Novel role of estrogen receptor-α on regulating chondrocyte phenotype and response to mechanical loading

OBJECTIVE

In knee cartilage from patients with osteoarthritis (OA), both preserved cartilage and damaged cartilage are observed. In this study, we aim to compare preserved with damaged cartilage to identify the molecule(s) that may be responsible for the mechanical loading-induced differences within cartilage degradation.

METHODS

Preserved and damaged cartilage were harvested from the same OA knee joint. RNA Sequencing was performed to examine the transcriptomic differences between preserved and damaged cartilage cells. Estrogen receptor-α (ERα) was identified, and its function of was tested through gene knockin and knockout. The role of ERα in mediating chondrocyte response to mechanical loading was examined via compression of chondrocyte-laded hydrogel in a strain-controlled manner. Findings from the studies on human samples were verified in animal models.

RESULTS

Level of estrogen receptor α (ERα) was significantly reduced in damaged cartilage compared to preserved cartilage, which were observed in both human and mice samples. Knockdown of ESR1, the gene encoding ERα, resulted in an upregulation of senescence- and OA-relevant markers in chondrocytes. Conversely, knockin of ESR1 partially reversed the osteoarthritic and senescent phenotype of OA chondrocytes. Using a three-dimensional (3D) culture model, we demonstrated that mechanical overload significantly suppressed ERα level in chondrocytes with concomitant upregulation of osteoarthritic phenotype. When ESR1 expression was suppressed, mechanical loading enhanced hypertrophic and osteogenic transition.

CONCLUSION

Our study demonstrates a new estrogen-independent role of ERα in mediating chondrocyte phenotype and its response to mechanical loading, and suggests that enhancing ERα level may represent a new method to treat osteoarthritis.

Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs

Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.

Development of a NanoBRET assay to validate dual inhibitors of Sirt2-mediated lysine deacetylation and defatty-acylation that block prostate cancer cell migration

Sirtuin2 (Sirt2) with its NAD⁺-dependent deacetylase and defatty-acylase activities plays a central role in the regulation of specific cellular functions. Dysregulation of Sirt2 activity has been associated with the pathogenesis of many diseases, thus making Sirt2 a promising target for pharmaceutical intervention. Herein, we present new high affinity Sirt2 selective Sirtuin-Rearranging Ligands (SirReals) that inhibit both Sirt2-dependent deacetylation and defatty-acylation in vitro and in cells. We show that simultaneous inhibition of both Sirt2 activities results in strongly reduced levels of the oncoprotein c-Myc and an inhibition of cancer cell migration. Furthermore, we describe the development of a NanoBRET-based assay for Sirt2, thereby providing a method to study cellular target engagement for Sirt2 in a straightforward and accurately quantifiable manner. Applying this assay, we could confirm cellular Sirt2 binding of our new Sirt2 inhibitors and correlate their anticancer effects with their cellular target engagement.

Sirt2 inhibitors that show simultaneous inhibition of Sirt2 deacetylase and defatty-acylase activity block prostate cancer cell migration and their target engagement is shown by a newly developed NanoBRET assay.

Effects of edaravone combined with Oxiracetam on neuronal apoptosis in rats with cerebral infarction through targeting SIRT1/NF-κB inflammatory pathway

OBJECTIVE

The objective of this study was to investigate the effects of edaravone combined with oxiracetam on neuronal apoptosis in rats with cerebral infarction (CI) and to explore the potential molecular mechanism.

MATERIALS AND METHODS

A total of 36 Sprague-Dawley rats were randomly divided into sham-operation group (n=12), model group (n=12) and treatment group (n=12). Only the external carotid artery was exposed in sham-operation group, while the models of CI were established using suture method in the other two groups. After modeling, the rats in sham-operation group and model group were intraperitoneally injected with normal saline, and those in treatment group were administered with edaravone and oxiracetam solutions via intraperitoneal injection. Then, the specimens were obtained at 2 weeks after intervention. The cognitive function of the rats was evaluated using a water maze, Nissl staining was applied to observe the neuronal morphology, and the relative protein expressions of silent information regulator 1 (SIRT1) and NF-κB were measured by means of Western blotting. Furthermore, quantitative polymerase chain reaction (qPCR) was performed to determine the messenger ribonucleic acid (mRNA) expressions of interleukin-1 beta (IL-1β) and IL-6, the content of IL-1β and IL-6 was detected by enzyme-linked immunosorbent assay (ELISA), and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was conducted to examine the cell apoptosis.

RESULTS

Model group displayed a significantly longer escape latency and significantly fewer times of crossing the original platform than sham-operation group (p<0.05), whereas treatment group had a significantly shorter escape latency but significantly more times of crossing the original platform than model group (p<0.05). The relative protein expression level of SIRT1 was lowered significantly, while that of NF-κB was elevated significantly in model group in comparison with those in sham-operation group (p<0.05), and the opposite results were observed between model group and treatment group (p<0.05). Besides, the content of IL-1β and IL-6 in brain tissues was increased significantly in model group compared with that in sham-operation group (p<0.05), but it was decreased significantly in treatment group in comparison with that in model group (p<0.05). The relative mRNA expression levels of IL-1β and IL-6 were significantly higher in model group than those in sham-operation group (p<0.05). Moreover, model group exhibited more positive apoptotic cells and a significantly higher apoptosis rate than sham-operation group (p<0.05) and treatment group (p<0.05). No apparent abnormalities of neuronal morphology and structure were detected in sham-operation group, with many Nissl bodies. The neurons were damaged, with abnormal morphology and structure, and there were a small number of Nissl bodies in model group. The neurons were damaged in treatment group, but their morphology and structure were improved evidently compared with those in model group.

CONCLUSIONS

Edaravone combined with oxiracetam can inhibit the neuronal apoptosis in CI rats by regulating the SIRT1/NF-κB signaling pathway, thereby exerting a neuroprotective effect.

An application research for near-surface repository of strontium-90 sorption kinetic model on mudrocks

In this study,90Sr was used as the test radionuclide to characterize the sorption kinetics and effects of initial 90Sr activity and remaining 90Sr in solid concentration were simulated for a near-surface repository. The study focused on the sorption characteristics of radionuclides in unsaturated groundwater environment (or vadose zone) is the important information for investigating the near-surface disposal of intermediate and low-level radioactive waste (ILLW). Moreover, the 90Sr sorption experiments reached equilibrium within 56 h, which fit to the first order sorption kinetic model, and the remaining 90Sr in mudrock samples showed obvious sorption equilibrium hysteresis, which fit to the second order sorption kinetic model. Before reaching the maximum sorption capacity, the sorption rate constant increases with 90Sr increasing; the distribution coefficient (Kd) of 56 h decreases with the remaining 90Sr decreasing. In addition, it showed that the slow sorption process dominated before the sorption reaches equilibrium. In fact, a reliable safety assessment methodology for on-going near-surface repository required a lot of the radionuclides parameters with local environment including the radionuclides sorption/desorption rate constant and maximum sorption capacity.

Lipopolysaccharide inhibits hypothalamic Agouti-related protein gene expression via activating mechanistic target of rapamycin signaling in chicks

Lipopolysaccharide (LPS) induces profound anorexia in birds. However, the neuronal regulatory network underlying LPS-provoked anorexia is unclear. To determine whether any cross talk occurs among hypothalamic mechanistic target of rapamycin (mTOR) and LPS in the regulation of appetite, we performed an intracerebroventricular injection of rapamycin (an mTOR inhibitor) on LPS-treated chicks. The results indicate that peripheral administrations of LPS decreased the agouti-related protein (AgRP) mRNA level, but increased the phosphorylated mTOR and nuclear factor-кB (NF-кB) protein level. Blocking mTOR significantly attenuated LPS-induced anorexia, AgRP suppression, and p-NF-кB increase. Thus, the results suggest that LPS causes anorexia via the mTOR-AgRP signaling pathway, and mTOR signaling is also associated with the regulation of LPS in p-NF-кB.

Evaluation of the siemens N Latex free light chain assay and comparison to Binding Site Freelite™ assay

Introduction/Objective

The International Myeloma Working Group (IMWG) guidelines include serum free light chain (sFLC) level and κ/λ ratio as excellent indicators of clonality. The Binding Site Freelite ™ was the first FDA approved assay for quantitative measurement of sFLC, the assay was based on a mixture of polyclonal antibodies directed against a variety of FLC epitopes. The Siemens N-Latex assay employs a probe mixture of mouse monoclonal antibodies. Both assays can be run on nephelometers. We assessed the analytical performance of the N-Latex assays and compared it with the Freelite™ assays.

Methods/Case Report

Analytical accuracy, precision, reproducibility and linearity were evaluated according to the regulatory standards. Method comparison was performed with 220 clinical samples for statistic correlation and clinical concordance analysis.

Results (if a Case Study enter NA)

The N-Latex FLC κ and λ assays had coefficient variation of 1-5% with-in run and 3-8% between run precision. Accuracy was verified using assayed controls in the duration of 21 days. Within analytical measuring range, almost perfect linearity was achieved for both κ and λ FLC assays. In comparison study to Freelite™ with 220 clinical samples, good agreement in classification was observed for κ, λ and κ/λ ratio (Cohen’s κ 0.73, 0.82 and 0.87). Pearson correlation analysis showed correlation coefficient value r &gt;0.90 for all the analytes.

Conclusion

The N-Latex FLC assay has good analytical performance, did not exhibit gross antigen excess and can be used in clinical practice. However, it showed markedly lower absolute values for κ/λ ratio compared with Freelite™. Our data demonstrated that although good clinical concordance between N-Latex and Freelite™ FLC assays was achieved, the absolute values from the two assay are not interchangeable. Further studies in modification of the assay-specific diagnostic (involved FLC/non-involved FLC) thresholds for smoldering multiple myeloma (SMM) and multiple myeloma (MM) are needed.

Diagnostic utility of flow cytometric immunophenotyping in cerebrospinal fluid specimen

Introduction/Objective

Flow cytometric immunophenotyping (FCI) of cerebrospinal fluids (CSF) has increasingly been used for diagnosing and monitoring hematologic malignancies. We reviewed CSF specimens sent for flow cytometry evaluation to identify the utility and limitations of FCI.

Methods/Case Report

We performed a retrospective review on CSF specimens received from July to October 2020. Samples were sent with requisition for unexplained neurologic signs or symptoms, to determine CNS involvement of neoplasm, or to stage a neoplasm. We reviewed specimen volume and cell count of flow cytometry samples and electronic medical records for possible diagnosis at time of specimen submission, final diagnosis, and concurrent cytology diagnosis.

Results (if a Case Study enter NA)

A total of 104 CSF samples from 59 patients were processed by the Flow Cytometry Laboratory during the review period. Of the 104 samples, 66% were from patients with a prior history of a hematologic malignancy, of which 20% had abnormal findings by FCI and cytomorphology. FCI was noncontributory for the cases in which patient did not have a previously diagnosed hematologic malignancy and underwent lumbar puncture for neurological abnormalities (n = 34). Concurrent cytology results were available in all but one case. Atypical or reactive findings by cytomorphology were seen in 21 cases (20%), for which flow cytometry studies showed no diagnostic immunophenotype in 12 cases. Abnormal FCI results occurred in 5 cases with history of hematologic malignancies, while concurrent cytomorphologic reports were negative.

Conclusion

Our findings suggest that CSF flow cytometry has low utility for screening patients with undifferentiated neurologic symptoms or without a prior hematologic malignancy history. Use as a screening tool for cases without clinical suspicion of hematolymphoid neoplasm is debatable. Flow cytometric and cytomorphologic analysis should be performed concurrently. While flow cytometric analysis in CSF may have higher sensitivity in hematologic malignancies, cytomorphology appears more favorable in identifying atypia or reactive conditions.

[Development of a fluorescent recombinase-aided isothermal amplification-based nucleic acid assay for detection of Leishmania]

OBJECTIVE

To develop a fluorescent recombinase-aided isothermal amplification (RAA)-based nucleic acid assay for detection of Leshimania.

METHODS

Specific primers and probes were designed targeting Leishmania internal transcribed spacer 1 (ITS1) gene for RAA assay, and a fluorescent RAA assay was developed for detection of Leishmania following screening of primer pairs and optimization of primer and probe concentrations. The sensitivity of RAA assay for detection of Leishmania was evaluated using recombinant plasmid containing Leishmania ITS1 gene sequences at different copies and Leshimania genomic DNA at different concentrations as templates, and the specificity of RAA assay for detection of Leishmania was evaluated using the genomic DNA of transfusion-transmitted parasites, including Babesia microti, Toxoplasma gondii, Plamodium vivax, P. ovale, P. falciparum, P. malariae, L. donovani and L. infantum.

RESULTS

After the optimal primer pair was screened from 9 pairs of primer combinations, the final primer and probe concentrations were optimized as 0.3 μmol/L and 0.08 μmol/L, respectively. Nucleic acid detection of Leishmania was completed by the fluorescent RAA assay at an isothermal temperature of 39 °C within 20 min. Remarkable florescent signals were seen within 5 min following RAA detection of genomic DNA of L. donovani and L. infantum, and no cross-reactions were observed with B. microti, T. gondii, P. vivax, P. ovale, P. falciparum or P. malariae. The lowest limitation of detection of the fluorescent RAA assay was 10 copies/μL recombinant plasmid containing Leishmania ITS1 gene sequences and 1 fg/μL Leishmania genomic DNA.

CONCLUSIONS

A rapid, simple, sensitive and specific fluorescent RAA assay is successfully developed for detection of L. donovani and L. infantum, which is effective for field screening of leishmaniasis.

HSP90 pathway in intermediate mononuclear cells causes plaque erosion via induction of neutrophil hyper-responsiveness

Aim

To explore the function(s) of HSP90 in intermediate monocyte-mediated plaque erosion.

Materials and methods

We used single-cell RNA sequencing to map cardiac immune response composition in patients with plaque rupture and plaque erosion. By focusing our analyses on CD14 positive monocytes, we obtained a higher resolution identification of the immune cell subsets in patients experiencing plaque erosion and rupture. We interpreted our findings with analyses using gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases and by performing receiver operating characteristic (ROC) curve analysis.

Results

Single-cell sequencing analysis of mononuclear cells in the peripheral blood of five ACS patients experiencing plaque erosion and rupture confirmed that CD14 positive monocytes were the main immune cells leading to ACS. Interestingly, our results suggested a significant increase in the proportion of atypical monocytes (C4 subsets) in patients with plaque rupture, which was a novel finding. This increase may be caused by increased migration of atypical monocytes into a plaque during plaque rupture. We found that intermediate monocyte activation was most obvious in patients with plaque erosion (C1, C10, and C11), and the proportion of C1 subgroup monocytes (FCGR3B/CMTM2 double strong positive; subsequently defined as intermediate monocytes) was very high. To further explore the role of C1 subgroup intermediate monocytes in plaque erosion, GO and KEGG pathway analyses were performed. GO analysis indicated that C1 subgroup intermediate monocytes are highly involved in neutrophil metabolism. Because neutrophils are the main effector cells that induce plaque erosion, we reasonably infer that intermediate monocytes can induce plaque erosion. KEGG pathway analysis indicated that all subtypes of HSP90 were highly expressed in C1 subgroup intermediate monocytes. We thus collected peripheral blood from ACS patients with plaque rupture (n=150) and plaque erosion (n=150) for mononuclear cell transcriptomics and intracellular proteomics analysis. ROC curve analysis demonstrated that the area under the curve for HSP90-based prediction was 0.86, indicating that HSP90 could be used to predict if patients would experience plaque erosion.

Conclusion

Activation of intermediate mononuclear HSP90 expression may be the crucial event that induces neutrophil hyper-responsiveness and leads to plaque erosion.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): China,Shanghai Science and Technology Commission

Effects of egg storage duration on egg quality, metabolic rate, hematological parameters during embryonic and post-hatch development of guinea fowl broilers

Considering the value of guinea fowl keets, successful incubation of eggs is particularly desirable in this poultry species. This study evaluated the effect of egg storage duration on egg quality, heat production, hematological parameters during embryonic development and post hatch performance of guinea fowl broilers. A total of 800 hatching eggs of guinea fowl were used for this study. Before incubation, 12 eggs per treatment were used to analyse egg quality. Then, eggs were numbered, weighed, and assigned to 2 treatment groups of 400 eggs each according to storage duration of 5, and 10 d at a temperature of 18°C. The eggs were set for incubation at 37.7°C and 55% relative humidity for 28 d in a forced-draft incubator. To determine heat production as a measure of metabolism, 60 eggs in each replicate were transferred to respiratory cages post hatch two 12 wk old guinea fowl were also used to determine heat production. CO₂ and O₂ were recorded to calculate heat production at internal pipping, hatch and at 12 wk of age. The hatched keets were reared for 12 wk and data were collected on feed intake, body weight and feed conversion ratio. Blood samples were collected at hatch and at 12 wk of age from 24 guinea fowls per treatment to analyze haematological parameters. The results showed that embryos and guinea fowls at 12 wks of age from eggs stored for 5 d had higher (P ˂ 0.05) heat production and body weights. However, a significant higher (P ˂ 0.05) level of basophile, eosinophils, and lymphocytes was observed in guinea fowls from 10 d storage egg. It was concluded that extended duration of egg storage negatively influenced the metabolic rate of embryos. It also impacted hematological parameters which may suggest influence on immune response during embryonic and post-hatch growth.

[The distribution of peripheral anterior synechiae in patients with primary angle-closure glaucoma]

Objective: To describe the distribution and characteristics of peripheral anterior synechiae (PAS) in patients with primary angle-closure glaucoma (PACG). Methods: Retrospective case study. A total of 285 PACG patients (406 eyes) diagnosed in the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University from January 2017 to August 2019 were included. They were 102 males and 183 females, with a median age of 67 years old (range, 21 to 95 years old). The PAS range was detected by gonioscopy examination, and the frequency distribution of PAS at 12 clock points was counted by clockwise. The PAS distribution at the middle point of PAS with continuous distribution and ≤6 clock points was assessed. Results: In all cases, PAS of the right eye was concentrated at 11:00 to 4:00 regions [range, 62.0% (129/208) to 78.8% (164/208)]. PAS of the left eye was concentrated at 7:00 to 1:00 regions [range, 50.0% (99/198) to 75.8% (150/198)]. When the PAS range of the atrial angle was ≤6 clock regions, it was mainly at 12:00 to 3:00 [range, 58.3% (74/127) to 67.7% (86/127)] in the right eye and at 10:00 to 12:00 [range, 54.8% (68/124) to 66.1% (82/124)] in the left eye. Among 121 cases (242 eyes) with both eyes involved, the PAS region was at 11:00 to 5:00 [range, 52.1% (63/121) to 79.3% (96/121)] in the right eye and at 8:00 to 1:00 [range, 50.4% (61/121) to 76.9% (93/121)] in the left eye. When the PAS range of the atrial angle was ≤6 clock regions, it was mainly at 12:00 to 4:00 [range, 53.2% (41/77) to 71.4% (55/77)] in the right eye and at 10:00 to 12:00 [range, 50.6% (39/77) to 64.9% (50/77)] in the left eye. In all cases, there were 171 cases of right eyes and 175 cases of left eyes with continuous angle PAS. The central PAS clock position of the right eye was mainly at 11:00 to 3:00 [range, 15.2% (26/171) to 24.0% (41/171)], and that of the left eye was mainly at 8:00 to 12:00 [range, 15.4% (27/175) to 20.6% (36/175)]. Among cases with both eyes involved, there were 98 cases of right eyes and 104 cases of left eyes with continuous angle PAS. The clock distribution of the middle position of the right eye angle PAS was concentrated at 11:00 to 3:00 [range, 17.3% (17/98) to 26.5% (26/98)], and that of the left eye was concentrated at 8:00 to 12:00 [range, 13.5% (14/104) to 20.2% (21/104)]. Conclusions: The PAS of PACG patients is mainly located in the upper and nasal sides, and the closer to the temporal side, the smaller the PAS frequency, showing a gradual downward trend. The PAS distribution of binocular angles is of obvious mirror symmetry. (Chin J Ophthalmol, 2021, 57: 666-671).

[Prevalence and influencing factors of deciduous dental caries among preschool children in Qingdao city in 2019]

In 2019, the rate of primary tooth caries rate among 1 598 preschool children in Shinan District and Shibei District of Qingdao was 59.4%. The multivariate logistic regression model showed that compared with children ≤ 2 years old with history of iron deficiency anemia (IDA), suffering IDA, breastfeeding to 2 years old and no tooth melanin, children ≤ 2 years old without history of IDA, not suffering IDA, breastfeeding to less than 2 years old and heavy tooth melanin had a lower risk of primary tooth caries, with OR (95%CI) values about 0.328 (0.197-0.549), 0.354 (0.208-0.603), 0.636 (0.437-0.926) and 0.301 (0.143-0.635), respectively.