Intracellular Protein Transport Research Articles

The c-terminal region of BLT2 restricts its localization to the lateral membrane in a LIN7C-dependent manner.

Leukotriene B4 receptor type 2 (BLT2) is a G protein-coupled receptor (GPCR) mainly expressed in epithelial cells, where it enhances barrier function. A unique characteristic of BLT2 is its restricted localization to the lateral membrane. However, the molecular mechanism underlying the localization of BLT2 to the lateral membrane and the physiological roles of laterally localized BLT2 are unknown. BLT1 is the most homologous GPCR to BLT2 and localizes to both the apical and lateral membranes. In this study, we generated chimeric receptors of BLT2 and BLT1 as well as deletion mutants of BLT2 to determine the region(s) of BLT2 responsible for its localization. Chimeric receptors containing the C-terminal domain of BLT2 localized only to the lateral membrane, and the C-terminal deletion mutant of BLT2 accumulated at the Golgi apparatus. Furthermore, the middle and C-terminal regions of BLT2 were important for maintaining epithelial barrier function. Proteomics analysis using the chimeric BLT-ascorbate peroxidase 2 biotinylation method showed that some proteins involved in intracellular protein transport, cell-cell junctions, and actin filament binding were located very close to the C-terminal domain of BLT2. Knockdown of lin-7 homolog C (LIN7C), a membrane trafficking protein, led to accumulation of BLT2 in the Golgi apparatus, resulting in diminished epithelial barrier function. These results suggest that the C-terminal region of BLT2 plays an important role in the transport of BLT2 from the Golgi apparatus to the plasma membrane in a LIN7C-dependent manner.

Bioinformatics analysis of miRNA and mRNA expression profiles to reveal the key miRNAs and genes in osteoarthritis

BackgroundOsteoarthritis (OA) is a chronic degenerative joint disease and the most frequent type of arthritis. This study aimed to identify the key miRNAs and genes associated with OA progression.MethodsThe GSE105027 (microRNA [miRNA/miR] expression profile; 12 OA samples and 12 normal samples) and GSE48556 (messenger RNA [mRNA] expression profile; 106 OA samples and 33 normal samples) datasets were selected from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and miRNAs (DEMs) were analyzed using the limma and ROCR packages in R, respectively. The target genes that negatively correlated with the DEMs were predicted, followed by functional enrichment analysis and construction of the miRNA-gene and miRNA-transcription factor (TF)-gene regulatory networks. Additionally, key miRNAs and genes were screened, and their expression levels were verified by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR).ResultsA total of 1696 DEGs (739 upregulated and 957 downregulated) and 108 DEMs (56 upregulated and 52 downregulated) were identified in the OA samples. Furthermore, 56 target genes that negatively correlated with the DEMs were predicted and found to be enriched in three functional terms (e.g., positive regulation of intracellular protein transport) and three pathways (e.g., human cytomegalovirus infection). In addition, three key miRNAs (miR-98-5p, miR-7-5p, and miR-182-5p) and six key genes (murine double minute 2, MDM2; glycogen synthase kinase 3-beta, GSK3B; transmembrane P24-trafficking protein 10, TMED10; DDB1 and CUL4-associated factor 12, DCAF12; caspase 3, CASP3; and ring finger protein 44, RNF44) were screened, among which the miR-7-5p → TMED10/DCAF12, miR-98-5p → CASP3/RNF44, and miR-182-5p → GSK3B pairs were observed in the regulatory network. Moreover, the expression levels of TMED10, miR-7-5p, CASP3, miR-98-5p, GSK3B, and miR-182-5p showed a negative correlation with qRT-PCR verification.ConclusionMiR-98-5p, miR-7-5p, miR-182-5p, MDM2, GSK3B, TMED10, DCAF12, CASP3, and RNF44 may play critical roles in OA progression.

Global Histone H3 Lysine 4 Trimethylation (H3K4me3) Landscape Changes in Response to TGFβ.

TGFβ expression acts as a biomarker of poor prognosis in prostate cancer. It plays a dual functional role in prostate cancer. In the early stages of the tumor, it acts as a tumor suppressor while at the later stages of tumor development, it promotes metastasis. The molecular mechanisms of action of TGFβ are largely understood through the canonical and non-canonical signal transduction pathways. Our understanding of the mechanisms that establish transient TGFβ stimulation into stable gene expression patterns remains incomplete. Epigenetic marks like histone H3 modifications are directly linked with gene expression and they play an important role in tumorigenesis. In this report, we performed chromatin immunoprecipitation-sequencing (ChIP-Seq) to identify the genome-wide regions that undergo changes in histone H3 Lysine 4 trimethylation (H3K4me3) occupancy in response to TGFβ stimulation. We also show that TGFβ stimulation can induce acute epigenetic changes through the modulation of H3K4me3 signals at genes belonging to special functional categories in prostate cancer. TGFβ induces the H3K4me3 on its own ligands like TGFβ, GDF1, INHBB, GDF3, GDF6, BMP5 suggesting a positive feedback loop. The majority of genes were found to be involved in the positive regulation of transcription from the RNA polymerase II promoter in response to TGFβ. Other functional categories were intracellular protein transport, brain development, EMT, angiogenesis, antigen processing, antigen presentation via MHC class II, lipid transport, embryo development, histone H4 acetylation, positive regulation of cell cycle arrest, and genes involved in mitotic G2 DNA damage checkpoints. Our results link TGFβ stimulation to acute changes in gene expression through an epigenetic mechanism. These findings have broader implications on epigenetic bases of acute gene expression changes caused by growth factor stimulation.

Endoplasmic reticulum-targeting nanomedicines for cancer therapy

In drug development research, the specific affinity of drug delivery systems for particular pathological sites, cells, and even subcellular structures can largely reduce the side effects, systemic toxicity, and minimally required drug dose. Since endoplasmic reticulum (ER) plays an essential role in many important cellular activities and functions, including the synthesis and intracellular transport of secretory and membrane-associated proteins, the synthesis and transport of steroids and lipids, Ca2+ signaling, and stress response, the ER dysfunction is associated with many diseases. Developing delivery systems that can effectively enter the cell and target ER is highly important for achieving satisfactory therapeutic performance in certain diseases, such as cancer. This review summarizes the currently available ER-targeting nanoparticle systems for cancer therapy. We first discuss the background knowledge involved in the ER-targeted nanotherapies for cancer. Then, we describe the examples about ER-targetable nanoparticles from several aspects, such as the components, the construction, and the therapeutic effect and mechanisms of these nanoparticles. Finally, we summarize the ER-targeted nanotherapeutic strategies for cancer and point out the current challenges and future research directions in this field. We hope that this review will promote the further development of ER-targeting nanotheranostics and inspire future research on ER-targeted cancer treatments.

The retromer CSC subcomplex is recruited by MoYpt7 and sequentially sorted by MoVps17 for effective conidiation and pathogenicity of the rice blast fungus.

In eukaryotic cells, Rab GTPases and the retromer complex are important regulators of intracellular protein transport. However, the mechanistic relationship between Rab GTPases and the retromer complex in relation to filamentous fungal development and pathogenesis is unknown. In this study, we used Magnaporthe oryzae, an important pathogen of rice and other cereals, as a model filamentous fungus to dissect this knowledge gap. Our data demonstrate that the core retromer subunit MoVps35 interacts with the Rab GTPase MoYpt7 and they colocalize to the endosome. Without MoYpt7, MoVps35 is mislocalized in the cytoplasm, indicating that MoYpt7 plays an important role in the recruitment of MoVps35. We further demonstrate that the expression of an inactive MoYpt7‐DN (GDP‐bound form) mutant in M. oryzae mimicks the phenotype defects of retromer cargo‐sorting complex (CSC) null mutants and blocks the proper localization of MoVps35. In addition, our data establish that MoVps17, a member of the sorting nexin family, is situated at the endosome independent of retromer CSC but regulates the sorting function of MoVps35 after its recruitment to the endosomal membrane by MoYpt7. Taken together, these results provide insight into the precise mechanism of retromer CSC recruitment to the endosome by MoYpt7 and subsequent sorting by MoVps17 for efficient conidiation and pathogenicity of M. oryzae.

Modulation of the Cell Membrane Potential and Intracellular Protein Transport by High Magnetic Fields.

To explore cellular responses to high magnetic fields (HMF), we present a model of the interactions of cells with a homogeneous HMF that accounts for the magnetic force exerted on paramagnetic/diamagnetic species. There are various chemical species inside a living cell, many of which may have large concentration gradients. Thus, when an HMF is applied to a cell, the concentration-gradient magnetic forces act on paramagnetic or diamagnetic species and can either assist or oppose large particle movement through the cytoplasm. We demonstrate possibilities for changing the machinery in living cells with HMFs and predict two new mechanisms for modulating cellular functions with HMFs via (i) changes in the membrane potential and (ii) magnetically assisted intracellular diffusiophoresis of large proteins. By deriving a generalized form for the Nernst equation, we find that an HMF can change the membrane potential of the cell and thus have a significant impact on the properties and biological functionality of cells. The elaborated model provides a universal framework encompassing current studies on controlling cell functions by high static magnetic fields. Bioelectromagnetics. 2021;42:27-36. © 2020 Bioelectromagnetics Society.

Transcriptomic profile analysis of the halophyte Suaeda rigida response and tolerance under NaCl stress

Suaeda rigida is a lignified, true haplotype that predominantly grows in the Tarim basin, China. It has significant economic and ecological value. Herein, with aim to determine the genes associated with salt tolerance, transcriptome sequencing was performed on its stem, leaves and root over three set NaCl gradients regimens at treatment intervals of 3 h and 5 days. From our findings, we identified 829,095 unigenes, with 331,394 being successfully matched to at least one annotation database. In roots, under 3 h treatment, no up-regulated DEGs were identified in 100 and 500 mM NaCl treated samples. Under 5 days treatment, 97, 60 and 242 up-regulated DEGs were identified in 100, 300, 500 mM NaCl treated samples, respectively. We identified 50, 22 and 255 down-regulated DEGs in 100, 300, 500 mM NaCl treated samples, respectively. GO biological process enrichment analysis established that down-regulated DEGs were associated with nitrogen compound transport, organic substance transport and intracellular protein transport while the up-regulated genes were enriched in cell wall biogenesis, such as plant-type cell wall biogenesis, cell wall assembly, extracellular matrix organization and plant-type cell wall organization. These findings provide valuable knowledge on genes associated with salt tolerance of Suaeda rigida, and can be applied in other downstream haplotype studies.

Intracellular Transport of Ribosome-Inactivating Proteins Depends on Annexin 13.

In the present study, we assessed the role of annexin 13 membrane-binding protein (ANXA13) in the intracellular transport of vesicles containing type II ribosome-inactivating proteins (RIP-IIs). A modified human intestinal epithelial cell line HT29 was used, in which the expression of ANXA13 was significantly reduced. The cytotoxic effect of ricin and viscumin was evaluated by modification of 28S ribosome RNA. The observed differences in the activity of toxins on the parental and modified HT29 lines indicate that ANXA13 plays a different role in the intracellular transport of vesicles containing the RIP-IIs.

Transcriptomic profiling revealed key signaling pathways for cold tolerance and acclimation of two carp species

BackgroundClosely related species of the carp family (Cyprinidae) have evolved distinctive abilities to survive under cold stress, but molecular mechanisms underlying the generation of cold resistance remain largely unknown. In this study, we compared transcriptomic profiles of two carp species to identify key factors and pathways for cold tolerance and acclimation.ResultsLarvae of Songpu mirror carp and Barbless carp that were pretreated at 18 °C for 24 h significantly improved their survival rates under lethal cold temperature at 8 °C or 10 °C, indicating that two carp species possess the ability of cold acclimation. However, Songpu mirror carp exhibited stronger abilities of cold tolerance and acclimation than Barbless carp. Transcriptomic profiles of Songpu mirror carp and Barbless carp larvae at 28 °C and 18 °C were compared during cold acclimation through RNA-seq. Differentially expressed genes that are closely associated with the differences in cold acclimation between two carp species were identified through bioinformatics and Venn’s diagram analysis. GO enrichment analysis of these genes indicated that cellular component assembly involved in morphogenesis, secondary alcohol metabolism and drug transport were the most up-regulated biological processes during cold acclimation of Songpu mirror carp. Conversely, positive regulation of macroautophagy, intracellular protein transport, and organonitrogen compound catabolism were the most down-regulated biological processes during cold acclimation of Barbless carp. KEGG enrichment analysis revealed that factors in the FoxO-related signaling pathways are mainly responsible for the development of differences in cold tolerance and acclimation between two carp species since altering the phosphorylation of key proteins in the FoxO-related signaling pathways with inhibitors or an activator significantly decreased the cold tolerance and acclimation of Songpu mirror carp. These data provided key clues for dissection of molecular mechanisms underlying the development of cold tolerance and acclimation in carps.ConclusionsThese findings indicate that larvae of two carp species possess different abilities of cold tolerance and can build cold acclimation under mild low temperature. Multiple biological processes and FoxO-related signaling pathways are closely associated with the development of differences in cold tolerance and acclimation between two carp species.

Abstract 505: Diabetes Mellitus-Induced Metabolic Remodeling is Alleviated by Transgenic Overexpression of Mir-133a in the Heart

Diabetic mellitus (DM) cardiomyopathy is a DM-induced metabolic disorder where energy dependence on fatty acid (FA) metabolism causes FA influx overload. While we reported that miR-133a overexpression prevented deleterious lipid accumulation in the diabetic Akita heart, it is unclear whether miR-133a regulates diabetes-induced metabolic remodeling in the DM heart. Thus, we performed deep sequencing on the heart from DM Akita (Ak), cardiac-specific miR-133aTg (Tg), Ak/Tg mice, and sibling wild-type (WT) mice. Ingenuity pathway analysis showed that FAO was the highest activated pathway in the DM heart (p-value=4.59E-11). Therefore, we hypothesized that miR-133a overexpression in the DM heart improves cardiac metabolism by increasing FA clearance via enhancing FA oxidation (FAO). Notably, mitochondrial FA transport protein carnitine palmitoyltransferase I (CPT1) was upregulated (WT: 0.02±0.01, Ak: 0.06±0.02, Ak/Tg: 0.17±0.02, Tg: 0.06±0.01) while changes in the intracellular FA transport protein CD36 were not significant. Interestingly, the rate-limiting enzyme of ketogenesis, the FAO spillover pathway, 3-Hydroxy-3-Methylglutaryl-CoA Synthase 2 (HMGCS2) was downregulated (WT: 0.13±0.02, Ak: 0.74±0.13, Ak/Tg: 0.39±0.07, Tg: 0.05±0.01) in Ak/Tg mice. These results support that increased miR-133a in the diabetic heart contributes to improved FAO and FA metabolism in addition to downregulating FA deposition and ketogenesis in the diabetic heart.

Expansion of Single Cell Transcriptomics Data of SARS-CoV Infection in Human Bronchial Epithelial Cells to COVID-19

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 19 (COVID-19) that was emerged as a new member of coronaviruses since December 2019 in Wuhan, China and then after was spread in all continentals. Since SARS-CoV-2 has shown about 77.5% similarity to SARS-CoV, the transcriptome and immunological regulations of SARS-CoV-2 was expected to have high percentage of overlap with SARS-CoV.ResultsIn this study, we applied the single cell transcriptomics data of human bronchial epithelial cells (2B4 cell line) infected with SARS-CoV, which was annotated in the Expression Atlas database to expand this data to COVID-19. In addition, we employed system biology methods including gene ontology (GO) and Reactome pathway analyses to define functional genes and pathways in the infected cells with SARS-CoV. The transcriptomics analysis on the Expression Atlas database revealed that most genes from infected 2B4 cell line with SARS-CoV were downregulated leading to immune system hyperactivation, induction of signaling pathways, and consequently a cytokine storm. In addition, GO:0016192 (vesicle-mediated transport), GO:0006886 (intracellular protein transport), and GO:0006888 (ER to Golgi vesicle-mediated transport) were shown as top three GOs in the ontology network of infected cells with SARS-CoV. Meanwhile, R-HAS-6807070 (phosphatase and tensin homolog or PTEN regulation) showed the highest association with other Reactome pathways in the network of infected cells with SARS-CoV. PTEN plays a critical role in the activation of dendritic cells, B- and T-cells, and secretion of proinflammatory cytokines, which cooperates with downregulated genes in the promotion of cytokine storm in the COVID-19 patients.ConclusionsBased on the high similarity percentage of the transcriptome of SARS-CoV with SARS-CoV-2, the data of immunological regulations, signaling pathways, and proinflammatory cytokines in SARS-CoV infection can be expanded to COVID-19 to have a valid platform for future pharmaceutical and vaccine studies.

Secretion of a low and high molecular weight \u03b2-glycosidase by Yarrowia lipolytica

BackgroundThe secretory production of recombinant proteins in yeast simplifies isolation and purification but also faces possible complications due to the complexity of the secretory pathway. Therefore, correct folding, maturation and intracellular transport of the recombinant proteins are important processing steps with a higher effort needed for complex and large proteins. The aim of this study was to elucidate the secretion potential of Yarrowia lipolytica for low and high molecular weight β-glycosidases in a comparative cultivation approach.ResultsA low sized β-glucosidase from Pyrococcus furiosus (CelB; 55 kDa) and a large sized β-galactosidase isolated from the metagenome (M1; 120 kDa) were integrated into the acid extracellular protease locus using the CRISPR–Cas9 system to investigate the size dependent secretion of heterologous proteins in Y. lipolytica PO1f. The recombinant strains were cultivated in the bioreactor for 78 h and the extra- and intracellular enzyme activities were determined. The secretion of CelB resulted in an extracellular volumetric activity of 187.5 µkatoNPGal/Lmedium, while a volumetric activity of 2.98 µkatoNPGal/Lmedium was measured during the M1 production. However, when the amount of functional intra- and extracellular enzyme was investigated, the high molecular weight M1 (85%) was secreted more efficiently than CelB (27%). Real-time PCR experiments showed a linear correlation between the transcript level and extracellular activity for CelB, while a disproportional high mRNA level was observed regarding M1. Interestingly, mass spectrometry data revealed the unexpected secretion of two endogenous intracellular glycolytic enzymes, which is reported for the first time for Y. lipolytica.ConclusionThe results of this study provide deeper insights into the secretion potential of Y. lipolytica. A secretion limitation for the low-size CelB was observed, while the large size M1 enzyme was produced in lower amounts but was secreted efficiently. It was shown for the first time that Y. lipolytica is a promising host for the secretion of heterologous high molecular weight proteins (> 100 kDa), although the total secreted amount has to be increased further.

NEK7: a potential therapy target for NLRP3-related diseases.

NLRP3 inflammasome plays an essential role in innate immunity, yet the activation mechanism of NLRP3 inflammasome is not clear. In human or animal models, inappropriate NLRP3 inflammasome activation is implicated in many NLRP3-related diseases, such as tumors, inflammatory diseases and autoimmune diseases. Until now, a great number of inhibitors have been used to disturb the related signaling pathways, such as IL-1β blockade, IL-18 blockade and caspase-1 inhibitors. Unfortunately, most of these inhibitors just disturb the signaling pathways after the activation of NLRP3 inflammasome. Inhibitors that directly regulate NLRP3 to abolish the inflammation response may be more effective. NEK7 is a multifunctional kinase affecting centrosome duplication, mitochondrial regulation, intracellular protein transport, DNA repair and mitotic spindle assembly. Researchers have made significant observations on the regulation of gene transcription or protein expression of the NLRP3 inflammasome signaling pathway by NEK7. Those signaling pathways include ROS signaling, potassium efflux, lysosomal destabilization, and NF-κB signaling. Furthermore, NEK7 has been proved to be involved in many NLRP3-related diseases in humans or in animal models. Inhibitors focused on NEK7 may regulate NLRP3 to abolish the inflammation response and NEK7 may be a potential therapeutic target for NLRP3-related diseases.

Roles of Plant-Specific Inserts in Plant Defense.

Ubiquitously expressed in plants, the plant-specific insert (PSI) of typical plant aspartic proteases (tpAPs) has been associated with plant development, stress response, and defense processes against invading pathogens. Despite sharing high sequence identity, structural studies revealed possible different mechanisms of action among species. The PSI induces signaling pathways of defense hormones in vivo and demonstrates broad-spectrum activity against phytopathogens in vitro. Recent characterization of the PSI-tpAP relationship uncovered novel, nonconventional intracellular protein transport pathways and improved tpAP production yields for industrial applications. In spite of research to date, relatively little is known about the structure-function relationships of PSIs. A comprehensive understanding of their biological roles may benefit plant protection strategies against virulent phytopathogens.

Proteomics Analysis of Brain Tissue in a Rat Model of Ischemic Stroke in the Acute Phase.

Background: Stroke is a leading health issue, with high morbidity and mortality rates worldwide. Of all strokes, approximately 80% of cases are ischemic stroke (IS). However, the underlying mechanisms of the occurrence of acute IS remain poorly understood because of heterogeneous and multiple factors. More potential biomarkers are urgently needed to reveal the deeper pathogenesis of IS.Methods: We identified potential biomarkers in rat brain tissues of IS using an iTRAQ labeling approach coupled with LC-MS/MS. Furthermore, bioinformatrics analyses including GO, KEGG, DAVID, and Cytoscape were used to present proteomic profiles and to explore the disease mechanisms. Additionally, Western blotting for target proteins was conducted for further verification.Results: We identified 4,578 proteins using the iTRAQ-based proteomics method. Of these proteins, 282 differentiated proteins, comprising 73 upregulated and 209 downregulated proteins, were observed. Further bioinformatics analysis suggested that the candidate proteins were mainly involved in energy liberation, intracellular protein transport, and synaptic plasticity regulation during the acute period. KEGG pathway enrichment analysis indicated a series of representative pathological pathways, including energy metabolite, long-term potentiation (LTP), and neurodegenerative disease-related pathways. Moreover, Western blotting confirmed the associated candidate proteins, which refer to oxidative responses and synaptic plasticity.Conclusions: Our findings highlight the identification of candidate protein biomarkers and provide insight into the biological processes involved in acute IS.

RNA sequencing revealed the abnormal transcriptional profile in cloned bovine embryos

Somatic cell nuclear transfer (SCNT) has potential applications in agriculture and biomedicine, but the efficiency of cloning is still low. In this study, the transcriptional profiles in cloned and fertilized embryos were measured and compared by RNA sequencing. The 2-cell embryos were detected to identify the earliest transcriptional differences between embryos derived through IVF and SCNT. As a result, 364 genes showed decreased expression in cloned 2-cell embryos and were enriched in “intracellular protein transport” and “ubiquitin mediated proteolysis”. In blastocysts, 593 genes showed decreased expression in cloned blastocysts and were enriched in “RNA binding”, “nucleotide binding”, “embryo development”, and “adherens junction”. We identified 14 development related genes that were not activated in the cloned embryos. Then, 68 and 245 long non-coding RNAs were recognized abnormally expressed in cloned 2-cell embryos and cloned blastocysts, respectively. Furthermore, we found that incomplete RNA-editing occurred in cloned embryos and might be caused by decreased ADAR expression. In conclusion, our study revealed the abnormal transcripts and deficient RNA-editing sites in cloned embryos and provided new data for further mechanistic studies of somatic nuclear reprogramming.

The START-domain proteins in intracellular lipid transport and beyond

The Steroidogenic Acute Regulatory Protein-related Lipid Transfer (START) domain is a ~210 amino acid sequence that folds into an α/β helix-grip structure forming a hydrophobic pocket for lipid binding. The helix-grip fold structure defines a large superfamily of proteins, and this review focuses on the mammalian START domain family members that include single START domain proteins with identified ligands, and larger multi-domain proteins that may have novel roles in metabolism. Much of our understanding of the mammalian START domain proteins in lipid transport and changes in metabolism has advanced through studies using knockout mouse models, although for some of these proteins the identity and/or physiological role of ligand binding remains unknown. The findings that helped define START domain lipid-binding specificity, lipid transport, and changes in metabolism are presented to highlight that fundamental questions remain regarding the biological function(s) for START domain-containing proteins.

Identification and characterization of differentially expressed exosomal microRNAs in bovine milk infected with Staphylococcus aureus

BackgroundMicroRNAs (miRNAs) in milk-derived exosomes may reflect pathophysiological changes caused by mastitis. This study profiled miRNAs in exosomes from both normal milk and mastitic milk infected by Staphylococcus aureus (S. aureus). The potential targets for differentially expressed (DE) miRNAs were predicted and the target genes for bta-miR-378 and bta-miR-185 were also validated.ResultsTotal RNA from milk exosomes was collected from healthy cows (n = 3, the control group) and S. aureus infected cows (n = 6, the SA group). Two hundred ninety miRNAs (221 known and 69 novel ones) were identified. Among them, 22 known and 15 novel miRNAs were differentially expressed. Target genes of DE miRNAs were significantly enriched in intracellular protein transport, endoplasmic reticulum and identical protein binding. The expression of two miRNAs (bta-miR-378 and bta-miR-185) with high read counts and log2 fold changes (> 3.5) was significantly higher in mastitic milk infected with S. aureus. One target gene (VAT1L) of bta-miR-378 and five target genes (DYRK1B, MLLT3, HP1BP3, NPR2 and PGM1) of bta-miR-185 were validated.ConclusionDE miRNAs in exosomes from normal and S. aureus infected milk were identified. The predicted targets for two DE miRNAs (bta-miR-378 and bta-miR-185) were further validated. The linkage between the validated target genes and diseases suggested that we should pay particular attention to exosome miRNAs from mastitic milk in terms of milk safety.

Pathogenic Effects of Impaired Retrieval between the Endoplasmic Reticulum and Golgi Complex.

Cellular activities, such as growth and secretion, are dependent on correct protein folding and intracellular protein transport. Injury, like ischemia, malnutrition, and invasion of toxic substances, affect the folding environment in the endoplasmic reticulum (ER). The ER senses this information, following which cells adapt their response to varied situations through the unfolded protein response. Activation of the KDEL receptor, resulting from the secretion from the ER of chaperones containing the KDEL sequence, plays an important role in this adaptation. The KDEL receptor was initially shown to be necessary for the retention of KDEL sequence-containing proteins in the ER. However, it has become clear that the activated KDEL receptor also regulates bidirectional transport between the ER and the Golgi complex, as well as from the Golgi to the secretory pathway. In addition, it has been suggested that the signal for KDEL receptor activation may also affect several other cellular activities. In this review, we discuss KDEL receptor-mediated bidirectional transport and signaling and describe disease models and human diseases related to KDEL receptor dysfunction.

Membrane proteomic analysis reveals the intestinal development is deteriorated by intrauterine growth restriction in piglets.

The alterations of the intestinal proteome were observed in intrauterine growth restriction (IUGR) piglets during early life by gel-based approaches. Nevertheless, how IUGR affects the intestinal membrane proteome during neonatal development remains unclear. Here, we applied the iTRAQ-based proteomics technology and biochemical analysis to investigate the impact of IUGR on the membrane proteome of the jejunal mucosa in the piglets. Three hundred sixty-one membrane proteins were screened by functional prediction. Among them, eight, five, and one differentially expressed membrane proteins were identified between IUGR and NBW piglets at day 0, day 7, and day 21 after birth, respectively. Differentially expressed membrane proteins (DEMPs) including F1SBL3, F1RRW8, F1S539, F1S2Z2, F1RIR2, F1RUF2 I3LP60, Q2EN79, and F1SIH8 were reduced while the relative abundance of I3L6A2, F1SCJ1, F1RI18, I3LRJ7, and F1RNN0 were increased in IUGR piglets than NBW piglets. From the aspects of function, F1RRW8, F1S539, F1S2Z2, and F1RIR2 are mainly associated with D2 dopamine receptor binding, transmembrane transport of small molecules, signal transduction, and translocation of GLUT4, respectively, and F1SIH8, I3LRJ7, and F1RNN0 are related to autophagy, metabolism of vitamins, and intracellular protein transport. Additionally, IUGR decreased the level of proteins (F1RRW8, Q2EN79, and F1RI18) that are involved in response to oxidative stress.