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Abstract Background Free fatty acids (FFAs) play vital roles as energy sources and substrates in organisms; however, the molecular mechanism regulating the homeostasis of FFA levels in various circumstances, such as feeding and nonfeeding stages, is not fully clarified. Holometabolous insects digest dietary triglycerides (TAGs) during larval feeding stages and degrade stored TAGs in the fat body during metamorphosis after feeding cessation, which presents a suitable model for this study. Results This study reported that two lipases are differentially regulated by hormones to maintain the homeostasis of FFA levels during the feeding and nonfeeding stages using the lepidopteran insect cotton bollworm Helicoverpa armigera as a model. Lipase member H-A-like (Lha-like), related to human pancreatic lipase (PTL), was abundantly expressed in the midgut during the feeding stage, while the monoacylglycerol lipase ABHD12-like (Abhd12-like), related to human monoacylglycerol lipase (MGL), was abundantly expressed in the fat body during the nonfeeding stage. Lha-like was upregulated by juvenile hormone (JH) via the JH intracellular receptor methoprene-tolerant 1 (MET1), and Abhd12-like was upregulated by 20-hydroxyecdysone (20E) via forkhead box O (FOXO) transcription factor. Knockdown of Lha-like decreased FFA levels in the hemolymph and reduced TAG levels in the fat body. Moreover, lipid droplets (LDs) were small, the brain morphology was abnormal, the size of the brain was small, and the larvae showed the phenotype of delayed pupation, small pupae, and delayed tissue remodeling. Knockdown of Abhd12-like decreased FFA levels in the hemolymph; however, TAG levels increased in the fat body, and LDs remained large. The development of the brain was arrested at the larval stage, and the larvae showed a delayed pupation phenotype and delayed tissue remodeling. Conclusions The differential regulation of lipases expression by different hormones determines FFAs homeostasis and different TAG levels in the fat body during the feeding larval growth and nonfeeding stages of metamorphosis in the insect. The homeostasis of FFAs supports insect growth, brain development, and metamorphosis.

Abstract Objective To summarize and discuss the guiding role of endoscopic ultrasound (EUS) in selecting endoscopic treatments for submucosal tumors (SMTs) in the upper gastrointestinal tract. Methods A retrospective investigation was conducted on 156 SMT patients who received endoscopic resection guided by EUS in the endoscopy center of the Second Affiliated Hospital of Guangzhou University of Chinese Medicine from May 2019 to September 2021. Next, the size, pathological type, and distribution of lesions were analyzed; the correlation of the tumor origin with distribution of lesions and selection of treatments was explored; and the consistency of preoperative EUS diagnosis and postoperative pathological diagnosis was summarized and analyzed. Results The tumor diameters of the included SMT patients ranged from 0.3 to 4 cm, with a mean diameter of 0.95 cm; the lesions were mostly located in the esophagus, gastric fundus or fundic cardia and gastric body. As for the pathological types, liomyoma was the most common tumor in the esophagus, liomyoma and mesenchymoma were mainly located in the fundic cardia and gastric body, and heterotopic pancreas was mostly discovered in the gastric sinus. Among 38 esophageal SMT patients, some with lesions originating from muscularis mucosa and submucosa under EUS mainly underwent endoscopic submucosal dissection (ESD) and endoscope band ligation (EBL); while others with lesions originated from muscularis propria mainly received submucosal tunneling endoscopic resection (STER). Of 115 gastric SMT patients under EUS, some with lesion origins from the muscularis mucosa and submucosa mainly underwent endoscopic submucosal excavation (ESE), while others from muscularis propria mainly underwent ESE, ESD, and endoscopic full-thickness resection (EFTR). Besides, 3 duodenal SMT patients with lesion origins from submucosa and muscularis propria under EUS were given ESD and ESE, respectively. Additionally, 121 cases showed a consistency between the EUS diagnosis and the postoperative pathological nature, and the consistency rate was 84.6%. Conclusion Clarifying the origin layer, size, growth pattern, and pathological nature of the lesion through preoperative EUS can guide the precise selection of endoscopic treatments, thereby ensuring a safe, effective, and complete surgical outcomes and reducing complications.

ObjectivesThis study attempted to explore the hemodynamics and potential mechanisms driving pulmonary circulation in status of ventricular fibrillation (VF) following continuous-flow left ventricular assist device (CF-LVAD) implantation.MethodsAn ovine CF-LVAD model was built in small-tailed Han sheep, with the pump speed set as 2,400 rpm. VF was induced following ventricular tachycardia using a temporary pacemaker probe to stimulate the right and left ventricular free walls. The central venous pressure (CVP), pump flow (PF), pulmonary artery flow (PAF) and other major indicators were observed and recorded after VF.ResultsLow-flow systemic and pulmonary circulation could be sustained for 60 min under VF with sinus atrial rhythm after CF-LVAD implantation. The CVP gradually increased. The mean PF declined from 1.80 to 1.20 L/min, and the mean PAF decreased from 1.62 L/min to 0.87 L/min. Under VF with atrial fibrillation, the systemic and pulmonary circulation couldn’t be sustained. The CVP jumped from the 5 mmHg baseline to 12 mmHg, the mean PF rapidly decreased from 3.45 L/min to 0.79 L/min, and the PAF declined from 3.94 L/min to 0.77 L/min.ConclusionThe atrial rhythm and function might be essential for the circulation maintenance in patients with VF after CF-LVAD implantation.

Selective gene expression in cells in physiological or pathological conditions is important for the growth and development of organisms. Acetylation of histone H4 at K16 (H4K16ac) catalyzed by histone acetyltransferase 8 (KAT8) is known to promote gene transcription; however, the regulation of KAT8 transcription and the mechanism by which KAT8 acetylates H4K16ac to promote specific gene expression are unclear. Using the lepidopteran insect Helicoverpa armigera as a model, we reveal that the transcription factor FOXO promotes KAT8 expression and recruits KAT8 to the promoter region of autophagy-related gene 8 (Atg8) to increase H4 acetylation at that location, enabling Atg8 transcription under the steroid hormone 20-hydroxyecdysone (20E) regulation. H4K16ac levels are increased in the midgut during metamorphosis, which is consistent with the expression profiles of KAT8 and ATG8. Knockdown of Kat8 using RNA interference results in delayed pupation and repression of midgut autophagy and decreases H4K16ac levels. Overexpression of KAT8-GFP promotes autophagy and increases H4K16ac levels. FOXO, KAT8, and H4K16ac colocalized at the FOXO-binding region to promote Atg8 transcription under 20E regulation. Acetylated FOXO at K180 and K183 catalyzed by KAT8 promotes gene transcription for autophagy. 20E via FOXO promotes Kat8 transcription. Knockdown or overexpression of FOXO appeared to give similar results as knockdown or overexpression of KAT8. Therefore, FOXO upregulates KAT8 expression and recruits KAT8 to the promoter region of Atg8, where the KAT8 induces H4 acetylation to promote Atg8 transcription for autophagy under 20E regulation. This study reveals the mechanism that KAT8 promotes transcription of a specific gene. [ABSTRACT FROM AUTHOR]