Solid-liquid transition induced by rigidity disparity in a binary mixture of cell tissues.

The two-dimensional melting of a binary mixture of cell tissues is numerically investigated in the presence of rigidity disparity. We present the full melting phase diagrams of the system by using the Voronoi-based cellular model. It is found that the enhancement of rigidity disparity can induce a solid-liquid transition at both zero temperature and finite temperature. (i) In the case of zero temperature, the system undergoes a continuous solid-hexatic transition followed by a continuous hexatic-liquid transition for zero rigidity disparity, but a discontinuous hexatic-liquid transition for finite rigidity disparity. Remarkably, the solid-hexatic transitions always arise when the soft cells reach the rigidity transition point of monodisperse systems. (ii) In the case of finite temperature, the melting occurs via a continuous solid-hexatic transition followed by a discontinuous hexatic-liquid transition. Our study may contribute to the understanding of solid-liquid transitions in binary mixture systems with rigidity disparity.

Bestrophin3 Deficiency in Vascular Smooth Muscle Cells Activates MEKK2/3-MAPK Signaling to Trigger Spontaneous Aortic Dissection.

BACKGROUND: Aortic dissection (AD) is a fatal cardiovascular disorder without effective medications due to unclear pathogenic mechanisms. Bestrophin3 (Best3), the predominant isoform of bestrophin family in vessels, has emerged as critical for vascular pathological processes. However, the contribution of Best3 to vascular diseases remains elusive. METHODS: Smooth muscle cell-specific and endothelial cell-specific Best3 knockout mice (Best3SMKO and Best3ECKO, respectively) were engineered to investigate the role of Best3 in vascular pathophysiology. Functional studies, single-cell RNA sequencing, proteomics analysis, and coimmunoprecipitation coupled with mass spectrometry were performed to evaluate the function of Best3 in vessels. RESULTS: Best3 expression in aortas of human AD samples and mouse AD models was decreased. Best3SMKO but not Best3ECKO mice spontaneously developed AD with age, and the incidence reached 48% at 72 weeks of age. Reanalysis of single-cell transcriptome data revealed that reduction of fibromyocytes, a fibroblast-like smooth muscle cell cluster, was a typical feature of human ascending AD and aneurysm. Consistently, Best3 deficiency in smooth muscle cells decreased the number of fibromyocytes. Mechanistically, Best3 interacted with both MEKK2 and MEKK3, and this interaction inhibited phosphorylation of MEKK2 at serine153 and MEKK3 at serine61. Best3 deficiency induced phosphorylation-dependent inhibition of ubiquitination and protein turnover of MEKK2/3, thereby activating the downstream mitogen-activated protein kinase signaling cascade. Furthermore, restoration of Best3 or inhibition of MEKK2/3 prevented AD progression in angiotensin II-infused Best3SMKO and ApoE-/- mice. CONCLUSIONS: These findings unveil a critical role of Best3 in regulating smooth muscle cell phenotypic switch and aortic structural integrity through controlling MEKK2/3 degradation. Best3-MEKK2/3 signaling represents a novel therapeutic target for AD.

Flow and clogging of particles in shaking random obstacles.

Transport of three types of particles (passive particles, active particles, and polar particles) is investigated in a random obstacle array in the presence of a dc drift force. The obstacles are static or synchronously shake along the given direction. When the obstacles are static, the average velocity is a peaked function of the dc drift force (negative differential mobility) for low particle density, while the average velocity monotonically increases with the dc drift force (positive differential mobility) for high particle density. Under the same conditions, passive particles are most likely to pass through the obstacles, while polar particles are easily trapped by the obstacles. The polar alignment can strongly reduce the overall mobility of particles. When the obstacles shake along the given direction, the optimal shaking frequency or amplitude can maximize the average velocity. It is more effective to reduce clogging for the transverse shaking than that for the longitudinal shaking.

[Study on Archaeological Lime Powders from Taosi and Yinxu Sites by FTIR].

Archaeological lime powders samples from Taosi and Yinxu sites, natural limestone and experimentally prepared lime mortar were investigated by means of Fourier transform infrared spectrometry (FTIR) to identify the raw material of lime powders from Taosi and Yinxu sites. Results show that ν2/ν4 ratio of calcite resulted from carbonation reaction of man-made lime is around 6.31, which is higher than that of calcite in natural limestone and reflects the difference in the disorder of calcite crystal structure among the natural limestone and prepared lime mortar. With additional grinding, the values of v2 and ν4 in natural limestone and prepared lime mortar decrease. Meanwhile, the trend lines of ν2 versus ν4 for calcite in experimentally prepared lime mortar have a steeper slope when compared to calcite in natural limestone. These imply that ν2/ν4 ratio and the slope of the trend lines of ν2 versus ν4 can be used to determine the archaeological man-made lime. Based on the experiment results, it is possible that the archaeological lime powder from Taosi and Yinxu sites was prepared using man-made lime and the ancient Chinese have mastered the calcining technology of man-made lime in the late Neolithic period about 4 300 years ago.

Stretch-inducible expression of connective tissue growth factor (CTGF) in human osteoblasts-like cells is mediated by PI3K-JNK pathway.

To explore the possible role for connective tissue growth factor (CTGF) during tooth movement, we evaluated CTGF gene and protein expression in MG-63 cells subjected to cyclic stretch. Cyclic stretch caused a time-dependent increase in CTGF mRNA and protein levels.Inhibition of p38 MAP kinase or ERK activation did not affect cyclic stretch-induced CTGF expression. Specific inhibitors of PI3K suppressed stretch -induced CTGF expression in a time-dependent manner. cyclic stretch activated JNK and ERK, but not p38 MAP kinase in osteoblast-like cells. PI3K inhibitors suppressed cyclic stretch-induced JNK, but not p38 MAP kinase activation. Finally, SP600125, a Specific Inhibitor of JNK, suppressed stretch -induced CTGF Expression. These results suggest that stretch-induced CTGF expression is mediated through the PI3K-JNK -dependent pathway, not by p38 MAP kinase and ERK pathways.

Type I natural killer T cells: naturally born for fighting.

Type capital I, Ukrainian natural killer T cells (NKT cells), a subset of CD1d-restricted T cells with invariant Valphabeta TCR, are characterized by prompt production of large amounts of Th1 and/or Th2 cytokines upon primary stimulation through the TCR complex. The rapid release of cytokines implies that type capital I, Ukrainian NKT cells may play a critical role in modulating the upcoming immune responses, such as anti-tumor response, protection against infection, and autoimmunity. As a bridge between innate and adaptive immunity, type capital I, Ukrainian NKT cells differentiate and mature upon stimulations to achieve and maintain a homeostasis. Orchestrating with other arms of adaptive immunity, type capital I, Ukrainian NKT cells show strong cytotoxic effects in response to various tumors in a direct and/or indirect manner(s). This review will focus primarily on type capital I, Ukrainian NKT cell development, homeostasis, and effector functions, especially in anti-tumor immunity, and followed by their potential applications in treatment of cancers.

Insulin receptor substrate 1 regulates the cellular differentiation and the matrix metallopeptidase expression of preosteoblastic cells.

Insulin receptor substrate 1 (IRS1) is an essential molecule for the intracellular signaling of IGF1 and insulin, which are potent anabolic regulators of bone metabolism. Osteoblastic IRS1 is essential for maintaining bone turnover; however, the mechanism underlying this regulation remains unclear. To clarify the role of IRS1 in bone metabolism, we employed RNA interference to inhibit IRS1 gene expression and observed the effects of silencing this gene on the proliferation and differentiation of and the expression of matrix metallopeptidase (MMP) and tumor necrosis factor receptor superfamily, member 11b (TNFRSF11B) in MC3T3-E1 cells. Our results showed that IRS1 short hairpin RNAs can effectively suppress the expression of IRS1, and inhibit the phosphorylation of AKT in IRS1 pathway; reduce the expression of MMP2, MMP3, MMP13, and MMP14, decrease the expression of TNFRSF11B and RANKL (also known as tumor necrosis factor (ligand) superfamily, member 11), however increase the RANKL/TNFRSF11B ratio; decrease cell survival, proliferation, and mineralization, and impair the differentiation of MC3T3-E1 cells. The downregulation of IRS1 had no effect on the expression of MMP1. Our findings suggest that IRS1 not only promotes bone formation and mineralization but also might play roles in bone resorption partly via the regulation of MMPs and RANKL/TNFRSF11B ratio, thus regulates the bone turnover.

[Construction of WISP3 gene's mutants in SEDT-PA and their expression in COS-7 cells].

OBJECTIVE: To construct two types of Wnt-inducible secreted protein 3(WISP3) gene's mutants(1000T/C,840delT) found in spondyloepiphyseal dysplasia tarda with progressive anthopathy (SEDT-PA) patients, and to observe their expression in COS-7 cells. METHODS: Full-length cDNA of wild type WISP3 gene(WT-WISP3) was amplified from human chondrocytes by RT-PCR, and site-directed mutagenesis was used to obtain full-length cDNAs of the mutated WISP3 genes(MUT1000T/C and MUT840delT). The recombined plasmids WT-WISP3/pcDNA3.1(+), MUT1000T/C/pcDNA3.1(+) and MUT840delT/pcDNA3.1(+) were transfected transiently into COS-7 cells by liposome-mediated method, and pcDNA3.1(+) vector was used as a control. The total RNA and protein of the transfected COS-7 cells were extracted after 48 hours of transfection. The expression of WISP3 gene in the transfected COS-7 cells was detected by semi-quantitative RT-PCR and Western blot. RESULTS: By restriction endonuclease analysis and sequencing, the sequence of MUT1000T/C and MUT840delT were consistent with that mutated in SEDT-PA, and the open reading frames matched with the vector sequence. Semi-quantitative RT-PCR and Western blot showed that the recombined plasmids were highly expressed in COS-7 cells. CONCLUSION: WISP3 gene's mutants of SEDT-PA are successfully constructed by genetic recombination, and expressed in COS-7 cells, which lays the foundation for the further study on its molecular functions in SEDT-PA.

Cellular and molecular responses in progressive pseudorheumatoid dysplasia articular cartilage associated with compound heterozygous WISP3 gene mutation.

Progressive pseudorheumatoid dysplasia (PPD) is characterized by continuous degeneration and loss of articular cartilage, which has been attributed to mutations in the gene encoding WISP3. We collected a PPD family and analyzed their WISP3 genes mutation. Articular chondrocytes (ACs) were purified from the femurs of a PPD patient after hip replacement surgery. Cell growth, proliferation, and viability were examined. Gene expression profiling and analyses of matrix metalloproteinases (MMP)-1, -3, and -13 proteins were carried out using cDNA differential microarrays, real-time reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis. We found that two probands carried a deletion (840delT) mutation in maternal allele, which leads to truncated WISP3 protein missing 43 residues in C terminus; and a 1000T>C substitution in paternal allele, which was also passed on to four other members in the PPD kindred. PPD ACs were heterogeneous in size with an enhanced rate of cell proliferation and viability compared with the normal ACs. MMP-1, -3, and -13 mRNA expressions were dereased in PPD ACs. MMP-1, -3, and -13 protein levels, however, were increased in cell lysates from PPD ACs, but markedly decreased in the supernatants from cultured ACs. WISP3 mRNA expression in PPD ACs was also decreased. Our results show, for the first time, a compound heterozygous mutation of WISP3 and a series of cellular and molecular changes disturbing the endochondral ossification in this PPD patient.