Sub-chronic administration of benzo[a]pyrene disrupts hippocampal long-term potentiation via inhibiting CaMK II/PKC/PKA-ERK-CREB signaling in rats.

Benzo[a]pyrene (B[a]P) is recognized as a neurotoxic pollutant to mammals, which could impair learning and memory function. Although there is some evidence to suggest that N-methyl-d-aspartate receptor (NMDAR), a glutamate receptor and ion channel protein in nerve cells, is involved into the B[a]P induced neurotoxicity, the exact molecular mechanisms remain to be elucidated, particularly the effects of B[a]P on the NMDAR downstream signaling transduction pathways. In the present study, we examined the neurotoxicity of sub-chronic administrated B[a]P on male Sprague-Dawley rats. Our data suggested that B[a]P exposure caused significant deficits in learning and memory function and the impairment of hippocampal LTP in rats. Further mechanistic studies indicate that B[a]P-induced learning and memory deficits are associated with the inhibition of NMDAR NR1 subunit transcription and protein phosphorylation. More importantly, the inactivation of CaMK II/PKC/PKA-ERK-CREB signaling pathways in hippocampus was detected at both the 2.5 and 6.25 mg/kg B[a]P-treated groups, indicating that multiple targets in NMDAR and downstream signaling pathways are involved in the B[a]P-induced neurotoxicity.

Interaction of heat shock protein 70 (HSP70) polymorphisms and occupational hazards increases the risk of hypertension in coke oven workers.

OBJECTIVES: The interaction between genetic, epigenetic inheritance and environmental factors determines susceptibility to hypertension. Previous epidemiology studies have shown that coke oven workers who are frequently exposed to various occupational hazards have remarkable increase in the risk for hypertension. Among many genetic variants identified in hypertension, heat shock protein 70 (HSP70) was found to play important roles in the pathogenesis of hypertension and associated diseases. We therefore explore the possible role of HSP70 polymorphisms and their interaction with occupational environment in hypertension risk. METHODS: We carried out a case-control study among 367 coke oven workers in northwest China, focused on three common HSP70 polymorphisms (HSP70-1 G190C, HSP70-2 A1267G and HSP70-hom T2437C), and evaluated the association of HSP70 gene polymorphisms with work sites for high risk of hypertension. RESULTS: The results indicated that HSP70-1 GC and CC genotype had 2.73-fold and 4.26-fold increased relative risk (95% CI 1.33 to 5.55 and 1.17 to 15.53), respectively, comparing with HSP70-1 GG genotype. HSP70-2 AG and GG conferred a 47% and 36% reduced risk (95% CI 0.23 to 0.99 and 0.14 to 0.92) comparing with HSP70-2 AA genotype. Further analysis of the interaction of HSP70 polymorphisms with occupational environment indicated a strong positive interaction between HSP70 genotype (HSP70-1 GC+CC, HSP70-2 AA and HSP70-hom TC+CC) and oven top workplace. CONCLUSIONS: Collectively, these data indicate that HSP70 polymorphisms interact with occupational hazards might increase the risk of hypertension in coke oven workers.

Nr2e1 Downregulation Is Involved in Excess Retinoic Acid-induced Developmental Abnormality in the Mouse Brain.

OBJECTIVE: This study aimed to investigate the expression pattern and function of Nuclear receptor subfamily 2 group E member 1 (Nr2e1) in retinoic acid (RA)-induced brain abnormality. METHODS: The mouse model of brain abnormality was established by administering 28 mg/kg RA, and neural stem cells (NSCs) were isolated from the mouse embryo and cultured in vitro. Nr2e1 expression was detected by whole mount in situ hybridization, RT-PCR, and Western blotting. Nr2e1 function was determined by transducing Nr2e1 shRNA into NSCs, and the effect on the sonic hedgehog (Shh) signaling pathway was assessed in the cells. In addition, the regulation of Nr2e1 expression by RA was also determined in vitro. RESULTS: Nr2e1 expression was significantly downregulated in the brain and NSCs of RA-treated mouse embryos, and knockdown of Nr2e1 affected the proliferation of NSCs in vitro. In addition, a similar expression pattern of Nr2e1 and RA receptor (RAR) α was observed after treatment of NSCs with different concentrations of RA. CONCLUSION: Our study demonstrated that Nr2e1 could be regulated by RA, which would aid a better understanding of the mechanism underlying RA-induced brain abnormality.

Rare POLN mutations confer risk for familial nasopharyngeal carcinoma through weakened Epstein-Barr virus lytic replication.

BACKGROUND: Nasopharyngeal carcinoma (NPC) exhibits significant familial aggregation; however, its susceptibility genes are largely unknown. Thus, this study aimed to identify germline mutations that might contribute to the risk of familial NPC, and explore their biological functions. METHODS: Whole-exome sequencing was performed in 13 NPC pedigrees with multiple cases. Mutations co-segregated with disease status were further validated in a cohort composed of 563 probands from independent families, 2,953 sporadic cases, and 3,175 healthy controls. Experimental studies were used to explore the functions of susceptibility genes and their disease-related mutations. FINDINGS: The three rare missense mutations in POLN (DNA polymerase nu) gene, P577L, R303Q, and F545C, were associated with familial NPC risk (5/576 [0·87%] in cases vs. 2/3374 [0·059%] in healthy controls with an adjusted OR of 44·84 [95% CI:3·91-514·34, p = 2·25 × 10-3]). POLN was involved in Epstein-Barr virus (EBV) lytic replication in NPC cells in vitro. POLN promoted viral DNA replication, immediate-early and late lytic gene expression, and progeny viral particle production, ultimately affecting the proliferation of host cells. The three mutations were located in two pivotal functional domains and were predicted to alter the protein stability of POLN in silico. Further assays demonstrated that POLN carrying any of the three mutations displayed reduced protein stability and decreased expression levels, thereby impairing its ability to promote complete EBV lytic replication and facilitate cell survival. INTERPRETATION: We identified a susceptibility gene POLN for familial NPC and elucidated its function. FUNDING: This study was funded by the National Key Research and Development Program of China (2021YFC2500400); the National Key Research and Development Program of China (2020YFC1316902); the Basic and Applied Basic Research Foundation of Guangdong Province, China (2021B1515420007); the National Natural Science Foundation of China (81973131); the National Natural Science Foundation of China (82003520); the National Natural Science Foundation of China (81903395).

Polymorphism in a Plasmodium falciparum erythrocyte-binding ligand changes its receptor specificity.

Recognition of human erythrocytes by Plasmodium species depends in part on Region II of the Duffy binding-like family of parasite ligands, which includes BA erythrocyte binding ligand (BAEBL) of P. falciparum. In previous studies of BAEBL from two clones, Dd2/Nm from Vietnam and E12 from Papua New Guinea (PNG), it was found that BAEBL bound different erythrocyte receptors. Because of variation in binding specificity, we studied the sequence and erythrocyte binding specificity of Region II of BAEBL in P. falciparum clones from different parts of the world. We observed five nucleotide substitutions leading to five amino acid changes and five polymorphisms in Region II of BAEBL in parasites from both PNG and other parts of the world. We expressed four of the polymorphisms on COS cells and determined their binding to enzyme-treated erythrocytes and to Gerbich-negative erythrocytes. We also performed erythrocyte-binding assay using the native protein from radiolabeled culture supernatant. Both assays demonstrated that each of the four polymorphisms in the parasite ligand, BAEBL, bound to a different receptor on erythrocytes. These results suggest that P. falciparum has evolved multiple invasion pathways dependent on polymorphisms in the BAEBL ligand.

Heat-shock protein 70 (HSP70) polymorphisms affect the risk of coke-oven emission-induced neurobehavioral damage.

OBJECTIVES: Epidemiology studies indicated that coke-oven workers with long-term exposure to polycyclic aromatic hydrocarbons (PAHs) often have some neurobehavioral abnormalities especially impairment for cognitive function, while the underlying mechanisms are not fully understood. Numerous studies have indicated the antioxidant and anti-apoptosis roles of heat shock protein 70 (Hsp70). The genetic polymorphisms in HSP70 genes are associated with multiple diseases including neurotoxicity. However, it is unclear whether HSP70 polymorphisms are related to the neurotoxicity of PAH. We, therefore, investigate the possible association between HSP70 polymorphisms and neurobehavioral abnormalities. METHODS: 188 coke-oven workers and 137 control workers were recruited in this study. Emotional and cognitive function was assessed using the WHO/NCTB. HSP70 polymorphisms (HSP70-1 G190C, HSP70-2 G1267 A and HSP70-hom T2437C) were checked by PCR-RFLP. RESULTS: The results indicated that HSP70-1 CC genotypes in coke-oven workers were associated with poor neurobehavioral performance such as the attention /response speed and visual perception/memory, while the HSP70-2 AA genotypes were associated with lower short-term auditory memory. CONCLUSIONS: HSP70-1 CC and HSP70-2 AA genotypes in coke-oven workers may increase the risk for neurobehavioral damage, especially attention, learning and memory.

Radiofrequency deep hyperthermia combined with chemotherapy in the treatment of advanced non-small cell lung cancer.

BACKGROUND: In the era of precision medicine, chemotherapy is still considered the cornerstone of treatment for lung cancer patients without gene mutations. How to reduce the toxicity and increase the efficiency of chemotherapy is worth exploring. This study aimed to investigate the curative effects and safety of hyperthermia combined with chemotherapy (HCT) for advanced patients with non-small cell lung cancer (NSCLC), especially those with malignant pleural effusion. METHODS: We retrospectively evaluated medical records of 93 patients with advanced NSCLC (stage IIIB-IV) from March 2011 to January 2014. The patients were divided into HCT and chemotherapy (CT) groups. The HCT group was treated with gemcitabine and cisplatin (GP) regimen combined with regional radiofrequency deep hyperthermia, while the CT group was treated with GP regimen only. Those with malignant pleural effusion extra underwent thoracentesis and intrapleural injection chemotherapy combined with hyperthermic or not. Clinical treatment results and adverse reactions were compared and analyzed after treatment. SPSS 19.0 software (SPSS Inc., USA) was used for statistical data processing. P values less than 0.05 were accepted to be statistically significant. RESULTS: Among the 93 patients, HCT group included 48 patients (16 patients with malignant pleural effusion), CT group included 45 patients (10 patients with malignant pleural effusion). There was no significant difference between the two groups in patient characteristics. The overall response rate (ORR) of pleural effusions was much better in HCT group than that in CT group (81.2% vs. 40.0%, P = 0.046). The patients in HCT group had lower incidence rate of weakness (12.5% vs. 46.7%, χ = 13.16, P < 0.001) and gastrointestinal (25.0% vs. 77.8%, χ = 25.88, P < 0.001) adverse reactions than that in CT group. The objective tumor response and survival showed no significant differences. CONCLUSIONS: Hyperthermia combined with chemotherapy might lead to the development of better therapeutic strategy for advanced NSCLC with malignant pleural effusion patients. Also, it could greatly reduce the chemotherapy toxic effects in the incidence of weakness and gastrointestinal adverse reactions in advanced NSCLC patients.

CD4+ T-cell response to mitochondrial cytochrome B in human melanoma.

Mitochondrial DNA (mtDNA) is highly susceptible to mutations due to the low level of DNA repair and the presence of a high level of reactive oxygen species in the organelle. Although mtDNA mutations have been implicated in degenerating diseases, aging, and cancer, very little is known about the role of T cells in immunosurveillance for mtDNA aberrations. Here, we describe T-cell recognition of a peptide translated from an alternative open reading frame of the mitochondrial cytochrome b (cyt b) gene in melanoma cells established from a patient. To understand how the cyt b gene is transcribed and translated in tumor cells, we found that cyt b-specific CD4(+) T cells only recognized protein fractions derived from cytoplasm and not from mitochondria. However, T-cell recognition of tumor cells could be inhibited by treatment of tumor cells with rhodamine 6G inhibitor, which depletes mitochondria. These findings suggest that cyt b mRNA is leaked out of the mitochondria and then translated in the cytoplasm for presentation to CD4(+) T cells. The cyt b cDNAs from this patient contain highly heteroplasmic transition mutations compared with control cell lines, suggesting a compromise of mitochondrial integrity that may have contributed to melanoma induction or progression. These findings provide the first example of a mitochondrial immune target for CD4(+) T cells and therefore have implications for the immunosurveillance of mitochondrial aberrations in cancer patients.

Revision of the concept of anti-angiogenesis and its applications in tumor treatment.

Anti-angiogenesis therapy, by blocking formation of new blood vessels in tumors, is the standard-of-care therapy for various cancer types. The classic concept of anti-angiogenesis is expected to turn a tumor into a "dormant" disease. However, the combination of anti-angiogenesis agents with conventional therapeutics has generally produced only modest survival benefits for cancer patients in clinical trials. Therefore, the concept and applications of anti-angiogenesis have evolved dramatically along with lessons learned from recent clinical experience. In this article, we will discuss the revised concept of anti-angiogenesis therapy and the applications of anti-angiogenesis drugs, and focus particularly on how to utilize current anti-angiogenesis agents and develop new approaches to provide more benefits to patients with cancer.

Polymorphism in the Plasmodium falciparum erythrocyte-binding ligand JESEBL/EBA-181 alters its receptor specificity.

The malaria parasite lives within erythrocytes and depends on the binding of parasite ligands to host cell surface receptors for invasion. The most virulent human malaria parasite, Plasmodium falciparum, uses multiple ligands, including EBA-175, BAEBL, and JESEBL of the Duffy-binding-like (DBL) family of erythrocyte-binding proteins, for invasion of human erythrocytes. Region II of these parasite ligands is the erythrocyte-binding domain. Previously, we had shown that polymorphism in region II of BAEBL leads to different erythrocyte-binding specificities. We have now identified and characterized the binding specificity of six JESEBL variants. We sequenced region II of JESEBL from 20 P. falciparum clones collected from various parts of the world where malaria is endemic. We observed eight JESEBL variants that contained amino acid polymorphisms at five positions among all clones. Seven of the eight variants could be connected by a single base change that led to an amino acid change. We investigated the functional significance of these polymorphisms by transiently expressing region II from six of JESEBL variants on the surface of Chinese hamster ovary cells. We observed four erythrocyte-binding patterns to enzyme-treated erythrocytes. Thus, P. falciparum DBL ligands JESEBL and BAEBL can recognize multiple receptors on the erythrocyte surface. In contrast to Plasmodium vivax, which has disappeared from West Africa because of the Duffy-negative blood group, P. falciparum may have been successful in endemic areas because it has mutated the ligands of the DBL family to create multiple pathways of invasion, thus making selection of refractory erythrocytes unlikely.