[Prickle planar cell polarity protein 1 involved in the pathogenesis of skeletal class Ⅲ malocclusion]

Objective: To explore the mechanisms of prickle planar cell polarity protein 1 (PRICKLE1) involved in the occurrence of skeletal Class Ⅲ malocclusion. Methods: After extracting the genomic DNA of all family members of the skeletal Class Ⅲ malocclusion pedigree with maxillary hypoplasia collected in the Department of Orthodontics at the Affiliated Stomatological Hospital of Nanjing Medical University in October 2021, whole exome sequencing and Sanger sequencing were performed to screen pathogenic genes/mutation sites and validate the mutations. Jaw tissue was collected during the operation of orthognathic patients who were treated in the Department of Oral and Maxillofacial Surgery at the same hospital from October 2021 to December 2022. Following the extraction of human jaw bone marrow mesenchymal stem cells and transfection with overexpressing lentivirus (lentiviruses overexpressing the gene of interest served as the wild group, lentiviruses overexpressing mutation site served as the mutant group) and knockdown lentivirus (divided into knockdown group 1 and 2, with transfection interference negative lentiviruses as the control group). Various assays including real-time fluorescence quantitative PCR (RT-qPCR), Western blotting, proliferation and Transwell assays, alkaline phosphatase staining and alizarin red staining were performed. Construction of zebrafish animal model, morpholino oligonucleotide (MO) were injected to knock down the expression of prickle1a and prickle1b in zebrafish (co-knocking group), and the control group was injected with standardized MO as a reference. Transcriptome sequencing, enrichment analysis and co-expression analysis were performed on the zebrafish craniofacial tissues of the two groups. Results: Two patients of this family carried this mutation PRICKLE1 c.113C>T. The transfection experiments showed that compared with the wild group (relative expression of PRICKLE1 was 21.97±0.60), the relative expression of mutant group (5.05±0.05) was significantly reduced (P<0.05), and cell proliferation and migration ability significantly enhanced (P<0.05), and osteogenic differentiation ability was significantly reduced (P<0.05). Compared with the control group, the proliferation and migration ability of cells in the two knockdown groups were significantly enhanced (P<0.05), and the osteogenic differentiation ability was significantly reduced (P<0.05). Zebrafish model experiments showed the width of the ethmoid plate was significantly reduced in the co-knocking group (282.50±61.77, t=5.29, P<0.001) compared with the control group (338.80±24.92). Transcriptome data and enrichment analysis showed that the differentially expressed genes were significantly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway after the simultaneous knockdown of prickle1a and prickle1b in zebrafish. Conclusions: PRICKLE1 c.113C>T mutation might suppress the osteoblastic differentiation ability of jaw bone marrow mesenchymal stem cells by downregulating the MAPK signaling pathway, thereby involving the development of skeletal Class Ⅲ malocclusion.

Fabrication of Metallic Superhydrophobic Surfaces with Tunable Condensate Self-Removal Capability and Excellent Anti-Frosting Performance

Laser fabrication of metallic superhydrophobic surfaces (SHSs) for anti-frosting has recently attracted considerable attention. Effective anti-frosting SHSs require the efficient removal of condensed microdroplets through self-propelled droplet jumping, which is strongly influenced by the surface morphology. However, detailed analyses of the condensate self-removal capability of laser-structured surfaces are limited, and guidelines for laser processing parameter control for fabricating rationally structured SHSs for anti-frosting have not yet been established. Herein, a series of nanostructured copper-zinc alloy SHSs are facilely constructed through ultrafast laser processing. The surface morphology can be properly tuned by adjusting the laser processing parameters. The relationship between the surface morphologies and condensate self-removal capability is investigated, and a guideline for laser processing parameterization for fabricating optimal anti-frosting SHSs is established. After 120 min of the frosting test, the optimized surface exhibits less than 70% frost coverage because the remarkably enhanced condensate self-removal capability reduces the water accumulation amount and frost propagation speed (<1 μm/s). Additionally, the material adaptability of the proposed technique is validated by extending this methodology to other metals and metal alloys. This study provides valuable and instructive insights into the design and optimization of metallic anti-frosting SHSs by ultrafast laser processing.

Improvements in Brazed-Joint Properties of Silicon Nitride and Titanium Alloys Using Laser-Induced Microscale Rice Leaf Structures

Si₃N₄ ceramics with a microscale rice leaf structure (MRLS) and titanium alloy were connected via brazing, and the influence of the surface microstructure on the ceramic connection was analyzed. MRLS fabrication is an efficient and high-degree-of-freedom method that can be used to change a material's surface morphology and wettability. The MRLS was obtained at a laser power of 110 W, with line spacings of 100 and 50 μm. The laser-treated surface included nanoparticles and micro particles, exhibiting a coral-like structure after agglomeration. When the MRLS was used to braze the titanium alloy, no defects were observed at the brazing interface, and the formation was excellent. Throughout the brazed joint, the MRLS remained intact and formed a strong metallurgical bond with the brazing filler metal. A finite element analysis was performed to study the cross-sectional morphology after joint fracture; from the load-time curve, it was found that the MRLS on the surface not only helped improve the mechanical occlusion and brazing area at the interface, but also helped generate compressive stress on the Si₃N₄ side. Crack propagation was hindered, thereby increasing the joint strength.

Region specific increase of dopamine receptor D1/D2 mRNA expression in the brain of mu-opioid receptor knockout mice

Previous pharmacological studies have indicated the possible existence of functional interactions between opioidergic and dopaminergic neurons in the CNS. In this study, the expression of mRNAs encoding dopamine receptor D1/D2 was examined to investigate whether there is a change in the dopamine pathway of mice lacking the mu-opioid receptor by in situ hybridization technique. In the mu-opioid receptor knockout mice, the expression of dopamine receptor D1 mRNA was increased in the olfactory tubercle, nucleus accumbens, caudate putamen, and the layer VI of the neocortex compared with that of wild-type mice. The expression of dopamine receptor D2 mRNA was also increased in the olfactory tubercle, caudate putamen, and the nucleus accumbens of mu-opioid receptor knockout mice. These results indicate that there are compensational changes in the dopaminergic systems of mu-opioid receptor knockout mice.

Forskolin inhibits 5-hydroxytryptamine-induced phosphoinositide hydrolysis and Ca+2 Mobilisation in canine cultured aorta smooth muscle cells

The effect of forskolin on 5-hydroxytryptamine (5-HT)-induced inositol phosphate (IP) and Ca2+ mobilisation was investigated in canine cultured aorta smooth muscle cells (ASMCs). Pretreatment of ASMCs with forskolin attenuated 5-HT-induced IP accumulation and Ca2+ mobilisation in a time- and concentration-dependent manner. The half-maximal effects (pEC50) of forskolin to attenuate IP and Ca2+ responses to 5-HT occurred at concentrations of 6.28 and 6.64, respectively. Pretreatment of ASMCs with cholera toxin caused a similar inhibition on 5-HT-induced responses. Even after treatment with forskolin for 24 h, the 5-HT-induced responses were still inhibited. The inhibitory effect of forskolin resulted from both a depression of the maximal response and a shift to the right of the concentration-effect curves of 5-HT in these responses. The water-soluble forskolin analogue L-858051 [7-deacetyl-7beta-(gamma-N-methylpiperazino)-butyryl forskolin] significantly inhibited the 5-HT-stimulated IP accumulation. In contrast, the addition of 1,9-dideoxy forskolin, an inactive forskolin analogue, had little effect on IP response. Moreover, SQ-22536 [9-(tetrahydro-2-furanyl)-9-H-purin-6-amine], an inhibitor of adenylate cyclase, and both H-89 [N-(2-aminoethyl)-5-iosquinolinesulphonamide] and HA-1004 [N-(2-guanidinoethyl)-5-iosquinolinesulphonamide], inhibitors of cAMP-dependent protein kinase (PKA), attenuated the ability of forskolin to inhibit the 5-HT-stimulated accumulation of IP in ASMCs. These results indicate that activation of cAMP/PKA might inhibit the 5-HT-stimulated IP accumulation and consequently reduce Ca2+ mobilisation, or inhibit both responses independently.

Regulation of 5-hydroxytryptamine-induced signal transduction in canine cultured aorta smooth muscle cells by phorbol ester

Regulation of the increase in inositol phosphates (IPs) production and intracellular Ca2+ concentration ([Ca2+]i) by protein kinase C (PKC) was investigated in cultured canine aorta smooth muscle cells (ASMCs). Stimulation of ASMCs by 5-hydroxytryptamine (5-HT) led to IPs formation and caused an initial transient [Ca2+]i peak followed by a sustained elevation of [Ca2+]i in a concentration-dependent manner. Pretreatment of ASMCs with phorbol 12-myristate 13-acetate (PMA) for 30 min almost abolished the 5-HT-induced IPs formation and Ca2+ mobilization. This inhibition was reduced after long-term incubating the cells with PMA. Prior treatment of ASMCs with staurosporine or GF109203X, PKC inhibitors, inhibited the ability of PMA to attenuate 5-HT-induced responses, suggesting that the inhibitory effect of PMA is mediated through the activation of PKC. In parallel with the effect of PMA on the 5-HT-induced IP formation and Ca2+ mobilization, the translocation and down-regulation of PKC isozymes were determined by Western blotting with antibodies against different PKC isozymes. The results revealed that treatment of ASMCs with PMA for various times, translocation of PKC-alpha, betaI, betaII, delta, epsilon, theta, and zeta isozymes from the cytosol to the membrane was seen after 5-min, 30-min, 2-h, and 4-h treatment. However, 24-h treatment caused a partial down-regulation of these PKC isozymes. In conclusion, these results demonstrate that translocation of PKC-alpha, betaI, betaII, delta, epsilon, theta, and zeta induced by PMA caused an attenuation of 5-HT-induced IPs accumulation and Ca2+ mobilization in ASMCs.

5-Hydroxytryptamine-induced phosphoinositide hydrolysis and Ca2+ mobilisation in canine cultured aorta smooth muscle cells

The effect of 5-hydroxytryptamine (5-HT) on phospholipase C (PLC)-mediated phosphoinositide (PI) hydrolysis and intracellular Ca2+ ([Ca2+]i) changes was investigated in canine cultured aorta smooth muscle cells (ASMCs). 5-HT-stimulated inositol phosphate (IP) accumulation was time and concentration dependent with a half-maximal response (pEC50) and a maximal response at 6.4 and 10 microM, n = 6, respectively. Stimulation of ASMCs by 5-HT produced an initial transient peak followed by a sustained, concentration-dependent elevation in [Ca+]i. The half-maximal response (pEC50) values of 5-HT for the peak and sustained plateau were 7.1 and 6.9, respectively. Ketanserin and mianserin (1 and 3 nM), 5-HT2A antagonists, were equipotent and had high affinity in antagonising the 5-HT-induced IP accumulation and [Ca2+]i change with pK(B) values of 8.6-9.1 and 8.6-9.4, respectively. In contrast, the concentration-effect curves of 5-HT-induced IP and [Ca2+]i responses were not shifted until the concentrations of NAN-190 and metoctopramide (5-HT1A and 5-HT3 receptor antagonists, respectively) were increased to as high as 1 microM with pK(B) values of 5.7-6.3 and 6.1-6.6, respectively, indicating that the 5-HT receptor-mediated responses had low affinity for these antagonists. Pre-treatment of ASMCs with pertussis toxin (100 ng/mL, 24 h) caused a significant inhibition of 5-HT-induced IP accumulation and [Ca2+]i change in ASMCs. Depletion of external Ca2+ or removal of Ca2+ by addition of EGTA led to a significant attenuation of IP accumulation and [Ca2+]i change induced by 5-HT. Influx of external Ca2+ was required for the 5-HT-induced responses, because Ca2+-channel blockers--verapamil, nifedipine and Ni2+--partly inhibited the 5-HT-induced IP accumulation and Ca2+ mobilisation. The sustained elevation of [Ca2+]i response to 5-HT was dependent on the presence of external Ca2+. Removal of external Ca2+ by addition of 5 mM EGTA during the sustained phase caused a rapid decline in [Ca2+]i to lower than the resting level. The sustained elevation of [Ca2+]i could then be evoked by addition of 1.8 mM Ca2+ in the continued presence of 5-HT. These results demonstrate that 5-HT directly stimulates PLC-mediated PI hydrolysis and Ca2+ mobilisation, at least in part, through a pertussis toxin-sensitive G protein in canine ASMCs. 5-HT2A receptors may be predominantly mediating IP accumulation, and subsequently IP-induced Ca2+ mobilisation may function as the transducing mechanism for 5-HT-stimulated contraction of aorta smooth muscle.

Effect of forskolin on bradykinin-induced calcium mobilization in cultured canine tracheal smooth muscle cells

The effects of increases in intracellular adenosine 3':5'-cyclic monophosphate (cyclic AMP) on bradykinin (BK)-induced generation of inositol phosphates (IPs) and Ca2+ mobilization were investigated in canine cultured tracheal smooth muscle cells (TSMCs). Pretreatment of TSMCs with either forskolin or dibutyryl cyclic AMP attenuated BK-stimulated responses. The inhibitory effects of these agents produced both a depression of the maximal response and a shift to the right of the concentration-response curves of BK. The water-soluble forskolin analogue L-858051, 7-deacetyl-7 beta-(r-N-methylpiperazino)-butyryl forskolin, significantly attenuated BK-stimulated IPs accumulation, while 1,9-dideoxy forskolin, an inactive forskolin, had little effect on IPs response. Moreover, SQ-22536, 9-(tetrahydro-2-furanyl)-9-H-purin-6-amine, an inhibitor of adenylate cyclase, and both H-89, N-(2-aminoethyl)-5-isoquinolinesulfonamide, and HA-1004, N-(2-guanidinoethyl)-5-isoquinolinesulfonamide, inhibitors of cyclic AMP-dependent protein kinase (PKA), reversed the ability of forskolin to attenuate BK-stimulated IPs accumulation. The KD and Bmax, values of the BK receptor for [3H]BK binding were not significantly changed by forskolin treatment for 30 min and 4 h. The AlF4(-)-induced IPs accumulation was attenuated by forskolin, indicating that G protein(s) are directly activated by AlF4- and uncoupled to phospholipase C by forskolin treatment. These results suggest that activation of cyclic AMP/PKA might inhibit the BK-stimulated PI breakdown and consequently reduce the [Ca2+]i increases or inhibit independently both responses, which is distal to the BK receptor in canine cultured TSMCs.

Regulation of 5-hydroxytryptamine-induced calcium mobilization by cAMP-elevating agents in cultured canine tracheal smooth muscle cells

The effects of increases in cellular adenosine 3'5'-cyclic monophosphate (cAMP) on 5-hydroxytryptamine-(5-HT-) induced generation of inositol phosphates (IPs) and increases in intracellular Ca2+ ([Ca2+]i) were investigated using canine cultured tracheal smooth muscle cells (TSMCs). Cholera toxin and forskolin induced concentration- and time-dependent cAMP formation with half-maximal effects (-logEC50) produced at concentrations of 7.0 +/- 0.5 and 4.9 +/- 0.4 respectively. Pretreatment of TSMCs with either forskolin or dibutyryl cAMP inhibited 5-HT-stimulated responses. Even after treatment for 24h, these agents still inhibited the 5-HT-induced Ca2+ mobilization. The inhibitory effects of these agents produced both depression of the maximal response and a shift to the right of the concentration response curves of 5-HT. The water-soluble forskolin analogue L-858051 [7-deacetyl-7beta-(gamma-N-methylpiperazino)-butyryl forskolin] significantly inhibited the 5-HT-stimulated accumulation of IPs. In contrast, the addition of 1,9-dideoxy forskolin, an inactive forskolin analogue, had little effect on this response. Moreover, SQ-22536 [9-(tetrahydro-2-furanyl)-9-H-purin-6-amine], an inhibitor of adenylate cyclase, and both H-89 [N-(2-aminoethyl)-5-isoquinolinesulphonamide] and HA-1004[N-(2-guanidinoethyl)-5-isoquinolinesulphonamide], inhibitors of cAMP-dependent protein kinase (PKA), attenuated the ability of forskolin to inhibit the 5-HT-stimulated accumulation of IPs. These results suggest that activation of cAMP/PKA was involved in these inhibitory effects of forskolin. The AlF4--induced accumulation of IPs was inhibited by forskolin, suggesting that G protein(s) are directly activated by AlF4-- and uncoupled from phospholipase C by forskolin treatment. These results suggest that activation of cAMP/PKA might inhibit the 5-HT-stimulated phosphoinositide breakdown and consequently reduce the [Ca2+]i increase or inhibit both responses independently.

Effect of cAMP elevating agents on carbachol-induced phosphoinositide hydrolysis and calcium mobilization in cultured canine tracheal smooth muscle cells

The effects of increases in intracellular adenosine 3',5'-cyclic monophosphate (cAMP) on carbachol-induced generation of inositol phosphates (IPs) and increases in intracellular Ca2+ ([Ca2+]i) were investigated in canine cultured tracheal smooth muscle cells (TSMCs). The cAMP elevating agents, cholera toxin (CTX) and forskolin, induced concentration- and time-dependent cAMP formation with half-maximal effects (-logEC50) at concentrations of 7.6 +/- 1.3 g/ml and 4.8 +/- 0.9 M, respectively. Forskolin caused a concentration-dependent inhibition of carbachol-induced increase in [Ca2+]i with half-maximal inhibition (-logEC50) at 5.2 +/- 0.7 M. Pretreatment of TSMCs with either CTX (10 micrograms/ml, 4 h), forskolin (10-100 microM, 30 min), or dibutyryl cAMP (1 mM, 30 min) inhibited carbachol-stimulated Ca2+ mobilization and IPs accumulation. The inhibitory effects of these agents produced both depression of the maximal response and a shift to the right of the concentration-response curve of carbachol without changing the EC50 values. After treatment with forskolin for 24 h, carbachol-induced IPs accumulation and Ca2+ mobilization were close to those of control group. SQ-22536 [9-(tetrahydro-2-furanyl)-9H-purin-6-amine, 10 microM], an inhibitor of adenylate cyclase, and HA-1004 [N-(2-guanidinoethyl)-5-isoquinolinesulfonamide hydrochloride, 50 microM], an inhibitor of cAMP-dependent protein kinase (PKA), attenuated the ability of forskolin to inhibit carbachol-induced IPs accumulation. Moreover, the inactive analogue of forskolin, 1,9-dideoxy forskolin, did not inhibit these responses evoked by carbachol, suggesting that activation of cAMP/PKA was involved in these inhibitory effects of forskolin. The KD and Bmax values of the muscarinic receptor (mAChR) for [3H]-N-methyl scopolamine binding were not significantly changed by forskolin treatment for 30 min and 24 h, suggesting that the inhibitory effect of forskolin is distal to the mAChR. The locus of this inhibition was further investigated by examining the effect of forskolin treatment on AIF4(-)-stimulated IPs accumulation in canine TSMCs. The AIF4(-)-induced response was inhibited by forskolin, supporting the notion that G protein(s) are directly activated by AIF4- and uncoupled to phospholipase C by forskolin treatment. We conclude that cAMP elevating agents inhibit carbachol-stimulated generation of IPs and Ca2+ mobilization in canine cultured TSMCs. Since generation of IPs and increases in [Ca2+]i are very early events in the activation of mAChRs, attenuation of these events by cAMP elevating agents might well contribute to the inhibitory effect of cAMP on tracheal smooth muscle formation.