Multiomic study of the protective mechanism of Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross against streptozotocin-induced diabetic nephropathy in Guizhou miniature pigs.

BACKGROUND: Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross (P. capitata, PCB), a traditional drug of the Miao people in China, is potential traditional drug used for the treatment of diabetic nephropathy (DN). PURPOSE: The purpose of this study is to investigate the function of P. capitata and clarify its protective mechanism against DN. METHODS: We induced DN in the Guizhou miniature pig with injections of streptozotocin, and P. capitata was added to the pigs' diet to treat DN. In week 16, all the animals were slaughtered, samples were collected, and the relative DN indices were measured. 16S rRNA sequencing, metagenomics, metabolomics, RNA sequencing, and proteomics were used to explore the protective mechanism of P. capitata against DN. RESULTS: Dietary supplementation with P. capitata significantly reduced the extent of the disease, not only in term of the relative disease indices but also in hematoxylin-eosin-stained tissues. A multiomic analysis showed that two microbes (Clostridium baratii and Escherichia coli), five metabolites (oleic acid, linoleic acid, 4-phenylbutyric acid, 18-ß-glycyrrhetinic acid, and ergosterol peroxide), four proteins (ENTPD5, EPHX1, ARVCF and TREH), four important mRNAs (encoding ENTPD5, EPHX1, ARVCF, and TREH), six lncRNAs (TCONS_00024194, TCONS_00085825, TCONS_00006937, TCONS_00070981, TCONS_00074099, and TCONS_00097913), and two circRNAs (novel_circ_0001514 and novel_circ_0017507) are all involved in the protective mechanism of P. capitata against DN. CONCLUSIONS: Our results provide multidimensional theoretical support for the study and application of P. capitata.

lncRNA-Gm5532 regulates osteoclast differentiation through the miR-125a-3p/TRAF6 axis.

Long noncoding RNAs (lncRNAs) are important regulators of bone metabolism. In this study, lncRNA microarray analysis was used to identify differentially expressed lncRNAs in differentiated osteoclasts. lncRNA-Gm5532 is highly expressed during osteoclast differentiation. lncRNA-Gm5532 knockdown impairs osteoclast formation and bone resorption. Mechanistic experiments show that lncRNA-Gm5532 functions as a competing endogenous RNA (ceRNA) and acts as a sponge for miR-125a-3p, which promotes TNF receptor-associated factor 6 (TRAF6) expression. miR-125a-3p mimics suppress osteoclast differentiation and TAK1/NF-κB/MAPK signaling. The miR-125a-3p inhibitor reverses the negative effects of siGm5532 on osteoclast differentiation. In summary, our study reveals that lncRNA-Gm5532 functions as an activator in osteoclast differentiation by targeting the miR-125a-3p/TRAF6 axis, making it a novel biomarker and potential therapeutic target for osteoporosis.

NRF2 is essential for iron-overload stimulated osteoclast differentiation through regulation of redox and iron homeostasis.

Iron overload enhances osteoclastic bone resorption and induces osteoporosis. Excess iron is highly toxic. The modulation of redox and iron homeostasis is critical for osteoclast differentiation under iron-overload condition. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that regulates the cellular defense against oxidative stress and iron overload through the expression of genes involved in anti-oxidative processes and iron metabolism. Our studies demonstrated that NRF2 activation was suppressed during osteoclast differentiation. Under iron-overload condition, NRF2 and its mediated antioxidant and iron metabolism genes were activated by reactive oxygen species (ROS), which enhanced antioxidant capability. NRF2 mediated the upregulation of iron exporter ferroportin 1 (FPN1) and iron storage protein ferritin, contributing to decreased levels of intracellular iron. Nfe2l2 knockout induced oxidative stress and promoted osteoclast differentiation under normal condition, but induced ferroptosis under iron-overload condition. Nfe2l2 knockout alleviated iron overload induced bone loss by inhibiting osteoclast differentiation. Our results suggest that NRF2 activation is essential for osteoclast differentiation by enhancing antioxidant capability and reducing intracellular iron under iron-overload condition. Targeting NRF2 to induce ferroptosis could be a potential therapy for the treatment of iron-overload induced osteoporosis.

Artesunate inhibits osteoclast differentiation by inducing ferroptosis and prevents iron overload-induced bone loss.

Artemisinin compounds have been demonstrated to have anti-osteoporosis effects by inhibiting bone resorption. During osteoclast differentiation, osteoclasts take up a large amount of iron through transferrin receptor 1 (TfR1) mediated endocytosis of transferrin (Tf). Since iron-dependent cleavage of endoperoxide bridge is of great importance for the antimalarial effects of artemisinin compounds, we raised a hypothesis that the cytotoxic effects of artemisinin compounds on osteoclasts were associated with enhanced iron uptake. In the present study, we found that Tf aggravated the inhibitory effects of artesunate (ART) on osteoclast viability and differentiation. ART induced the production of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) in a dose-dependent manner and led to the appearance of mitochondrial features of ferroptotic cells. TfR1 knockdown alleviated these cytotoxic effects of ART on osteoclasts. In addition, ART effectively prevented bone loss induced by iron overload. Our results indicate that ART inhibits iron-uptake stimulated osteoclast differentiation by inducing ferroptosis. Artemisinin compounds are potential drugs for treating iron overload-induced osteoporosis.

The study on the impact of sex on the structure of gut microbiota of bamboo rats in China.

Introduction: Bamboo rats are rodents that eat bamboo, and their robust capacity for bamboo digestion is directly correlated with their gut flora. Chinese bamboo rat (Rhizomys sinensis) is a common bamboo rat in Chinese central and southern regions. As a single-stomach mammal, bamboo rats are a famous specificity bamboo-eating animal and their intestinal microbial composition may also play a key role in the digestion of cellulose and lignin. So, the gut microbiota of bamboo rat may play an important role in the adaptation of bamboo rats for digesting lignocellulose-based diet. Methods: To study the microbiome differences of bamboo rats from different sexes, the microbial genomic DNA was extracted from each fecal sample and the V4 region of 16S rRNA genes was amplified and sequencing on an IlluminaHiSeq6000 platform. The operational taxonomic units (OTUs) were classified, the OTUs in different sexes was identified and compared at phylum and genus levels. For isolation and screening of cellulose degradation bacteria from bamboo rats, fresh feces from randomly selected bamboo rats were collected and used for the isolation and screening of cellulose degradation bacteria using Luria Bertani (LB) Agar medium containing Carboxymethyl cellulose. The cellulase activity, biochemical characterization and phylogenetic analysis of the purified bacteria strains were characterized. Results and discussion: A total of 3,833 OTUs were classified. The total microbial diversity detected in the female and male rats was 3,049 OTUs and 3,452 OTUs, respectively. The Shannon index revealed significant differences between the two groups (p < 0.05), though they were all captive and had the same feeding conditions. At the phylum level, Firmicutes, Bacteroidota, and Proteobacteria were prominent in the microbial community. At the genus level, the microbial community was dominated by Lachnospiraceae, Lactobacillus, Bacteroides, and Prevotella, but there was a significant difference between the two groups of bamboo rats; ~90 bacteria genus in the female group was significantly higher than the male group. Among them, Bacteroides, Colidextribacter, and Oscillibacter were significantly higher genera, and the genera of Lachnoclostridium, Oscillibacter, and Papillibacter had the highest FC value among the male and female bamboo rats. The KEGG function annotation and different pathways analysis revealed that membrane transport, carbohydrate metabolism, and amino acid metabolism were the most enriched metabolic pathways in the two groups, and multiple sugar transport system permease protein (K02025 and K02026), RNA polymerase sigma-70 factor (K03088), and ATP-binding cassette (K06147) were the three different KEGG pathways (p < 0.05). Two cellulose degradation bacteria strains-Bacillus subtilis and Enterococcus faecalis-were isolated and characterized from the feces of bamboo rats.

Porcine Endogenous Retroviruses: Quantification of the Viral Copy Number for the Four Miniature Pig Breeds in China.

Domestic pigs has served not only as one of the most important economy livestock but also as ideal organ-source animals owing to similarity in anatomy, physiology, and organ size to humans. Howerer, the barrier of the cross-species transmission risk of porcine endogenous retrovirus (PERVs) blocked the pig-to-human xenotransplantation. PERVs are integrated into pigs' genomes and cannot be eliminated by designated or specified pathogen-free breeding. PERVs are an important biosafety issue in xenotransplantation because they can be released from normal pig cells and infect human cells in vitro under certain conditions. Screening and analyzing the presence of PERVs in pig genome will provide essential parameters for pig breed sources. In China, four miniature pig breeds, such as Guizhou miniature pig (GZ), Bama miniature pig (BM), Wuzhishan miniature pig (WZS), and Juema miniature pig (JM), were the main experimental miniature pig breeds, which were widely used. In this study, PCR was performed to amplify env-A, env-B, and env-C for all individuals from the four breeds. The results revealed that PERV env-A and env-B were detected in all individuals and the lowest ratios of PERV env-C was 17.6% (3/17) in the GZ breed. Then, PERV pol and GAPDH were detected using the droplet digital PCR (ddPCR) method. As the reference of GAPDH copy number, the copy numbers of PERVs were at the median of 12, 16, 14, and 16 in the four miniature pig breeds (GZ, BM, WZS, and JM), respectively. Furthermore, the copy number of the PERV pol gene in many organs from the GZ breed was analyzed using ddPCR. The copy numbers of PERV pol gene were at the median of 7 copies, 8 copies, 8 copies, 11 copies, 5 copies, 6 copies, and 7 copies in heart, liver, spleen, lung, kidney, muscle, and skin, and the maximum number was 11 copies in the lung. The minimum number was 5 copies in the kidney as the reference of GAPDH. These data suggest that GZ breed has the lower PERVs copy number in the genome, and may be an ideal organ-source miniature pig breed for the study of the pig-to-human xenotransplantation.

Comparatively analyzing the liver-specific transcriptomic profiles in Kunming mice afflicted with streptozotocin- and natural food-induced type 2 diabetes mellitus.

BACKGROUND: Streptozotocin is a classic drug used to induce diabetes in animal models. OBJECTIVE: The aim of this study is to investigate the liver transcriptome of Kunming mice with diabetes induced by either streptozotocin (STZ) or Non-STZ. METHODS: Forty male mice were randomly assigned into four groups: Control (Ctr, standard diet), mHH (high fat and high carbohydrate diet), mHS (high fat and high carbohydrate diet for 4 weeks followed by 60 mg/kg STZ for 3 consecutive days) and mSH (60 mg/kg STZ for 3 consecutive days followed by a high fat and high carbohydrate diet for 12 weeks). All mice injected with STZ were identified as diabetic despite the sequential feeding of high fat and high carbohydrate diets. RESULTS: Only 7 of 13 mice in the mHH group met the diagnostic criteria for diabetes. The asting blood glucose (FBG) of the mHH, mHS, mSH and Ctrl groups was 13.27 ± 1.14, 15.01 ± 2.59, 15.95 ± 4.38 and 6.28 ± 0.33 mmol/L at the 12th week, respectively. Compared with the mHH group, transcription was elevated in 85 genes in the livers of mHS mice, while 21 genes were downregulated and 97 genes were upregulated in the mSH group while 35 genes were decreased. A total of 43 co-expressed genes were identified in the mHS vs mHH and mSH vs mHH groups. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses showed that two corporate GO terms and two KEGG pathways were significantly annotated in the STZ-treated groups. Both the GO term and pathway were related to the metabolism mediated by p53. CONCLUSION: A high fat and high carbohydrate diet combined with a low dose of STZ can effectively induce diabetes in Kunming mice despite the abnormal expressions of genes in the liver. The differentially expressed genes were related to metabolism mediated by p53.

Nrf2 Is a Potential Modulator for Orchestrating Iron Homeostasis and Redox Balance in Cancer Cells.

Iron is an essential trace mineral element in almost all living cells and organisms. However, cellular iron metabolism pathways are disturbed in most cancer cell types. Cancer cells have a high demand of iron. To maintain rapid growth and proliferation, cancer cells absorb large amounts of iron by altering expression of iron metabolism related proteins. However, iron can catalyze the production of reactive oxygen species (ROS) through Fenton reaction. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an important player in the resistance to oxidative damage by inducing the transcription of antioxidant genes. Aberrant activation of Nrf2 is observed in most cancer cell types. It has been revealed that the over-activation of Nrf2 promotes cell proliferation, suppresses cell apoptosis, enhances the self-renewal capability of cancer stem cells, and even increases the chemoresistance and radioresistance of cancer cells. Recently, several genes involving cellular iron homeostasis are identified under the control of Nrf2. Since cancer cells require amounts of iron and Nrf2 plays pivotal roles in oxidative defense and iron metabolism, it is highly probable that Nrf2 is a potential modulator orchestrating iron homeostasis and redox balance in cancer cells. In this hypothesis, we summarize the recent findings of the role of iron and Nrf2 in cancer cells and demonstrate how Nrf2 balances the oxidative stress induced by iron through regulating antioxidant enzymes and iron metabolism. This hypothesis provides new insights into the role of Nrf2 in cancer progression. Since ferroptosis is dependent on lipid peroxide and iron accumulation, Nrf2 inhibition may dramatically increase sensitivity to ferroptosis. The combination of Nrf2 inhibitors with ferroptosis inducers may exert greater efficacy on cancer therapy.

Major histocompatibility complex class II genetic diversity and the genetic influence on gut microbiota in Guizhou minipigs.

Major histocompatibility complex (MHC) is an important complex that presents antigen to T cells. The second exon of swine MHC (SLA) class II genes has antigen binding sites that bind with extracellular antigen. Populations with high MHC gene diversity result in low gut microbiota, and individuals with MHC gene heterozygote have lower gut microbiota diversity than that of homozygote. The pig is an animal with organs physiologically and anatomically similar to humans than any other mammal, and the pig is also suitably developed as a laboratory animal to establish the animal models of human disease. However, the relationship between SLA genetic diversity and the gut microbes of the pig is ambiguous. We studied the characterization of SLA class II genes and calculated the genetic diversity, and then we selected experimental animal groups divided by different SLA genotypes to investigate the gut microbiota composition by sequencing V3 to V4 hypervariable regions of bacterial 16 s rRNA from fecal samples. Our results showed that Guizhou minipigs had a low SLA genetic diversity, which may be due to the small founder population. The Guizhou minipig population deviated from neutral selection and balancing selection, which shows that Guizhou minipigs experience a strong artificial selection in recent years. We observed that the sex differences influenced gut microbiota much more deeply than that of genetics. Our results also showed that the individual with heterozygote of genes at the SLA class II region had much higher abundant gut microbiota than that of the homozygote.

Curcumin ameliorates ischemic stroke injury in rats by protecting the integrity of the blood-brain barrier.

The blood-brain barrier (BBB) is critical for proper cerebral homeostasis and its dysfunction during ischemic stroke can result in significant neurological injury. The major goal of the present study was to identify whether curcumin pretreatment possessed protective effects on BBB integrity during the 24 h of acute ischemic brain injury. To investigate the protective effects of curcumin, male Sprague-Dawley rats were divided into multiple groups, including sham, middle cerebral artery occlusion/reperfusion (MCAO/R) vehicle and curcumin pretreated MCAO/R groups. The effects of curcumin were measured by analyzing neurological deficits, infarct size, BBB permeability and expression levels of permeability-related proteins in the brain. It was found that curcumin pretreatment significantly improved neurological scores, decreased infarct size, and protected synaptic remodeling of hippocampal neurons and upregulated the protein expression level of tight junction proteins, ZO-1, occludin and claudin-5 in ischemic rat brains. Furthermore, curcumin pretreatment before stroke was shown to downregulate the phosphorylation of NF-κB and MMP-9, which are central mediators of inflammation. The results from the present study indicated that curcumin pretreatment ameliorated ischemic stroke injury by protecting BBB integrity and synaptic remodeling, as well as inhibiting inflammatory responses.

Therapeutic potential of iron chelators on osteoporosis and their cellular mechanisms.

Iron is an essential trace element in the metabolism of almost all living organisms. Iron overload can disrupt bone homeostasis by significant inhibition of osteogenic differentiation and stimulation of osteoclastogenesis, consequently leading to osteoporosis. Iron accumulation is also involved in the osteoporosis induced by multiple factors, such as estrogen deficiency, ionizing radiation, and mechanical unloading. Iron chelators are first developed for treating iron overloaded disorders. However, growing evidence suggests that iron chelators can be potentially used for the treatment of bone loss. In this review, we focus on the therapeutic effects of iron chelators on bone loss. Iron chelators have therapeutic effects not only on iron overload induced osteoporosis, but also on osteoporosis induced by estrogen deficiency, ionizing radiation, and mechanical unloading, and in Alzheimer's disease-associated osteoporotic deficits. Iron chelators differently affect the cellular behaviors of bone cells. For osteoblast lineage cells (bone mesenchymal stem cells and osteoblasts), iron chelation stimulates osteogenic differentiation. Conversely, iron chelation significantly inhibits osteoclast differentiation. These different responses may be associated with the different needs of iron during differentiation. Fibroblast growth factor 23, angiogenesis, and antioxidant capability are also involved in the osteoprotective effects of iron chelators.

Development of a reverse transcription loop mediated isothermal amplification assay for the detection of Mouse reovirus type 3 in laboratory mice.

Mouse reovirus type 3 (Reo-3) infection is a viral disease that is harmful for laboratory mice. No rapid and accurate detection methods are currently available for this infection. In this study, we describe a rapid, simple, closed-tube, one step, reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for Reo-3 and compare our assay with indirect enzyme-linked immunosorbent assay (ELISA). Three sets of RT-LAMP primers were designed by sequence analysis of a specific conserved sequence of the Reo-3 S1 gene. Using RS2 primer set, the RT-LAMP assay required 60 min at 65 °C to amplify the S1 gene in one step by using Reo-3 RNA template and had no cross-reactivity with the other related pathogens, such as Sendai virus (SV), pneumonia virus of mice (PVM), mouse hepatitis virus (MHV), Ectromelia virus (Ect), minute virus of mice (MVM), P. pneumotropica, B. bronchiseptica, K. pneumonia and P. aeruginosa. in our LAMP reaction system. The limit of detection (LOD) of our RT-LAMP assay is 4 fg/µL. The established RT-LAMP assay enabled visual detection when fluorescence detection reagents were added, and was demonstrated to be effective and efficient. We tested 30 clinical blood samples and five artificial positive samples from SPF mice, the concordance between the two methods for blood samples was 100% compared with indirect ELISA and RT-PCR. Considering its performance, specificity, sensitivity, and repeatability, the developed RT-LAMP could be a valuable tool to supply a more effective Reo-3 detection method in laboratory animal quality monitoring.

Aptamer-targeting of Aleutian mink disease virus (AMDV) can be an effective strategy to inhibit virus replication.

Aleutian mink disease (AMD), which is caused by Aleutian mink disease virus (AMDV), is an important contagious disease for which no effective vaccine is yet available. AMD causes major economic losses for mink farmers globally and threatens some carnivores such as skunks, genets, foxes and raccoons. Aptamers have exciting potential for the diagnosis and/or treatment of infectious viral diseases, including AMD. Using a magnetic beads-based systemic evolution of ligands by exponential enrichment (SELEX) approach, we have developed aptamers with activity against AMDV after 10 rounds of selection. After incubation with the ADVa012 aptamer (4 µM) for 48 h, the concentration of AMDV in the supernatant of infected cells was 47% lower than in the supernatant of untreated cells, whereas a random library of aptamers has no effect. The half-life of ADVa012 was ~ 32 h, which is significantly longer than that of other aptamers. Sequences and three dimensions structural modeling of selected aptamers indicated that they fold into similar stem-loop structures, which may be a preferred structure for binding to the target protein. The ADVa012 aptamer was shown to have an effective and long-lasting inhibitory effect on viral production in vitro.

Effect of Senecio scandens ethanol extract on gut microbiota composition in mice.

The gut microbiota inhabits the animal intestinal tract, and dysbiosis of the gut microbiota may result in disease. Senecio scandens has pharmaceutical antibacterial activities and is regarded as a broad-spectrum antibiotic in traditional Chinese medicine. Extracts of S. scandens are reported to show strong antimicrobial activity, and quercetin significantly decreases some species in the caecal microflora. However, the bactericidal effects of the extracts on the gut microbiota remain obscure. Here, we supplied ethanol extract of S. scandens, which might possibly be used as an alternative for chemical antibiotics, to mice to investigate the state of the intestinal microbiota. Our studies included a control group, low-, moderate-, and high-dose ethanol extract groups, and cefixime capsule group. The ethanol extract groups did not present reduced diversity or differences in the gut microbiota balance. There were significant differences between the ethanol extract and cefixime capsule groups in terms of the gut microbiota. The control and ethanol extract groups contained similar bacteria, which suggested that the ethanol extract has no inhibitory effect on the gut microbiota in vivo. Bifidobacteriales and Lactobacillus acidophilus were significantly increased in the high-dose group. Both secretory immunoglobulin A and mucin 2 concentrations increased as the dose of ethanol extract increased. The functional prediction differences between the control and ethanol extract groups decreased with increasing extract doses, which indicated that the low-dose and high-dose extract treatments might regulate different pathways and functions of the gut microbiota. The results also highlighted the prevention of bacterial drug resistance in the ethanol extract groups.

Development of an antigen-capture enzyme-linked immunosorbent assay for diagnosis of Aleutian mink disease virus.

Aleutian mink disease (AMD), caused by Aleutian mink disease virus (AMDV), is a very important infectious disease of mink. Currently, elimination of antibody- or antigen-positive animals is the most successful strategy for eradicating AMD, but the claw-cutting method of blood sampling is difficult to perform and painful for the animal. In this study, we aimed to establish an antigen capture enzyme-linked immunosorbent assay (AC-ELISA) method for the efficient detection of AMDV antigens using fecal samples. A purified mouse monoclonal antibody (mAb) was used as the capture antibody, and a rabbit polyclonal antibody (pAb) was used as the detection antibody. The assay was optimized by adjusting a series of parameters. Using a cutoff value of 0.205, the limit of detection of the AC-ELISA for strain AMDV-G antigen was 2 µg/mL, and there was no cross-reaction with other mink viruses. The intra- and inter-assay standard deviations were below 0.046, and the correlation of variance (CV) values were 1.24-7.12% when testing fecal samples. Compared with conventional PCR results, the specificity and sensitivity were 91.5% and 90.6%, respectively, and the concordance rate between the two methods was 91.1%.

Oxidative stress caused by a dysregulated Wnt/ß-catenin signalling pathway is involved in abnormal placenta formation in pregnant mice with chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) is characterized by extreme fatigue and disabling symptoms. Women with CFS often have a high risk of gynaecological problems such as irregular menstruation, endometriosis and pelvic pain and sexual dysfunction. Our previous results have shown that, in pregnant mice, CFS significantly decreased the progestational hormone level in serum, as well as learning and memory, and the function of the hypothalamus-pituitary-gonadal axis. In addition, the F1 generation also suffered from congenital hypothyroidism. At present, there has been no report about placenta formation and embryonic development in pregnant mice with CFS. The aim of the present study was to investigate the influence of CFS on the morphology, oxidative stress and Wnt/ß-catenin signalling pathway during placenta formation. In this study, we found that CFS decreased the number of implantation sites for blastocysts, and increased the number of absorbed, stillborn and malformed fetuses. The morphology and structure of the placenta were abnormal in pregnant mice with CFS. Further study found that the oxidative stress in serum, uterus and placenta was increased in pregnant mice with CFS, while the levels of antioxidase were decreased. CFS also inhibited the Wnt/ß-catenin signalling pathway in the placenta. These results suggested that inhibition of the Wnt/ß-catenin signalling pathway and enhanced oxidative stress play an important role in abnormal placentation in pregnant mice with CFS.

Ionizing Radiation Exacerbates the Bone Loss Induced by Iron Overload in Mice.

Patients with radiotherapy are at significant risks of bone loss and fracture. On the other hand, osteoporosis often occurs in disorders characterized by iron overload. Either ionizing radiation (IR) or iron overload alone has detrimental effects on bone metabolism, but their combined effects are not well defined. In this study, we evaluated the effects of IR on bone loss in an iron-overload mouse model induced by intraperitoneal injection of ferric ammonium citrate (FAC). In the present study, we found that IR additively aggravated iron overload induced by FAC injections. Iron overload stimulated hepcidin synthesis, while IR had an inhibitory effect and even inhibited the stimulatory effects of iron overload. Micro-CT analysis demonstrated that the loss of bone mineral density and bone volume, and the deterioration of bone microarchitecture were greatest in combined treatment group. Iron altered the responses of bone cells to IR. Iron enhanced the responses of osteoclasts to IR with elevated osteoclast differentiation, but did not affect osteoblast differentiation. Our study indicates that IR and iron in combination lead to a more severe impact on the bone homeostasis when compared with their respective effects. IR aggravated iron overload induced bone loss by heightened bone resorption relative to formation. The addictive effects may be associated with the exacerbated iron accumulation and osteoclast differentiation.

Constrained MLAMBDA Method for Multi-GNSS Structural Health Monitoring.

Deformation monitoring of engineering structures using the advanced Global Navigation Satellite System (GNSS) has attracted research interest due to its high-precision, constant availability and global coverage. However, GNSS application requires precise coordinates of points of interest through quick and reliable resolution of integer ambiguities in carrier phase measurements. Conventional integer ambiguity resolution algorithms have been extensively researched indeed in the past few decades, although the application of GNSS to structural health monitoring is still limited. In particular, known a priori information related to the structure of a body of interest is not normally considered. This study proposes a composite strategy that incorporates modified least-squares ambiguity decorrelation adjustment (MLAMBDA) method with priori information of the structural deformation. Data from the observation sites of Baishazhou Bridge are used to test method performance. Compared to MLAMBDA methods that do not consider priori information, the ambiguity success rate (ASR) improves by 20% for global navigation satellite system (GLONASS) and 10% for Multi-GNSS, while running time is reduced by 60 s for a single system and 180 s for Multi-GNSS system. Experimental results of Teaching Experiment Building indicate that our constrained MLAMBDA method improves positioning accuracy and meets the requirements of structural health monitoring, suggesting that the proposed strategy presents an improved integer ambiguity resolution algorithm.

Deferoxamine inhibits iron-uptake stimulated osteoclast differentiation by suppressing electron transport chain and MAPKs signaling.

Iron overload causes osteoporosis by enhancing osteoclastic bone resorption. During differentiation, osteoclasts demand high energy and contain abundant mitochondria. In mitochondria, iron is used for the synthesis of Fe-S clusters to support mitochondria biogenesis and electron transport chain. Moreover, mitochondrial reactive oxygen species (ROS) play an important role in osteoclastogenesis. Activation of MAPKs (ERK1/2, JNK, and p38) by ROS is essential and contribute to osteoclast differentiation. How iron chelation impairs electron transport chain and ROS dependent MAPKs activation during osteoclast differentiation is unknown. This study aimed to determine the direct effects of iron chelation on osteoclast differentiation, electron transport chain and MAPKs activation. In the present study, we found that when iron chelator, deferoxamine (DFO), was added, a dose-dependent inhibition of osteoclast differentiation and bone resorption was observed. Supplementation of transferrin-bound iron recovered osteoclastogenesis. Iron chelation resulted in a marked decrease in ferritin level, and increased expression of transferrin receptor 1 and ferroportin. As an iron chelator, DFO negatively affected mitochondrial function through decreasing activities of all the complexes. Expressions of mitochondrial subunits encoded both by mitochondrial and nuclear DNA were decreased. DFO augmented production of mitochondrial ROS, but inhibited the phosphorylation of ERK1/2, JNK, and p38, even in the presence of hydrogen peroxide. These results suggest that iron chelation directly inhibits iron-uptake stimulated osteoclast differentiation and suppresses electron transport chain. Iron chelation negatively regulates MAPKs activation, and this negative regulation is independent on ROS stimulation.

Different gut microbiome composition in obese Guizhou minipigs between female and castrated male.

Gut microbiome lives in the intestinal tract of animals and plays an important role in almost all life processes. Gut microbiome balance is beneficial to health, and imbalance leads to many diseases, one of which is obesity epidemic. However, gut microbiome is also influenced by host hormone, and different gut microbiome composition is observed between the sexes. Here, we studied whether castrated male Guizhou minipigs with obesity own the same gut microbiome composition and microbial function predictions with those in obese females. We sequenced the hypervariable regions V3 to V4 of bacterial 16s rRNA of fecal samples collected from our study subjects. We observed that the operational taxonomic units were small, which suggested that the abundance of gut microbiome may be influenced by low genetic diversity of host. Our results also suggested that the castrated male has different gut microbial composition compared to the obese female. An increasing Firmicutes/Bacteroidetes ratio was observed in both castrated male and obese female groups, which suggested that the main adipogenic gut microorganism in obese Guizhou minipigs in our studies is the same with that in other obese mammals. However, we also observed that there were function prediction differences of obese Guizhou minipigs between female and castrated male, which suggested that the influence of gut microbiome on obesity between them is different.