formation proceeds in a sealed tube via oxidative C-H activation of ortho-directed 2-aryl-benzimidazole to couple with various iodobenzene analogs in high yields. This arylation exhibited high regioselectivity which is able to increase molecular diversity in difficult functionalized positions of parent molecules. This strategy provides a convenient and simple synthesis of biphenyl heterocyclic compounds with high regioselectivity.