An STS-based radiation hybrid map of the human genome

We have constructed a physical map of the human genome by using a panel of 83 whole genome radiation hybrids (the Stanford G3 panel) in conjunction with 10,478 sequence-tagged sites (STSs) derived from random genomic DNA sequences, previously mapped genetic markers, and expressed sequences. Of these STSs, 5049 are framework markers that fall into 1766 high-confidence bins. An additional 945 STSs are indistinguishable in their map location from one or more of the framework markers. These 5994 mapped STSs have an average spacing of 500 kb. An additional 4484 STSs are positioned with respect to the framework markers. Comparison of the orders of markers on this map with orders derived from independent meiotic and YAC STS-content maps indicates that the error rate in defining high-confidence bins is < 5%. Analysis of 322 random cDNAs indicates that the map covers the vast majority of the human genome. This STS-based radiation hybrid map of the human genome brings us one step closer to the goal of a physical map containing 30,000 unique ordered landmarks with an average marker spacing of 100 kb.

Enantioselective epoxidation of terminal olefins by chiral dioxirane

[see reaction]. This paper describes an enantioselective epoxidation of terminal olefins using chiral ketone 3 as catalyst and Oxone as oxidant. Up to 85% ee has been obtained.

Electronic probing of ketone catalysts for asymmetric epoxidation. Search for more robust catalysts

[structure: see text]. Ketones with a fused oxazolidinone were synthesized and investigated to determine the electronic effect of the substituents at alpha-positions of ketone catalysts on the Baeyer-Villiger oxidation and catalytic properties for asymmetric epoxidation. These new ketones give high yields and ee's with only 1-5 mol % catalyst. The current studies further show that the electronic effect is very important for the ketone-catalyzed epoxidation.

Upregulation of cytoskeleton protein and extracellular matrix protein induced by stromal-derived nitric oxide promotes lung cancer invasion and metastasis

Lung cancer commonly metastasizes to lymph nodes, brain and bones, which is the main cause of death. It is still a challenge to detect molecular biomarkers for early diagnosis and therapeutics of lung cancer. Our previous study found that bone marrow-derived stroma cells (BMSCs) under tumor microenvironment produced nitric oxide (NO), which was induced by inducible nitric oxide synthase (iNOS), and promoted invasion and metastasis of cancer cells by remodeling cytoskeleton. The aim of this study is to elucidate the relationship between the expressions of iNOS, cytoskeleton protein caldesmon, OPN, and clinical parameters especially the metastasis of lung cancer. We found that nitric oxide can remodel cytoskeleton and promoted the mobility of lung cancer cells. The expressions of iNOS, caldesmon, and OPN are closely correlated to metastasis of lung cancer. The intracranial metastatic tissue samples of lung cancer showed significantly higher expression of iNOS, caldesmon and OPN. A flow-cytometry analysis for peripheral blood of lung cancer patients showed increased EPCAM+/OPN+ cells in circulation of patients with bone metastasis compared to that of patients without metastasis, which is indicative of cancer circulating cells. The concentration of serum OPN was also positively related to the bone metastasis of lung cancer. Taken together, these results suggested that iNOS, caldesmon and OPN may work as biomarkers for metastasis of lung cancer.

Effect of Sustained Joint Loading on TMJ Disc Nutrient Environment

The temporomandibular joint (TMJ) disc nutrient environment profoundly affects cell energy metabolism, proliferation, and biosynthesis. Due to technical challenges of in vivo measurements, the human TMJ disc extracellular nutrient environment under load, which depends on metabolic rates, solute diffusion, and disc morphometry, remains unknown. Therefore, the study objective was to predict the TMJ disc nutrient environment under loading conditions using combined experimental and computational modeling approaches. Specifically, glucose consumption and lactate production rates of porcine TMJ discs were measured under varying tissue culture conditions (n = 40 discs), and mechanical strain-dependent glucose and lactate diffusivities were measured using a custom diffusion chamber (n = 6 discs). TMJ anatomy and loading area were obtained from magnetic resonance imaging of healthy human volunteers (n = 11, male, 30 ± 9 y). Using experimentally determined nutrient metabolic rates, solute diffusivities, TMJ anatomy, and loading areas, subject-specific finite element (FE) models were developed to predict the 3-dimensional nutrient profiles in unloaded and loaded TMJ discs (unloaded, 0% strain, 20% strain). From the FE models, glucose, lactate, and oxygen concentration ranges for unloaded healthy human TMJ discs were 0.6 to 4.0 mM, 0.9 to 5.0 mM, and 0% to 6%, respectively, with steep gradients in the anterior and posterior bands. Sustained mechanical loading significantly reduced nutrient levels (P < 0.001), with a critical zone in which cells may die representing approximately 13.5% of the total disc volume. In conclusion, this study experimentally determined TMJ disc metabolic rates, solute diffusivities, and disc morphometry, and through subject-specific FE modeling, revealed critical interactions between mechanical loading and nutrient supply and metabolism for the in vivo human TMJ disc. The results suggest that TMJ disc homeostasis may be vulnerable to pathological loading (e.g., clenching, bruxism), which impedes nutrient supply. Given difficulties associated with direct in vivo measurements, this study provides a new approach to systematically investigate homeostatic and degenerative mechanisms associated with the TMJ disc.

A pilot study of nocturnal temporalis muscle activity in TMD diagnostic groups of women

Temporomandibular disorder (TMD) incidences are believed to be related to parafunctional behaviours like teeth clenching. This pilot study aimed to (i) develop an automated clench-detection algorithm, and (ii) apply the algorithm to test for differences in nocturnal clenching in women with and without TMD. Subjects gave informed consent to participate. Adult women were categorised using Diagnostic Criteria for TMD according to presence/absence (+/-) of both TM joint disc placement (DD) and chronic pain (P) into two groups (+DD+P, -DD-P) with 12 subjects each. Surface temporalis electromyography was recorded during oral tasks performed by subjects at two laboratory sessions. The data were used to characterise muscle activity per N of bite force (μV/N) for each subject, develop the clench-detection algorithm and test its accuracy. Ambulatory surface temporalis electromyography was self-recorded by each subject over three nights and analysed using the algorithm and bite force (N) versus muscle activity μV/N calibrations. Bonferroni-adjusted homoscedastic t-tests assessed for significant between-group differences in clenching (P < 0·05). Sensitivity, specificity and accuracy of algorithm-detected laboratory clenches were all ≥96%. During self-recordings 95% of clenches had durations of <4 s and peak forces of <10 N in both groups. Mean clench durations were significantly longer (P = 0·042) in +DD+P (1·9 ± 0·8 s) than -DD-P subjects (1·4 ± 0·4 s). Mean temporalis duty factors (%clench time/total recording time) were significantly larger (P = 0·041) in +DD+P (0·47 ± 0·34%) than -DD-P (0·26 ±0·22%) subjects. Nocturnal temporalis muscle activities detected by a validated algorithm were longer per clench and recording time in +DD+P compared to -DD-P women.

Fluid pressurization and tractional forces during TMJ disc loading: A biphasic finite element analysis

OBJECTIVES

To investigate the ploughing mechanism associated with tractional force formation on the temporomandibular joint (TMJ) disc surface.

SETTING AND SAMPLE POPULATION

Ten left TMJ discs were harvested from 6- to 8-month-old male Yorkshire pigs.

MATERIALS AND METHODS

Confined compression tests characterized mechanical TMJ disc properties, which were incorporated into a biphasic finite element model (FEM). The FEM was established to investigate load carriage within the extracellular matrix (ECM) and the ploughing mechanism during tractional force formation by simulating previous in vitro plough experiments.

RESULTS

Biphasic mechanical properties were determined in five TMJ disc regions (average±standard deviation for aggregate modulus: 0.077±0.040 MPa; hydraulic permeability: 0.88±0.37×10-3 mm4 /Ns). FE simulation results demonstrated that interstitial fluid pressurization is a dominant loading support mechanism in the TMJ disc. Increased contact load and duration led to increased solid ECM strain and stress within, and increased ploughing force on the surface of the disc.

CONCLUSION

Sustained mechanical loading may play a role in load carriage within the ECM and ploughing force formation during stress-field translation at the condyle-disc interface. This study further elucidated the mechanism of ploughing on tractional force formation and provided a baseline for future analysis of TMJ mechanics, cartilage fatigue and early TMJ degeneration.

A high-throughput screen identifies inhibitors of lung cancer stem cells

Metastasis is the main cause of cancer morbidity and mortality. Cancer stem cells (CSCs) are a rare subpopulation of cancer cells that can drive metastasis. The identification of CSC inhibitors and CSC-related genes is an alluring strategy for suppressing metastasis. Here, we established a simple and repeatable high-throughput CSC inhibitor screening platform that combined tumor sphere formation assays and cell viability assays. Human lung cancer cells were cocultured with 1280 pharmacologically active compounds (FDA-approved). Fifty-four candidate compounds obtained from our screening system completely or partially inhibited tumor sphere formation. A total of 5 of these 54 compounds (prochlorperazine dimaleate, thioridazine hydrochloride, ciproxifan hydrochloride, Ro 25-6981 hydrochloride, and AMN 082) completely inhibited the self-renewal of CSCs without cytotoxicity in vitro via their targets and suppressed lung cancer metastasis in vivo, suggesting that our screening platform is selective and reliable. DRD2, HRH3, and GRIN2B exhibited potent genes promoting CSCs in vitro experiments and clinical datasets. Further validation of the top hit (DRD2) and previously published studies demonstrate that our screening platform is a useful tool for CSC inhibitor and CSC-related gene screening.

Immune surveillance of brain metastatic cancer cells is mediated by IFITM1

Brain metastasis, most commonly originating from lung cancer, increases cancer morbidity and mortality. Although metastatic colonization is the rate-limiting and most complex step of the metastatic cascade, the underlying mechanisms are poorly understood. Here, in vivo genome-wide CRISPR-Cas9 screening revealed that loss of interferon-induced transmembrane protein 1 (IFITM1) promotes brain colonization of human lung cancer cells. Incipient brain metastatic cancer cells with high expression of IFITM1 secrete microglia-activating complement component 3 and enhance the cytolytic activity of CD8+ T cells by increasing the expression and membrane localization of major histocompatibility complex class I. After activation, microglia (of the innate immune system) and cytotoxic CD8+ T lymphocytes (of the adaptive immune system) were found to jointly eliminate cancer cells by releasing interferon-gamma and inducing phagocytosis and T-cell-mediated killing. In human cancer clinical trials, immune checkpoint blockade therapy response was significantly correlated with IFITM1 expression, and IFITM1 enhanced the brain metastasis suppression efficacy of PD-1 blockade in mice. Our results exemplify a novel mechanism through which metastatic cancer cells overcome the innate and adaptive immune responses to colonize the brain, and suggest that a combination therapy increasing IFITM1 expression in metastatic cells with PD-1 blockade may be a promising strategy to reduce metastasis.

The E3 Ligase NEDD4L Prevents Colorectal Cancer Liver Metastasis via Degradation of PRMT5 to Inhibit the AKT/mTOR Signaling Pathway

Colorectal cancer is the second most common cause of cancer mortality worldwide, and liver metastasis is the major cause of death of patients with colorectal cancer. Dysfunctional E3 ligase activity has recently been shown to be associated with colorectal cancer. However, the key E3 ligases affecting colorectal cancer liver metastasis remain unknown. Therefore, an shRNA library targeting 156 E3 ubiquitin ligases has been used to perform an in vivo loss-of-function screen of a human colorectal cancer cell line in a mouse model of liver metastasis. The screen reveals that neural precursor cell expressed developmentally down-regulated gene 4-like (NEDD4L) knockdown promotes colorectal cancer liver metastasis. Mechanistic studies reveal that NEDD4L binds to the PPNAY motif in protein arginine methyltransferase 5 (PRMT5) and ubiquitinates PRMT5 to promote its degradation. PRMT5 degradation attenuates the arginine methylation of AKT1 to inhibit the AKT/mTOR signaling pathway. The effect of NEDD4L decreases colorectal cancer cell proliferation to suppress colonization. This study is the first to show that PRMT5 is a substrate of NEDD4L and reveals not only the metastasis-inhibiting function of NEDD4L but also a novel mechanism by which NEDD4L prevents colorectal cancer liver metastasis. These findings may provide a new preventive strategy for liver metastasis.

MLN4924 protects against bleomycin-induced pulmonary fibrosis by inhibiting the early inflammatory process

Pulmonary fibrosis is a complex pathological process characterized by massive destruction of the structure of lung tissues and aggravated pulmonary function impairment. The underlying mechanisms of pulmonary fibrosis are incompletely understood and therefore limited treatment options are available currently. Here, we report that MLN4924, an NEDD8 activation enzyme (NAE) activity-inhibiting molecule, blocks the maintenance and progression of established pulmonary fibrosis. We found that MLN4924 acts against bleomycin-induced pulmonary fibrosis mainly at the early inflammatory stage. Pharmacologically targeting the neddylation of Cullin-Ring E3 ligase (CRL) by MLN4924, significantly abrogated NF-κB responses, suppressed MAPK activity, and reduced secretion of TNF-α-elicited pro-inflammatory cytokines and MCP1-induced chemokines. MLN4924 inhibited pro-inflammatory responses while maintaining or increasing the production of the anti-inflammatory mediators such as anti-inflammatory interleukins (ILs) following bleomycin administration, which is closely correlated to its blocking NF-κB-mediated signaling. Consistently, our studies identified MLN4924 as a promising therapeutic drug for pulmonary fibrosis and suggested a potential role of MLN4924 that fine tunes the MAPK signaling pathway controlling the inflammatory reactions at the early stages of pulmonary fibrosis. In addition, our findings may broaden the potential practical application of MLN4924 as an effective therapeutic strategy against other inflammation-associated diseases.

A gene map of the human genome

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.