CK2 phosphorylation of human Sec63 regulates its interaction with Sec62

Background

Protein kinase CK2 is a pleiotropic enzyme which is ubiquitously expressed in eukaryotic cells. Several years ago CK2 was found to be associated with the mammalian endoplasmic reticulum. So far nothing is known about the function of CK2 at the ER.

Methods

CK2 phosphorylation sites in the polypeptide chain of Sec63 were mapped using deletion mutants and a peptide library. Binding of Sec63 to CK2 and to Sec62 was analyzed by pull-down assays and by co-immunoprecipitation

Results

Sec63 was identified as a novel substrate and binding partner of protein kinase CK2.We identified serine 574, serine 576 and serine 748 as CK2 phosphorylation sites. Phosphorylation of Sec63 by CK2 enhanced its binding to Sec62.

Conclusions

Protein kinase CK2 phosphorylation of Sec63 leads to an enhanced binding of Sec63 to Sec62. This complex formation is a prerequisite for a functional ER protein translocon.

General significance

Thus, our present data indicate a regulatory role of CK2 in the ER protein translocation.     

Rotavirus Vaccination Coverage among Children Aged 2-59 Months: A Report from Guangzhou,China

Objective

We aimed to estimate the Lanzhou lamb rotavirus (LLR) vaccination coverage (VC) and timeliness among children aged 2 to 59 months in Guangzhou, China.

Methods

An electronic system-based VC survey was conducted using stratified cluster random sampling.

Results

We reported an overall Lanzhou lamb rotavirus vaccine coverage of 25.3% among children aged 2-59 months (2-8 months, 2.6%) in Guangzhou, China.

Conclusion

Great efforts should be taken to increase LLR VC in eligible children in Guangzhou, China.     

Complicaciones hospitalarias en una unidad geriátrica de agudos

Introduction:

In-hospital complications frequently occur in hospitalized people over 65 worsening their clinical outcomes. There are, however, few studies on the factors associated with in-hospital complications in elderly patient care.

Objective:

To evaluate factors associated with in-hospital complications in a geriatric acute care unit in Bogotá, Colombia

Materials and methods:

We conducted an analytical, observational, retrospective study in a cohort of 1,657 patients over 65 years of age who received care in the geriatric unit of a high complexity hospital in Bogotá, Colombia. The dependent variable was in-hospital complications and the independent variables, the degree of functional dependence on admission, dementia, nutritional status, social support, comorbidity, and polypharmacy. We used Poisson’s linear regression model to identify associated variables.

Results:

The bivariate analysis showed that functional dependence (PR=2.092, p≤0.001) and malnutrition (PR=2.850, p≤0.001) were associated with a higher rate of hospital-acquired infection. In the multivariate analysis, functional dependence (PR=1.931, p=0.003) and malnutrition (PR=2.502, p=0.002) remained independent factors for in-hospital complications.

Conclusion:

In acute care centers, integral assessment at admission to identify functional dependence and malnutrition predicts in-hospital complications.     

Red Blood Cell Fatty Acids and Incident Diabetes Mellitus in the Women’s Health Initiative Memory Study

Context

The relations between dietary and/or circulating levels of fatty acids and the development of type 2 diabetes is unclear. Protective associations with the marine omega-3 fatty acids and linoleic acid, and with a marker of fatty acid desaturase activity delta-5 desaturase (D5D ratio) have been reported, as have adverse relations with saturated fatty acids and D6D ratio.

Objective

To determine the associations between red blood cell (RBC) fatty acid distributions and incident type 2 diabetes.

Design

Prospective observational cohort study nested in the Women’s Health Initiative Memory Study.

Setting

General population.

Subjects

Postmenopausal women.

Main Outcome Measures

Self-reported incident type 2 diabetes.

Results

There were 703 new cases of type 2 diabetes over 11 years of follow up among 6379 postmenopausal women. In the fully adjusted models, baseline RBC D5D ratio was inversely associated with incident type 2 diabetes [Hazard Ratio (HR) 0.88, 95% confidence interval (CI) 0.81–0.95) per 1 SD increase. Similarly, baseline RBC D6D ratio and palmitic acid were directly associated with incident type 2 diabetes (HR 1.14, 95% CI 1.04–1.25; and HR 1.24, 95% CI 1.14–1.35, respectively). None of these relations were materially altered by excluding incident cases in the first two years of follow-up. There were no significant relations with eicosapentaenoic, docosahexaenoic or linoleic acids.

Conclusions

Whether altered fatty acid desaturase activities or palmitic acid levels are causally related to the development of type 2 diabetes cannot be determined from this study, but our findings suggest that proportions of certain fatty acids in RBC membranes are associated with risk for type 2 diabetes.     

In vitro characterization of ligand-induced oligomerization of the S. cerevisiae G-protein coupled receptor,Ste2p

Background

The S. cerevisiae α-factor receptor, Ste2p, is a G-protein coupled receptor that plays key roles in yeast signaling and mating. Oligomerization of Ste2p has previously been shown to be important for intracellular trafficking, receptor processing and endocytosis. However the role of ligand in receptor oligomerization remains enigmatic.

Methods

Using functional recombinant forms of purified Ste2p, atomic force microscopy, dynamic light scattering and chemical crosslinking are applied to investigate the role of ligand in Ste2p oligomerization.

Results

Atomic force microscopy images indicate a molecular height for recombinant Ste2p in the presence of α-factor nearly double that of Ste2p alone. This observation is supported by complementary dynamic light scattering measurements which indicate a ligand-induced increase in the polydispersity of the Ste2p hydrodynamic radius. Finally, chemical cross-linking of HEK293 plasma membranes presenting recombinant Ste2p indicates α-factor induced stabilization of the dimeric form and higher order oligomeric forms of the receptor upon SDS-PAGE analysis.

Conclusions

α-factor induces oligomerization of Ste2p in vitro and in membrane.

General significance

These results provide additional evidence of a possible role for ligand in mediation of Ste2p oligomerization in vivo.     

Persistent Inflammation and Endothelial Activation in HIV-1 Infected Patients after 12 Years of Antiretroviral Therapy

Objective

The study investigated markers of inflammation and endothelial activation in HIV infected patients after 12 years of successful combination antiretroviral treatment (cART).

Methods

Inflammation and endothelial activation were assessed by measuring levels of immunoglobulins, β2-microglobulin, interleukin (IL) 8, tumor necrosis factor α (TNFα), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), sE-Selectin, and sP-Selectin.

Results

HIV infected patients had higher levels of β2-microglobulin, IL-8, TNFα, and sICAM-1 than uninfected controls, and HIV infected patients lacked correlation between platelet counts and sP-Selectin levels found in uninfected controls.

Conclusion

Discrete signs of systemic and vascular inflammation persist even after very long term cART.     

Atorvastatin reduces lipopolysaccharide-induced expression of cyclooxygenase-2 in human pulmonary epithelial cells

Objective

To explore the effects of atorvastatin on expression of cyclooxygenase-2 (COX-2) in human pulmonary epithelial cells (A549).

Methods

A549 cells were incubated in DMEM medium containing lipopolysaccharide (LPS) in the presence or absence of atorvastatin. After incubation, the medium was collected and the amount of prostaglandin E₂ (PGE₂) was measured by enzyme-linked immunosorbent assay (ELISA). The cells were harvested, and COX-2 mRNA and protein were analyzed by RT-PCR and western-blot respectively.

Results

LPS increased the expression of COX-2 mRNA and production of PGE₂ in a dose- and time-dependent manner in A549. Induction of COX-2 mRNA and protein by LPS were inhibited by atorvastatin in a dose-dependent manner. Atorvastatin also significantly decreased LPS-induced production of PGE₂. There was a positive correlation between reduced of COX-2 mRNA and decreased of PGE₂ (r = 0.947, P < 0.05).

Conclusion

Atorvastatin down-regulates LPS-induced expression of the COX-2 and consequently inhibits production of PGE₂ in cultured A549 cells.     

MicroRNA-190b confers radio-sensitivity through negative regulation of Bcl-2 in gastric cancer cells

Objectives

To determine the role of miR-190b in radio-sensitivity of gastric cancer (GC).

Results

In radio-resistant GC cells, down-regulation of miR-190b and up-regulation of Bcl-2 were observed. The protein expression of Bcl-2 was negatively regulated by miR-190b. Overexpression of miR-190b significantly decreased cell viability and enhanced radio-sensitivity of GC cells. Of note, these effects of miR-190b on GC cells radio-sensitivity were abolished by Bcl-2.

Conclusion

miR-190b confers radio-sensitivity of GC cells, possibly via negative regulation of Bcl-2.

     

Exostosin-like 2 regulates FGF2 signaling by controlling the endocytosis of FGF2

Background

Heparan sulfate proteoglycans are ubiquitously expressed on cell surfaces and in extracellular matrices, and are engaged in heparin-binding growth factor-related signal transduction. Thus, changes in the amounts, structures, and chain lengths of heparan sulfate have profound effects on aspects of cell growth controlled by heparin-binding growth factors such as FGF2. Exostosin glycosyltransferases (EXT1, EXT2, EXTL1, EXTL2, and EXTL3) control heparan sulfate biosynthesis, and the expression levels of their genes regulate the amounts, chain lengths, and sulfation patterns of heparan sulfate. Unlike EXT1, EXT2, and EXTL3, EXTL2 functions chain termination of heparan sulfate. Here, we examined the importance of EXTL2 in FGF2-dependent signaling.

Preserved Antigen-Specific Immune Response in Patients with Multiple Sclerosis Responding to IFNβ-Therapy

Background

Interferon-beta (IFNβ) regulates the expression of a complex set of pro- as well as anti-inflammatory genes. In cohorts of MS patients unstratified for therapeutic response to IFNβ, normal vaccine-specific immune responses have been observed. Data capturing antigen-specific immune responses in cohorts of subjects defined by response to IFNβ-therapy are not available.

Objective

To assess antigen-specific immune responses in a cohort of MS patients responding clinically and radiologically to IFNβ.

Methods

In 26 MS patients, clinical and MRI disease activity were assessed before and under treatment with IFNβ. Humoral and cellular immune response to influenza vaccine was prospectively characterized in these individuals, and 33 healthy controls by influenza-specific Enzyme-Linked Immunosorbent Assay (ELISA) and Enzyme Linked Immuno Spot Technique (ELISPOT).

Results

Related to pre-treatment disease activity, IFNβ reduced clinical and radiological MS disease-activity. Following influenza vaccination, frequencies of influenza-specific T cells and concentrations of anti-influenza A and B IgM and IgG increased comparably in MS-patients and in healthy controls.

Conclusions

By showing in a cohort of MS-patients responding to IFNβ vaccine-specific immune responses comparable to controls, this study indicates that antigen-specific immune responses can be preserved under successful IFNβ-therapy.     

Expression and purification of classical swine fever virus E2 protein from Sf9 cells using a modified vector

Objective

To develop a simple method for efficient expression of classical swine fever virus (CSFV) E2 protein.

Results

The pFastBac HT B vector (pFastHTB-M1) was modified by adding a melittin signal peptide sequence. The E2 gene fragment without the transmembrane region was cloned into pFastHTB-M1. The modified vector has clear advantage over the original one, as evidenced by the purified recombinant E2 protein that was detected significantly by SDS-PAGE.

Conclusions

The modified vector has the potential for large-scale production and easy purification of the CSFV E2 protein or other proteins of interests.

     

PKM2 knockdown influences SREBP activation and lipid synthesis in bovine mammary-gland epithelial MAC-T cells

Objective

The purpose of the article is to evaluate the changes in lipid metabolism in bovine mammary-gland epithelial MAC-T cells after PKM2 knockdown.

Results

MAC-T cells stably expressing low levels of PKM2 were established with lentivirus-mediated small hairpin RNA. Although the knockdown of PKM2 had no effect on MAC-T cell growth, the reduced expression of PKM2 attenuated the mRNA and protein expression of key enzymes involved in sterol synthesis through the SREBP pathway.

Conclusions

The downregulation of PKM2 significantly influenced lipid synthesis in bovine mammary-gland epithelial MAC-T cells. These findings extend our understanding of the crosstalk between glycolysis and lipid metabolism in bovine mammary-gland epithelial cells.

     

Nf2/Merlin Controls Spinal Cord Neural Progenitor Function in a Rac1/ErbB2-Dependent Manner

Objective

Individuals with the neurofibromatosis type 2 (NF2) cancer predisposition syndrome develop spinal cord glial tumors (ependymomas) that likely originate from neural progenitor cells. Whereas many spinal ependymomas exhibit indolent behavior, the only treatment option for clinically symptomatic tumors is surgery. In this regard, medical therapies are unfortunately lacking due to an incomplete understanding of the critical growth control pathways that govern the function of spinal cord (SC) neural progenitor cells (NPCs).

Methods

To identify potential therapeutic targets for these tumors, we leveraged primary mouse Nf2-deficient spinal cord neural progenitor cells.

Results

We demonstrate that the Nf2 protein, merlin, negatively regulates spinal neural progenitor cell survival and glial differentiation in an ErbB2-dependent manner, and that NF2-associated spinal ependymomas exhibit increased ErbB2 activation. Moreover, we show that Nf2-deficient SC NPC ErbB2 activation results from Rac1-mediated ErbB2 retention at the plasma membrane.

Significance

Collectively, these findings establish ErbB2 as a potential rational therapeutic target for NF2-associated spinal ependymoma.     

Importancia de la determinación de variantes en el número de copias en neonatos con aneuploidías autosómicas

Introduction:

Aneuploidies are frequent genetic disorders in clinical practice. However, little is known about other genetic variants that may influence the final phenotype.

Objective:

To determine the variations in the number of copies and regions with homozygosity greater than 0.5% or larger than 10 Mb in newborns with autosomal aneuploidies.

Materials and methods:

We performed a chromosomal microarray analysis on newborns with autosomal aneuploidies (n=7), trisomy 21 (n=5), and trisomy 18 (n=2) evaluated at the Hospital Antonio Lorena and Hospital Regional of Cusco, Perú, during 2018.

Results:

We found pathogenic and probably pathogenic variants in the number of copies in other genomic regions different to chromosomes 21 or 18 in two neonates. Additionally, we found two variants bigger than 500 kpb of unknown pathogenicity.

Conclusions:

Although the number of analyzed individuals was small, it is important to highlight that we found other variants in the number of copies that have been described in association with neurodevelopmental disorders, congenital anomalies, deafness, and short/ tall stature, among others, in almost half of them, which will probably impact the phenotype negatively in patients with aneuploidies.     

Subtipos del carcinoma luminal de mama según el consenso de Saint Gallen en un grupo de pacientes venezolanas

Introduction:

Breast cancer is the most frequent malignancy in women worldwide. Different intrinsic subtypes have different prognoses and their prevalence varies significantly according to the criteria established in the Saint Gallen Consensus.

Objective:

To classify the luminal subtypes of breast carcinoma according to Saint Gallen 2009, 2011, 2013, and 2015 consensuses in a group of Venezuelan patients.

Materials and methods:

We conducted a retrospective study in 209 patients with infiltrating ductal carcinoma of the breast followed up at the Institute of Oncology "Dr. Miguel Pérez Carreno" in Valencia, Venezuela.

Results:

The distribution of the luminal A and B subtypes changed after the reclassification of the cases according to 2011, 2013, and 2015 Saint Gallen Consensuses. The luminal B subtype was the most common in the study series.

Conclusions:

With the use of a classification based on the latest Saint Gallen criteria we identified more luminal B tumors. This could contribute to selecting those patients who can avoid adjuvant chemotherapy and/or benefit from the adjuvant hormonal therapy in clinical practice.     

Absence of mutations in GJB2 (Connexin-26) gene in an ethnic group of southwest Iran

BACKGROUND:

The common GJB2 gene mutation (35delG) has been previously reported from Iranian patients that were affected with nonsyndromic autosomal recessive deafness. We, therefore, for the first time, investigated the prevalence and frequency of the GJB2 gene mutation in the Iranian deaf population with Arabian origins.

MATERIALS AND METHODs:

We amplified and sequenced the entire coding sequence of the GJB2 gene from 61 deaf patients and 26 control subjects.

RESULT:

None of the analyzed samples revealed deafness-associated mutation.

CONCLUSION:

This finding differs from several reports from Iran as we have focused on the GJB2 gene that possesses various mutations as the cause of congenital recessive deafness.     

Scavenger receptor CL-P1 mediates endocytosis by associating with AP-2μ2

Background

Scavenger receptor CL-P1 (collectin placenta 1) has been found recently as a first membrane-type collectin which is mainly expressed in vascular endothelial cells. CL-P1 can endocytose OxLDL as well as microbes but in general, the endocytosis mechanism of a scavenger receptor is not well elucidated.

Methods

We screened a placental cDNA library using a yeast two-hybrid system to detect molecules associated with the cytoplasmic domain of CL-P1. We analyzed the binding and endocytosis of several ligands in CL-P1 transfectants and performed the inhibition study using tyrphostin A23 which is a specific inhibitor of tyrosine kinase, especially in μ2-dependent endocytosis and the site-directed mutagenesis in the endocytosis YXXΦ motif in CL-P1 cytoplasmic region. Furthermore, the SiRNA study of clathrin, adaptor AP-2 and dynamin-2 during the endocytosis of OxLDL in CL-P1 transfectant cells was carried out.

Results

We identified μ2 subunit of the AP-2 adaptor complex as a molecule associated with the cytoplasmic region of CL-P1. We demonstrated that AP-2μ2 was essential for CL-P1 mediated endocytosis of OxLDL in CL-P1 transfectant cells and its endocytosis was also mediated by clathrin, dynamin and adaptin complex molecules.

Conclusions

Tyrosine-based YXXΦ sequences play an important role in CL-P1-mediated OxLDL endocytosis associated with AP-2μ2.

General Significance

This might be the first finding of the clear endocytosis mechanism in scavenger receptor CL-P1.     

Diagnosis and surgical treatment of multiple endocrine neoplasia type 2A

Background

This study aims to introduce the diagnosis and surgical treatment of the rare disease multiple endocrine neoplasia type 2A (MEN 2A).

Methods

Thirteen cases of MEN 2A were diagnosed as medullary thyroid carcinoma (MTC) and pheochromocytoma by biochemical tests and imaging examination. They were treated by bilateral adrenal tumor excision or laparoscopic surgery.

Results

Nine patients were treated by bilateral adrenal tumor excision and the remaining four were treated by laparoscopic surgery for pheochromocytoma. Ten patients were treated by total thyroidectomy and bilateral lymph nodes dissection and the remaining three were treated by unilateral thyroidectomy for MTC. Up to now, three patients have died of MTC distant metastasis.

Conclusions

We confirmed that MEN 2A can be diagnosed by biochemical tests and imaging examination when genetic testing is not available. Surgical excision is the predominant way to treat MEN 2A; pheochromocytoma should be excised at first when pheochromocytoma and MTC occur simultaneously.     

Conflicto armado,contaminación y riesgos en salud: una evaluación de riesgo de tres fuentes de exposición ambiental asociadas con el conflicto en Colombia

Introduction:

Armed conflicts affect territories rich in resources and biodiversity. As a result of the environmental damage caused by violent actions, the health of populations can be affected.

Objectives:

To assess the risks to human health due to environmental degradation associated with three violent actions in the context of the Colombian armed conflict: Pipeline bombing, informal mining with mercury, and spraying of illicit crops with glyphosate.

Materials and methods:

We conducted a quantitative evaluation of the risks to individual health associated with armed conflict activities using methodologies focused on the routes of pollutants dispersion, their concentrations in the environment, the exposure of the individuals, and the risks of carcinogenic and non-carcinogenic effects.

Results:

The risk assessment of the armed conflict-related actions under study evidenced intolerable carcinogenic risk and unacceptable non-carcinogenic risk due to the consumption of water and fish contaminated by polycyclic aromatic hydrocarbons (PAH), mercury, and glyphosate.

Conclusions:

The study reiterates the inextricable connections existing among the environment, society, and health, as well as the implications of environmental violence for the public health of vulnerable population groups and, in general, for the well-being of all living beings affected by the armed conflict.