Integrate structural analysis, isoform diversity, and interferon-inductive propensity of ACE2 to predict SARS-CoV2 susceptibility in vertebrates.

The current new coronavirus disease (COVID-19) has caused globally over 0.4/6 million confirmed deaths/infected cases across more than 200 countries. As the etiological coronavirus (a.k.a. SARS-CoV2) may putatively have a bat origin, our understanding about its intermediate reservoir between bats and humans, especially its tropism in wild and domestic animals are mostly unknown. This constitutes major concerns in public health for the current pandemics and potential zoonosis. Previous reports using structural analysis of the viral spike protein (S) binding its cell receptor of angiotensin-converting enzyme 2 (ACE2), indicate a broad potential of SARS-CoV2 susceptibility in wild and particularly domestic animals. Through integration of key immunogenetic factors, including the existence of S-binding-void ACE2 isoforms and the disparity of ACE2 expression upon early innate immune response, we further refine the SARS-CoV2 susceptibility prediction to fit recent experimental validation. In addition to showing a broad susceptibility potential across mammalian species based on structural analysis, our results also reveal that domestic animals including dogs, pigs, cattle and goats may evolve ACE2-related immunogenetic diversity to restrict SARS-CoV2 infections. Thus, we propose that domestic animals may be unlikely to play a role as amplifying hosts unless the virus has further species-specific adaptation. Findings may relieve relevant public concerns regarding COVID-19-like risk in domestic animals, highlight virus-host coevolution, and evoke disease intervention through targeting ACE2 molecular diversity and interferon optimization.

A Brain-Penetrating Hsp90 Inhibitor NXD30001 Inhibits Glioblastoma as a Monotherapy or in Combination With Radiation.

Glioblastoma multiforme (GBM) is a highly heterogeneous disease, which is initiated and sustained by various molecular alterations in an array of signal transduction pathways. Heat-shock protein 90 (Hsp90) is a molecular chaperone and is critically implicated in folding and activation of a diverse group of client proteins, many of which are key regulators for glioblastoma biology. We here assessed the anti-neoplastic efficacy of a novel brain-penetrating Hsp90 inhibitor NXD30001 as a monotherapy and combined with radiation in vitro and in vivo. Our results demonstrated that NXD30001 potently inhibited neurosphere formation, growth, and survival of CD133+ GBM cells with the half maximal inhibitory concentration at low nanomolar range, but CD133- GBM cells were less sensitive to NXD30001. NXD30001 also increased radio-sensitivity in glioblastoma stem cells (GSCs) at suboptimal concentrations. Moreover, NXD30001 dose-dependently decreased phosphorylation levels of multiple Hsp90 client proteins which play key roles in GBM, such as EGFR, Akt, c-Myc, and Notch1. In addition, NXD30001 could impair DNA damage response and endoplasmic reticulum stress response after radiotherapy by alteration of the related proteins expression. In a murine orthotopic model of human glioblastoma, NXD30001 marvelously induced tumor regression and extended median survival of tumor-bearing mice by approximately 20% when compared with the vehicle group (37 d vs 31 d, P<0.05). Radiotherapy solely increased median survival of tumor-bearing mice from 31 d to 38 d (P<0.05), while NXD30001 combined with radiation further extended survival to 43 d (P<0.05). We concluded that GSCs are more sensitive to NXD30001 than non-stem GBM cells, and NXD30001 in combination with radiation exerts better inhibitive effect in GBM progression than monotherapy.

Viral Infections and Interferons in the Development of Obesity.

Obesity is now a prevalent disease worldwide and has a multi-factorial etiology. Several viruses or virus-like agents including members of adenoviridae, herpesviridae, slow virus (prion), and hepatitides, have been associated with obesity; meanwhile obese patients are shown to be more susceptible to viral infections such as during influenza and dengue epidemics. We examined the co-factorial role of viral infections, particularly of the persistent cases, in synergy with high-fat diet in induction of obesity. Antiviral interferons (IFNs), as key immune regulators against viral infections and in autoimmunity, emerge to be a pivotal player in the regulation of adipogenesis. In this review, we examine the recent evidence indicating that gut microbiota uphold intrinsic IFN signaling, which is extensively involved in the regulation of lipid metabolism. However, the prolonged IFN responses during persistent viral infections and obesogenesis comprise reciprocal causality between virus susceptibility and obesity. Furthermore, some IFN subtypes have shown therapeutic potency in their anti-inflammation and anti-obesity activity.

Xenopus Interferon Complex: Inscribing the Amphibiotic Adaption and Species-Specific Pathogenic Pressure in Vertebrate Evolution?

Several recent studies have revealed previously unknown complexity of the amphibian interferon (IFN) system. Being unique in vertebrate animals, amphibians not only conserve and multiply the fish-like intron-containing IFN genes, but also rapidly evolve amniote-like intronless IFN genes in each tested species. We postulate that the amphibian IFN system confers an essential model to study vertebrate immune evolution in molecular and functional diversity to cope with unprecedented pathophysiological requirement during terrestrial adaption. Studies so far have ascribed a potential role of these IFNs in immune regulation against intracellular pathogens, particularly viruses; however, many knowledge gaps remain elusive. Based on recent reports about IFN's multifunctional properties in regulation of animal physiological and defense responses, we interpret that amphibian IFNs may evolve novel function pertinent to their superior molecular diversity. Such new function revealed by the emerging studies about antifungal and developmental regulation of amphibian IFNs will certainly promote our understanding of immune evolution in vertebrates to address current pathogenic threats causing amphibian decline.

Insulin-mediated signaling promotes proliferation and survival of glioblastoma through Akt activation.

BACKGROUND: Metabolic complications such as obesity, hyperglycemia, and type 2 diabetes are associated with poor outcomes in patients with glioblastoma. To control peritumoral edema, use of chronic high-dose steroids in glioblastoma patients is common, which can result in de novo diabetic symptoms. These metabolic complications may affect tumors via profound mechanisms, including activation of insulin receptor (InsR) and the related insulin-like growth factor 1 receptor (IGF1R) in malignant cells. METHODS: In the present study, we assessed expression of InsR in glioblastoma surgical specimens and glioblastoma response to insulin at physiologically relevant concentrations. We further determined whether genetic or pharmacological targeting of InsR affected oncogenic functions of glioblastoma in vitro and in vivo. RESULTS: We showed that InsR was commonly expressed in glioblastoma surgical specimens and xenograft tumor lines, with mitogenic isoform-A predominating. Insulin at physiologically relevant concentrations promoted glioblastoma cell growth and survival, potentially via Akt activation. Depletion of InsR impaired cellular functions and repressed orthotopic tumor growth. The absence of InsR compromised downstream Akt activity, but yet stimulated IGF1R expression. Targeting both InsR and IGF1R with dual kinase inhibitors resulted in effective blockade of downstream signaling, loss of cell viability, and repression of xenograft tumor growth. CONCLUSIONS: Taken together, our work suggests that glioblastoma is sensitive to the mitogenic functions of insulin, thus significant insulin exposure imposes risks to glioblastoma patients. Additionally, dual inhibition of InsR and IGF1R exhibits promise for treating glioblastoma.

Critical functions of RhoB in support of glioblastoma tumorigenesis.

BACKGROUND: RhoB is a member of the Rho small GTPase family that regulates cytoskeletal dynamics and vesicle trafficking. The RhoB homologs, RhoA and RhoC, have been shown to promote cancer progression and metastasis. In contrast, the functions of RhoB in human cancers are context dependent. Although expression of RhoB inversely correlates with disease progression in several epithelial cancers, recent data suggest that RhoB may support malignant phenotypes in certain cancer types. METHODS: We assessed RhoB protein levels in glioma surgical specimens and patient-derived xenografts. The roles of RhoB in glioblastoma were determined by loss-of-function and gain-of-function assays in vitro and in vivo. The impact on p53 and STAT3 signaling was investigated. RESULTS: RhoB expression was similar in tumor specimens compared with normal neural tissues obtained from epilepsy surgery. RhoB was expressed in the vast majority of xenograft tumors and spheroid cultures. Knockdown of RhoB induced cell-cycle arrest and apoptosis and compromised in vivo tumorigenic potential. However, overexpression of wild-type RhoB or a constitutively active mutant (RhoB-V14) did not significantly affect cell growth, which suggests that RhoB is not a rate-limiting oncogenic factor and is consistent with the scarcity of RhoB mutations in human cancer. Knockdown of RhoB reduced basal STAT3 activity and impaired cytokine-induced STAT3 activation. In glioblastoma tumors retaining wild-type p53, depletion of RhoB also activated p53 and induced expression of p21(CIP1) (/WAF1). CONCLUSIONS: Our data suggest that RhoB belongs to an emerging class of "nononcogene addiction" factors that are essential for maintenance of malignant phenotypes in human cancers.

Association study of promoter polymorphisms in the CETP gene with longevity in the Han Chinese population.

The cholesteryl ester transfer protein (CETP), which is involved in the regulation of reverse cholesterol transport and metabolism of high-density lipoprotein cholesterol, has been proposed as a candidate gene for human longevity. SNPs in the promoter region of the CETP gene is likely important in regulation of the expression of the CETP gene. To explore the potential effects of the promoter polymorphisms in the CETP gene on longevity, we investigated the promoter polymorphisms in a sample of long-lived (≥ 90 years old) Han Chinese collected from Southwestern China (N = 380). By resequencing 934 bp of the promoter region, genotypes of four SNPs (-573A/G, -629A/C, -971A/G, -1046T/C) were examined in this sample. However, no association could be confirmed between longevity and these SNPs or haplotypes inferred from them. A novel rare variant -573A/G was found and was found in heterozygote state only in five persons in the Longevity group. But it was not statistically significant (p = 0.075). We also examined this novel polymorphism -573A/G in another Han Chinese sample from Yunnan province, and it was not associated with longevity. The results from both samples suggest that there is likely no association of the CETP gene promoter polymorphisms with longevity, at least among Han Chinese.

Inhibition of BET bromodomain targets genetically diverse glioblastoma.

PURPOSE: Glioblastoma is refractory to conventional therapies. The bromodomain and extraterminal domain (BET) proteins are epigenetic readers that selectively bind to acetylated lysine residues on histone tails. These proteins recently emerged as important therapeutic targets in NUT midline carcinoma and several types of hematopoietic cancers. In this study, the therapeutic potential of a novel BET bromodomain inhibitor, JQ1, was assessed in a panel of genetically heterogeneous glioblastoma samples. EXPERIMENTAL DESIGN: The antineoplastic effects of JQ1 were shown using ex vivo cultures derived from primary glioblastoma xenograft lines and surgical specimens of different genetic background. The in vivo efficacy was assessed in orthotopic glioblastoma tumors. RESULTS: We showed that JQ1 induced marked G1 cell-cycle arrest and apoptosis, which was phenocopied by knockdown of individual BET family members. JQ1 treatment resulted in significant changes in expression of genes that play important roles in glioblastoma such as c-Myc, p21(CIP1/WAF1), hTERT, Bcl-2, and Bcl-xL. Unlike the observations in some hematopoietic cancer cell lines, exogenous c-Myc did not significantly protect glioblastoma cells against JQ1. In contrast, ectopically expressed Bcl-xL partially rescued cells from JQ1-induced apoptosis, and knockdown of p21(CIP1/WAF1) attenuated JQ1-induced cell-cycle arrest. Cells genetically engineered for Akt hyperactivation or p53/Rb inactivation did not compromise JQ1 efficacy, suggesting that these frequently mutated signaling pathways may not confer resistance to JQ1. Furthermore, JQ1 significantly repressed growth of orthotopic glioblastoma tumors. CONCLUSION: Our results suggest potentially broad therapeutic use of BET bromodomain inhibitors for treating genetically diverse glioblastoma tumors.

XMRV accelerates cellular proliferation, transformational activity, and invasiveness of prostate cancer cells by downregulating p27(Kip1).

BACKGROUND: Xenotropic murine leukemia virus-related retrovirus (XMRV) is a recently discovered gammaretrovirus that was originally detected in prostate tumors. However, a causal relationship between XMRV and prostate cancer remains controversial due to conflicting reports on its etiologic occurrence. Even though gammaretroviruses are known to induce cancer in animals, a mechanism for XMRV-induced carcinogenesis remains unknown. Several mechanisms including insertional mutagenesis, proinflammatory effects, oncogenic viral proteins, immune suppression, and altered epithelial/stromal interactions have been proposed for a role of XMRV in prostate cancer. However, biochemical data supporting any of these mechanisms are lacking. Therefore, our aim was to evaluate a potential role of XMRV in prostate carcinogenesis. METHODS: Growth kinetics of prostate cancer cells are conducted by MTT assay. In vitro transformation and invasion was carried out by soft agar colony formation, and Matrigel cell invasion assay, respectively. p27(Kip1) expression was determined by Western blot and MMP activation was evaluated by gelatin-zymography. Up-regulation of miR221 and miR222 expression was examined by real-time PCR. RESULTS: We demonstrate that XMRV infection can accelerate cellular proliferation, enhance transformation, and increase invasiveness of slow growing prostate cancer cells. The molecular basis of these viral induced activities is mediated by the downregulation of cyclin/cyclin dependent kinase inhibitor p27(Kip1) . Downstream analyses illustrated that XMRV infection upregulates miR221 and miR222 expression that target p27(Kip1) mRNA. CONCLUSIONS: We propose that downregulation of p27(Kip1) by XMRV infection facilitates transition of G1 to S, thereby accelerates growth of prostate cancer cells. Our findings implicate that if XMRV is present in humans, then under appropriate cellular microenvironment it may serve as a cofactor to promote cancer progression in the prostate.

A microsatellite polymorphism in IGF1 gene promoter and longevity in a Han Chinese population.

BACKGROUND: Previous studies have suggested a probable association between the polymorphism of a microsatellite locus located in the promoter of IGF1 (Insulin-like growth factor 1) gene and the serum level of IGF1, as well as many age-related diseases. Based on these results, we hypothesized that this polymorphism may influence longevity in humans. We performed an association study in a Han Chinese population to test this hypothesis. FINDINGS: We recruited 493 elderly Han Chinese individuals (females >/= 94; males >/= 90) and 425 young individuals (controls) from Dujiangyan (Sichuan province, China). The genotype distributions and allele frequencies of the microsatellite site in the elderly and control groups were compared by chi square test.Our results suggested that there was no association between the microsatellite polymorphism and longevity in our Han Chinese population. However, there were more male persons with 18/21 genotype in elderly group than that in control group (11.11 vs. 5.45%, p = 0.011). As the difference was not significant when corrected by Bonferroni method, we speculate that the 18/21 genotype can not be functional in longevity; however, it may link with the real functional loci as there is a long haplotype block embracing the microsatellite locus. CONCLUSIONS: There was no association between polymorphism of the microsatellite in promoter of IGF1 gene and longevity in our study. Future association studies containing the long haplotype block are deserved and can test our speculation of the potential linkage of 18/21 genotype and functional loci.

The neck-region polymorphism of DC-SIGNR in peri-centenarian from Han Chinese population.

BACKGROUND: DC-SIGNR (also called CD209L) has been extensively studied on its role in host genetic predisposition to viral infection. In particular, variable number tandem repeat (VNTR) of the neck-region of DC-SIGNR is highly polymorphic and the polymorphism has been investigated for genetic predisposition to various infectious diseases, though conflicting results had been reported. As infection is a major cause of human death and a mechanism of natural selection, we hypothesized that VNTR polymorphism of DC-SIGNR might have an effect on human life span. METHODS: Here we collected 361 peri-centenarian individuals (age >or=94 for female and age >or=90 for male) and 342 geographically matched controls (age 22-53, mean 35.0 +/- 12.0) from Han Chinese. The VNTR polymorphism of the neck region was determined by PCR and genotype was called by separating the PCR products in agarose gel. RESULTS: A total of 11 genotypes and 5 alleles were found in our population. The genotype distribution, allele frequencies and homozygote proportion did not show a significant difference between peri-centenarian and control group. As gender differences in lifespan are ubiquitously observed throughout the animal kingdom, we then stratified the samples by gender. There was more 6/7 genotypes in female peri-centenarian group than that in female control group, at a marginal level of significance (5.56 vs. 1.28%, p = 0.041). The difference was not significant after correction by Bonferroni method. It suggests a possible differential effect of DC-SIGNR VNTR genotypes between sexes. Further studies are warranted to confirm our preliminary findings and investigate the mechanisms of the underlying functions. CONCLUSIONS: Our study indicated that there was absence of association between the neck region polymorphism of DC-SIGNR and longevity in Han Chinese population. But the question of whether the DC-SIGNR could affect longevity in a gender-specific pattern remains open.

Lack of genetic association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and longevity in a Han Chinese population.

INTRODUCTION: The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to associate with human longevity. However, little information is available in a Han Chinese longevity population.Therefore, we investigated the association of the ACE gene insertion/ deletion polymorphism with longevity in a Han Chinese population. MATERIALS AND METHODS: We compared the distribution of ACE insertion/deletion genotype and allele frequencies in two groups: a longevity group (399 subjects) aged over 90 years and a control group (302 subjects) aged less than 60 years. RESULTS: No difference in genotype and allele frequencies of the ACE gene insertion/deletion polymorphism was observed between the longevity group and the control group.When adjusting for gender, the difference between the longevity group and the control group was also not significant regarding the frequencies of the genotypes (male, p=0.994 and female, p=0.797) as well as allele frequencies (male, p=0.969 and female, p=0.884). CONCLUSIONS: No association of the ACE gene insertion/deletion polymorphism with longevity was observed in our Han Chinese population.

Absence of association between SNPs in the promoter region of the insulin-like growth factor 1 (IGF-1) gene and longevity in the Han Chinese population.

Previous studies have indicated that genetic variations in the factors of insulin/insulin-like growth factor 1 (IGF-1) signaling pathway could influence human life-span by affecting IGF-1 levels. The promoter region of the IGF-1 gene is an obvious candidate and has not been studied clearly. To explore the potential role of the promoter region variation of IGF-1 gene in longevity, we investigated 485 longevity subjects and 392 younger individuals from Dujiangyan, China. By sequencing about 2.5 kb (kilo base pairs) upstream the transcription start site of exon 1 of the IGF-1 gene in 30 individuals from both groups respectively, we acquired three previously described SNPs (-439T/A (rs2288377), -541T/C (rs5742612) and -1246C/T (rs35767)). We examined the association between these three SNPs and longevity by comparing the distribution of genotypes, alleles, and haplotypes in both the longevity and control groups. None of these variants were found to be associated with longevity. Our results suggest that there is no association between SNPs in the promoter region of IGF-1 gene and longevity in the Han Chinese population.

Evolution of cd59 gene in mammals.

The CD59-coding sequences were obtained from 5 mammals by PCR and BLAST, and combined with the available sequences in GenBank, the nucleotide substitution rates of mammalian cd59 were calculated. Results of synonymous and nonsynonymous substitution rates revealed that cd59 experienced negative selection in mammals overall. Four sites experiencing positive selection were found by using "site-specific" model in PAML software. These sites were distributed on the molecular surface, of which 2 sites located in the key functional domain. Furthermore, "branch-site-specific" model detected 1 positive site in cd59a and cd59b lineages which underwent accelerated evolution caused by positive selection after gene duplication in mouse.

Independent origin of the growth hormone gene family in New World monkeys and Old World monkeys/hominoids.

The growth hormone (GH) gene family represents an erratic and complex evolutionary pattern, involving many evolutionary events, such as multiple gene duplications, positive selection, the birth-and-death process and gene conversions. In the present study, we cloned and sequenced GH-like genes from three species of New World monkeys (NWM). Phylogenetic analysis strongly suggest monophyly for NWM GH-like genes with respect to those of Old World monkeys (OWM) and hominoids, indicating that independent gene duplications have occurred in NWM GH-like genes. There are three main clusters of genes in putatively functional NWM GH-like genes, according to our gene tree. Comparison of the ratios of nonsynonymous and synonymous substitutions revealed that these three clusters of genes evolved under different kinds of selective pressures. Detailed analysis of the evolution of pseudogenes showed that the evolutionary pattern of this gene family in platyrrhines is in agreement with the so-called birth-and-death process.