Downregulation of microRNA-448 inhibits IL-1ß-induced cartilage degradation in human chondrocytes via upregulation of matrilin-3.

BACKGROUND: Osteoarthritis is characterized by the continuous degradation of the articular cartilage. The microRNA miR-448 has been found to be broadly involved in cellular processes, including proliferation, apoptosis, invasion and EMT. While aberrant expression of miR-448 has been found in multiple cancers, its level in osteoarthritis cartilage and its role in the progression of this disease are still unknown. Here, we examined the functional roles of miR-448 and its expression in osteoarthritis tissues, including IL-1ß-stimulated osteoarthritis chondrocytes. METHODS: Chondrocytes were isolated from human articular cartilage and stimulated with IL-1ß. The expression levels of miR-448 in the cartilage and chondrocytes were both determined. After transfection with an miR-448 mimic or inhibitor, the mRNA levels of aggrecan, type II collagen and MMP-13 were determined. Luciferase reporter assay, qRT-PCR and western blot were performed to explore whether matrilin-3 was a target of miR-448. Furthermore, we co-transfected chondrocytes with miR-448 inhibitor and siRNA for matrilin-3 and then stimulated them with IL-1ß to determine whether miR-448-mediated IL-1ß-induced cartilage matrix degradation resulted from directly targeting matrilin-3. RESULTS: The level of miR-448 was significantly higher and matrilin-3 expression was significantly lower in osteoarthritis cartilage and IL-1ß-induced chondrocytes than in normal tissues and cells. Furthermore, matrilin-3 expression was reduced by miR-448 overexpression. MiR-448 downregulation significantly alleviated the IL-1ß-induced downregulation of aggrecan and type II collagen expression, and upregulation of MMP-13 expression. MiR-448 overexpression had the opposite effects. Knockdown of matrilin-3 reversed the effects of the miR-448 inhibitor on the expressions of aggrecan, type II collagen and MMP-13. CONCLUSION: The findings showed that miR-448 contributed to the progression of osteoarthritis by directly targeting matrilin-3. This indicates that it has potential as a therapeutic target for the treatment of osteoarthritis.

Potential immune evasion of the severe acute respiratory syndrome coronavirus 2 Omicron variants.

Coronavirus disease 2019 (COVID-19), which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic. The Omicron variant (B.1.1.529) was first discovered in November 2021 in specimens collected from Botswana, South Africa. Omicron has become the dominant variant worldwide, and several sublineages or subvariants have been identified recently. Compared to those of other mutants, the Omicron variant has the most highly expressed amino acid mutations, with almost 60 mutations throughout the genome, most of which are in the spike (S) protein, especially in the receptor-binding domain (RBD). These mutations increase the binding affinity of Omicron variants for the ACE2 receptor, and Omicron variants may also lead to immune escape. Despite causing milder symptoms, epidemiological evidence suggests that Omicron variants have exceptionally higher transmissibility, higher rates of reinfection and greater spread than the prototype strain as well as other preceding variants. Additionally, overwhelming amounts of data suggest that the levels of specific neutralization antibodies against Omicron variants decrease in most vaccinated populations, although CD4+ and CD8+ T-cell responses are maintained. Therefore, the mechanisms underlying Omicron variant evasion are still unclear. In this review, we surveyed the current epidemic status and potential immune escape mechanisms of Omicron variants. Especially, we focused on the potential roles of viral epitope mutations, antigenic drift, hybrid immunity, and "original antigenic sin" in mediating immune evasion. These insights might supply more valuable concise information for us to understand the spreading of Omicron variants.

MS4A6D Promotes carrageenan-induced footpad swelling in mice through enhancing macrophages-derived inflammation.

Our previous work has demonstrated that the tetraspan MS4A6D interacts with MHC-II to be a complex that promotes macrophage activation (Mol Immunol. 2023; 160: 121-132), however, the exact role of MS4A6D in controlling macrophage-derived inflammation is still poorly understood. Here, we showed that Ms4a6d-deficient (Ms4a6d-/-) mice manifested a lower level of footpad swelling induced by subcutaneous injection of 100 µL of 1% Carrageenan (CGN, w/v) plus CaCl2 (50 mM), a phenomenon that is similar to Nlrp3-/-, Casp-1-/-, and Ilr1-/- mice. Mechanistically, F4/80+ macrophages infiltrated in the footpad tissues of the Ms4A6d-/- mice was significantly lower than that of the WT littermates, leading to dramatically lower levels of proIL-1ß in vivo. Moreover, macrophages from Ms4a6d-/- mice also showed a dramatical reduction of Il-1ß secretion following NLRP3 inflammsome activation in vitro. Interestingly, both Ms4a6dC237G mutant (Interruption of MS4A6D homodimerization) and Ms4a6dY241G mutant (deletion of heITAM motif) mice also significantly inhibited CGN-induced footpad swelling due to lower levels of Il-1ß secretion in vivo. Collectively, MS4A6D aggravates CGN-induced footpad swelling in mice by enhancing NLRP3 inflammasome in macrophages and inducing the release of IL-1ß, indicating that MS4A6D promotes the progression of acute inflammation.

High expression of ezrin predicts poor prognosis in uterine cervical cancer.

BACKGROUND: Ezrin, a member of the ezrin/radixin/moesin (ERM) protein family, plays a pivotal role in tumor invasion and metastasis. This study is aimed to investigate the clinicopathological significance of upregulated ezrin protein expression in uterine cervical cancers. METHODS: Immunohistochemical staining of ezrin protein was performed on uterine cervical cancer specimens from 235 patients. For comparison, 239 cases of cervical intraepithelial neoplasia (CIN), 17 cases of cervical glandular intraepithelial neoplasia (CGIN) and 52 normal cervix samples were also included. qRT-PCR was performed on fresh tissues to detect ezrin mRNA expression levels. HPV infection statuses were genotyped by oligonucleotide microarray, and 10-year survival rates were calculated using the Kaplan-Meier method for 109 cervical cancer patients. RESULTS: Apical membranous distribution of ezrin protein was only observed in normal cervical glands, while perinuclear staining was only observed in cervical cancers. Strong cytoplasmic and diffuse localization of ezrin were frequently seen in the cervical cancers compared with the normal counterparts. Furthermore, this strongly positive ezrin expression was significantly higher in cervical cancers than in CIN, CGIN, and normal cervical epithelia. Ezrin overexpression was closely related with poor differentiation, late stage, and lymph node metastasis. Additionally, ezrin overexpression was associated with lower 10-year survival rate for patients with early stage cervical cancer, but not for patients with advanced stage. CONCLUSIONS: Aberrant localization and overexpression of ezrin might be an independent effective biomarker for prognostic evaluation of cervical cancers.

HPD overexpression predicts poor prognosis in breast cancer.

BACKGROUND: The enzyme, 4-hydroxyphenylpyruvate dioxygenase (HPD), is critical to tyrosine metabolism; its deficiency can cause tyrosinemia. However, its precise contribution to tumorigenesis is unclear. Here, we investigated the correlation between HPD expression and prognosis in patients with breast cancer. METHODS: 145 breast cancer specimens were selected to analyze HPD protein expression by immunohistochemistry and evaluate its relationship to patients' clinicopathological features. HPD localization was confirmed in MCF-7 and MDA-MB-231 breast cancer cells, using immunofluorescence staining. The expression of HPD protein was detected in breast cancer and cancer-adjacent normal tissues using Western blot analysis. Survival rates were calculated by the Kaplan-Meier method. RESULTS: We found that HPD protein was mainly located in the cytoplasm/nucleoli/perinucleus in breast cancer cells, as shown by immunofluorescence staining in MCF-7 and MDA-MB-231 cells, and immunohistochemistry in breast cancer and adjacent normal tissues (HPD protein expression-breast cancer: 46.9% [68/145], ductal carcinoma in situ [DCIS]: 22.6% [12/53], and normal tissues: only 4.8% [2/42]). Similarly, the Western blot results further confirmed the increased expression of HPD in breast cancer compared with cancer-adjacent normal tissues (P < 0.05). HPD expression level was positively correlated with histological grade and clinical stage, and inversely correlated with 10-year overall survival (OS) rates, in patients with breast cancer. Among patients with breast cancer, those with high HPD expression had worse OS rates than those with low HPD expression. Additionally, when patients were subgrouped by disease stage or grade, those with high HPD expression had worse OS rates than those with low HPD expression for each respective stage or grade. CONCLUSIONS: Our findings indicate that HPD may be a useful prognostic predictor, and a potential therapeutic target for patients with breast cancer.

Clinical and Radiographic Outcomes of Unipolar and Bipolar Radial Head Prosthesis in Patients with Radial Head Fracture: A Systemic Review and Meta-Analysis.

PURPOSE: To compare clinical outcomes of unipolar and bipolar radial head prosthesis in the treatment of patients with radial head fracture. MATERIALS AND METHODS: Medline, Cochrane, EMBASE, Google Scholar databases were searched until April 18, 2016 using the following search terms: radial head fracture, elbow fracture, radial head arthroplasty, implants, prosthesis, unipolar, bipolar, cemented, and press-fit. Randomized controlled trials, retrospective, and cohort studies were included. RESULTS: The Mayo elbow performance score (MEPS), disabilities of the arm, shoulder, and hand (DASH) score, radiologic assessment, ROM, and grip strength following elbow replacement were similar between prosthetic devices. The pooled mean excellent/good ranking of MEPS was 0.78 for unipolar and 0.73 for bipolar radial head arthroplasty, and the pooled mean MEPS was 86.9 and 79.9, respectively. DASH scores for unipolar and bipolar prosthesis were 19.0 and 16.3, respectively. Range of motion outcomes were similar between groups, with both groups have comparable risk of flexion arc, flexion, extension deficit, rotation arc, pronation, and supination (p values <0.001 for both unipolar and bipolar prosthesis). However, bipolar radial head prosthesis was associated with an increased chance of heterotopic ossification and lucency (p values ≤0.049) while unipolar prosthesis was not (p values ≥0.088). Both groups had risk for development of capitellar osteopenia or erosion/wear (p values ≤0.039). CONCLUSION: Unipolar and bipolar radial head prostheses were similar with respect to clinical outcomes. Additional comparative studies are necessary to further compare different radial head prostheses used to treat radial head fracture.

The tissue distribution and significance of B7-H4 in laryngeal carcinoma.

The costimulatory signals CD28 and B7 have been shown to control tumor invasion and metastasis by regulating T cell activation, whereas the distribution characteristics of B7-associated proteins in laryngeal carcinoma (LC) tissue are still unclear. Here, the expression of members of the B7 superfamily, including B7-H1 (PD-L1), B7-DC (PD-L2) and B7-H4, in fifty-two LC samples was determined by immunohistochemistry, and the relationship between B7-H4 and epithelial-mesenchymal transition (EMT)-associated markers was further assessed by immunofluorescence double staining. Furthermore, the human LC cell lines, Hep-2 and TU212 cells, were further transfected to overexpress B7-H4, and cell invasion and metastasis were analyzed. The results showed that B7-H1, B7-DC and B7-H4 were expressed in the tumor cells, and their expression was restricted to the cell membrane and the cytoplasm. The positive rates of these molecules in the tumor tissues were 57.7% (30/52), 32.7% (17/52) and 34.6% (18/52), respectively. Interestingly, double immunofluorescence staining showed that B7-H4 is coexpression with EMT-related markers, including p-Smad2/3, Snail and Vimentin, in carcinoma cells. Moreover, overexpression of B7-H4 in Hep-2 cells promotes the expression of pSmad2/3 and Snail by activating AKT-STAT3 signaling. Transwell and wound-healing assays demonstrated that B7-H4 enhanced both Hep-2 and TU212 cell invasion and metastasis. Our results suggest that B7-H4 transmits feedback signaling to tumor cells and promotes invasion and metastasis by promoting EMT progression. Therefore, blocking B7-H4 signaling might be a novel treatment strategy for LC.

High expression of DEK predicts poor prognosis of gastric adenocarcinoma.

BACKGROUND: DEK, as an oncoprotein, plays an important role in cancer development and progression. This study aimed to investigate the clinicopathological significance of DEK overexpression in patients with gastric cancer. MATERIALS AND METHODS: The expression of DEK protein was evaluated by immunohistochemical (IHC) staining of 172 gastric cancer samples with complete clinicopathological features, and the correlation between DEK expression and clinicopathological features was examined. Survival rates were also calculated using the Kaplan-Meier method in gastric cancer patients with complete survival data. RESULTS: DEK protein showed a strictly nuclear staining pattern in gastric cancers with IHC and immunofluorescence. The strongly positive rate of DEK protein was 60.5% (104/172) in gastric cancers, which was significantly higher than that in either gastric dysplasia (19.4%, 7/36) or adjacent normal mucosa (0%, 0/27). DEK expression in gastric cancer correlated to tumor size, differentiation, clinical stage, disease-free survival, and overall survival rates. Further analysis showed that patients with early-stage gastric cancer and high DEK expression had shorter disease-free survival and overall survival duration than those with low DEK expression. CONCLUSION: High level of DEK protein expression predicts the poor prognosis of patients with gastric cancer. DEK expression might be potentially used as an independent effective biomarker for prognostic evaluation of gastric cancers. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5050145571193097.

TIM-3 expression in human osteosarcoma: Correlation with the expression of epithelial-mesenchymal transition-specific biomarkers.

Signals from the T cell Ig- and mucin-domain-containing molecules (TIMs) have been demonstrated to be actively involved in regulating the progression of carcinomas. However, the expression and distribution of these molecules in osteosarcoma, the most common primary bone malignancy with poor prognosis, have not been investigated. In this study, the expression of TIMs was examined in nine invasive human osteosarcomas using immunohistochemistry, and the phenotypes were detected by dual immunofluorescence staining. Using immunohistochemistry, it was observed that only TIM-3, rather than TIM-1 or TIM-4, was expressed in these tumor specimens, where it was localized in the cytoplasm and plasma membrane of tumor cells. Dual immunofluorescence staining revealed that the expression of TIM-3 was observed in all cell types investigated, including CD68+ macrophages, CD31+ endothelial cells, CK-18+ epithelial cells and PCNA+ tumor cells. Notably, in sarcoma cells, TIM-3 was co-expressed with certain biomarkers of epithelial-mesenchymal transition (EMT), including vimentin, Slug, Snail and Smad. These combined results suggest that TIM-3 triggers tumor cells to acquire features of aggressive EMT and may be involved in the pathogenesis of this malignancy.

The expression and distribution of immunomodulatory proteins B7-H1, B7-DC, B7-H3, and B7-H4 in rheumatoid synovium.

CD28/B7 signals have been shown to have the capacity to regulate T cell activation and participate in regulating the development of rheumatoid arthritis (RA). However, the expression and anatomical distribution of some members of the B7 superfamily including B7-H1, B7-DC, B7-H3 and B7-H4 in RA synovium is still unclear. We analyzed the expression of these molecules in synovial tissues from RA patients. Immunohistochemistry showed that all of these molecules were observed in synovium. On the cellular level, all of them were found on cell membrane and in cytoplasma. The expression of B7-DC and B7-H3 was major on capillaries, synovicytes and infiltrated inflammatory cells in the lining layer, while B7-H1 and B7-H4 were detected in some inflammatory cells residing in the sublining and lining layer. Fluorescent dual staining indicated that all these molecules were principally associated with CD31(+) endothelial cells and CD68(+) macrophages. In addition, B7-H1 and B7-H3 were also observed on CD3(+) T cells (including CD4(+) and CD8(+) T cells). Interestingly, B7-H1/B7-H4, B7-H3/B7-DC were co-expressed on the same cells. The characteristic expression and distribution of these molecules in synovium indicated that they probably have different effects during the progress of RA, and a clear understanding of their functional roles may further elucidate the pathogenesis of this disease.

The expression and anatomical distribution of BTLA and its ligand HVEM in rheumatoid synovium.

Co-inhibitory signaling from B and T lymphocyte attenuator (BTLA) can suppress lymphocyte activation and maintain peripheral tolerance. However, the expression and anatomical distribution of BTLA and its ligand, herpesvirus entry mediator (HVEM), in rheumatoid arthritis (RA) synovium have not been reported. In this study, we analyzed the expression of HVEM and BTLA in RA synovium by immunohistochemistry, and our results showed that both factors were observed in all four cases of RA samples. At the cellular level, both HVEM and BTLA were found on the cell membrane and in the cytoplasm. Fluorescence dual staining demonstrated that HVEM was chiefly on CD3(+) T cells, CD68(+) macrophages, and to a lesser extent was found on CD31(+) endothelial cells. Similarly, the expression of BTLA was observed on infiltrated CD3(+) T cells and CD68(+) macrophages. The co-expression of HVEM and BTLA with some members of the B7 family in these sections was also analyzed, and the results showed that HVEM antigen was also found on B7-H3(+) capillaries, while it was absent on B7-H1(+), B7-DC(+), B7-H4(+), and Z39Ig(+) cells. Interestingly, BTLA was observed on B7-H1(+), B7-H4(+), and HVEM(+) cells in the synovium. The characteristic expression and distribution of BTLA/HVEM in the synovium indicated that their signaling probably affects the pathogenesis of RA, and a clear understanding of their functional roles may further elucidate the pathogenesis of this disease.

[Expression of the costimulatory molecule BTLA in synovial tissues from rheumatoid arthritis patients].

AIM: To detect the expression of B and T lymphocyte attenuator (BTLA) antigen in synovial tissues from rheumatoid arthritis (RA) patients. METHODS: The expression and distribution of BTLA antigen was analyzed by immunohistochemistry. Moreover, fluorescence double-staining was used to further identify the cell types expressing BTLA. RESULTS: Immunohistochemical analysis revealed that a great deal of BTLA positive cells were found in RA synovium, and fluorescence double-staining further demonstrated that BTLA positive cells were CD3(+); T cells, CD68(+); macrophages, and occasionally CD31(+); endothelial cells. In contrast to other members of B7 superfamily, the expression of BTLA was also found on B7-H1(+);, B7-H4(+); and HVEM(+); cells, while it was absence on B7-DC(+); cells as well as B7-H3(+); cells. CONCLUSION: The expression of BTLA has been observed on the surface of several kinds of cells within synovial tissues of RA patients, which indicates this signal might be involved in the regulation of local T cell activation and the pathogenesis of RA.