Arabidopsis protein S-acyl transferases positively mediate BR signaling through S-acylation of BSK1.

Protein S-acyl transferases (PATs) catalyze S-acylation, a reversible post-translational modification critical for membrane association, trafficking, and stability of substrate proteins. Many plant proteins are potentially S-acylated but few have corresponding PATs identified. By using genomic editing, confocal imaging, pharmacological, genetic, and biochemical assays, we demonstrate that three Arabidopsis class C PATs positively regulate BR signaling through S-acylation of BRASSINOSTEROID-SIGNALING KINASE1 (BSK1). PAT19, PAT20, and PAT22 associate with the plasma membrane (PM) and the trans-Golgi network/early endosome (TGN/EE). Functional loss of all three genes results in a plethora of defects, indicative of reduced BR signaling and rescued by enhanced BR signaling. PAT19, PAT20, and PAT22 interact with BSK1 and are critical for the S-acylation of BSK1, and for BR signaling. The PM abundance of BSK1 was reduced by functional loss of PAT19, PAT20, and PAT22 whereas abolished by its S-acylation-deficient point mutations, suggesting a key role of S-acylation in its PM targeting. Finally, an active BR analog induces vacuolar trafficking and degradation of PAT19, PAT20, or PAT22, suggesting that the S-acylation of BSK1 by the three PATs serves as a negative feedback module in BR signaling.

Leveraging Isoreticular Principle to Elucidate the Key Role of Inherent Hydrogen-Bonding Anchoring Sites in Enhancing Water Sorption Cyclability of Zr(IV) Metal-Organic Frameworks.

Water adsorption/desorption cyclability of porous materials is a prerequisite for diverse applications, including atmospheric water harvesting (AWH), humidity autocontrol (HAC), heat pumps and chillers, and hydrolytic catalysis. However, unambiguous molecular insights into the correlation between underlying building blocks and the cyclability are still highly elusive. In this work, by taking advantage of the well-established isoreticular synthetic principle in Zr(IV) metal-organic frameworks (Zr-MOFs), we show that the inherent density of hydrogen atoms in the organic skeleton can play a key role in regulating the water sorption cyclability of MOFs. The ease of isoreticular practice of Zr-MOFs enables the successful syntheses of two pairs of isostructural Zr-MOFs (NU-901 and NU-903, NU-950 and SJTU-9) from pyrene- or benzene-cored carboxylate linkers, which feature scu and sqc topological nets, respectively. NU-901 and NU-950 comprised of pyrene skeletons carrying more hydrogen-bonding anchoring sites show distinctly inferior cyclability as compared with NU-903 and SJTU-9 built of benzene units. Single-crystal X-ray crystallography analysis of the hydrated structure clearly unveils the water molecule-involved interactions with the hydrogen-bonding donors of benzene moieties. Remarkably, NU-903 and SJTU-9 isomers exhibit outstanding water vapor sorption capacities as well as working capacities at the desired humidity range with potential implementations covering indoor humidity control and water harvesting. Our findings uncover the importance of hydrogen-bonding anchoring site engineering of organic scaffold in manipulating the framework durability toward water sorption cycle and will also likely facilitate the rational design and development of highly robust porous materials.

Arabidopsis calcineurin B-like-interacting protein kinase 8 and its functional homolog in tomato negatively regulates ABA-mediated stomatal movement and drought tolerance.

Stomatal movement is critical for water transpiration, gas exchange, and responses to biotic stresses. Abscisic acid (ABA) induces stomatal closure to prevent water loss during drought. We report that Arabidopsis CIPK8 negatively regulates ABA-mediated stomatal closure and drought tolerance. CIPK8 is highly enriched in guard cells and transcriptionally induced by ABA. Functional loss of CIPK8 results in hypersensitive stomatal closure to ABA and enhanced drought tolerance. Guard cell-specific downregulation of CIPK8 mimics the phenotype of cipk8 whereas guard cell-specific expression of a constitutive active CIPK8 (CIPK8CA) has an opposite effect, suggesting a cell autonomous activity of CIPK8. CIPK8 physically interacts with CBL1 and CBL9. Functional loss of CBL1 and CBL9 mimics ABA-hypersensitive stomatal closure of cipk8 whereas abolishes the effect of CIPK8CA, indicating that CIPK8 and CBL1/CBL9 form a genetic module in ABA-responsive stomatal movement. SlCIPK7, the functional homolog of CIPK8 in tomato (Solanum lycopersicum), plays a similar role in ABA-responsive stomatal movement. Genomic editing of SlCIPK7 results in more drought-tolerant tomato, making it a good candidate for germplasm improvement.

Cinnamaldehyde Regulates the Migration and Apoptosis of Gastric Cancer Cells by Inhibiting the Jak2/Stat3 Pathway.

OBJECTIVE: Gastric cancer is a malignant tumor with high morbidity and mortality all around the world. Because of its poor prognosis and low survival rate, the treatment of gastric cancer has received extensive attention. Cinnamaldehyde (CA) is the main single active component of the Chinese herbal medicine cinnamon, which has a variety of pharmacological effects. The inhibitory effect of CA on the growth of some tumor cells has been proven, but its therapeutic effect on gastric cancer has rarely been reported. METHODS: Through network pharmacology, bioinformatics methods, and molecular docking technology, we predicted the interaction targets of CA and gastric cancer. Moreover, we found that apoptosis is an important mode of action of CA on gastric cancer cells. Subsequently, we validated it in gastric cancer cell lines cultured in vitro. RESULTS: The results showed that in the presence of CA, the Jak2/Stat3 pathway was inhibited, the ratio of Bcl-2/Bax decreased, and the apoptosis of gastric cancer cells was promoted in a concentration-dependent. CONCLUSION: In conclusion, CA can promote the apoptosis of gastric cancer cells by inhibiting the activity of the Jak2/Stat3 pathway, which may achieve the effect of treating gastric cancer.

Polystyrene nano-plastics impede skeletal muscle development and induce lipid accumulation via the PPARγ/LXRß pathway in vivo and in vitro in mice.

Nano-plastics (NPs) have emerged as a significant environmental pollutant, widely existing in water environment, and pose a serious threat to health and safety with the intake of animals. Skeletal muscle, a vital organ for complex life activities and functional demands, has received limited attention regarding the effects of NPs. In this study, the effects of polystyrene NPs (PS-NPs) on skeletal muscle development were studied by oral administration of different sizes (1 mg/kg) of PS-NPs in mice. The findings revealed that PS-NPs resulted in skeletal muscle damage and significantly hindered muscle differentiation, exhibiting an inverse correlation with PS-NPs particle size. Morphological analysis demonstrated PS-NPs caused partial disruption of muscle fibers, increased spacing between fibers, and lipid accumulation. RT-qPCR and western blots analyses indicated that PS-NPs exposure downregulated the expression of myogenic differentiation-related factors (Myod, Myog and Myh2), activated PPARγ/LXRß pathway, and upregulated the expressions of lipid differentiation-related factors (SREBP1C, SCD-1, FAS, ACC1, CD36/FAT, ADIPOQ, C/EBPα and UCP-1). In vitro experiments, C2C12 cells were used to confirm cellular penetration of PS-NPs (0, 100, 200, 400 µg/mL) through cell membranes along with activation of PPARγ expression. Furthermore, to verify LXRß as a key signaling molecule, silencing RNA transfection experiments were conducted, resulting in no increase in the expressions of PPARγ, LXRß, SREBP1C, FAS, CD36/FAT, ADIPOQ, C/EBPα and UCP-1 even after exposure to PS-NPs. However, the expressions of SCD-1and ACC1 remained unaffected. The present study evidenced that exposure to PS-NPs induced lipid accumulation via the PPARγ/LXRß pathway thereby influencing skeletal muscle development.

Organosiloxane-Modified Auricularia Polysaccharide (Si-AP): Improved High-Temperature Resistance and Lubrication Performance in WBDFs.

This study introduces a novel organosilicon-modified polysaccharide (Si-AP) synthesized via grafting and comprehensively evaluates its performance in water-based drilling fluids (WBDFs). The molecular structure of Si-AP was characterized using Fourier-transform infrared spectroscopy (FTIR) and 1H-NMR experiments. Thermalgravimetric analysis (TGA) confirmed the good thermal stability of Si-AP up to 235 °C. Si-AP significantly improves the rheological properties and fluid loss performance of WBDFs. With increasing Si-AP concentration, system viscosity increases, API filtration rate decreases, clay expansion is inhibited, and drilling cuttings hydration dispersion is suppressed, especially under high-temperature conditions. Additionally, mechanistic analysis indicates that the introduction of siloxane groups can effectively inhibit the thermal degradation of AP chains and enhance their high-temperature resistance. Si-AP can form a lubricating film by adsorbing on the surface of clay particles, improving mud cake quality, reducing the friction coefficient, and significantly enhancing the lubricating performance of WBDFs. Overall, Si-AP exhibits a higher temperature-resistance limit compared to AP and more effectively optimizes the lubrication, inhibition, and control of the filtration rate of WBDFs under high-temperature conditions. While meeting the requirements of drilling fluid systems under high temperatures, Si-AP also addresses environmental concerns and holds promise as an efficient solution for the exploitation of deep-seated oil and gas resources.

Chemical tools for dissecting cell division.

Components of the cell division machinery typically function at varying cell cycle stages and intracellular locations. To dissect cellular mechanisms during the rapid division process, small-molecule probes act as complementary approaches to genetic manipulations, with advantages of temporal and in some cases spatial control and applicability to multiple model systems. This Review focuses on recent advances in chemical probes and applications to address select questions in cell division. We discuss uses of both enzyme inhibitors and chemical inducers of dimerization, as well as emerging techniques to promote future investigations. Overall, these concepts may open new research directions for applying chemical probes to advance cell biology.

Polyethylene microplastics trigger cell apoptosis and inflammation via inducing oxidative stress and activation of the NLRP3 inflammasome in carp gills.

Microplastics cause varying degrees of damage to aquatic organisms. Exposure to microplastics contaminated water, the gills are among the first tissues, after the skin, to be affected by microplastics. As an essential immune organ, prolonged stimulation by microplastics disrupts immune function not only in the gills but throughout the body, yet the underlying mechanisms remain elusive. A model of gill injury from exposure to polyethylene (PE) microplastics was developed in this study. H&E staining revealed that polyethylene microplastics caused gill inflammation, vascular remodeling, and mucous cell proliferation. An increase in collagen indicates severe tissue damage. Additional analysis showed that polyethylene microplastics profoundly exacerbated oxidative stress in the gills. TUNEL assay demonstrated cell apoptosis induced by polyethylene microplastic. The mRNA levels were subsequently quantified using RT-PCR. The results showed that polyethylene microplastics increased the expression of the nuclear factor-κB (NF-κB) pathway (NF-κB p65, IKKα, IKKß) and apoptosis biomarkers (p53, caspase-3, caspase-9, and Bax). Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasomes, which is an influential component of innate immunity, were overactive. What's more, the pro-inflammatory factors (TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-1ß) that induce immune disorder also increased significantly, while the anti-inflammatory factors (IL-4, IL-10) decreased significantly. These results suggested that oxidative stress acted as an activation signal of apoptosis triggered by the NF-κB pathway and activating the NLRP3 inflammasome to promote inflammatory immune responses. The present study provided a different target for the prevention of toxin-induced gill injury under polyethylene microplastics.

Conservation and diversification of HAIRY MERISTEM gene family in land plants.

The shoot apical meristems (SAMs) of land plants are crucial for plant growth and organ formation. In several angiosperms, the HAIRY MERISTEM (HAM) genes function as key regulators that control meristem development and stem cell homeostasis. To date, the origin and evolutionary history of the HAM family in land plants remains unclear. Potentially shared and divergent functions of HAM family members from angiosperms and non-angiosperms are also not known. In constructing a comprehensive phylogeny of the HAM family, we show that HAM proteins are widely present in land plants and that HAM proteins originated prior to the divergence of bryophytes. The HAM family was duplicated in a common ancestor of angiosperms, leading to two distinct groups: type I and type II. Type-II HAM members are widely present in angiosperms, whereas type-I HAM members were independently lost in different orders of monocots. Furthermore, HAM members from angiosperms and non-angiosperms (including bryophytes, lycophytes, ferns and gymnosperms) are able to replace the role of the type-II HAM genes in Arabidopsis, maintaining established SAMs and promoting the initiation of new stem cell niches. Our results uncover the conserved functions of HAM family members and reveal the conserved regulatory mechanisms underlying HAM expression patterning in meristems, providing insight into the evolution of key stem cell regulators in land plants.

Modified Le Fort I interpositional grafting of the severe atrophied maxilla-a retrospective study of 106 patients over 10 years.

OBJECTIVES: The objective of this study was to evaluate a modified Le Fort I interpositional grafting followed by dental implants for the rehabilitation of edentulous atrophied maxillae (Cawood classes IV and V). The surgical modification was a bilateral sinus floor augmentation prior to the osteotomy. This generated a closed recipient bed which allowed the use of particulated bone grafts (xenogenic bone mineral) and a reduced amount of autologous iliac bone grafts. MATERIALS AND METHODS: A total of 106 patients with maxillary interpositional bone grafts were included in this retrospective analysis between 2006 and 2020. The panoramic radiographs and lateral cephalograms were analyzed to assess the gain and stability of the maxillary bone and the peri-implant bone loss. In addition, the observational period of up to 14 years implant survival and success was evaluated. RESULTS: A stable vertical bone height with mean 0.63 ± 1.41 mm resorption over 5 years after implant loading was observed. A mean of 0.20 ± 0.37 mm marginal bone loss was noted after 5 years. The implant survival was 96.4% after 5 years and implant success can be rated 91.7% in a mean follow-up period of 93 months and 168 months maximal observation time. Perioperative complications included sinus membrane perforation (59.43%), wound healing disturbances (25.47%), and transient primary complications (13.78%). All receded apart from two subtotal graft losses (1.8%). CONCLUSIONS: The modified Le Fort I osteotomy with interpositional bone grafts is a predictable procedure in terms of bone and implant stability. Patients with atrophic maxillae who are fit for surgery should be informed about risks and benefits of this treatment alternative.

Cryopreservation of porcine skin-derived stem cells using melatonin or trehalose maintains their ability to self-renew and differentiate.

Porcine skin-derived stem cells (pSDSCs) are a type of adult stem cells (ASCs) that retain the ability to self-renew and differentiate. Currently, pSDSCs research has entered an intense period of development; however there has been no research regarding methods of cryopreservation. In this paper, we explored an efficient cryopreservation method for pSDSCs. Our results demonstrated that cryopreserving 50 µm diameter pSDSCs aggregates resulted in a lower apoptosis rate and a greater ability to proliferate to form larger spherical cell aggregates than during single-cell cryopreservation. To further optimize the cryopreservation method, we added different concentrations of melatonin (N-acetyl-5-methoxytryptamine, MLT) and trehalose (d-trehalose anhydrous, TRE) to act as cryoprotectants (CPAs) for the pSDSCs. After comparative experiments, we found that the cryopreservation efficiency of 50 mM TRE was superior. Further experiments demonstrated that the reason why 50 mM TRE improved cryopreservation efficiency was that it reduced the intracellular oxidative stress and mitochondrial damage caused by cryopreservation. Taken together, our results suggest that cryopreserving 50 µm diameter pSDSCs aggregates in F12 medium with 10% dimethyl sulfoxide (DMSO) and 50 mM TRE promotes the long-term storage of pSDSCs.

The effect of ultrasound-guided lung recruitment maneuvers on atelectasis in lung-healthy patients undergoing laparoscopic gynecologic surgery: a randomized controlled trial.

BACKGROUND: Atelectasis is the primary cause of hypoxemia during general anesthesia. This study aimed to evaluate the impact of the combination of recruitment maneuvers (RM) and positive end-expiratory pressure (PEEP) on the incidence of atelectasis in adult women undergoing gynecologic laparoscopic surgery using pulmonary ultrasound. METHODS: In this study, 42 patients with healthy lungs undergoing laparoscopic gynecologic surgery were randomly divided into the recruitment maneuver group (RM group; 6 cm H2O PEEP and RM) or the control group (C group; 6 cm H2O PEEP and no RM), 21 patients in each group. Volume-controlled ventilation was used in all selected patients, with a tidal volume of 6-8 mL·kg-1 of ideal body weight. When atelectasis was detected, patients in the RM group received ultrasound-guided RM, while those in the C group received no intervention. The incidence and severity of atelectasis were determined using lung ultrasound scores. RESULTS: A total of 41 patients were investigated. The incidence of atelectasis was lower in the RM group (40%) than in the C group (80%) 15 min after arrival in the post-anesthesia care unit (PACU). Meanwhile, lung ultrasound scores (LUSs) were lower in the RM group compared to the C group. In addition, the differences in the LUS between the two groups were mainly due to the differences in lung ultrasound scores in the posterior regions. However, this difference did not persist after 24 h of surgery. CONCLUSIONS: In conclusion, the combination of RM and PEEP could reduce the incidence of atelectasis in patients with healthy lungs 15 min after arrival at the PACU; however, it disappeared within 24 h after surgery. TRIAL REGISTRATION: (Prospectively registered): ChiCTR2000033529 . Registered on 4/6/2020.

Effect of Lung Recruitment Maneuvers on Reduction of Atelectasis Determined by Lung Ultrasound in Patients More Than 60 Years Old Undergoing Laparoscopic Surgery for Colorectal Carcinoma: A Prospective Study at a Single Center.

BACKGROUND Atelectasis occurs in patients of all ages during various surgeries. Previous studies have mainly focused on perioperative atelectasis in infants. However, research on the incidence of atelectasis among elderly patients, particularly those undergoing laparoscopic surgeries, is limited. Therefore, this prospective study aimed to investigate the effect of lung recruitment maneuvers (LRMs) on the reduction of atelectasis determined by lung ultrasound in patients more than 60 years old undergoing laparoscopic surgery for colorectal carcinoma. MATERIAL AND METHODS In this evaluator-blinded clinical study, 42 patients more than 60 years old diagnosed with colorectal carcinoma were randomly grouped either into a lung recruitment maneuver (RM) group or control (C) group. All patients were scheduled for laparoscopic surgery under general anesthesia using the lung-protective ventilation strategy. Lung ultrasonography was carried out at 3 predetermined time intervals. Patients in the RM group received ultrasound-guided recruitment maneuvers once atelectasis was discovered by lung ultrasound. Scores of lung ultrasound were used for assessing the severity of lung atelectasis. RESULTS At the end of the operation, the occurrence of atelectasis was 100% in the RM group and 95% in the C group. After RMs, the frequency of atelectasis in the RM group and C group was 50% and 95%, respectively (P<0.01). Postoperative pulmonary complications were not different between the 2 groups. CONCLUSIONS At a single center, patients more than 60 years old undergoing laparoscopic surgery for colorectal carcinoma had a prevalence of lung atelectasis of 100% and although LRMs significantly reduced the incidence of pulmonary atelectasis, they did not improve postoperative pulmonary complications.

Effect of Moringa oleifera supplementation on productive performance, colostrum composition and serum biochemical indexes of sow.

Moringa oleifera has been considered as a potential functional feed or food, since it contains multiple components beneficial to animal and human. However, little is known about the effects of Moringa oleifera supplementation on productive performances in sows. In the current study, the results showed that dietary Moringa oleifera significantly decreased the farrowing length and the number of stillborn (p < .05), while had an increasing trend in the number of live-born (0.05 < p < .10). Furthermore, 8% Moringa oleifera supplementation significantly elevated protein levels in the colostrum (p < .05); 4% Moringa oleifera lowed serum urea nitrogen of sows after 90 days of gestation (p < .05) and significantly decreased serum glucose on 10 days of lactation (p < .05). Both groups showed significant elevation in serum T-AOC activity (p < .05). The serum malondialdehyde (MDA) of sows declined significantly in 4% Moringa oleifera addition group (p < .05). 8% Moringa oleifera meal significantly elevated serum CAT activity after 60 days of gestation (p < .05), while decreased the serum MDA level and increased the serum GSH-Px activity of sows at 10 days of lactation (p < .05). Of piglets, both two dosages of Moringa oleifera supplementation essentially reduced the serum urea nitrogen (p < .05), and 4% Moringa oleifera meal increased serum total protein (p < .05). In addition, piglets that received 8% Moringa oleifera had the highest serum CAT and SOD activities among all groups (p < .05). The present study indicated that Moringa oleifera supplementation could enhance the reproduction performances, elevate protein levels in the colostrum and improve the serum antioxidant indices in both sows and piglets.

Dental implant location via surface scanner: a pilot study.

PURPOSE: Implant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro. MATERIAL AND METHODS: A total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad). RESULTS: In IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements. CONCLUSIONS: Dental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.

ß-Glucanase specific expression in the intestine of transgenic pigs.

Producing heterologous enzymes in the animal digestive tract to improve feed utilization rate is a new research strategy by transgenic technology. In this study, transgenic pigs specifically expressing ß-glucanase gene in the intestine were successfully produced by somatic cell nuclear transfer technology in order to improve digestibility of dietary ß-glucan and absorption of nutrients. The ß-glucanase activity in the intestinal juice of 4 transgenic pigs was found to be 8.59 ± 2.49 U/mL. The feeding trial results showed that the crude protein digestion of 4 transgenic pigs was significantly increased compared with that of the non-transgenic pigs. In order to investigate the inheritance of the transgene, 7 G1 transgenic pigs were successfully obtained. The ß-glucanase activity in the intestinal juice of 7 G1 transgenic pigs was found to be 2.35 ± 0.72 U/mL. The feeding trial results showed the crude protein digestion and crude fat digestion were significantly higher in 7 G1 transgenic pigs than in non-transgenic pigs. Taken together, our study demonstrated that the foreign ß-glucanase expressing in the intestine of the transgenic pigs could reduce the anti-nutritional effect of ß-glucans in feed. In addition, ß-glucanase gene could be inherited to the offsprings and maintain its physiological function. It is a promising approach to improve feed utilization by producing transgenic animals.

Dual inhibition of Kif15 by oxindole and quinazolinedione chemical probes.

The mitotic spindle is a microtubule-based machine that segregates a replicated set of chromosomes during cell division. Many cancer drugs alter or disrupt the microtubules that form the mitotic spindle. Microtubule-dependent molecular motors that function during mitosis are logical alternative mitotic targets for drug development. Eg5 (Kinesin-5) and Kif15 (Kinesin-12), in particular, are an attractive pair of motor proteins, as they work in concert to drive centrosome separation and promote spindle bipolarity. Furthermore, we hypothesize that the clinical failure of Eg5 inhibitors may be (in part) due to compensation by Kif15. In order to test this idea, we screened a small library of kinase inhibitors and identified GW108X, an oxindole that inhibits Kif15 in vitro. We show that GW108X has a distinct mechanism of action compared with a commercially available Kif15 inhibitor, Kif15-IN-1 and may serve as a lead with which to further develop Kif15 inhibitors as clinically relevant agents.

Sandwich osteotomy in atrophic mandibles: A retrospective study with a 2- to 144-month follow-up.

OBJECTIVES: The aim of the present retrospective study was to assess the long-term clinical outcome of sandwich osteotomy in pre-implant augmentation of atrophic mandible. MATERIALS AND METHODS: Sandwich osteotomies were performed in partially and fully edentulous mandibles of 63 consecutive patients in the present study. The vertical bone gain, graft stability, and marginal bone loss were measured radiographically. Implant survival and success rates were estimated in the follow-up ranged from 2 to 144 months (mean, 58 months). RESULTS: A total of 75 procedures were reviewed. After an average healing time of 148 days, 220 implants were placed in 74 procedures. Perioperative complications included intraoperative fracture (1/75), transient paresthesia (18/75), wound healing disturbance (18/75), and keratinized tissue deficiency (14/75). The average vertical bone gain was 5.4 mm at the time of implant placement. Significant marginal bone loss occurred during the first 6 months, after which the resorption remained stable. The implant survival rate was estimated as 96.7%, and the success rate was 95.3%. Implant survival and success showed no significant correlation with higher age, anticoagulation therapy, cardiovascular disease, or thyroid disorder. Smoking was correlated with significant lower success rate. CONCLUSION: Sandwich osteotomy is a suitable augmentation procedure for atrophic mandible, allowing for implant placement with promising outcome.

[Heterogenous expression and enzymatic property analysis of microbial-derived pectinases in pig PK15 cells].

As one of plant cell wall components, pectin is the main anti-nutritional factor in livestock and poultry feeds and has an adverse effect on utilization efficiency of feed energy and nitrogen. Pectinases, which are widely found in microorganisms such as bacteria, yeast and filamentous fungi in nature,can improve feed efficiency by relieving the anti-nutritional effect of pectin through promoting the hydrolysis reaction of feed pectin. To explore the feasibility of expressing microbial-derived pectinase genes in pig cells, we introduced microbial-derived pectinase genes pg5a, pgI, pga3A, and pgaA into porcine PK 15 cells by lipofection for heterogenous expression. Enzymatic activities of the pectinases encoded by these genes were analyzed using the 3,5 dinitrosalicylic acid (DNS) method. Results showed that all four pectinase genes were able to be transcribed into mRNAs in porcine PK 15 cells, but only pg5a and pgI were adapted to the porcine cell expression system. Among them, the maximum activity of pectinase PG5A was 0.95 U/mL, the optimum pH was pH 4.0, and the enzymatic activity was maintained above 46% in the range of pH 4.6 to 6.0. Pectinase PGI obtained the highest enzymatic activity at pH 5.0, which was 0.30 U/mL, and maintained more than 35% of the activity in the range of pH 4.0 to 6.0. The results of digestive protease tolerance test showed that PG5A and PGI were highly resistant to pepsin and trypsin. After treatment with 1 mg/mL pig pepsin for two hours, the residual enzymatic activities of PG5A and PGI were 76% and 71%, respectively. And after two hours treatment with 1 mg/mL of pig trypsin, the remaining enzymatic activities of PG5A and PGI were 44% and 93%, respectively. In summary, pectinase PG5A and PGI can be effectively expressed in pig cells, and have strong tolerance to pig intestinal pH environment and digestive proteases. Therefore, both pg5a and pgI can be used as candidate genes for production of transgenic pigs.

[Histone H3K27me3 in the regulation of skeletal muscle development].

Histone methylation is a modification which occurs in the N-terminal peptide chains of the histone nucleosome. The 4th, 9th, 27th, 36th and 79th lysines in N-terminal peptide chain of histone H3 are hot spots for this modification, including mono-, di-, and tri-methylation. H3K27me3 is the tri-methylation modification on histone H3 lysine 27, which mainly functions as a transcriptional repressor regulating skeletal muscle development. Studies have shown that H3K27me3 can finely regulate skeletal muscle proliferation, including the level and duration of skeletal muscle development by specifically binding to myogenic regulatory factors (e.g., MyoD, MyoG, etc.), cell cycling regulators, and epigenetic regulators including lncRNA and miRNA. In this review, we introduce the types and mechanisms of histone methylation and de-methylation of H3K27. We also summarize how H3K27me3 functions in the proliferation and differentiation of skeletal muscle cell. This review will contribute to the comprehension of the function of H3K27me3 in regulating skeletal muscle development and provide reference for further improving our understanding of mammalian muscle.