Polymorphisms in inflammation associated genes ALOX15 and IL-6 are associated with bone properties in young women and fracture in elderly

Association of Rs7217186 Polymorphism of Arachidonic Acid 15-Lipoxygenase (ALOX15) Gene with Susceptibility to Allergic Rhinitis

Background

Allergic rhinitis (AR) is an inflammatory disorder of the nasal mucosa, caused by exposure to environmental allergens. It is known that 15-lipoxygenase (15-LOX) is involved in the biosynthetic pathways of anti-inflammatory lipid mediators, including resolvins and protectins.

Methods

In this study, which was performed on 130 AR patients and 130 healthy controls, we aimed to investigate the association of susceptibility to AR with two selected single-nucleotide polymorphisms (SNPs), that is, rs2619112:A>G and rs7217186:C>T, in the intron regions of arachidonic acid 15-LOX (ALOX15) gene, using SNPinfo and Regulome DB tools.

Results

The results showed that the CT genotype of rs7217186: C>T was significantly associated with the increased risk of AR compared to the CC genotype (P= 0.037, OR=1.943, CI: 1.038-0.638). However, there was no strong evidence of the association of rs2619112: A>G with susceptibility to AR (P> 0.05).

Conclusions

The present results indicated that rs7217186 polymorphism of ALOX15 gene might be a potential biomarker for susceptibility to AR.

Proteomic global proteins analysis in blast lung injury reveals the altered characteristics of crucial proteins in response to oxidative stress, oxidation-reduction process and lipid metabolic process

Background: Blast lung injury (BLI) is the most common fatal blast injury induced by overpressure wave in the events of terrorist attack, gas and underground explosion. Our previous work revealed the characteristics of inflammationrelated key proteins involved in BLI, including those regulating inflammatory response, leukocyte transendothelial migration, phagocytosis, and immune process. However, the molecular characteristics of oxidative-related proteins in BLI ar still lacking. Methods: In this study, protein expression profiling of the blast lungs obtained by tandem mass tag (TMT) spectrometry quantitative proteomics were re-analyzed to identify the characteristics of oxidative-related key proteins. Forty-eight male C57BL/6 mice were randomly divided into six groups: control, 12 h, 24 h, 48 h, 72 h and 1 w after blast exposure. The differential protein expression was identified by bioinformatics analysis and verified by western blotting. Results: The results demonstrated that thoracic blast exposure induced reactive oxygen species generation and lipid peroxidation in the lungs. Analysis of global proteins and oxidative-related proteomes showed that 62, 59, 73, 69, 27 proteins (accounted for 204 distinct proteins) were identified to be associated with oxidative stress at 12 h, 24 h, 48 h, 72 h, and 1 week after blast exposure, respectively. These 204 distinct proteins were mainly enriched in response to oxidative stress, oxidation-reduction process and lipid metabolic process. We also validated these results by western blotting. Conclusions: These findings provided new perspectives on blast-induced oxidative injury in lung, which may potentially benefit the development of future treatment of BLI.

Dilemmas in the Management of Osteoporosis in Younger Adults

Osteoporosis in premenopausal women and men younger than 50 years is challenging to diagnose and treat. There are many barriers to optimal management of osteoporosis in younger adults, further enhanced by a limited research focus on this cohort. Herein we describe dilemmas commonly encountered in diagnosis, investigation, and management of osteoporosis in younger adults. We also provide a suggested framework, based on the limited available evidence and supported by clinical experience, for the diagnosis, assessment, and management of osteoporosis in this cohort. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Network Pharmacology Integrated with Molecular Docking Explores the Mechanisms of Naringin against Osteoporotic Fracture by Regulating Oxidative Stress

Naringin (NG), as the most abundant component of Drynariae Rhizoma (Chinese name: Gusuibu), has been proved to be an antioxidant flavonoid on promoting osteoporotic fracture (OF) healing, but relevant research is scanty on the underlying mechanisms. We adopted target prediction, protein-protein interaction (PPI) analysis, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and molecular docking to establish a system pharmacology database of NG against OF. Totally 105 targets of naringin were obtained, including 26 common targets with OF. A total of 415 entries were obtained through GO Biological Process enrichment analysis (P < 0.05), and 37 entries were obtained through KEGG pathway enrichment analysis with seven signaling pathways included (P < 0.05), which were primarily concerned with p53, IL-17, TNF, estrogen, and PPAR signaling pathways. According to the results of molecular docking, naringin is all bound in the active pockets of the core targets with 3-9 hydrogen bonds through some connections such as hydrophobic interactions, Pi-Pi stacked interactions, and salt bridge, demonstrating that naringin binds tightly to the core targets. In general, naringin may treat OF through multiple targets and multiple pathways via regulating oxidative stress, etc. Notably, it is first reported that NG may regulate osteoclast differentiation and oxidative stress through the expression of the core targets so as to treat OF.

Association between ALOX15 gene polymorphism and brick-tea type skeletal fluorosis in Tibetans, Kazaks and Han, China

To evaluate the association between ALOX15 gene polymorphism and skeletal fluorosis (SF), a case-control study was conducted. A total of 1023 individuals, including 308 Tibetans, 290 Kazaks and 425 Han, were enrolled in this study, in which cases and controls were 278 and 745, respectively. SF was diagnosed by X-ray absorptiometry. SNPs were genotyped using the Sequenom Mass ARRAY system. The genotypes of ALOX15 rs7220870, rs2664593 and rs1107852 were not associated with the risk of SF. After reconstructing the haplotype of rs7220870 and rs11078528, the risk effect of haplotype CA was found in Han participants aged ≤45 years or with moderate fluoride intake. Diplotype of CC/CC had a protective effect on SF risk in Han participants; whereas, CA/CC diplotype showed a risk effect on SF risk in participants aged ≥65; Our results provide the first evidence of an association between ALOX15 gene polymorphism and SF risk in Han participants.Abbreviation: SF: Skeletal fluorosis; SNP: Single Nucleotide polymorphism.

Polymorphisms in genes involved in inflammation, the NF-kB pathway and the renin-angiotensin-aldosterone system are associated with the risk of osteoporotic fracture. The Hortega Follow-up Study

Osteoporosis is the most common bone disorder worldwide and is associated with a reduced quality of life with important clinical and economic consequences. The most widely accepted etiopathogenic hypothesis on the origin of osteoporosis and its complications is that they are a consequence of the synergic action of environmental and genetic factors. Bone is constantly being remodelled through anabolic and catabolic pathways in which inflammation, the NF-kB pathway and the renin-angiotensin-aldosterone system (RAAS) are crucial. The aim of our study was to determine whether polymorphisms in genes implicated in inflammation, the NF-kB pathway and RAAS modified the risk of osteoporotic fracture. We analysed 221 patients with osteoporotic fracture and 354 controls without fracture from the HORTEGA sample after 12-14 years of follow up. In addition, we studied the genotypic distribution of 230 single nucleotide polymorphisms (SNPs) in genes involved in inflammation, NF-kB pathway and RAAS. Our results showed that be carrier of the C allele of the rs2228145 IL6R polymorphism was the principal genetic risk factor associated with osteoporotic fracture. The results also showed that variant genotypes of the rs4762 AGT, rs4073 IL8, rs2070699 END1 and rs4291 ACE polymorphisms were important genetic risk factors for fracture. The study provides information about the genetic factors associated with inflammation, the NF-kB pathway and RAAS, which are involved in the risk of osteoporotic fracture and reinforces the hypothesis that genetic factors are crucial in the etiopathogenesis of osteoporosis and its complications.

Identification of genetic variants associated with skeletal muscle function deficit in childhood acute lymphoblastic leukemia survivors

Background: Although 80% of childhood acute lymphoblastic leukemia (ALL) cases are cured with current treatment protocols, exposure to chemotherapeutics or radiation therapy during a vulnerable period of child development has been associated with a high frequency of late adverse effects (LAE). Previous observations suggest important skeletal muscle size, density and function deficits in ALL survivors.

Purpose: Given that only a fraction of all patients will suffer from this particular complication, we investigated whether it could be predicted by genetic markers. 

Patients and methods: We analysed associations between skeletal muscle force (Fmax) and power (Pmax) and germline genetic variants from 1039 genes derived through whole-exome sequencing. Top-ranking association signals retained after correction for multiple testing were confirmed through genotyping, and further analysed through stratified analyses and multivariate models. 

Results: Our results show that skeletal muscle function deficit is associated with two common single nucleotide polymorphisms (SNPs) (rs2001616DUOX2, P=0.0002 (Pmax) and rs41270041ADAMTS4, P=0.02 (Fmax)) and two rare ones located in the ALOX15 gene (P=0.001 (Pmax)). These associations were further modulated by sex, body mass index and risk groups, which reflected glucocorticoid dose and radiation therapy (P≤0.02). 

Conclusion: Occurrence of muscle function deficit in childhood ALL is thus strongly modulated by variations in the DUOX2, ADAMTS4 and ALOX15 genes, which could lead to personalized prevention strategies in childhood ALL survivors.

High-mobility group box-B1 (HMGB1) mediates the hypoxia-induced mesenchymal transition of osteoblast cells via activating ERK/JNK signaling

High-mobility group box 1 (HMGB1) is a nuclear protein that involves the binding with DNA and influences chromatin regulation and transcription. HMGB1 activates monocytes and neutrophils, which are involved in inflammation during wounding. In this study, we investigated the promotion of HMGB1 under hypoxia and determined the regulatory role of HMGB1 on the fibrosis of mouse osteoblast-like MC3T3-E1 cells or of human osteoblast MG-63 cells. Results demonstrated that HMGB1 expression was significantly upregulated in MC3T3-E1 or MG-63 cells under hypoxia. We also found that treatment with 10 and 100 ng/mL of HMGB1 significantly promoted the fibrosis-associated markers such as Collagen I, α-SMA, whereas downregulated the E-cadherin, indicating the differentiation of MC3T3-E1 or MG-63 cells into fibroblast cells. Further investigation indicated that the HMGB1 treatment markedly activated the mitogen-activated protein kinases (MAPKs), including extracellular signal-related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38) phosphorylation, as well as nuclear factor (NF)-κB nuclear translocation. On the other side, using specific inhibitors and shRNAs of protein kinases, we observed that repression of ERK, JNK, p38, and NF-κB all inhibited HMGB1-induced cellular differentiation and migration of MC3T3-E1 cells. In addition, knocking down of advanced glycation end products (RAGE) but not Toll-like receptor (TLR)2 and TLR4 by shRNAs attenuated HMGB1-induced myofibroblast differentiation and migration. In conclusion, our study demonstrated that HMGB1 induced the fibrosis of osteoblasts in vitro via activating the RAGE-MAPK and NF-κB interaction signaling pathways.