[Cardiovascular complications in malaria: a review].

Malaria, one of the major global public health events, is a leading cause of mortality and morbidity among children and adults in tropical and subtropical regions(mainly in sub-Saharan Africa), threatening human health. It is well known that malaria can cause various complications including anemia, blackwater fever, cerebral malaria, and kidney damage. Conventionally, cardiac involvement has not been listed as a common reason affecting morbidity and mortality of malaria, which may be related to ignored cases or insufficient diagnosis. However, the serious clinical consequences such as acute coronary syndrome, heart failure, and malignant arrhythmia caused by malaria have aroused great concern. At present, antimalarials are commonly used for treating malaria in clinical practice. However, inappropriate medication can increase the risk of cardiovascular diseases and cause severe consequences. This review summarized the research advances in the cardiovascular complications including acute myocardial infarction, arrhythmia, hypertension, heart failure, and myocarditis in malaria. The possible mechanisms of cardiovascular diseases caused by malaria were systematically expounded from the hypotheses of cell adhesion, inflammation and cytokines, myocardial apoptosis induced by plasmodium toxin, cardiac injury secondary to acute renal failure, and thrombosis. Furthermore, the effects of quinolines, nucleoprotein synthesis inhibitors, and artemisinin and its derivatives on cardiac structure and function were summarized. Compared with the cardiac toxicity of quinolines in antimalarial therapy, the adverse effects of artemisinin-derived drugs on heart have not been reported in clinical studies. More importantly, the artemisinin-derived drugs demonstrate favorable application prospects in the prevention and treatment of cardiovascular diseases, and are expected to play a role in the treatment of malaria patients with cardiovascular diseases. This review provides reference for the prevention and treatment of malaria-related cardiovascular complications as well as the safe application of antimalarials.

CDKN1C gene mutation causing familial Silver-Russell syndrome: A case report and review of literature.

BACKGROUND: Cyclin-dependent kinase inhibitor 1C (CDKN1C) is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest. CDKN1C mutations can lead to IMAGe syndrome (CDKN1C allele gain-of-function mutations lead to intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenital, and genitourinary malformations). We present a Silver-Russell syndrome (SRS) pedigree that was due to a missense mutation affecting the same amino acid position, 279, in the CDKN1C gene, resulting in the amino acid substitution p.Arg279His (c.836G>A). The affected family members had an SRS phenotype but did not have limb asymmetry or adrenal insufficiency. The amino acid changes in this specific region were located in a narrow functional region that contained mutations previously associated with IMAGe syndrome. In familial SRS patients, the PCNA region of CDKN1C should be analysed. Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants. CASE SUMMARY: We describe the case of an 8-year-old girl who initially presented with short stature. Her height was 91.6 cm, and her weight was 10.2 kg. Physical examination revealed that she had a relatively large head, an inverted triangular face, a protruding forehead, a low ear position, sunken eye sockets, and irregular cracked teeth but no limb asymmetry. Family history: The girl's mother, great-grandmother, and grandmother's brother also had a prominent forehead, triangular face, and severely proportional dwarfism but no limb asymmetry or adrenal insufficiency. Exome sequencing of the girl revealed a new heterozygous CDKN1C (NM_000076. 2) c.836G>A mutation, resulting in a variant with a predicted evolutionarily highly conserved arginine substituted by histidine (p.Arg279His). The same causative mutation was found in both the proband's mother, great-grandmother, and grandmother's brother, who had similar phenotypes. Thus far, we found an SRS pedigree, which was due to a missense mutation affecting the same amino acid position, 279, in the CDKN1C gene, resulting in the amino acid substitution p.Arg279His (c.836G>A). Although the SRS-related CDKN1C mutation is in the IMAGe-related mutation hotspot region [the proliferating cell nuclear antigen (PCNA) domain], no adrenal insufficiency was reported in this SRS pedigree. The reason may be that the location of the genomic mutation and the type of missense mutation determines the phenotype. The proband was treated with recombinant human growth hormone (rhGH). After 1 year of rhGH treatment, the height standard deviation score of the proband increased by 0.93 standard deviation score, and her growth rate was 8.1 cm/year. No adverse reactions, such as abnormal blood glucose, were found. CONCLUSION: Functional mutations in CDKN1C can lead to familial SRS without limb asymmetry, and some patients may have glucose abnormalities. In familial SRS patients, the PCNA region of CDKN1C should be analysed. Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.

Heat shock protein 40 of Streptococcus pneumoniae induces immune response of human dendritic cells via TLR4-dependent p38 MAPK and JNK signaling pathways.

INTRODUCTION: Heat shock protein 40 (HSP40) is a vaccine adjuvant candidate for Streptococcus pneumoniae. The mechanism by which HSP40 activates the human dendritic cells (DCs) is unclear. METHODS: DCs were isolated from human peripheral blood and their markers (HLA-DR, CD86, CD83, and CD80) were detected by flow cytometry. The messenger RNA (mRNA) and secretion levels of inflammary cytokines were measured after DCs were stimulated with recombinant HSP40 (rHSP40). Short hairpin RNAs were used to knock down toll-like receptor 2 (TLR2) and TLR4. The TLR2- or TLR4-deficient DCs were treated with lipopolysaccharides, rHSP40, or peptidoglycan, and then the secretion levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured. Moreover, the secretion levels of TNF-α and IL-6 were measured after DCs were treated with mitogen-activated protein kinase (MAPK) inhibitors including SB203580, SP600125, and U0126. In addition, the phosphorylation levels of p38 MAPK and Jun N-terminal kinase (JNK) in DC cells were determined using western blot analysis after treatment with rHSP40 for different times. RESULTS: DCs were successfully isolated and cultured. rHSP40 treatment significantly increased cytokine levels in a concentration-dependent manner. TLR4 deficiency, but not TLR2 deficiency, significantly suppressed the rHSP40-induced secretion of tumor necrosis factor-α  (TNF-α) and interleukin-6 (IL-6). SB203580 and SP600125 significantly inhibited the rHSP40-induced secretion of TNF-α and IL-6. rHSP40 significantly enhanced the phosphorylation of p38 MAPK and JNK. CONCLUSION: HPS40 stimulates the immune response of DCs via the p38 MAPK and JNK signaling pathways, which depend on TLR4.

A 7-year-old boy with recurrent cyanosis and tachypnea: A case report.

BACKGROUND: Brain tumors are the most common solid tumors in children and comprise 25% of all malignancies in children. Common presentations include headache, nausea and vomiting, gait abnormality, papilledema, and epileptic seizure; however, some symptoms can be very insidious, with atypical and misleading manifestations. CASE SUMMARY: Here, we report a 7-year-old boy who presented with recurrent cyanosis and tachypnea after exercise for 2 years. His body mass index was 26.43 kg/m2. Hepatosplenomegaly, blood gas analysis, biochemical parameters, chest computed tomography scan, and echocardiograph suggested type II respiratory failure, pulmonary heart disease, and mild liver injury. Non-invasive breathing support, antibiotics, and anti-heart failure therapy were given. The patient's pulse oxygen saturation increased to over 95% when he was awake but dropped to 50%-60%, accompanied by cyanosis, during sleep while receiving high-flow nasal cannula oxygen. Sleep-related breathing disorder was suspected. In the intensive care unit, however, polysomnography was unavailable. Brain magnetic resonance imaging revealed a space-occupying (cerebellum and brainstem) lesion, which was later confirmed to be pleomorphic xanthoastrocytoma by surgery and histopathology by tissue biopsy. CONCLUSION: When treating patients with cyanosis and tachypnea, a broad differential diagnosis should be considered, including brain tumor.

Rejection of Acellular Porcine Corneal Stroma Transplantation During Coronavirus Disease 2019 Pandemic.

ABSTRACT: To report 2 successfully managed cases of graft rejection with acellular porcine corneal stroma (APCS) transplantation in patients with fungal corneal ulcer. Two patients were diagnosed with fungal corneal ulcer and received APCS transplantation. Graft rejection developed due to the lost follow-up during the period of coronavirus disease 2019 outbreak. Amniotic membranes transplantation and cauterization of neovascularization was performed, respectively. The graft failure resolved successfully after the procedure. To the best of our knowledge, amniotic membranes transplantation and cauterization of new vessels are the firstly reported in treating APCS graft failure. Amniotic membranes transplantation or cauterization of neovascularization appear to be a safe and costeffective method for treating graft failure.

Pulmonary lymphomatoid granulomatosis in a 4-year-old girl: A case report.

BACKGROUND: Pulmonary lymphomatoid granulomatosis (PLG) is a lymphoproliferative disease associated with Epstein-Barr viral infection occurring mainly in adults and rarely in children. It is characterized by multiple pulmonary nodules. Its diagnosis depends on lung biopsy findings. Most patients are immunodeficient, and it commonly presents in children undergoing chemotherapy for leukemia. We report the case of a child with PLG caused by a mutation in the macrophage-expressed gene 1 (MPEG1), suggesting possible PLG occurrence in children undergoing treatment for pulmonary nodular lesions. CASE SUMMARY: This study reports a case of PLG without apparent immunodeficiency, suggesting the possibility of this disease occurrence during the treatment of pulmonary nodular lesions in children. Initially, the cause was assumed to be an atypical pathogen. Following conventional anti-infective treatment, chest computed tomography findings revealed that there were still multiple nodules in the lungs. Additionally, the patient was found to be infected with the Epstein-Barr virus. Histopathological examination of the resected lung revealed lymphoproliferative lesions with necrosis. Small lymphocytes, plasma cells, and histiocytes were observed in the background, although Reed-Sternberg cells were absent. Immunohistochemical staining [CD20(+), CD30(+), and CD3(+)] and EBV-encoded small RNA1/2 in situ hybridization of small lymphocytes revealed approximately 200 cells/high-power field. Whole exon sequencing of the patient revealed a mutation in the MPEG1. The patient was eventually diagnosed with PLG and transferred to the Department of Pediatric Oncology for bone marrow transplantation. CONCLUSION: As PLG is rare and fatal, it should be suspected in clinical settings when treatment of initial diagnosis is ineffective.

[Pharmacodynamic substances and therapeutic potential of Wuji Pills:based on UPLC-Q-TOF-MS/MS and network pharmacology].

As a classic prescription, Wuji Pills is composed of Coptidis Rhizoma, Euodiae Fructus Preparata, and stir-fried Paeo-niae Radix Alba at the ratio of 6∶1∶6. The practical application of it is limited compared with other famous Chinese medicine prescriptions. Only one company produces Wuji Pills in China. In this study, ultra-performance liquid chromatography quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS/MS) was used to analyze and identify 26 identical compounds from Wuji Pills and drug-containing plasma of rats. Based on these components, 46 potential targets were screened out with network pharmacology methods, followed by the component-target network construction, Gene Ontology(GO) term enrichment, Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment, and disease prediction. It was concluded that Wuji Pills acted on core targets such as PTGS2, PTSG1, NCOA2, HSP9 OAD1, and RXRA through magnoflorine, hydroxyevodiamine, daucosterol, and berberine and exerted pharmacodynamic effects through various pathways such as calcium ion signaling pathway, phosphatidylinositol-3-kinase-protein kinase B(PI3 K-Akt) signaling pathway, and vascular endothelial growth factor(VEGF) signaling pathway. Thus, Wuji Pills has therapeutic potential for Alzheimer's disease, diabetes mellitus, myocardial ischemia, and other diseases in addition to the conventional disease(irritable bowel syndrome, IBS). The above research results can provide a reference for the comprehensive interpretation of the pharmacodynamic basis of Wuji Pills and the expansion of clinical application. At the same time, a lot of components in serum and the in vivo transformed and metabolized components of Wuji Pills have similar structure and relative molecular weight. In theory, these components may show additive effects and the competitive/antagonistic effects on the same target. According to the hypothesis of "additive effect of multiple components for a single target" in traditional Chinese medicine, multiple similar components may exert the additive effects on local targets. This study can partly prove the scientificity of this hypothesis and provide laboratory evidence.

Resveratrol acts via melanoma-associated antigen A12 (MAGEA12)/protein kinase B (Akt) signaling to inhibit the proliferation of oral squamous cell carcinoma cells.

The present study examined how resveratrol affects cell growth and MAGEA12/Akt signaling pathway in OSCC cells. Cal-27 cells were transiently transfected with a plasmid encoding MAGEA12, and the effects of overexpression were assessed in terms of cell viability, colony formation and the epithelial-mesenchymal transition. Cal-27 cells and MAGEA12-overexpressing cells were treated with resveratrol, then the cell viability and colony formation were also assessed by CCK8 assay and microscope, respectively. Levels of MAGEA12, p-Akt, Akt, Cyclin D1, and CDK14 genes and these proteins were analyzed using quantitative reverse-transcription polymerase-chain reaction and western blot. In the present research, we first generated and transiently transfected MAGEA12 plasmid into Cal-27 cells. Our results suggested that overexpressing MAGEA12 led to an increase in levels of phospho-Akt, which was associated with increased cell viability, colony formation. Moreover, overexpressing MAGEA12 also resulted in the up-regulation of Cyclin D1 and CDK14, indicating MAGEA12 induces the cell proliferation of Cal-27 cells. In addition, these effects were partially reversed by inhibiting Akt. Furthermore, resveratrol could inhibit the proliferation and colony in Cal-27 cells and decrease the expressions of MAGEA12 and p-Akt depending on the time and concentration. These effects were also partially reversed by MAGEA12 overexpression and Akt activation. In summary, resveratrol may suppress the growth of OSCC cells by inactivating MAGEA12/Akt signaling. These findings suggest that resveratrol may be a therapeutic drug for OSCC in clinical.

[Association of age distribution with the expression of angiotensin-converting enzyme 2 in lung tissues in severe acute respiratory syndrome coronavirus 2 infection: reflections from the study of RAS pathway expression in mice].

OBJECTIVE: To study the expression of angiotensin-converting enzyme 2 (ACE2) and other key molecules of the RAS pathway in normal mice at different developmental stages, and to provide ideas for understanding the infection mechanism of coronavirus disease 2019 (COVID-19) as well as the diagnosis and treatment of children with COVID-19. METHODS: The mice at different developmental stages were enrolled, including fetal mice (embryonic days 14.5 and 18.5), neonatal mice (0, 3, 7, 14, and 21 days old), young mice (28 and 42 days old), and adult mice (84 days old). The lung tissues of all fetal mice from 4 pregnant mice were collected at each time point in the fetal group. Four mice were sampled in other age groups at each time point. Whole transcriptome resequencing was used to measure the mRNA expression of AGT, ACE, ACE2, Renin, Agtr1a, Agtr1b, Agtr2, and Mas1 in mouse lung tissue. RESULTS: The expression of ACE2 in the lungs showed changes from embryonic stage to adult stage. It increased gradually after birth, reached a peak on day 3 after birth, and reached a nadir on day 14 after birth (P<0.05). The expression of AGT reached a peak on days 0 and 7 after birth and reached a nadir on day 21 after birth (P<0.05). The expression of ACE increased rapidly after birth and reached a peak on day 21 after birth (P<0.05). Agtr1a expression reached a peak on day 21 after birth (P<0.05). Agtr2 expression gradually decreased to a low level after birth. Renin, Agtr1b, and Mas1 showed low expression in lung tissues at all developmental stages. CONCLUSIONS: At different developmental stages of mice, ACE2 has dynamic expression changes, with high expression in early neonatal and adult mice. The other key molecules of the RAS pathway have their own expression patterns. These suggest that the difference in clinical features between children and adults with COVID-19 might be associated with the different expression levels of ACE2 in the different stages, and further studies are needed for the mechanism.

[Nicorandil improves cognitive dysfunction in mice with streptozotocin-induced diabetes].

OBJECTIVE: To observe the protective effects of potassium channel opener nicorandil against cognitive dysfunction in mice with streptozotocin (STZ)-induced diabetes. METHODS: C57BL/6J mouse models of type 1 diabetes mellitus (T1DM) were established by intraperitoneal injection of STZ and received daily treatment with intragastric administration of nicorandil or saline (model group) for 4 consecutive weeks, with normal C57BL/6J mice serving as control. Fasting blood glucose level was recorded every week and Morris water maze was used to evaluate the cognitive behavior of the mice in the 4th week. At the end of the experiment, the mice were sacrificed to observe the ultrastructural changes in the hippocampus and pancreas under transmission electron microscopy; the contents of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) in the hippocampus and SOD activity and MDA level in the brain tissue were determined. RESULTS: Compared with the control group, the model group showed significantly increased fasting blood glucose (P<0.001), significantly prolonged escape latency (P<0.05) and increased swimming distance (P<0.01) with ultrastructural damage of pancreatic ß cells and in the hippocampus; GIP and GLP-1 contents in the hippocampus (P<0.01) and SOD activity in the brain were significantly decreased (P<0.05) and MDA content was significantly increased in the model group (P<0.05). Compared with the model group, nicorandil treatment did not cause significant changes in fasting blood glucose, but significantly reduced the swimming distance (P<0.05); nicorandil did not improve the ultrastructural changes in pancreatic ß cells but obviously improved the ultrastructures of hippocampal neurons and synapses. Nicorandil also significantly increased the contents of GIP and GLP-1 in the hippocampus (P<0.05), enhanced SOD activity (P<0.05) and decreased MDA level (P<0.01) in the brain tissue. CONCLUSION: Nicorandil improves cognitive dysfunction in mice with STZ-induced diabetes by increasing GIP and GLP-1 contents in the hippocampus and promoting antioxidation to relieve hippocampal injury.

Promoting Ethylene Selectivity from CO2 Electroreduction on CuO Supported onto CO2 Capture Materials.

Cu is a unique catalyst for CO2 electroreduction, since it can catalyze CO2 reduction to a series of hydrocarbons, alcohols, and carboxylic acids. Nevertheless, such Cu catalysts suffer from poor selectivity. High pressure of CO2 is considered to facilitate the activity and selectivity of CO2 reduction. Herein, a new strategy is presented for CO2 reduction with improved C2 H4 selectivity on a Cu catalyst by using CO2 capture materials as the support at ambient pressure. N-doped carbon (Nx C) was synthesized through high-temperature carbonization of melamine and l-lysine. We observed that the CO2 uptake capacity of Nx C depends on both the microporous area and the content of pyridinic N species, which can be controlled by the carbonization temperature (600-800 °C). The as-prepared CuO/Nx C catalysts exhibit a considerably higher C2 H4 faradaic efficiency (36 %) than CuO supported on XC-72 carbon black (19 %), or unsupported CuO (20 %). Moreover, there is a good linear relationship between the C2 H4 faradaic efficiency and CO2 uptake capacity of the supports for CuO. The local high CO2 concentration near Cu catalysts, created by CO2 capture materials, was proposed to increase the coverage of CO intermediate, which is favorable for the coupling of two CO units in the formation of C2 H4 . This study demonstrates that pairing Cu catalysts with CO2 capture supports is a promising approach for designing highly effective CO2 reduction electrocatalysts.

Long-term administration of pyridostigmine attenuates pressure overload-induced cardiac hypertrophy by inhibiting calcineurin signalling.

Cardiac hypertrophy is associated with autonomic imbalance, characterized by enhanced sympathetic activity and withdrawal of parasympathetic control. Increased parasympathetic function improves ventricular performance. However, whether pyridostigmine, a reversible acetylcholinesterase inhibitor, can offset cardiac hypertrophy induced by pressure overload remains unclear. Hence, this study aimed to determine whether pyridostigmine can ameliorate pressure overload-induced cardiac hypertrophy and identify the underlying mechanisms. Rats were subjected to either sham or constriction of abdominal aorta surgery and treated with or without pyridostigmine for 8 weeks. Vagal activity and cardiac function were determined using PowerLab. Cardiac hypertrophy was evaluated using various histological stains. Protein markers for cardiac hypertrophy were quantitated by Western blot and immunoprecipitation. Pressure overload resulted in a marked reduction in vagal discharge and a profound increase in cardiac hypertrophy index and cardiac dysfunction. Pyridostigmine increased the acetylcholine levels by inhibiting acetylcholinesterase in rats with pressure overload. Pyridostigmine significantly attenuated cardiac hypertrophy based on reduction in left ventricular weight/body weight, suppression of the levels of atrial natriuretic peptide, brain natriuretic peptide and ß-myosin heavy chain, and a reduction in cardiac fibrosis. These effects were accompanied by marked improvement of cardiac function. Additionally, pyridostigmine inhibited the CaN/NFAT3/GATA4 pathway and suppressed Orai1/STIM1 complex formation. In conclusion, pressure overload resulted in cardiac hypertrophy, cardiac dysfunction and a significant reduction in vagal discharge. Pyridostigmine attenuated cardiac hypertrophy and improved cardiac function, which was related to improved cholinergic transmission efficiency (decreased acetylcholinesterase and increased acetylcholine), inhibition of the CaN/NFAT3/GATA4 pathway and suppression of the interaction of Orai1/STIM1.

Overexpression of PLK3 Mediates the Degradation of Abnormal Prion Proteins Dependent on Chaperone-Mediated Autophagy.

Polo-like kinase 3 (PLK3) is the main cause of cell cycle reentry-related neuronal apoptosis which has been implicated in the pathogenesis of prion diseases. Previous work also showed the regulatory activity of exogenous PLK3 on the degradation of PrP (prion protein) mutants and pathogenic PrPSc; however, the precise mechanisms remain unknown. In this study, we identified that the overexpression of PLK3-mediated degradation of PrP mutant and PrPSc was repressed by lysosome rather than by proteasomal and macroautophagy inhibitors. Core components of chaperone-mediated autophagy (CMA) effectors, lysosome-associated membrane protein type 2A (LAMP2a), and heat shock cognate protein 70 (Hsc70) are markedly decreased in the HEK293T cells expressing PrP mutant and scrapie-infected cell line SMB-S15. Meanwhile, PrP mutant showed ability to interact with LAMP2a and Hsc70. Overexpression of PLK3 sufficiently increased the cellular levels of LAMP2a and Hsc70, accompanying with declining the accumulations of PrP mutant and PrPSc. The kinase domain (KD) of PLK3 was responsible for elevating LAMP2a and Hsc70. Knockdown of endogenous PLK3 enhanced the activity of macroautophagy in the cultured cells. Moreover, time-dependent reductions of LAMP2a and Hsc70 were also observed in the brain tissues of hamster-adapted scrapie agent 263K-infected hamsters, indicating an impairment of CMA during prion infection. Those data indicate that the overexpression of PLK3-mediated degradation of abnormal PrP is largely dependent on CMA pathway.

A small molecule induces integrin ß4 nuclear translocation and apoptosis selectively in cancer cells with high expression of integrin ß4.

Increased integrin ß4 (ITGB4) level is accompanied by malignant progression of multiple carcinomas. However, selective therapeutic strategies against cancer cells expressing a high level of ITGB4 have not been reported. Here, for the first time, we report that a chiral small molecule, SEC, selectively promotes apoptosis in cancer cells expressing a high level of ITGB4 by inducing ITGB4 nuclear translocation. Nuclear ITGB4 can bind to the ATF3 promoter region and activate the expression of ATF3, then upregulate the downstream pro-apoptosis genes. Furthermore, SEC promoted the binding of annexin A7 (ANXA7) to ITGB4 and increased ANXA7 GTPase activity. Activated ANXA7 promoted ITGB4 nuclear translocation by triggering ITGB4 phosphorylation at Y1494. SEC also inhibited the growth of xenograft tumors in the avian embryo model. We identified a small molecule, SEC, with selective pro-apoptosis effects on cancer cells with high expression of ITGB4, both in vitro and in vivo, by triggering the binding of ITGB4 and ANXA7, ITGB4 nuclear trafficking, and pro-apoptosis gene expression.

Expression of prion protein is closely associated with pathological and clinical progression and abnormalities of p53 in head and neck squamous cell carcinomas.

Prion protein (PrP) is a glycosyl-phosphatidylinositol (GPI)-anchored membrane protein that functions as a unique pathogenic agent in transmissible spongiform encephalopathy (TSE). In the past decade, overexpression of PrP was observed in a number of human malignant tumors, such as gastric, breast and pancreatic cancer. However, the role of PrP expression in squamous cell carcinoma is rarely documented. To screen PrP expression in head and neck squamous cell carcinoma (HNSCCs), the paraffin-embedded specimens of 92 pathologically diagnosed HNSCCs were assessed by PrP-specific immunohistochemistry (IHC). A total of 55.43% (51/92) of the tested carcinoma tissues were PrP-positive. The rate of positivity and the staining intensity of PrP were closely related with the pathological degree of the HNSCCs; a higher rate of PrP expression was noted in the group of poorly differentiated cancers. PrP-positivity rates increased along with the progression of the clinical grade of the carcinomas. Further evaluation of the associations between PrP expression and the data concerning p53 abnormalities and human papillomavirus (HPV) infection in these samples as previously described, revealed that PrP-positive staining was more frequently detected in the tissues with p53-positive accumulation and the wild-type TP53 gene. The patients with a proline (Pro) polymorphism in SNP72 of TP53 showed significantly higher PrP-positive rates than those with arginine (Arg). No notable difference in PrP expression was identified between the HPV-positive and HPV-negative group. These data indicate a close association of PrP expression with clinical and histological differentiation of HNSCCs, as well as abnormalities of p53.

Proteomic Analyses for the Global S-Nitrosylated Proteins in the Brain Tissues of Different Human Prion Diseases.

Human prion diseases are fatal neurodegenerative disorders characterized by neuronal damage in brain. Protein S-nitrosylation, the covalent adduction of a NO to cysteine, plays a role in human brain biology, and brain dysfunction is a prominent feature of prion disease, yet the direct brain targets of S-nitrosylation are largely unknown. We described the first proteomic analysis of global S-nitrosylation in brain tissues of sporadic Creutzfeldt-Jakob disease (sCJD), fatal familial insomnia (FFI), and genetic CJD with a substitution of valine for glycine at codon 114 of the prion protein gene (G114V gCJD) accompanying with normal control with isobaric tags for relative and absolute quantitation (iTRAQ) combined with a nano-HPLC/Q-Exactive mass spectrometry platform. In parallel, we used several approaches to provide quality control for the experimentally defined S-nitrosylated proteins. A total of 1509 S-nitrosylated proteins (SNO-proteins) were identified, and data are available via ProteomeXchange with identifier PXD002813. The cerebellum tissues appeared to contain more commonly differentially expressed SNO-proteins (DESPs) than cortex of sCJD, FFI, and gCJD. Three selected SNO-proteins were verified by Western blots, consistent with proteomics assays. Gene ontology analysis showed that more up-regulated DESPs were involved in metabolism, cell cytoskeleton/structure, and immune system both in the cortex and cerebellum, while more down-regulated ones in both regions were involved in cell cytoskeleton/structure, cell-cell communication, and miscellaneous function protein. Pathway analysis suggested that systemic lupus erythematosus, pathogenic Escherichia coli infection, and extracellular matrix-receptor interaction were the most commonly affected pathways, which were identified from at least two different diseases. Using STRING database, the network of immune system and cell cytoskeleton and structure were commonly identified in the context of the up-regulated and down-regulated DESPs, respectively, both in the cortex and cerebellum. Our study thus have implications for understanding the molecular mechanisms of human prion diseases related to abnormal protein S-nitrosylation and pave the way for future studies focused on potential biomarkers for the diagnosis and therapy of human prion diseases.

Erythropoietin improves glucose metabolism and pancreatic ß-cell damage in experimental diabetic rats.

Previous studies have implicated erythropoietin (EPO) signaling in the regulation of glucose metabolism. Whether EPO can be used treat diabetes and the underlying mechanism remain to be elucidated. The present study aimed to investigate whether EPO affects glucose metabolism, and the underlying mechanisms, in experimental diabetic rats. The effects of EPO (300 U/kg three times a week for 4 weeks) on glucose metabolism, hematopoietic function, blood selenium content and the ultrastructure of pancreatic ß­cells were investigated in low dose (25 mg/kg body weight) streptozotocin­induced experimental diabetic rats provided with a high­fat diet. The results demonstrated that EPO significantly decreased the fasting blood glucose, the area under the curve of the oral glucose tolerance and insulin tolerance tests and L­alanine gluconeogenesis. Ultrastructural examination of the pancreatic islets revealed that EPO prevented the dysfunction of pancreatic ß­cells in experimental diabetic rats, ameliorated cytoplasmic vacuolation and fragmentation of mitochondria, and increased the number of secretory granules. EPO administration increased the activities of superoxide dismutase and glutathione peroxidase, and decreased the level of malondialdehyde. Additionally, EPO increased blood selenium in the diabetic rats and produced a hematopoietic effect. These results indicated that EPO modulated glucose metabolism and improved pancreatic ß­cells damage by increasing anti­oxidation. The detailed mechanisms underlying these effects require further investigation.

Polo-like kinase 3 (PLK3) mediates the clearance of the accumulated PrP mutants transiently expressed in cultured cells and pathogenic PrP(Sc) in prion infected cell line via protein interaction.

Polo-like kinases (PLKs) family has long been known to be critical for cell cycle and recent studies have pointed to new dimensions of PLKs function in the nervous system. Our previous study has verified that the levels of PLK3 in the brain are severely downregulated in prion-related diseases. However, the associations of PLKs with prion protein remain unclear. In the present study, we confirmed that PrP protein constitutively interacts with PLK3 as determined by both in vitro and in vivo assays. Both the kinase domain and polo-box domain of PLK3 were proved to bind PrP proteins expressed in mammalian cell lines. Overexpression of PLK3 did not affect the level of wild-type PrP, but significantly decreased the levels of the mutated PrPs in cultured cells. The kinase domain appeared to be responsible for the clearance of abnormally aggregated PrPs, but this function seemed to be independent of its kinase activity. RNA-mediated knockdown of PLK3 obviously aggravated the accumulation of cytosolic PrPs. Moreover, PLK3 overexpression in a scrapie infected cell line caused notable reduce of PrP(Sc) level in a dose-dependent manner, but had minimal effect on the expression of PrP(C) in its normal partner cell line. Our findings here confirmed the molecular interaction between PLK3 and PrP and outlined the regulatory activity of PLK3 on the degradation of abnormal PrPs, even its pathogenic isoform PrP(Sc). We, therefore, assume that the recovery of PLK3 in the early stage of prion infection may be helpful to prevent the toxic accumulation of PrP(Sc) in the brain tissues.

Scrapie infection in experimental rodents and SMB-S15 cells decreased the brain endogenous levels and activities of Sirt1.

Prion diseases are composed of a group of fatal neurodegenerative disorders resulting from misfolding of cellular prion (PrP(C)) into scrapie prion (PrP(Sc)). Sirt1, a class III histone deacetylase, has been reported to protect neuronal cells against PrP (106-126)-induced cell death. To address the potential role of Sirt1 during prion infection, the levels and enzyme activities of Sirt1 in the brains of scrapie-infected rodents, including hamsters infected with strain 263K, mice infected with strains 139A and ME7, and in prion infected SMB-S15 cells, were analyzed. Western blots revealed that endogenous Sirt1 levels were significantly decreased in all tested scrapie-infected models. Dynamic assays of brain Sirt1 levels in 263K-infected hamsters during incubation period showed a time-dependent decrease. The acetylating forms of Sirt1 target proteins, P53, PGC-1, and STAT3, markedly increased both in the brains of scrapie-infected rodents and in SMB-S15 cells, representing decreased Sirt1 activity. Immunofluorescent assays illustrated that Sirt1 predominately localized in cytosol of SMB-S15 cells but clearly distributed in nucleus of its normal partner cell line, SMB-PS. Moreover, accompanying with increase of Sirt1 level and decrease of acetyl-P53 level, treatments with Sirt1 activators SRT1720 and resveratrol in SMB-S15 cells significantly reduced PrP(Sc); at the same time, the cellular distribution of PrP proteins became normal, and the cell proliferating state was slightly improved. These data indicate that prion infection notably attenuates the Sirt1 activity in host cells. Sensitivity of the PrP(Sc) to Sirt1 activators highlights a potential role of Sirt1 in prion therapeutics.

CD147 up-regulates calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils via a TRPM-7-mediated mechanism.

OBJECTIVES: We aimed to investigate whether CD147 can up-regulate the chemotactic, adhesive and invasive properties of human neutrophils and to determine the mechanism underlying this process. METHODS: Human promyelocytic leukaemia cells (HL-60) cells and peripheral blood or synovial fluid neutrophils were isolated from RA patients. Under cyclophilin A (CypA) stimulation, chemotaxis, adhesion potential and invasion ability were assessed using chemotaxis, adhesion and invasiveness assays. Lipid raft isolation and western blot were used to determine the mechanism underlying the effects of CypA stimulation. RESULTS: CD147 up-regulates the calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils in RA patients. Transient receptor potential melastatin 7 may be responsible for this phenomenon. CONCLUSION: These findings suggest that in RA patients, abundant CypA up-regulates the calcium-induced chemotactic, adhesive and invasive properties of neutrophils via direct binding to CD147. Cyclophilin-CD147 interactions might contribute to the destruction of cartilage and bone in RA.