Substrate stiffness promotes dentinogenesis via LAMB1-FAK-MEK1/2 signaling axis.

OBJECTIVES: In vivo, the principal function of mechanosensitive odontoblasts is to synthesize and secrete the matrix which then calcifies and forms reactive dentin after exposure to appropriate stimuli. This study aims to develop the influence of mechanical factors on dentinogenesis based on odontoblasts, which contribute to reparative dentin formation. METHODS: We fabricated polydimethylsiloxane with different stiffnesses and seeded 17IIA11 odontoblast-like cells on the substrates in different stiffnesses. Cell morphology was detected by scanning electron microscope, and the mineralization phenotype was detected by alkaline phosphatase staining and alizarin red staining, while expression levels of dentinogenesis-related genes (including Runx2, Osx, and Alp) were assayed by qPCR. To explore mechanism, protein distribution and expression levels were detected by immunofluorescent staining, Western blotting, and immunoprecipitation. RESULTS: In our results, during dentinogenesis, 17IIA11 odontoblast-like cells appeared better extension on stiffer substrates. The binding between LAMB1 and FAK contributed to converting mechanical stimuli into biochemical signaling, thereby controlling mitogen-activated protein kinase kinase 1/2 activity in stiffness-driven dentinogenesis. CONCLUSION: The present study suggests odontoblast behaviors can be directly regulated by mechanical factors at cell-material interfaces, which offers fundamental mechanism in remodeling cell microenvironment, thereby contributing to physiological phenomena explanation and tissue engineering progress.

Microbiological profile of distinct virulence of Nocardia cyriacigeorgica strains in vivo and in vitro.

There are significant differences between different Nocardia species regarding geographical distribution, biochemical features, phenotypic characterization, and drug sensitivity. In this study, we explored the differences in virulence and pathogenic mechanisms of two Nocardia cyriacigeorgica strains. We examined the difference in virulence between N. cyriacigeorgica ATCC14759 and N. cyriacigeorgica GUH-2 by measuring cytotoxicity, animal survival after infection, the ability of host cell invasion, and viability in host cells. Western blotting was used to compare the differences in activation of MAPKs, including p38, ERK, and JNK, the NF-κB signaling pathway, and the PI3K/Akt signaling pathway in A549 and RAW264.7 cells. We measured the difference in stimulatory effects on production of the cytokines IL-6, IL-10, and TNF-α by ELISA. We found that N. cyriacigeorgica ATCC14759 causes higher cytotoxicity in cultured cells and higher lethality in mice, and exhibits superior invasion ability and viability in host cells compared with N. cyriacigeorgica GUH-2. Moreover, these two strains show marked differences in activation of the expression of cytokines and signaling pathways. N. cyriacigeorgica ATCC14759 is more virulent than N. cyriacigeorgica GUH-2. Furthermore, there is a significant difference in pathogenesis between the two strains. Our results provide a theoretical basis for the prevention and treatment of Nocardia infection.

Mediating effect of mindfulness level on the relationship between marital quality and postpartum depression among primiparas.

BACKGROUND: Postpartum depression refers to a depressive episode or depressive symptoms up to 12 mo after delivery. Trait mindfulness has presented a protective factor for postpartum depressive symptoms and proved efficient in improving relationship satisfaction among couples. AIM: To investigate the correlations among mindfulness, marital quality, anxiety, and depression in a large city in western China during the post-corona virus infectious disease-2019 era and determine whether trait mindfulness mediates the relationship between marital quality and postpartum anxiety and depression among primiparas. METHODS: A cross-sectional study was conducted. The self-administered questionnaire was submitted online through smartphones. The levels of mindfulness, anxiety, depression, and marital quality were respectively investigated by the mindful attention awareness scale (MAAS), the self-rating anxiety scale (SAS), the self-rating depression scale (SDS), and the marriage perception scale (MPS) in these enrolled Han and Tujia primiparas. RESULTS: No statistical significance was observed in the prevalence of postpartum anxiety and depression, nor scores of MAAS and MPS-Total in different regions or ethnicities (P > 0.05). However, MPS-Marital interaction (P < 0.05), MPS-Family relationship (MPS-FR) (P < 0.01), and MPS-Marital conflict (MPS-MC) (P < 0.01) scores of urban primiparas were higher than those of rural primiparas. The MPS-MC score of Han primiparas was higher than that of Tujia primiparas (P < 0.05). Negative correlations were observed between MAAS and SAS (r = -0.457, P < 0.01), and MAAS and SDS (r = -0.439, P < 0.01). SAS has revealed a highly positive correlation with SDS (r = 0.720, P < 0.01) and a weak negative correlation with MPS (r = -0.200, P < 0.05). Besides, a weak negative correlation was observed between MAAS and MPS-MC (r = -0.184, P < 0.05), and a weak positive correlation was noticed between SAS and MPS-MC (r = -0.225, P < 0.01). Mediation analysis demonstrated a full mediation effect of mindfulness level on the relationship between MPS-FR and postpartum anxiety (P < 0.05, 95%CI: -0.384 to 0.033), MPS-MC and postpartum anxiety (P < 0.01, 95%CI: 0.027-0.193), MPS-FR and postpartum depression (P < 0.05, 95%CI: -0.365 to 0.031), and MPS-MC and postpartum depression (P < 0.01, 95%CI: 0.022-0.206). CONCLUSION: Mindfulness demonstrates negative correlations with marital conflict, postpartum anxiety and depression, and it may have cross-ethnic and trans-regional characteristics. Although the mindfulness levels have revealed no significant mediating effect between the total score of marital quality and postpartum depression in this study, it demonstrates a full mediation effect on the relationships between family relationships, marital conflict, and postpartum anxiety and depression.

Investigation of Genetic Relatedness of Brucella Strains in Countries Along the Silk Road.

In this study, MLVA (multiple-locus variable-number tandem repeat analysis) genotype data of Brucella strains from 11 countries along the Silk Road were downloaded from the MLVAbank. MLVA data of strains were applied to the constructed Minimum Spanning Tree to explore the species/biovars distribution, geographic origins, and genetic relationships of the strains analyzed. Moreover, whole-genome sequencing-single-nucleotide polymorphism (WGS-SNP) phylogenetic analysis of the genome of Brucella melitensis strains from GenBank was performed to discriminate the relatedness of strains further and investigate the transmission pattern of B. melitensis brucellosis. A total of 1,503 Brucella strains were analyzed in this study: 431 Brucella abortus strains (29.8%), 1,009 B. melitensis strains (65.7%), and 63 Brucella suis strains (4.5%). B. melitensis biovar 3 was the dominant species and was shown to be widespread in all of the examined regions, suggesting that the prevention and surveillance of the B. melitensis population are a main challenge in these countries. A wide host spectrum was observed for this Brucella population; many animal reservoirs are a potential reason for the continuous brucellosis circulation in these countries. Although the B. abortus strains from the examined regions had common geographic origins, only a few shared genotypes were observed in different countries. These data revealed that the majority of B. abortus strains were spreading within the national borders. However, the B. melitensis strains from Italy originated from a Western Mediterranean lineage; strains from the other 10 countries originated from Eastern Mediterranean lineage, and this lineage was shared by strains from three to nine different countries, suggesting that the introduction and reintroduction of the disease in the 10 countries might have occurred in the past. Furthermore, the most shared MLVA-16 genotypes were formed in the B. melitensis strains from China, Kazakhstan, and Turkey, suggesting that the introduction and trade in sheep and goats have occurred frequently in these countries. WGS-SNP analysis showed that the B. melitensis in this study originated from the Malta (Italy) region. According to their territorial affiliation between four clade strains from these countries in genotype B, the absence of a clear differentiation suggests that strains continuously expand and spread in countries along with Silk Road. Active exchange and trade of animals (sheep and goats) among these countries are reasonable explanations. B. suis strains from different nations showed unique geographic origins and epidemiological characteristics. Therefore, there is an urgent need for the control of transfer and trade of infected sheep (goats) in countries along the Silk Road, namely, the strengthening of the entry-exit quarantine of sheep and goats and improvements in the diagnosis of animal brucellosis.

Epidemiologically characteristics of human brucellosis and antimicrobial susceptibility pattern of Brucella melitensis in Hinggan League of the Inner Mongolia Autonomous Region, China.

BACKGROUND: Hinggan League is located in the Northeast of the Inner Mongolia Autonomous Region, the historically endemic area of animal and human brucellosis. In this study, the epidemiological characteristics of human brucellosis were analyzed, and the genotypic profile and antimicrobial susceptibilities of Brucella melitensis strains isolated from humans in Hinggan League were investigated. METHODS: The epidemic characteristics were described using case number, constituent ratio, and rate. The 418 human blood samples were collected and tested by bacteriology, and suspect colonies were isolated and identified by conventional biotyping assays, the VITEK 2.0 microbial identification system, and AMOS (Brucella abortus, B. melitensis, B. ovis, and B. suis)-PCR. Subsequently, all strains were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) assays, and the antimicrobial susceptibility pattern of Brucella strains against the 10 most commonly used antibiotics was determined by microdilution method. RESULTS: A total of 22 848 cases of human brucellosis were reported from 2004 to 2019, with an annual average incidence of 87.2/100 000. The incidence rates in developed areas of animal husbandry (Horqin Youyi Qianqi [161.2/100 000] and Horqin Youyi Zhongqi [112.1/100 000]) were significantly higher than those in forest areas (Arxan [19.2/100 000]) (χ2 = 32.561, P < 0.001). In addition, peak morbidity occurred during May-August, accounting for 72.6% (16582/22 848) of cases. The highest number of cases occurred in the 40+ age group, accounting for 44.4% (10 137/22484) of cases, and morbidity in males was significantly higher than that in females in all age groups (χ2 = 299.97, P < 0.001), the most common occupation was farmers. A total of 54 B. melitensis strains were divided into 37 genotypes (GT1-37) with 80-100% genetic similarity. All 25 strains were sensitive to seven tested antibiotics, phenotypic resistance to cotrimoxazole and azithromycin was observed in 5 (20%) and 25 (100%) of the isolates, respectively. CONCLUSIONS: Human brucellosis exhibited a significant increasing trend and B. melitensis is the main pathogen responsible for human brucellosis in this region. Improved surveillance of infected animals (sheep) and limiting their transfer and trade are optional strategies for decreasing the incidence of this disease.