Meniscus heterogeneity and 3D-printed strategies for engineering anisotropic meniscus

The meniscus is a fibrocartilaginous tissue of the knee joint that plays an important role in load transmission, shock absorption, joint stability maintenance, and contact stress reduction. Mild meniscal injuries can be treated with simple sutures, whereas severe injuries inevitably require meniscectomy. Meniscectomy destroys the mechanical microenvironment of the knee joint, leading to cartilage degeneration and osteoarthritis. Tissue engineering techniques, as a strategy with diverse sources and customizable and adjustable mechanical and biological properties, have emerged as promising approaches for the treatment of meniscal injuries and are represented by 3D printing. Notably, the heterogeneity of the meniscus, including its anatomical structure, cell phenotype, extracellular matrix, and biomechanical properties, is crucial for its normal function. Therefore, the construction of heterogeneous tissue-engineered menisci (TEM) has become a research hotspot in this field. In this review, we systematically summarize the heterogeneity of menisci and 3D-printed strategies for tissue-engineered anisotropic menisci. The manufacturing techniques, biomaterial combinations, surface functionalization, growth factors, and bioreactors related to 3D-printed strategies are introduced and a promising direction for the future research is proposed.

Integrated Analysis of lncRNA and mRNA Expression Profiles Indicates Age-Related Changes in Meniscus

Little has been known about the role of long non-coding RNA (lncRNA) involves in change of aged meniscus. Microarray analyses were performed to identify lncRNAs and mRNAs expression profiles of meniscus in young and aging adults and apple bioinformatics methods to analyse their potential roles. The differentially expressed (DE) lncRNAs and mRNAs were confirmed by qRT-PCR. A total of 1608 DE lncRNAs and 1809 DE mRNAs were identified. Functional and pathway enrichment analyses of all DE mRNAs showed that DE mRNAs were mainly involved in the TGF-beta, Wnt, Hippo, PI3K-Akt signaling pathway. The expressions of TNFRSF11B and BMP2 were significantly upregulated in aging group. LASSO logistic regression analysis of the DE lncRNAs revealed four lncRNAs (AC124312.5, HCG11, POC1B-AS1, and AP001011.1) that were associated with meniscus degradation. CNC analysis demonstrated that AP001011 inhibited the expression of TNFRSF11B and AC1243125 upregulated the expression of TNFRSF11B. CeRNA analysis suggested that POC1B-AS1 regulates the expression of BMP2 by sponging miR 130a-3p, miR136-5p, miR 18a-3p, and miR 608. Furthermore, subcellular localization and m⁶A modification sites prediction analysis of these four lncRNAs was performed. These data lay a foundation for extensive studies on the role of lncRNAs in change of aged meniscus.

[Mongolian medicine three acupoints balance needling improves depressive behavior by regulating p11/tPA/BDNF pathway and miRNA-16 of hippocampus and middle raphe nucleus in depression model rats]

OBJECTIVE

To observe the effect of Mongolian medicine three-acupoints balance needling on the expression of p11/tPA/BDNF pathway and miRNA-16 in the hippocampus and middle raphe nucleus (MRN) in chronic stress depression model rats, so as to explore its mechanisms underlying improvement of depression.

METHODS

Male SD rats were randomly divided into blank control, model, medication and Mongolian medicine acupuncture (acupuncture) groups, with 12 rats in each group. The depression model was established by using chronic unpredictable mild stress method. The rats in the medication group received gavage of prozac (2 mg/kg, diluted with normal saline, 1 mg/mL) 1 h after stress stimulation, once per day for 28 days, and those in the acupuncture group received three-acupoints (Heyi, Badagan and Xin) needling, once a day for 28 days. The behavioral changes were detected by using open field test and sugar consumption test before modeling and after the intervention. The immunoactivity of p11 and tPA proteins in the MRN, and their expression levels in both the MRN and hippocampus were detected by using immunofluorescence histochemistry and Western blot, separately, and the expression levels of miRNA-16 and BDNF mRNA in the hippocampus and MRN detected by using real-time quantitative PCR.

RESULTS

After modeling, the crossing and rearing scores of open field tests and the relative consumption of sucrose in the model group were apparently lower than those of the blank control group (P<0.05), the expression levels of p11 and tPA in the MRN, and those of p11 and tPA proteins and BDNF mRNA in the MRN and hippocampus were significantly down-regulated (P<0.05), while those of miRNA-16 in the hippocampus and MRN were significantly up-regulated (P<0.05). Compared with the model group, the crossing and rearing scores of open field tests and glucose consumption, as well as the expression levels of p11 and tPA proteins and BDNF mRNA in the hippocampus and MRN were obviously increased in both the medication and acupuncture groups (P<0.05), while the expression of miRNA-16 in hippocampus was markedly down-regulated in both the medication and acupuncture groups (P<0.05). No significant differences were found between the acupuncture and medication groups in all the indexes mentioned above (P>0.05).

CONCLUSION

Mongolian medicine three-acupoints balance needling can improve the depressive state in depression rats, which may be associated with its effects in up-regulating the expression of p11 and tPA proteins and BDNF mRNA in the hippocampus and MRN and in down-regulating miRNA-16 in the hippocampus, suggesting an involvement of miRNA-16 controlled p11/tPA/BDNF signaling pathway in the antidepressant effect of acupuncture.

Au20Si12: A hollow Catalan pentakis dodecahedron

A stable hollow Au₂₀Si₁₂ cage with I_h symmetry has been predicted using first-principles density functional theory. The stability of the cage-like Au₂₀Si₁₂ structure is verified by vibrational frequency analysis and molecular dynamics simulations. A relatively large highest occupied molecular orbital-lowest unoccupied molecular orbital gap of 1.057 eV is found. Electronic structure analysis shows that clearly p-d hybridizations between Si atoms and Au atoms are of great importance for the stability of Au₂₀Si₁₂ cage. The cage-like Au₂₀Si₁₂ structure may have potential applications in semiconductor industry and microelectronics.