Design, synthesis and biological evaluation of Thiazolo[3, 2-a]Pyrimidine derivatives as novel RNase H inhibitors.

Targeting Ribonuclease H (RNase H) has been considered a viable strategy for HIV therapy. In this study, a series of novel thiazolo[3, 2-a]pyrimidine derivatives were firstly designed and synthesized as potential inhibitors of HIV-1 RNase H. Among these compounds, A28 exhibited the most potent inhibition against HIV-1 RNase H with an IC50 value of 4.14 µM, which was about 5-fold increase in potency than the hit compound A1 (IC50 = 21.49 µM). To gain deeper insights into the structure-activity relationship (SAR), a CoMFA model was constructed to yield reasonable statistical results (q2 = 0.658 and R2 = 0.969). Results from magnesium ion chelation experiments and molecular docking studies revealed that these thiazolopyrimidine inhibitors may exert their inhibitory activity by binding to an allosteric site on RNase H at the interface between subunits p51 and p66. Furthermore, this analog demonstrated favorable physicochemical properties. Our findings provide valuable groundwork for further development of allosteric inhibitors targeting HIV-1 RNase H.

Additively manufactured bioceramic scaffolds based on triply periodic minimal surfaces for bone regeneration.

The study focused on the effects of a triply periodic minimal surface (TPMS) scaffolds, varying in porosity, on the repair of mandibular defects in New Zealand white rabbits. Four TPMS configurations (40%, 50%, 60%, and 70% porosity) were fabricated with ß-tricalcium phosphate bioceramic via additive manufacturing. Scaffold properties were assessed through scanning electron microscopy and mechanical testing. For proliferation and adhesion assays, mouse bone marrow stem cells (BMSCs) were cultured on these scaffolds. In vivo, the scaffolds were implanted into rabbit mandibular defects for 2 months. Histological staining evaluated osteogenic potential. Moreover, RNA-sequencing analysis and RT-qPCR revealed the significant involvement of angiogenesis-related factors and Hippo signaling pathway in influencing BMSCs behavior. Notably, the 70% porosity TPMS scaffold exhibited optimal compressive strength, superior cell proliferation, adhesion, and significantly enhanced osteogenesis and angiogenesis. These findings underscore the substantial potential of 70% porosity TPMS scaffolds in effectively promoting bone regeneration within mandibular defects.

Structure-guided design of novel biphenyl-quinazoline derivatives as potent non-nucleoside reverse transcriptase inhibitors featuring improved anti-resistance, selectivity, and solubility.

In pursuit of enhancing the anti-resistance efficacy and solubility of our previously identified NNRTI 1, a series of biphenyl-quinazoline derivatives were synthesized employing a structure-based drug design strategy. Noteworthy advancements in anti-resistance efficacy were discerned among some of these analogs, prominently exemplified by compound 7ag, which exhibited a remarkable 1.37 to 602.41-fold increase in potency against mutant strains (Y181C, L100I, Y188L, F227L + V106A, and K103N + Y181C) in comparison to compound 1. Compound 7ag also demonstrated comparable anti-HIV activity against both WT HIV and K103N, albeit with a marginal reduction in activity against E138K. Of significance, this analog showed augmented selectivity index (SI > 5368) relative to compound 1 (SI > 37764), Nevirapine (SI > 158), Efavirenz (SI > 269), and Etravirine (SI > 1519). Moreover, it displayed a significant enhancement in water solubility, surpassing that of compound 1, Etravirine, and Rilpivirine. To elucidate the underlying molecular mechanisms, molecular docking studies were undertaken to probe the critical interactions between 7ag and both WT and mutant strains of HIV-1 RT. These findings furnish invaluable insights driving further advancements in the development of DAPYs for HIV therapy.

Study on the effect of protein lysine lactylation modification in macrophages on inhibiting periodontitis in rats.

BACKGROUND: Protein lysine lactylation (Kla) has been proved to be closely related to inflammatory diseases, but its role in periodontitis (PD) is unclear. Therefore, this study aimed to establish the global profiling of Kla in PD models in rats. METHODS: Clinical periodontal samples were collected, the inflammatory state of tissues was verified by H&E staining, and lactate content was detected by a lactic acid kit. Kla levels were detected by immunohistochemistry (IHC) and Western blot. Subsequently, the rat model of PD was developed and its reliability verified by micro-CT and H&E staining. Mass spectrometry analysis was conducted to explore the expression profile of proteins and Kla in periodontal tissues. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed, and a protein-protein interaction (PPI) network was constructed. The lactylation in RAW264.7 cells was confirmed by IHC, immunofluorescence and Western blot. The relative expression levels of inflammatory factors IL-1ß, IL-6, TNF-α, macrophage polarization-related factors CD86, iNOS, Arg1, and CD206 in RAW264.7 cells were detected by real time-quantitative polymerase chain reaction (RT-qPCR). RESULTS: We observed substantial inflammatory cell infiltration in the PD tissues, and the lactate content and lactylation levels were significantly increased. The expression profiles of protein and Kla were obtained by mass spectrometry based on the established rat model of PD. Kla was confirmed in vitro and in vivo. After inhibiting the "writer" of lactylation P300 in RAW264.7 cells, the lactylation levels decreased, and the expression of inflammatory factors IL-1ß, IL-6, and TNF-α increased. Meanwhile, the levels of CD86 and iNOS increased, and Arg1 and CD206 decreased. CONCLUSIONS: Kla may play an important role in PD, regulating the release of inflammatory factors and polarization of macrophages.

SDF-1 Functionalized Hydrogel Microcarriers for Skin Flap Repair.

Critically sized skin flaps used to treat skin defects often suffer from necrosis due to insufficient blood supply. Hence there is an urgent need to improve the survival rate of skin flaps by promoting local angiogenesis. The delivery of growth factor loaded microcarriers have shown promise in enhancing defect repair, however, their rapid clearance from the defect site limits their regenerative potential. Thus, it is critical to develop microcarriers which can promote the sustained release of bioactive factors to effectively stimulate tissue repair. This study aimed to develop a stromal cell-derived factor 1 (SDF-1) loaded microcarrier coated with Matrigel (MC@SDF-1@Mat) to promote skin flap repair. SEM imaging showed that the surface of the microcarrier was coated by a porous Matrigel film. The drug release experiment showed that the Matrigel-coated microcarriers enhanced the sustained release of the model drug methylene blue when compared to uncoated group. MC@SDF-1@Mat significantly promoted the proliferation, migration, and angiogenesis of HUVECs via CCK-8, wound healing assay, and tube formation assay, respectively. Moreover, the murine random skin flap model was further established and treated. It was found that the flap necrosis area in the MC@SDF-1@Mat treated group was significantly reduced. H&E and Masson staining showed the histological structure and collagen organization exhibited a normal phenotype in the MC@SDF-1@Mat treated group. Additionally, CD31 immunohistochemical analysis showed that the MC@SDF-1@Mat treated group exhibited the greatest degree of neovascularization. In conclusion, our SDF-1 functionalized gelatin-based hydrogel microcarrier has potential clinical applications in promoting skin flap repair and drug delivery.

Roles of HDAC2, eIF5, and eIF6 in Lung Cancer Tumorigenesis.

OBJECTIVE: The expression levels of histone deacetylase 2 (HDAC2), eukaryotic initiation factor 5 (eIF5), and eukaryotic initiation factor 6 (eIF6), and relationship between HDAC2 and eIF5 or eIF6 in lung cancer tissues were investigated, in order to charify the relationship between HDAC2 and the prognosis of lung cancer patients and its influence on the expression of eIF5 and eIF6. METHODS: The expression of HDAC2, eIF5, and eIF6 in lung cancer tissues was detected by quantitative reverse transcription polymerase chain reaction. The expression correlation between HDAC2 and eIF5 or eIF6 was tested using a t test. The correlation between HDAC2 and eIF5 or eIF6 was analyzed using the TCGA database. The identified cells were constructed with small interfering siRNA and HDAC2 overexpression plasmid. The proliferation and migration ability of the identified cells was investigated by CCK8 and Transwell assays, respectively. RESULTS: HDAC2, eIF5, and eIF6 were overexpressed in lung cancer tissues, and HDAC2 expression level was negatively correlated with the prognosis of lung cancer patients. HDAC2 expression level was positively correlated with eIF5 and eIF6 expression levels. HDAC2 could regulate the expression of eIF5 and eIF6. The regulation of proliferation and invasion of lung cancer cells by HDAC2 depended on eIF5 and eIF6. CONCLUSION: HDAC2, eIF5, and eIF6 were closely related with lung cancer tumorigenesis, which might be potential biological markers and therapeutic targets for lung cancer.

Lysine-specific histone demethylase 1B (LSD2/KDM1B) represses p53 expression to promote proliferation and inhibit apoptosis in colorectal cancer through LSD2-mediated H3K4me2 demethylation.

Epigenetic alterations have been reported to play critical roles in the development of colorectal cancer (CRC). However, the biological function of the lysine-specific histone demethylase 1B (LSD2/KDM1B) in CRC is not well understood. Therefore, we investigated the characteristics of LSD2 in CRC. We observed significant upregulation of LSD2 in CRC tissue compared to that in normal colorectal tissue. LSD2 promotes CRC cell proliferation and inhibits cell apoptosis through cell cycle regulation, promoting CRC progression both in vitro and in vivo. We found that LSD2 performs these functions by inhibiting the p53-p21-Rb pathway. Finally, we found that LSD2 directly binds to p53 and represses p53 expression via H3K4me2 demethylation at the p53 promoter. Our results revealed that LSD2 acts as an oncogene by binding and inhibiting p53 activity in CRC. Thus, LSD2 may be a new molecular target for CRC treatment.

Overexpression of c-Ski promotes cell proliferation, invasion and migration of gastric cancer associated fibroblasts.

The present study aimed to investigate the effects of c-Ski on cell proliferation, invasion and migration of gastric cancer associated fibroblasts (CAFs). Expression of c-Ski in gastric cancer (GC) tissues was determined using immunohistochemistry. Both CAFs and non-cancerous gastric fibroblasts (NGFs) were isolated and cultured. c-Ski and Smad3 were over-expressed or knocked down using pcDNA3.0-c-Ski/Smad3 or siRNA, respectively. Cell viability, invasion and migration were measured and expression of c-Ski, α-SMA, and Smad3 in cells was determined using real time quantitative PCR (RT-qPCR) and Western blotting. Expression of c-Ski was significantly higher in both in GC tissues and cell lines, and was the highest in tissues of diffuse type. Both c-Ski and α-SMA were significantly over-expressed in CAFs compared with that in the NGFs. When c-Ski was over-expressed in NGFs, cell viability, cell invasion and migration were all enhanced and expression of Smad3 was downregulated. When c-Ski was inhibited, cell viability, cell invasion, and migration were all suppressed and expression of Smad3 was upregulated. Meanwhile, overexpression of Smad3 significantly reversed the effects of over-expressed c-Ski in NGFs, and knockdown of Smad3 dramatically reversed the effects of si-c-Ski in CAFs. Over-expressed c-Ski could enhance cell viability, promote cell invasion, and migration of GC CAFs, and the effects might be through regulation of Smad3 signaling. This study may give deeper insights for relationship between c-Ski and CAFs, as well as role of c-Ski in cancer development, and also provide some novel research targets for treatment of GC.

[Application of intracorporeal uncut Roux-en-Y anastomosis in digestive tract reconstruction after laparoscopic total gastrectomy].

OBJECTIVE: To explore the safety, feasibility and short-term efficacy of intracavitary uncut Roux-en-Y (URY) anastomosis in digestive tract reconstruction following laparoscopic total gastrectomy (LTG). METHODS: From November 2015 to January 2018, 67 gastric cancer patients underwent intracavitary URY following LTG to reconstruct the digestive tract at Oncological Surgery Department of Fujian Provincial Hospital. There were 41 males and 26 females with age of 50 to 81 (61.9±7.4) years and body mass index (BMI) of (23.4±3.2) kg/m². Among 67 patients, 19 were gastric cardia carcinomas, 33 were gastric body carcinomas, and 15 were gastric fundus carcinomas; tumor size was (3.4±2.3) cm; 22 were Borrmann type I, 15 were type II, 21 were type III, and 19 were type IV; 29 were highly or moderately differentiated adenocarcinoma, 23 were lowly differentiated adenocarcinoma, and 15 were signet-ring cell carcinoma. After conventional laparoscopic D2 radical gastrectomy, the duodenum was closed and dissociated at 2 cm below the pyloric ring using the Echelon-flex endoscopic articulated linear Endo-GIA stapler, and the esophagus was dissociated above the esophagogastric junction (EGJ).URY and digestive tract reconstruction were performed under the direct vision of laparoscope: (1) Side-to-side esophagojejunostomy: An incision of 0.5 cm was made in the left lower edge of the esophageal closed end; jejunum about 25 cm distal away from the Treitz ligament was elevated to the lower end of esophagus; another incision of 0.5 cm was made in the contralateral of mesenteric side; both arms of the linear Endo-GIA stapler were inserted into the windows opened through esophagus and jejunum respectively to complete side-to-side anastomosis. The common opening of esophagus and jejunum was closed to complete esophagojejunostomy, forming the chyme outflow tract. (2) Side-to-side Braun jejunojejunostomy: Incisions of 0.5 cm were made in the proximal jejunum about 10 cm away from the esophagojejunal anastomosis and 35-40 cm away from the contralateral of mesenteric side of distal jejunum respectively for proximal-distal side-to-side jejunojejunostomy. The common opening was closed to form the biliopancreatic duodenal juice outflow tract. (3) Closure of the input loop jejunum in the esophagojejunal anastomosis: The input loop jejunum 2-3 cm away from the esophagojejunal anastomosis was closed using the non-blade linear stapler (ATS45NK), and the biliopancreatic duodenal juice reflux was blocked. Clinical data of these patients were collected for retrospective case series study. Surgical and digestive tract functional recovery, perioperative complications, as well as postoperative nutritional status were observed. Moreover, related indexes, such as anastomosis function and tumor recurrence were evaluated through endoscopic and imaging examinations during postoperative follows-up. RESULTS: All the 67 patients completed the surgery successfully. The mean operative time was (259.4±38.5) minutes, digestive tract reconstruction time was (38.2±13.2) minutes, intraoperative blood loss was (73.4±38.4) ml, and number of harvested lymph node was 36.2±14.2. The mean distance from upper resection margin to upper tumor edge was (3.3±1.2) cm, distance from upper resection margin to dentate line was (1.2±0.7) cm, and 1 case had positive upper incisal margin, which became negative after the second resection. Moreover, the average length of the auxiliary incision was (3.2±0.4) cm. The mean postoperative intestinal exhaust time was (52.8±26.4) hours, time to liquid diet was (64.8±28.8) hours, and postoperative hospital stay was (8.4±2.5) days. The morbidity of postoperative complication was 10.4%(7/67). Among these 7 cases, 4 cases were grade IIIa of Clavien-Dindo classification, including 2 with esophagojejunal anastomosis leakage, 1 with duodenal stump leakage, and 1 with abdominal infection, and all these patients were recovered after conservative treatment. All the 67 patients were followed up. The mean nutrition index 12 months after surgery was 53.4±4.2, diameter of esophagojejunal anastomosis was (3.9±0.6) cm, the incidence of Roux-en-Y stasis syndrome was 3.0% (2/67), and the incidence of reflux esophagitis was 4.5% (3/67). No patient had recanalization of the closed input loop of esophagojejunal anastomosis, anastomotic stenosis, obstruction, or tumor recurrence at anastomosis. CONCLUSION: Intracavitary URY anastomosis following LTG for digestive tract reconstruction is safe and feasible, leading to fast postoperative recovery of digestive tract function and favorable short-term efficacy.