Placental inflammatory injury induced by chlorinated polyfluorinated ether sulfonate (F-53B) through NLRP3 inflammasome activation

Chlorinated polyfluorinated ether sulfonate, commercially known as F-53B, has been associated with adverse birth outcomes. However, the reproductive toxicology of F-53B on the placenta remains poorly understood. To address this gap, we examined the impact of F-53B on placental injury and its underlying molecular mechanisms in vivo. Pregnant C57BL/6 J female mice were randomly allocated to three groups: the control group, F-53B 0.8 µg/kg/day group, and F-53B 8 µg/kg/day group. After F-53B exposure through free drinking water from gestational day (GD) 0.5-14.5, the F-53B 8 µg/kg/day group exhibited significant increases in placental weights and distinctive histopathological alterations, including inflammatory cell infiltration, heightened syncytiotrophoblast knots, and a loosened trophoblastic basement membrane. Within the F-53B 8 µg/kg/day group, placental tissue exhibited increased apoptosis, as indicated by increased caspase3 activation. Furthermore, F-53B potentially induced the NF-κB signaling pathway activation through IκB-α phosphorylation. Subsequently, this activation upregulated the expression of inflammatory cytokines and components of the NLRP3 inflammasome, including activated caspase1, IL-1β, IL-18, and cleaved gasdermin D (GSDMD), ultimately leading to pyroptosis in the mouse placenta. Our findings reveal a pronounced inflammatory injury in the placenta due to F-53B exposure, suggesting potential reproductive toxicity at concentrations relevant to the human population. Further toxicological and epidemiological investigations are warranted to conclusively assess the reproductive health risks posed by F-53B.

Long-term efficacy and safety of leflunomide combined with low-dose prednisone in treatment of myasthenia gravis: a retrospective study

BACKGROUND

Leflunomide and low-dose prednisone (0.25 mg/kg/day) (LEF + Pred) rapidly improved the clinical symptoms of myasthenia gravis (MG) patients. Here, we aimed to analyze the long-term efficacy and safety of LEF + Pred in MG patients.

METHODS

This retrospective cohort study enrolled MG patients treated with LEF + Pred in our center between 2012 and 2020. We reviewed all the MG patients continuously treated with LEF + Pred for more than 1 year. MG activities of daily living (MG-ADL) profile score and quantitative MG scale (QMG) score in each clinical follow-up visits were collected for the efficacy analysis. The laboratory testing results of MG patients, the relevant chief complain and physical examination results in each follow-up visits were collected for the safety evaluation.

RESULTS

In total, 103 patients were examined. Effective treatment was achieved in 58.3% of patients after 1 month and in 88.4% after 12 months. Overall, 63 patients (61.2%) exhibited only minimal manifestations after 12 months of treatment. The average MG-ADL score decreased from 6.0 to 1.0, while the average QMG score decreased from 10.0 to 4.0. The decrease in MG-ADL and QMG scores of patients with generalized MG was more pronounced than those of the ocular MG patients. Patients with MG who had a thymectomy had a smaller decrease in MG-ADL and QMG scores than those who did not have a thymectomy. Sixteen adverse effects associated with LEF + Pred were observed; none was severe.

CONCLUSIONS

Long-term LEF + Pred therapy could considerably improve clinical symptoms in MG patients while being well tolerated with just few side effects.

A new ant species of the genus Carebara Westwood, 1840 (Hymenoptera, Formicidae, Myrmicinae) with a key to Chinese species

A new Chinese ant species Carebaralaevicepssp. nov. is described based on the major and minor workers. This species is most similar to C.lusciosa (Wheeler, 1928) due to a spineless propodeum, the absence of horns, and a smooth head capsule. It is distinguished by the following features: (1) antenna 10-segmented; (2) katepisternum rugose-reticulate; (3) in major workers, lateral sides of head in full-face view parallel; (4) metanotal groove distinct, anterodorsal corner forming an acute tooth behind metanotal groove. Moreover, an updated key to Chinese Carebara species is presented based on major workers, with a checklist comprising a total of 36 Chinese Carebara species and subspecies. Morphological structures and scanning electron micrographs of the newly discovered species' minor and major workers are provided.

Targeting HIF-1α alleviates the inflammatory responses and rebuilds the CD4+ T cell subsets balance in the experimental autoimmune myasthenia gravis inflammation model via regulating cellular and humoral immunity

BACKGROUND

Cells and tissues in an inflammatory state are usually hypoxic. The hypoxic environment can affect the differentiation of immune cells and produce Hypoxia-inducible Factor-1α (HIF-1α). Inflammation is also a major contributor to the development and deterioration of Myasthenia Gravis (MG). There are limited studies on the immunopathological mechanism and targeted therapy associated with MG exacerbated with inflammation. This research aimed to explore whether BAY 87-2243 (HIF-1α inhibitor) ameliorates the symptoms of the Experimental Autoimmune Myasthenia Gravis (EAMG) inflammation model and study its regulatory mechanism on cellular immunity and humoral immunity.

METHODS

We first establish the EAMG inflammation model using Lipopolysaccharide (LPS), BAY 87-2243 was applied to the EAMG inflammation model and its therapeutic effects were evaluated in vivo and in vitro experiments.

RESULTS

The proportion of Treg cells was increased whereas Th1, Th17, and Th1/17 cells were decreased in BAY 87-2243-treated EAMG inflammation model. BAY 87-2243 ameliorated the acetylcholine receptors (AChRs) loss and the complement deposited at the neuromuscular junction of the EAMG inflammation model, declined the levels of IFN-γ, IL-17, and IL-6 in serum, and further attenuated responses in the germinal center and reduced the antibody levels by inhibiting the IL-6-dependent STAT3 axis.

CONCLUSION

BAY 87-2243 restored the balance of CD4+T cell subsets and reduced the production of the pro-inflammatory cytokines, thus acting as both an immune imbalance regulator and anti-inflammatory. The current study suggests that HIF-1α might be a potential target for the treatment of MG exacerbated with inflammation.

Interspecific competition predicts the potential impact of little fire ant Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) invasion on resident ants in southern China

The little fire ant Wasmannia auropunctata (Roger) is a major invasive species that seriously threatens the biodiversity of invaded areas. W. auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown. To evaluate the impact of W. auropunctata invasion on the ant communities in southern China, a series of interspecific competition experiments were conducted in this study. The individual aggression index and group aggression experiments showed the advantage of W. auropunctata in competition with 5 resident ants under equal worker numbers. When encountering Anoplolepis gracilipes, Camponotus nicobarensis, Tetramorium bicarinatum, Polyrhachis dives, and Solenopsis invicta, W. auropunctata gradually gained a competitive advantage with an increase in its number of workers. In the group aggression experiments with equal worker numbers, there was a negative correlation between the body length and mortality rate of resident ants. The results of the foraging behavior experiments showed that W. auropunctata was able to dominate food resources under competition with Carebara diversa, which also displayed weak competition in the group aggression bioassay. In addition, the abilities to recruit workers and retrieve food were inhibited under competition with S. invicta and T. bicarinatum. The results of the nesting behavior experiments showed that in the 24-h bout of space resource competition, W. auropunctata was dominant over C. diversa, S. invicta, and T. bicarinatum. The results of this study show that W. auropunctata has certain advantages in competition for food and space resources over resident ants in southern China, and some resident ant species may be replaced in the future.

Electrowetting-assisted printing of 3D-architectured microelectrodes inside flexible piezoelectric films for sensitive, robust responses to bending deformation

The voltage outputs of flexible piezoelectric films after bending deformation have always been limited by two factors, including the incompatible polarization direction with bending strain and the interfacial fatigue failure between the piezoelectric films and the electrode layers, largely hindering the applications in wearable electronics. Herein, we demonstrate a new piezoelectric film design, where 3D-architectured microelectrodes are fabricated inside a piezoelectric film by electrowetting-assisted printing of conductive nano-ink into the pre-formed meshed microchannels in the piezoelectric film. The 3D architectures increase the piezoelectric output of a typical P(VDF-TrFE) film by more than 7 fold compared with the conventional planar design at the same bending radius, and, more importantly, decrease the output attenuation down to only 5.3% after 10 000 bending cycles, less than one third of that for the conventional design. The dependence of piezoelectric outputs on feature sizes of 3D microelectrodes was investigated numerically and experimentally, providing a route for optimizing the 3D architecture design. Different composite piezoelectric films with internal 3D-architectured microelectrodes were fabricated, exhibiting improved piezoelectric outputs under bending deformations, demonstrating that our printing methods could have broad applications in various fields. The fabricated piezoelectric films, worn on human fingers, are used for remotely controlling the robot hand gestures by human-machine interaction; furthermore, the fabricated piezoelectric patches are used to successfully sense the pressure distribution by integrating with spacer arrays to convert the pressing movement into bending deformation, demonstrating the enormous potential of our piezoelectric films in practical applications.

An observational study on the safety of COVID-19 vaccination in patients with myasthenia gravis

OBJECTIVE

There is concern that the coronavirus disease (COVID-19) vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of COVID-19 vaccination on symptom severity in patients with myasthenia gravis (MG).

METHODS

A total of 106 enrolled patients with MG who were vaccinated against COVID-19 were followed up, and a questionnaire was used to document in detail the exacerbation of muscle weakness after vaccination and all other uncomfortable reactions after vaccination. Demographic, clinical characteristics, medication, and vaccination data were collected by follow-up interview. The main observation outcome was whether the MG symptoms of patients were exacerbated. The definition of exacerbation is according to the subjective feeling of the patient or a 2-point increase in daily life myasthenia gravis activity score relative to before vaccination, within 30 days after vaccination.

RESULTS

Of 106 enrolled patients [median age (SD) 41.0 years, 38 (35.8%) men, 53 (50.0%) with generalized MG, 74 (69.8%) positive for acetylcholine receptor antibody, and 21 (19.8%) with accompanying thymoma], muscle weakness symptoms were stable in 102 (96.2%) patients before vaccine inoculation. Muscle weakness worsened in 10 (9.4%) people after vaccination, of which 8 patients reported slight symptom worsening that resolved quickly (within a few days). Two (1.9%) of patients showed serious symptom aggravation that required hospitalization.

CONCLUSION

Our results suggest that inactivated virus vaccines against COVID-19 may be safe for patients with MG whose condition is stable. Patients with generalized MG may be more likely to develop increased muscle weakness after vaccination.

Microstructure Heterogeneity and Mechanical Properties of a High-Strength Ductile Laminated Steel by Electron Beam Welding

The aim of this study is to fabricate high-strength steel with exceptional yield strength and superior ductility by employing a novel design approach of nanolamellar/equiaxial crystal "sandwich" heterostructures, utilizing rolling and electron-beam-welding techniques. The microstructural heterogeneity of the steel is manifested in the phase content and grain size, ranging from nanolamellae comprising a small quantity of martensite on both sides to the completely coarse austenite in the center, which are interconnected via gradient interfaces. The structural heterogeneity and phase-transformation-induced plasticity (TIRP) offer remarkable strength and ductility for the samples. Furthermore, the synergistic confinement of the heterogeneous structures leads to the formation of Lüders bands, which exhibit stable propagation under the TIRP effect and impede the onset of plastic instability, ultimately resulting in a significant improvement in the ductility of the high-strength steel.

Corrigendum: Leflunomide combined with low-dose prednisone inhibits proinflammatory T cells responses in myasthenia gravis patients

[This corrects the article DOI: 10.3389/fneur.2022.961628.].

Clinical evaluation of efficacy of leflunomide combined with low-dose prednisone for treatment of myasthenia gravis

This study evaluated the clinical efficacy of leflunomide combined with low-dose prednisone (0.25 mg/kg/day) for treatment of myasthenia gravis (MG). We enrolled 32 MG patients treated with leflunomide combined with low-dose prednisone. In the control group, 14 patients were treated with low-dose prednisone. Improvement in MG composite (MGC) score of ≥ 3 points from enrollment to 12-week follow-up indicated that the treatment was effective. In the leflunomide combined low-dose prednisone group, the median of MGC score at the time of enrollment was 8.5 points. After 12 weeks, the MGC score dropped to four points. There was statistically significant difference in MGC score before and after treatment (p < 0.001). In the low-dose prednisone group also followed up for 12 weeks, the median of MGC score of the patients decreased from 7 to 4 points, and the change was not statistically significant (p = 0.05). In the leflunomide combined low-dose prednisone group, the improvement of clinical symptoms occurred mainly in the first 4 weeks and the last 4 weeks. Relatively, the decline of the score was mostly seen during the first 8 weeks in the low-dose prednisone group. In leflunomide combined with low-dose prednisone group, the effective rate of generalized MG(gMG) was significantly higher than ocular MG(oMG) (χ² test, p = 0.036). However, there is no significant difference in the effective rate between AChR-Ab-positive and -negative groups (Fisher's Exact Test, p = 0.625). No serious side effects were observed in any of the subjects. Leflunomide combined with low-dose prednisone rapidly improved the clinical symptoms of patients with MG. It may be a promising treatment for gMG.

JAK2 inhibitor ameliorates the progression of experimental autoimmune myasthenia gravis and balances Th17/Treg cells via regulating the JAK2/STAT3-AKT/mTOR signaling pathway

BACKGROUND

An imbalance in Th17/regulatory T (Treg) cells is the major pathogenic mechanism underlying myasthenia gravis (MG). JAK2 inhibitors selectively inhibit JAK2 and reduce inflammatory responses. However, there have been no studies examining the therapeutic effects of JAK2 inhibitors in the context of MG.

METHODS

Here, an experimental autoimmune MG (EAMG) rat model was established to explore the therapeutic effect of JAK2 inhibitors on EAMG rats immunized with the AChR α-subunit (97-116 peptide). A JAK2 inhibitor was administered to EAMG rats both in vivo and in vitro. The following experimental methods were used to evaluate the effects of JAK2 inhibitors. The behavioral scores and body weights of the rats were assessed on alternate days. Serum anti-AChR (97-116) IgG and cytokine levels were detected using ELISA. CD4⁺ T cell subsets and related transcription factors in mononuclear cells were detected using flow cytometry and qPCR, respectively. The expression levels of protein molecules in the signaling pathway were detected by western blotting, and the neuromuscular junctions were observed using immunofluorescence.

RESULTS

The results revealed that JAK2 inhibitors could regulate Th17/Treg balance in vivo and in vitro. JAK2 inhibitors reduced the immune response in EAMG rats (including reducing pro-inflammatory cytokines and postsynaptic membrane complement deposition), improved clinical symptoms, and increased AChR aggregation in the postsynaptic membrane. Meanwhile, this study demonstrated that JAK2 inhibitor treatment suppressed the phosphorylation of JAK2/STAT3 and AKT/mTOR pathways and decreased the expression level of the IL-23 receptor.

CONCLUSIONS

This study reveals that there is crosstalk between the JAK2/STAT3 and AKT/mTOR pathways in EAMG rats. JAK2 inhibitors can ameliorate EAMG by regulating Th17/Treg balance by inhibiting both signaling pathways. Our study provides new potential therapeutic targets for MG immunotherapy.

Unparalleled details of soft tissues in a Cretaceous ant

For social insects such as ants, the internal organs are likely important in understanding their eusocial behavior and evolution. Such organs, however, are rarely preserved on fossils. In each of the few cases reporting exceptionally fossilized soft tissues in arthropods, the nervous, muscular and cardiovascular systems have been described individually, but never in combination. Here, we report a female specimen (gyne) of the extinct ant group-^†Zigrasimecia-included in a Cretaceous amber piece from Kachin, Myanmar, with an almost complete system formed by various internal organs. These include the brain, the main exocrine system, part of the digestive tract, and several muscle clusters. This research expands our knowledge of internal anatomy in stem group ants. As the gyne bears a morphologically unique labrum, our specimen's internal and external features support the notion that the early ant may have special ecological habits during the Cretaceous period.

[Application of pretrained model based on electronic medical record in recognition of acute respiratory infection]

Objective: To evaluate the recognition of acute respiratory infection (ARI) by a pretrained model based on electronic medical records (EMRs). Methods: 38 581 EMRs were obtained from Chongqing University Three Gorges Hospital in December 2021. Bidirectional encoder representation from transformers (BERT) pretrained model was used to identify ARI in EMRs. The results of medical professionals were considered as the gold standard to calculate the sensitivity, specificity, Kappa value, and area under the curve of the receiver operating characteristic (AUC). Results: There were 3 817 EMRs in the test set, with 1 200 ARIs. A total of 1 205 cases were determined as ARI by the model, with a sensitivity of 92.67% (1 112/1 200) and a specificity of 96.45% (2 524/2 617). The model identified ARI with similar accuracy in males and females (AUCs 0.95 and 0.94, respectively), and was more accurate in identifying ARI cases in those aged less than 18 than in adults 18-59 and adults 60 and older (AUCs 0.94, 0.89 and 0.94, respectively). The current model had a better identification of ARIs in outpatient patients than that in hospitalized patients, with AUCs of 0.74 and 0.95, respectively. Conclusion: The use of the BERT pretrained model based on EMRs has a good performance in the recognition of ARI cases, especially for the outpatients and juveniles. It shows a great potential to be applied to the monitoring of ARI cases in medical institutions.

Leflunomide combined with low-dose prednisone inhibits proinflammatory T cells responses in myasthenia gravis patients

We previously found that leflunomide combined with low-dose prednisone rapidly improved the clinical symptoms of myasthenia gravis (MG), but we had not investigated the mechanism of this phenomenon. This study documents the effect of leflunomide combined with low-dose prednisone on pro-inflammatory T cells in MG patients. We compared 32 treated MG patients with 18 controls. We collected peripheral blood before treatment and 4, 8, and 12 weeks after treatment. We extracted peripheral blood mononuclear cells (PBMCs) and stimulated them with phorbol 12-myristate 13-acetate (PMA) + ionomycin and quantified IFN-γ, IL-4, IL-17, and IL-9 secretion through ELISA. We quantified T helper (Th) cells Th1 (CD3+CD4+IFN-γ+), Th2 (CD3+CD4+IL-4+), Th17 (CD3+CD4+IL-17A+) and Th9 (CD3+CD4+IL-9+) among PBMCs. The treatment significantly reduced IL-17 and IL-9 secretion in peripheral blood but did not affect IFN-γ levels. Significant decreases in IL-17 and IL-9 appeared at week 12, and the trend of change was similar to that of the MG composite score. Flow cytometry indicated that leflunomide combined with low-dose prednisone significantly reduced the frequency of Th1 and Th17 cells. These findings demonstrate the potential of this treatment as an alternative immunosuppressive therapy for MG.

Studying the relationship between clinical features and mental health among late-onset myasthenia gravis patients

BACKGROUND

Mental disorders are common comorbidities among individuals with neurological diseases, and the prevalence of depressive and anxiety-related symptoms in newly referred patients at neurology outpatient clinics is high. There have been few studies on the mental health of patients with late-onset myasthenia gravis (MG).

AIM

To examine the relationship between clinical features and the mental health symptoms within late-onset MG patients.

METHODS

A total of 105 patients diagnosed with MG were recruited consecutively from a neuromuscular outpatient clinic between December 2020 and February 2021. Patients were classified into two groups: early-onset MG (age at onset < 50 years, n = 63) and late-onset MG (age at onset ≥ 50 years, n = 42). Social demographic data and information about marital status, education level, clinical symptoms, serum antibody levels, and therapies used were collected for all participants. Participants were also evaluated using the Myasthenia Gravis Composite scale, the Myasthenia Gravis Activities of Daily Living scale, the Myasthenia Gravis Quality of Life 15 (MG-QOL-15) questionnaire, the 17-item version of the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A). The relationship between clinical features and mental health in late-onset MG patients was examined using multivariate logistic regression analyses.

RESULTS

Late-onset MG patients were more prone to dyspnea, had higher levels of serum anti-acetylcholine receptor antibodies, and higher total scores on the MG-QOL-15, HAM-D, and HAM-A questionnaires, than early-onset MG patients had (P < 0.05). Among those with late-onset MG, female patients had higher total HAM-D and HAM-A scores than male patients had (P < 0.05). High scores on the QOL-15 questionnaire were associated with higher incidences of anxiety and depression, and the association was found to be independent after adjusting for confounding risk factors. In the late-onset subgroup, the areas under the receiver operating characteristic curves for the MG-QOL-15 score-based diagnostic accuracy for anxiety and depression state were 0.816 (P = 0.001) and 0.983 (P < 0.001), respectively.

CONCLUSION

Higher MG-QOL-15 scores were a risk factor for anxiety and depression in late-onset MG, and women with late-onset MG were more likely to have anxiety and depression than men were.

Quantification of dendritic cell subsets in human thymus tissues of various ages

Background

Dendritic cells (DCs) in the thymus are involved in central tolerance formation, but they also have other functions in the thymus, such as pathogen recognition. The density changes of human thymic DCs have been hardly investigated. In this study, human thymus samples of various ages were collected for tissue sectioning and staining. The thymic cortex and medulla area as well as the densities of various subsets of thymic DCs were calculated.

Results

All common DC subsets were found in the human thymus of various ages. Most DCs had accumulated in the human thymic epithelial space, especially the medulla. We also found that the human thymic cortex had atrophied relatively faster than the medulla, which led to a gradual increase of the area ratio of the medulla to cortex with the increase of age. The densities of DC subsets in the human thymus showed various changes with increasing age, which contributed to the composition changes of DC subsets. The density of plasmacytoid DCs (pDCs) in the human thymus had increased gradually with aging, which suggested that pDCs plays another essential role in the thymus in addition to central tolerance.

Conclusions

Inconsistent with the shrinking of the epithelial space in the thymus, the densities of DC subsets in the epithelial space of the thymus are maintained at a constant level with aging to preserve highly efficient autoreactive thymocyte screening. An increasing density of the thymic pDCs with aging implies an extra function of DCs in the thymus beyond central tolerance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-021-00255-8.

SHP2 inhibition diminishes KRASG12C cycling and promotes tumor microenvironment remodeling

KRAS is the most frequently mutated human oncogene, and KRAS inhibition has been a longtime goal. Recently, inhibitors were developed that bind KRASG12C-GDP and react with Cys-12 (G12C-Is). Using new affinity reagents to monitor KRASG12C activation and inhibitor engagement, we found that an SHP2 inhibitor (SHP2-I) increases KRAS-GDP occupancy, enhancing G12C-I efficacy. The SHP2-I abrogated RTK feedback signaling and adaptive resistance to G12C-Is in vitro, in xenografts, and in syngeneic KRASG12C-mutant pancreatic ductal adenocarcinoma (PDAC) and non-small cell lung cancer (NSCLC). SHP2-I/G12C-I combination evoked favorable but tumor site-specific changes in the immune microenvironment, decreasing myeloid suppressor cells, increasing CD8+ T cells, and sensitizing tumors to PD-1 blockade. Experiments using cells expressing inhibitor-resistant SHP2 showed that SHP2 inhibition in PDAC cells is required for PDAC regression and remodeling of the immune microenvironment but revealed direct inhibitory effects on tumor angiogenesis and vascularity. Our results demonstrate that SHP2-I/G12C-I combinations confer a substantial survival benefit in PDAC and NSCLC and identify additional potential combination strategies.

Oleophylic Nanospheres Self-Assembly by Emulsion Technique Utilizing the Automatic Nanoscalar Interfacial Alternation (ANIAE)

BACKGROUND

The administration of many pharmaceutical active ingredients is often performed by the injection of an aqueous-based solution. Numerous active ingredients are however, insoluble in water, which complicates their administration and restricts their efficacy.

OBJECTIVE

The current solutions are hindered by both, a time-consuming manufacturing process and unsuitability for hydrophilic and hydrophobic materials.

METHODS

Emulsions of oleophilic active ingredients and polyprotein microspheres are an important step to overcome insolubility issues.

RESULTS

Polyprotein microspheres offer a versatile modifiable morphology, thermal responsivity, and size variation, which allows for the protection and release of assembled biomaterials. In addition, nanospheres present promising cell phagocytosis outcomes in vivo.

CONCLUSION

In this research, a reproducible multifunctional approach, to assemble nanospheres in one step, using a technique termed "automatic nanoscalar interfacial alternation in emulsion" (ANIAE) was developed, incorporating a thermally controlled release mechanism for the assembled target active ingredients. These results demonstrate a viable, universal, multifunctional principal for the pharmaceutical industry.

Leflunomide ameliorates experimental autoimmune myasthenia gravis by regulating humoral and cellular immune responses

Leflunomide, an immunosuppressive disease-modifying anti-rheumatic drug (DMARD), is widely used in the treatment of rheumatoid arthritis (RA), psoriatic arthritis (PA) as well as multiple sclerosis. However, its role in myasthenia gravis (MG) has not yet been clearly explored. Here, we investigated the effect of leflunomide on experimental autoimmune myasthenia gravis (EAMG) in vivo and in vitro. The results demonstrated that leflunomide alleviated the severity of EAMG associated with reduced serum total anti-acetylcholine receptor (AChR) IgG levels. During the development of EAMG, the increase of follicular helper T cells (Tfh) 1, Tfh 17 cells and decrease of follicular regulatory T cells (Tfr) were reversely altered after leflunomide administration. Our work further found that leflunomide might inhibit Tfh cells through the IL-21/STAT3 pathway to reduce the secretion of antibodies by B cells. In addition, leflunomide rebuilt the balance of Th1/Th2/Th17/Treg subsets. These results suggested that leflunomide ameliorated EAMG severity by regulating humoral immune responses and Th cell profiles thereby providing a novel effective treatment strategy for MG.

High-quality chromosome-level genome assembly and full-length transcriptome analysis of the pharaoh ant Monomorium pharaonis

Background

Ants with complex societies have fascinated scientists for centuries. Comparative genomic and transcriptomic analyses across ant species and castes have revealed important insights into the molecular mechanisms underlying ant caste differentiation. However, most current ant genomes and transcriptomes are highly fragmented and incomplete, which hinders our understanding of the molecular basis for complex ant societies.

Findings

By hybridizing Illumina, Pacific Biosciences, and Hi-C sequencing technologies, we de novo assembled a chromosome-level genome for Monomorium pharaonis, with a scaffold N50 of 27.2 Mb. Our new assembly provides better resolution for the discovery of genome rearrangement events at the chromosome level. Analysis of full-length isoform sequencing (ISO-seq) suggested that ∼15 Gb of ISO-seq data were sufficient to cover most expressed genes, but the number of transcript isoforms steadily increased with sequencing data coverage. Our high-depth ISO-seq data greatly improved the quality of gene annotation and enabled the accurate detection of alternative splicing isoforms in different castes of M. pharaonis. Comparative transcriptome analysis across castes based on the ISO-seq data revealed an unprecedented number of transcript isoforms, including many caste-specific isoforms. We also identified a number of conserved long non-coding RNAs that evolved specifically in ant lineages and several that were conserved across insect lineages.

Conclusions

We produced a high-quality chromosome-level genome for M. pharaonis, which significantly improved previous short-read assemblies. Together with full-length transcriptomes for all castes, we generated a highly accurate annotation for this ant species. These long-read sequencing results provide a useful resource for future functional studies on the genetic mechanisms underlying the evolution of social behaviors and organization in ants.

Genetically Defined, Syngeneic Organoid Platform for Developing Combination Therapies for Ovarian Cancer

The paucity of genetically informed, immunocompetent tumor models impedes evaluation of conventional, targeted, and immune therapies. By engineering mouse fallopian tube epithelial organoids using lentiviral gene transduction and/or CRISPR/Cas9 mutagenesis, we generated multiple high-grade serous tubo-ovarian cancer (HGSC) models exhibiting mutational combinations seen in patients with HGSC. Detailed analysis of homologous recombination (HR)-proficient (Trp53^-/-;Ccne1^OE;Akt2^OE;Kras^OE ), HR-deficient (Trp53^-/-;Brca1^-/-;Myc^OE ), and unclassified (Trp53^-/-;Pten^-/-;Nf1^-/- ) organoids revealed differences in in vitro properties (proliferation, differentiation, and "secretome"), copy-number aberrations, and tumorigenicity. Tumorigenic organoids had variable sensitivity to HGSC chemotherapeutics, and evoked distinct immune microenvironments that could be modulated by neutralizing organoid-produced chemokines/cytokines. These findings enabled development of a chemotherapy/immunotherapy regimen that yielded durable, T cell-dependent responses in Trp53^-/-;Ccne1^OE;Akt2^OE;Kras HGSC; in contrast, Trp53^-/-;Pten^-/-;Nf1^-/- tumors failed to respond. Mouse and human HGSC models showed genotype-dependent similarities in chemosensitivity, secretome, and immune microenvironment. Genotype-informed, syngeneic organoid models could provide a platform for the rapid evaluation of tumor biology and therapeutics. SIGNIFICANCE: The lack of genetically informed, diverse, immunocompetent models poses a major barrier to therapeutic development for many malignancies. Using engineered fallopian tube organoids to study the cell-autonomous and cell-nonautonomous effects of specific combinations of mutations found in HGSC, we suggest an effective combination treatment for the currently intractable CCNE1-amplified subgroup.This article is highlighted in the In This Issue feature, p. 211.

Abstract PR12: Genetic aberrations dictate distinct tumor immune landscape and chemosensitivity in HGSOC

High-grade serous ovarian cancer (HGSOC) is the most common and deadly subtype of ovarian epithelial cancer and is known for its aggressiveness, high recurrence rate, metastasis to other sites, development of resistance to conventional chemotherapy, and general lack of response to immune checkpoint inhibitors. The absence of genomically relevant, immune-competent HGSOC models represents a major barrier to developing new therapies. Taking advantage of a mouse fallopian tube organoid system that we developed, along with lentiviral gene transduction and/or CRISPR/Cas9 technology, we generated multiple new HGSOC models containing combinations of mutations seen in human HGSOC, including homologous recombination (HR)-proficient (Tp53-/-;Ccne1amp;Akt2ampand Tp53-/-;Ccne1amp;Krasamp) and -deficient (Tp53-/-;Brca1-/-;Pten-/-and Tp53-/-;Brca1-/-;Mycamp), and poorly characterized (Tp53-/-;Pten-/-;Nf1-/-) models. These models differ in proliferation, differentiation, and polarity/organoid structure in vitro, as well as tumorigenic capacity and behavior upon orthotopic injection into syngeneic mice. Organoids bearing different mutational spectra show differential sensitivity to conventional HGSOC chemotherapies, signal transduction inhibitors and DDR inhibitors, and evoke distinctly different immune microenvironment in vivo. In particular, the immune microenvironment induced by HR-deficient tumors shows more T-cell infiltration/Treg cells, whereas HR-proficient lines show lower T-cell infiltration but higher levels of myeloid-derived suppressor cells and macrophages. The results of these studies suggest novel, genotype-informed combination therapies for this devastating disease.

This abstract is also being presented as Poster B19.

Citation Format: Shuang Zhang, Sonia Iyer, Hao Ran, Wei Wei, Robert A. Weinberg, Benjamin G. Neel. Genetic aberrations dictate distinct tumor immune landscape and chemosensitivity in HGSOC [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr PR12.

Abstract PR1: Development of new immune therapy combinations for ovarian cancer using genetically defined organoid platform

High-grade serous ovarian cancer (HGSOC) is the most common, deadly subtype of ovarian epithelial cancer. HGSOC typically presents at an advanced stage, with widespread peritoneal metastasis. Surgical debulking and platinum/taxane-based chemotherapy can result in complete responses, but disease almost always recurs, eventually in drug-resistant form. The recent addition of Avastin and PARP inhibitors benefits a subset of patients, yet survival has improved marginally in the past 30 years. Responses to immune checkpoint inhibitors have been disappointing. Genomic studies (e.g., TCGA) show that HGSOC is a complex, diverse disease with widespread copy number abnormalities affecting multiple pathways. Nevertheless, most studies aimed at developing new therapies treat HGSOC as a single entity. The absence of genetically relevant, immune-competent HGSOC models poses a major barrier to developing new therapies. By exploiting a mouse fallopian tube organoid system that we developed, along with lentiviral gene transduction and/or CRISPR/Cas9 technology, we generated multiple new HGSOC models containing combinations of mutations seen in the human disease, including homologous recombination (HR)-proficient (Tp53-/-;Ccne1OE;Akt2OE and Tp53-/-;Ccne1OE;KrasOE) -deficient (Tp53-/-;Brca1-/-;Pten-/-and Tp53-/-; Brca1-/-;MycOE and unclassified (Tp53-/-;Pten-/-;Nf1-/-) models. These cells differ in proliferation, differentiation, and polarity/organoid structure in vitro, as well as tumorigenicity and metastatic spread upon orthotopic injection into syngeneic mice. Organoids with different mutations show differential sensitivity to current HGSOC drugs and evoke distinctly different immune microenvironments in vivo. Brca1-/- and CcneOE tumors show significant T-cell infiltration/Treg cells; the latter also have increased myeloid-derived suppressor cells (MDSCs). Pten-/- tumors have lower T-cell infiltration but high levels of MDSCs and macrophages. To test the utility of this platform for new therapeutic development, we focused on CcneOE tumors, because human CCNE-amplified HGSOC responds poorly to current therapy. CcneOE organoids were sensitive to gemcitabine (GEM), probably due to CCNE-evoked replication stress. GEM treatment reduced pro-MDSC cytokines in organoid-conditioned media, and decreased tumor burden in mice. Consistent with these in vitro data, residual tumors had decreased MDSCs (CD11b+Ly6CloLy6Ghi), but persistent Treg (CD24+CD25+FoxP3+) and “exhausted” CD8 T cells (CD8+PD1+). Intriguingly, a combination regimen aimed at attacking tumor cells (gemcitabine) and the residual microenvironment (CTLA4 and PDL1 antibodies) produced complete responses in mice with widespread metastatic disease. Our results argue that genotype-informed combination therapies will be necessary for better outcomes for this devastating disease.

This abstract is also being presented as Poster A42.

Citation Format: Shuang Zhang, Sonia Iyer, Hao Ran, Wei Wei, Robert A. Weinberg, Benjamin G. Neel. Development of new immune therapy combinations for ovarian cancer using genetically defined organoid platform [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr PR1.

Hospital and healthcare insurance system record-based epidemiological study of myasthenia gravis in southern and northern China

OBJECTIVE

This is the first cross-region epidemiological study of myasthenia gravis (MG) in China. We estimated the incidence, prevalence, and medical costs of MG in southern China and explored the differences between the southern and northern Chinese populations.

METHODS

We collected and analyzed records from 20 hospitals in the southern city, Guangzhou, 13 hospitals in the northern city, Harbin, and two healthcare insurance systems: job based and residence based in Guangzhou during 2000-2017.

RESULTS

(1) The estimated annual incidence of MG was 1.55-3.66 per 100,000, and the estimated prevalence of MG was 2.19-11.07 per 100,000 in southern China based on insurance records. (2) The proportion of hospitalized MG patients in the south-based hospital records was three times as high as that in the north-based hospital records. (3) Female MG prevalence was significantly higher than male MG prevalence in Guangzhou, while the similar gender difference in Harbin was not statistically significant due to higher variation in earlier years. (4) The average expense was $35-42 for each outpatient service and $2526-2673 for each hospitalization expense in the south. (5) Contrary to the increase of insurance-based estimate of MG prevalence, the proportion of hospitalized MG patients did not increase over the years, suggesting rising awareness and utilization of health insurance.

CONCLUSIONS

The southern MG population had a significantly higher prevalence and a lower response threshold to medication than the northern MG population. These results are calling for further investigations on the genetic, cultural, and environmental variations of the Chinese MG populations between north and south.

P1739 Diameter of the pulmonary artery in relation to the ascending aorta: a promising parameter for the diagnosis of pulmonary hypertension

Background

Pulmonary hypertension (PH) is a disease with significant morbidity and mortality. The first imaging modality in the diagnostic algorithm is transthoracic echocardiography (TTE). Despite significant technological advances in recent years, there are still patients with PH who are missed by TTE. The pulmonary artery to ascending aorta ratio (PA/Ao-R) has been evaluated in cardiac magnetic resonance (CMR) and computed tomography (CT) studies. The ratio was able to detect patients with PH, it correlated with hemodynamics, and it was predictive for mortality. We sought to evaluate the diagnostic accuracy of PA/Ao-R measured by TTE in the detection of PH.

Methods

We evaluated consecutive patients who received quasi-simultaneous transthoracic echocardiography and right heart catheterization (RHC) for evaluation of pulmonary hypertension between July 2015 and July 2016.

Results

A total of 84 patients fulfilled the inclusion criteria, 47 were female, mean age was 65 years. Median PA/Ao-R was 0.8 (Q1;Q3 0.69;0.94). Seventy patients had PH (median mean pulmonary artery pressure (mPAP) was 35.5 mmHg, Q1;Q3 27;47). The area under the curve for the diagnosis of PH via PA/Ao-R was 0.853. A cut-off of 1 was chosen for further analysis. Sensitivity for the diagnosis of PH was 100%, specificity was 23%. PA/Ao-R correlated with mPAP (r = 0.65, p &lt; 0.001), and pulmonary vascular resistance (r = 0.68, p &lt; 0.001). In the subgroup of patients with PH, those patients with a PA/Ao-R of ≥1 had significantly (p &lt; 0.001) higher pulmonary pressures than those below, with a mean mPAP of 53 mmHg as compared to 38.5 mmHg.

Conclusion

PA/Ao-R correlates with mPAP. A ratio of ≥1 should prompt suspicion for the presence of PH. PA/Ao-R should be reported in every patient who is evaluated for PH.

MicroRNA-219-5p inhibits wound healing by targeting TMEM98 in keratinocytes under normoxia and hypoxia condition

OBJECTIVE

Wound healing is closely related to the production of inflammatory cytokines, keratinocytes proliferation and migration. This study aims to investigate the role of transmembrane protein 98 (TMEM98) on wound healing and whether miRNA-219-5p could inhibit wound healing by targeting TMEM98 in keratinocytes.

MATERIAL AND METHODS

Hypoxia model was established by CoCl2 (2000 μmol/L) treatment. TMEM98 protein expression, inflammatory cytokines (IL-6, IL-8, TNF-α) and cell proliferation and migration were detected in hypoxia group.

RESULTS

Overexpression of TMEM98 could significantly reverse the effects caused by hypoxia. MiR-219-5p was markedly increased in hypoxia group and miR-219-5p could downregulate TMEM98 expression by direct binding its 3'-UTR.

CONCLUSIONS

We demonstrated that miR-219-5p could inhibit wound healing by targeting TMEM98.

Abstract PR05: Development of new immune therapy combinations for ovarian cancer using genetically defined organoid platform

High-grade serous ovarian cancer (HGSOC) is the most common and deadly subtype of ovarian epithelial cancer. HGSOC typically presents at an advanced stage, with widespread peritoneal metastasis. Although surgical debulking and platinum/taxane-based chemotherapy can result in complete responses, disease almost always recurs, eventually in drug-resistant forms. Although the recent addition of Avastin and PARP inhibitors benefits a subset of patients, survival has improved only marginally in the past 30 years. Responses to immune checkpoint inhibitors have also been disappointing. Genomic studies (e.g., by TCGA) have shown that HGSOC is a complex, diverse disease with widespread copy number abnormalities affecting multiple pathways. Nevertheless, most studies aimed at developing new therapies treat HGSOC as a single entity. The absence of genomically relevant, immune-competent HGSOC models poses a major barrier to developing new therapies. Capitalizing on a mouse fallopian tube organoid system that we developed, along with lentiviral gene transduction and/or CRISPR/Cas9 technology, we generated multiple new HGSOC models containing combinations of mutations seen in human HGSOC, including homologous recombination (HR)-proficient (Tp53-/-;Ccne1OE;Akt2OE and Tp53-/-;Ccne1OE;KrasOE) and -deficient (Tp53-/-;Brca1-/-;Pten-/-and Tp53-/-;Brca1-/-;MycOE), and poorly characterized (Tp53-/-;Pten-/-;Nf1-/-) models. These models differ in proliferation, differentiation, and polarity/organoid structure in vitro, as well as tumorigenic capacity and behavior upon orthotopic injection into syngeneic mice. Organoids bearing different mutational spectra show differential sensitivity to conventional HGSOC chemotherapies and PARP inhibitors, and evoke distinctly different immune microenvironment in vivo. The immune microenvironment induced by Brca1-/- and CcneOE tumors show significant T cell infiltration/Treg cells, the latter also has increased myeloid-derived suppressor cells (MDSCs), and Pten-/-lines show lower T cell infiltration but higher levels of MDSCs and macrophages. To test the utility of this platform for new therapeutic development, we focused on CcneOE tumors, because human CCNE-amplified HGSOC responds poorly to current therapy. CcneOE organoids were sensitive to gemcitabine (GEM), probably due to CCNE-evoked replication stress. GEM treatment reduced pro-MDSC cytokines in organoid conditioned media, and decreased tumor burden in mice. Consistent with the in vitro data, residual tumors had decreased MDSCs (CD11b+Ly6CloLy6Ghi), but persistent Treg (CD24+CD25+FoxP3+) and “exhausted” CD8 T cells (CD8+PD1+) in their microenvironment. Intriguingly, a combination regimen aimed at attacking tumor cells (gemcitabine) and the residual microenvironment (CTLA4 and PDL1 antibodies) produced complete responses in mice with widepresad metastatic disease, Our results argue that genotype-informed combination therapies will be necessary for better outcomes for this devastating disease.

Citation Format: Shuang Zhang, Sonia Iyer, Hao Ran, Wei wei, Robert A Weinberg, Benjamin G Neel. Development of new immune therapy combinations for ovarian cancer using genetically defined organoid platform [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr PR05. doi:10.1158/1535-7163.TARG-19-PR05

Both fallopian tube and ovarian surface epithelium are cells-of-origin for high-grade serous ovarian carcinoma

The cell-of-origin of high grade serous ovarian carcinoma (HGSOC) remains controversial, with fallopian tube epithelium (FTE) and ovarian surface epithelium (OSE) both considered candidates. Here, by using genetically engineered mouse models and organoids, we assessed the tumor-forming properties of FTE and OSE harboring the same oncogenic abnormalities. Combined RB family inactivation and Tp53 mutation in Pax8 + FTE caused Serous Tubal Intraepithelial Carcinoma (STIC), which metastasized rapidly to the ovarian surface. These events were recapitulated by orthotopic injection of mutant FTE organoids. Engineering the same genetic lesions into Lgr5 + OSE or OSE-derived organoids also caused metastatic HGSOC, although with longer latency and lower penetrance. FTE- and OSE-derived tumors had distinct transcriptomes, and comparative transcriptomics and genomics suggest that human HGSOC arises from both cell types. Finally, FTE- and OSE-derived organoids exhibited differential chemosensitivity. Our results comport with a dualistic origin for HGSOC and suggest that the cell-of-origin might influence therapeutic response.

[Characteristics of electromyography in 111 patients with generalized myasthenia gravis: a retrospective study]

Objective: To retrospectively analyze the characteristics of the electromyography (EMG) study in generalized myasthenia gravis (gMG) patients. Methods: A total of 111 gMG patients were enrolled. Patients were divided into two groups: 36 severe patients discontinuing pyridostigmine bromide (PB) for 8 hours were included in 8 h group, and 75 g MG patients discontinuing PB for at least 18 hours were included in>18 h group. The clinical information and EMG study data were collected and analyzed. Results: There were statistically significant differences in the initial location of the myasthenia muscle (P=0.027), the affected muscle detected by the EMG (P=0.015) and quantitative myasthenia gravis (QMG) score (P<0.01) between the two groups. Comparisons in each group revealed that the highest positive rate of low-frequency repetitive nerve stimulation (RNS) of facial in 8 h group and>18 h group was 94.4% and 60.0%, respectively. Comparisons between the two groups showed that the positive rate of low-frequency RNS in 8 h group was significantly higher than that in>18 h group (94.4% vs 70.7%, χ(2)=8.115, P=0.004). In particular, the positive rate of RNS in facial nerves and the extent of the amplitude decrease under different electrical stimulations (1 Hz, 3 Hz, and 5 Hz) were dramatically higher in the 8 h group (P<0.01). Conclusions: For gMG patients, the facial and accessory nerve detection can improve the positive rate of RNS. Different muscles had various sensitivity to PB, and orbicularis oculi muscle seemed the least sensitive muscle to PB. For suspect MG patients in severe condition, only discontinuing PB medication for 8 h before low-frequency RNS testing can avoid the deterioration and also obtain similar positive rate.

Imbalance of the two main circulating dendritic cell subsets in patients with myasthenia gravis

Although it is well documented that circulating dendritic cells (DCs) have specialized features during many kinds of physiological and pathological conditions, there are few reports about the features of DCs in the peripheral blood of myasthenia gravis (MG) patients. We investigated the quantitative and component features of DCs and their implications in MG. Peripheral blood samples from different kinds of MG patients were collected and their clinical characteristics were recorded. Using flow cytometry, we distinguished circulating DC subsets [plasmacytoid DCs (pDCs) and myeloid DCs (mDCs)] and enumerated their densities in peripheral blood. Absolute numbers of circulating pDCs were significantly decreased in naïve MG patients compared with healthy controls, resulting in a markedly lower ratio of the pDC to mDC percentage in total circulating DCs (pDCs/mDCs), suggesting an imbalance in the proportions of the two main circulating DC subsets. The clinical status of MG patients was improved after drug treatment, together with increased pDCs/mDCs. In a longitudinal follow-up, we observed that circulating mDCs were significantly reduced after 1 month of therapy with a corticosteroid and immunosuppressant, resulting in recovery of pDCs/mDCs. Although the exact meaning of the proportion change in circulating DC subsets is unknown, pDCs/mDCs might reflect the balance between the autoimmune response and immune tolerance of a patient. Moreover, changes in pDCs/mDCs during treatment might be a promising marker to predict the efficacy of a specific drug used for MG patients.

SHP2 Inhibition Prevents Adaptive Resistance to MEK Inhibitors in Multiple Cancer Models

Adaptive resistance to MEK inhibitors (MEKi) typically occurs via induction of genes for different receptor tyrosine kinases (RTK) and/or their ligands, even in tumors of the same histotype, making combination strategies challenging. SHP2 (PTPN11) is required for RAS/ERK pathway activation by most RTKs and might provide a common resistance node. We found that combining the SHP2 inhibitor SHP099 with a MEKi inhibited the proliferation of multiple cancer cell lines in vitro PTPN11 knockdown/MEKi treatment had similar effects, whereas expressing SHP099 binding-defective PTPN11 mutants conferred resistance, demonstrating that SHP099 is on-target. SHP099/trametinib was highly efficacious in xenograft and/or genetically engineered models of KRAS-mutant pancreas, lung, and ovarian cancers and in wild-type RAS-expressing triple-negative breast cancer. SHP099 inhibited activation of KRAS mutants with residual GTPase activity, impeded SOS/RAS/MEK/ERK1/2 reactivation in response to MEKi, and blocked ERK1/2-dependent transcriptional programs. We conclude that SHP099/MEKi combinations could have therapeutic utility in multiple malignancies.Significance: MEK inhibitors show limited efficacy as single agents, in part because of the rapid development of adaptive resistance. We find that SHP2/MEK inhibitor combinations prevent adaptive resistance in multiple cancer models expressing mutant and wild-type KRAS. Cancer Discov; 8(10); 1237-49. ©2018 AACR. See related commentary by Torres-Ayuso and Brognard, p. 1210 This article is highlighted in the In This Issue feature, p. 1195.

A liquid crystalline precursor incorporating chlorhexidine acetate and silver nanoparticles for root canal disinfection

Lyotropic liquid crystals (LLC) have received increasing attention as a drug delivery system. In this study, a novel intra-canal disinfectant based on the glycerol monooleate (GMO) LLC precursor incorporation with chlorhexidine (CHX) and silver nanoparticles (Ag-NPs) was designed and evaluated. The LLC precursor with excellent fluidity was able to penetrate deeply into the complex tiny collateral branch root canals. The transformation of cubic LLC in root canals upon coming into contact with water provided long-lasting disinfection against multidrug-resistant bacteria to avoid the endodontic reinfection and follow-up visits. The GMO-ethanol-water (48% : 12% : 40%, w/w) formulation containing 0.5% CHX and 0.02% Ag-NPs was selected for further studies. The low viscosity of the precursor presented excellent injectability and flowabilities. From the in vitro release test, the release behaviours were found to be influenced by CHX and Ag-NP contents, allowing the optimized precursor to obtain a 28-day release profile. The CHX-Ag-NP containing LLC precursor exhibited an excellent and sustained sterilization effect on Enterococcus faecalis for more than one month with a bacterial inactivation rate of ≥98.5%, which was far more than the minimum clinical requirement (7 days). Furthermore, no in vitro toxicity was observed in the cytotoxicity evaluation. The CHX-Ag-NP containing LLC precursor was proved to be a promising intra-canal disinfectant in our study.

Off-target inhibition by active site-targeting SHP2 inhibitors

Due to the involvement of SHP2 (SH2 domain-containing protein-tyrosine phosphatase) in human disease, including Noonan syndrome and cancer, several inhibitors targeting SHP2 have been developed. Here, we report that the commonly used SHP2 inhibitor NSC-87877 does not exhibit robust inhibitory effects on growth factor-dependent MAPK (mitogen-activated protein kinase) pathway activation and that the recently developed active site-targeting SHP2 inhibitors IIB-08, 11a-1, and GS-493 show off-target effects on ligand-evoked activation/trans-phosphorylation of the PDGFRβ (platelet-derived growth factor receptor β). GS-493 also inhibits purified human PDGFRβ and SRC in vitro, whereas PDGFRβ inhibition by IIB-08 and 11a-1 occurs only in the cellular context. Our results argue for extreme caution in inferring specific functions for SHP2 based on studies using these inhibitors.

SHP2 Inhibition Prevents Adaptive Resistance to MEK Inhibitors in Multiple Cancer Models

Adaptive resistance to MEK inhibitors (MEKi) typically occurs via induction of genes for different receptor tyrosine kinases (RTK) and/or their ligands, even in tumors of the same histotype, making combination strategies challenging. SHP2 (PTPN11) is required for RAS/ERK pathway activation by most RTKs and might provide a common resistance node. We found that combining the SHP2 inhibitor SHP099 with a MEKi inhibited the proliferation of multiple cancer cell lines in vitro PTPN11 knockdown/MEKi treatment had similar effects, whereas expressing SHP099 binding-defective PTPN11 mutants conferred resistance, demonstrating that SHP099 is on-target. SHP099/trametinib was highly efficacious in xenograft and/or genetically engineered models of KRAS-mutant pancreas, lung, and ovarian cancers and in wild-type RAS-expressing triple-negative breast cancer. SHP099 inhibited activation of KRAS mutants with residual GTPase activity, impeded SOS/RAS/MEK/ERK1/2 reactivation in response to MEKi, and blocked ERK1/2-dependent transcriptional programs. We conclude that SHP099/MEKi combinations could have therapeutic utility in multiple malignancies.Significance: MEK inhibitors show limited efficacy as single agents, in part because of the rapid development of adaptive resistance. We find that SHP2/MEK inhibitor combinations prevent adaptive resistance in multiple cancer models expressing mutant and wild-type KRAS. Cancer Discov; 8(10); 1237-49. ©2018 AACR. See related commentary by Torres-Ayuso and Brognard, p. 1210 This article is highlighted in the In This Issue feature, p. 1195.

Abstract LB-338: SHP2 inhibition enhances sensitivity to MEK inhibitors in multiple resistant cancer models

Targeting tumors with kinase inhibitors induces complex adaptive programs that enable the persistence of a fraction of the original cell population, facilitating the eventual outgrowth of inhibitor-resistant tumor clones. Most tumors developing resistance to MEK inhibitors upregulate and/or activation of at least one of several different receptor tyrosine kinases (RTKs), which drive resistance. Notably, different RTKs or RTK combinations are upregulated in different cancer cells, even those from the same histotype. SHP2 (encoded by PTPN11) is required for RAS/ERK pathway activation downstream of most RTKs, suggesting that it might provide a common targetable resistance node in multiple resistant cancer cell lines. We show that the addition of a newly identified SHP2 inhibitor, SHP099, to MEK therapy enhances cell killing and impedes the emergence of drug-resistant cell populations in diverse cancer models in vitro and in vivo. These effects occurred in a wide range of malignancies, including KRAS mutant pancreas, lung cancer, triple negative breast cancer, and serous ovarian cancer cell lines, as well as in PDX and GEMM models. SHP099 effects were overcome by expressing an SHP2 mutant that loses drug binding but retain catalytic activity and regulation, demonstrating that on target effects of the inhibitor. Mechanistic studies across multiple cellular cancer models suggest that SHP2 inhibition by SHP099 prevents the compensatory RAS and ERK1/2 reactivation in response to MEK therapy and impedes the engagement of the ERK1/2 transcriptional programs (i.e., MYC, ETV1, FOSL1, etc.) and signaling outputs that characterize the drug-tolerant state. Combining full doses of MEK inhibitors and SHP099 causes significant toxicity in mice, but non-toxic, efficacious dosing regimens can be achieved. Our findings suggest that SHP099, in combination with MEK inhibition is a promising therapeutic strategy for enhancing the effectiveness of targeted therapies.

Citation Format: Carmine Fedele, Kwan Ho Tang, Hao Ran, Wei Wei, Brian Diskin, George Miller, Benjamin G. Neel. SHP2 inhibition enhances sensitivity to MEK inhibitors in multiple resistant cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-338.

Possible bite-induced abscess and osteomyelitis in Lufengosaurus (Dinosauria: sauropodomorph) from the Lower Jurassic of the Yimen Basin, China

We report an osseous abnormality on a specimen of the sauropod dinosaur Lufengosaurus huenei from the Fengjiahe Formation in Yuxi Basin, China. A gross pathological defect occurs on the right third rib, which was subjected to micro-computed tomographic imaging as an aid in diagnosis. The analysis of pathological characteristics and the shape of the abnormality is incompatible with impact or healed trauma, such as a common rib fracture, and instead suggests focal penetration of the rib, possibly due to a failed predator attack. The identification of characteristics based on gross morphology and internal micro-morphology presented by the specimen, suggests an abscess with osteomyelitis as the most parsimonious explanation. Osteomyelitis is a severe infection originating in the bone marrow, usually resulting from the introduction of pyogenic (pus-producing) bacteria into the bone. Micro-tomographic imaging of the lesion suggests a degree of healing and bone remodelling following post-traumatic wound infection with evidence of sclerotic bone formation at the site of pathological focus, indicating that L. huenei survived the initial trauma. However, as osteomyelitis can express through widespread systemic effects, including a lowering of immune response and overall condition, this disease may have been a contributing factor to the eventual death of the individual.

[Correlation factors of 127 times pre-crisis state in patients with myasthenia gravis]

Objective: To investigate the clinical features of the Pre-Crisis State and analyze the correlated risk factors of Pre-Crisis State of myasthenia crisis. Methods: We included 93 patients with myasthenia gravis (MG) who experienced 127 times Pre-Crisis State between October 2007 and July 2016. Those patients were hospitalized in the MG specialize center, Department of Neurological Science, first Affiliated Hospital of Sun Yat-sen University. The information of the general situation, the clinical manifestations and the blood gas analysis in those patients were collected using our innovated clinical research form. Statistic methods were applied including descriptive analysis, univariate logistic analysis, multivariate correlation logistic analysis, etc. Results: (1)The typical features of MG Pre-Crisis State included: dyspnea (127 times, 100% not requiring intubation or non-invasive ventilation), bulbar-muscle weakness (121 times, 95.28%), the increased blood partial pressure of carbon dioxide (PCO(2)) (94 times, 85.45%), expectoration weakness (99 times, 77.95%), sleep disorders (107 times, 84.25%) and the infection (99 times, 77.95%). The occurrence of dyspnea in combination with bulbar-muscle weakness (P=0.002) or the increased blood PCO(2) (P=0.042) often indicated the tendency of crisis. (2) The MG symptoms which were proportion to the occurrence of crisis includes: bulbar-muscle weakness (P=0.028), fever (P=0.028), malnutrition (P=0.066), complications (P=0.071), excess oropharyngeal secretions (P=0.005) and the increased blood PCO(2) (P=0.007). The perioperative period of thymectomy would not increase the risk of crisis. Conclusions: Dyspnea indicates the occurrence of the Pre-Crisis State of MG. In order to significantly reduce the morbidity of myasthenia crisis, the bulbar-muscle weakness, the increased blood PCO(2), expectoration weakness, sleep disorders, infection & fever and excess oropharyngeal secretions should be treated timely.

Preparation of Acid-Resistant Microcapsules with Shell-Matrix Structure to Enhance Stability of Streptococcus Thermophilus IFFI 6038

Microencapsulation is an effective technology used to protect probiotics against harsh conditions. Extrusion is a commonly used microencapsulation method utilized to prepare probiotics microcapsules that is regarded as economical and simple to operate. This research aims to prepare acid-resistant probiotic microcapsules with high viability after freeze-drying and optimized storage stability. Streptococcus thermophilus IFFI 6038 (IFFI 6038) cells were mixed with trehalose and alginate to fabricate microcapsules using extrusion. These capsules were subsequently coated with chitosan to obtain chitosan-trehalose-alginate microcapsules with shell-matrix structure. Chitosan-alginate microcapsules (without trehalose) were also prepared using the same method. The characteristics of the microcapsules were observed by measuring the freeze-dried viability, acid resistance, and long-term storage stability of the cells. The viable count of IFFI 6038 in the chitosan-trehalose-alginate microcapsules was 8.34 ± 0.30 log CFU g^-1 after freeze-drying (lyophilization), which was nearly 1 log units g^-1 greater than the chitosan-alginate microcapsules. The viability of IFFI 6038 in the chitosan-trehalose-alginate microcapsules was 6.45 ± 0.09 log CFU g^-1 after 120 min of treatment in simulated gastric juices, while the chitosan-alginate microcapsules only measured 4.82 ± 0.22 log CFU g^-1 . The results of the long-term storage stability assay indicated that the viability of IFFI 6038 in chitosan-trehalose-alginate microcapsules was higher than in chitosan-alginate microcapsules after storage at 25 °C. Trehalose played an important role in the stability of IFFI 6038 during storage. The novel shell-matrix chitosan-trehalose-alginate microcapsules showed optimal stability and acid resistance, demonstrating their potential as a delivery vehicle to transport probiotics.

A novel design for stable self-assembly cubosome precursor-microparticles enhancing dissolution of insoluble drugs

Cubosomes have been presented to enhance dissolution of insoluble drugs, but their applications are limited by the practical hurdles associated with both preparation and storage instability, resulting in drug delivery failure. In the present study, an innovative cubosome precursor-microparticles (CPMs) spray dried from an aqua-free precursor solution was developed to improve cubosome stability during both preparation and storage as well as to enhance the dissolution of insoluble drugs. These CPMs spontaneously self-assembled in situ forming homogeneous cubosome dispersion by hydration and disintegration after exposure to the aqueous medium. The stable cubosome dispersion was obtained from self-assembly (SA) of CPMs after administration instead of fragmentation of bulk cubic phase gel into cubosomes, which settled the preparation instability due to avoidance of high energy fragmentation (e.g. ultrasonic effect, high speed shear and high pressure homogenization). Also, the subsequent storage instability issue can be excluded as the CPMs were stored in a solid stable form. The CPMs disintegration and cubosome SA were demonstrated by the notable morphology variation and the distinct microparticle size decrease from CPMs (10-20 μm) to SA-cubosomes (150-200 nm). The cumulative release of docetaxel (DTX, model insoluble drug) incorporated in CPMs increased to 96.4% within 120 minutes compared with only 75.2% for blank CPMs and DTX physical mixture, demonstrating that CPMs significantly enhanced the dissolution extent of insoluble drug. The SA-cubosomes possessed quite high drug entrapment efficiency (>95%) and an integrated drug dissolution content, which significantly increased the drug utilization rate.

Response to: Phylogenetic placement, developmental trajectories and evolutionary implications of a feathered dinosaur tail in Mid-Cretaceous amber

In his correspondence, Markus Lambertz [1] raises some concerns about the phylogenetic placement and feather development of DIP-V-15103, the amber-entombed tail section that we recently reported [2] as fragmentary remains of a non-pygostylian coelurosaur (likely within the basal part of Coelurosauria). We here would like to respond to these concerns.

A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber

In the two decades since the discovery of feathered dinosaurs [1-3], the range of plumage known from non-avialan theropods has expanded significantly, confirming several features predicted by developmentally informed models of feather evolution [4-10]. However, three-dimensional feather morphology and evolutionary patterns remain difficult to interpret, due to compression in sedimentary rocks [9, 11]. Recent discoveries in Cretaceous amber from Canada, France, Japan, Lebanon, Myanmar, and the United States [12-18] reveal much finer levels of structural detail, but taxonomic placement is uncertain because plumage is rarely associated with identifiable skeletal material [14]. Here we describe the feathered tail of a non-avialan theropod preserved in mid-Cretaceous (∼99 Ma) amber from Kachin State, Myanmar [17], with plumage structure that directly informs the evolutionary developmental pathway of feathers. This specimen provides an opportunity to document pristine feathers in direct association with a putative juvenile coelurosaur, preserving fine morphological details, including the spatial arrangement of follicles and feathers on the body, and micrometer-scale features of the plumage. Many feathers exhibit a short, slender rachis with alternating barbs and a uniform series of contiguous barbules, supporting the developmental hypothesis that barbs already possessed barbules when they fused to form the rachis [19]. Beneath the feathers, carbonized soft tissues offer a glimpse of preservational potential and history for the inclusion; abundant Fe²⁺ suggests that vestiges of primary hemoglobin and ferritin remain trapped within the tail. The new finding highlights the unique preservation potential of amber for understanding the morphology and evolution of coelurosaurian integumentary structures.

Sticking It to Cancer with Molecular Glue for SHP2

Much effort has been expended to develop inhibitors against protein-tyrosine phosphatases (PTPs), nearly all of it unsuccessful. A recent report, describing a highly specific, orally bioavailable inhibitor of the PTP oncoprotein SHP2 with in vivo activity, suggests that allostery might provide a way forward for PTP inhibitor development.

A single fas gene mutation changes lupus onset, severity, location, and molecular abnormalities in mice

Although genetic predisposition plays a major role in the progression of systemic lupus erythematosus (SLE) and its variation in symptoms, the precise relationships between genetic changes and disease status are not well understood. Here, to demonstrate the effect of a single gene mutation on disease etiology, we examined two mouse models of SLE with the same genetic background but different Fas genes. Mice with the Fas(lpr) gene developed severe SLE with renal dysfunction and inflammatory responses in the lung and kidney. By contrast, mice with the Fas(+) gene showed disease-related abnormalities in the liver and joints. Patterns of inflammatory disease markers differed across organs between the two lines of mice. Fas(lpr) mice showed greater MMP signals in the kidney and IL-11 signals in the lung than Fas(+) mice. Fas(+) mice had higher IL-11 signal intensity in the knee region and higher CXCR4 signal intensity in the liver than Fas(lpr) mice. Our results exemplify the complexity of disease and suggest the need for individualized target-specific treatment regimens. Strengths and Limitations of this Study: Fas gene is a well characterized gene in this disease. The molecular components in human disease need more clinical data.