1.Lipid Droplet Biogenesis at the Endoplasmic Reticulum: Orchestrating Nucleation, Membrane Budding, and Expansion
Yue YU ; Wei-Ke JI ; Juan XIONG
Progress in Biochemistry and Biophysics 2025;52(9):2189-2204
Lipid droplets (LDs) are dynamic organelles that are ubiquitous across most organisms, including animals, plants, protists, and microorganisms. Their core consists of neutral lipids, surrounded by a phospholipid monolayer adorned with a specific set of proteins. As critical intracellular hubs of metabolic regulation, lipid droplets play essential roles in maintaining physiological homeostasis and contributing to the progression of various pathological processes. They store neutral lipids for energy production during periods of starvation or for membrane biosynthesis, and they sequester fatty acids to mitigate lipotoxicity. Clinically, dysregulation of lipid droplet function is associated with a wide range of diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD), obesity, type 2 diabetes mellitus (T2DM), neurodegenerative disorders, and cancer. Research into the biological functions of lipid droplets—as dynamic organelles and their links to multiple diseases—has emerged as a cutting-edge focus in cell biology. In recent years, significant advances have been made in understanding lipid droplet biogenesis. Researchers have developed a more refined framework that elucidates how LDs are assembled in the endoplasmic reticulum (ER). Triacylglycerols and sterol esters are synthesized between the inner and outer leaflets of the ER bilayer, and when they exceed the critical nucleation concentration (CNC), they coalesce to form neutral lipid lenses. These then bud from the ER under the coordinated action of key proteins such as Seipin, fat storage-inducing transmembrane protein 2 (FIT2), and the peroxisomal membrane protein Pex30. This budding process is driven by changes in membrane curvature and surface tension, induced by the asymmetric distribution of phospholipids. Nascent lipid droplets recruit lipid-synthesizing enzymes via ER-LD bridging structures, enabling localized lipid production and surface expansion, ultimately resulting in the formation of mature LDs. Biochemical and biophysical approaches have revealed important features of this process, underscoring the critical roles of ER membrane biophysical properties and specific phospholipids. Structural biology and proteomic studies have identified key regulators—particularly Seipin and FIT2—as central players in LD biogenesis. This review systematically summarizes recent advances in the molecular mechanisms of LD biogenesis. It delves into the processes of LD nucleation, membrane budding, and expansion in eukaryotic cells, with a special focus on how core factors such as Seipin and FIT2 dynamically regulate LD morphology. In addition, it examines the mechanisms and pathways by which class I and class II proteins are targeted to LDs, compares LD biogenesis involving different neutral lipid cores, and discusses the disease relevance of specific regulatory proteins. Finally, the review outlines critical unresolved questions in the field of LD biogenesis, offering clear directions for future research and providing a comprehensive framework for deepening our understanding of LD formation and its implications for disease intervention.
2.Single mini-incision combined with honeycomb titanium plate in treatment of acute acromioclavicular joint disloca-tion
Yu-Chen WANG ; Wei-Zhong YU ; Yun-Feng LI ; Wen-Ke ZHU ; Chuan JIA ; Jun-Qi WU ; Hua GAO ; Lin JI
China Journal of Orthopaedics and Traumatology 2024;37(6):576-582
Objective To explore clinical effect of single small incision with honeycomb titanium plate in treating acute acromioclavicular dislocation.Methods The clinical data of 40 patients with acute acromioclavicular dislocation admitted from December 2019 to December 2021 were retrospectively analyzed and divided into two groups according to different surgical methods.Among them,20 patients were fixed with single small incision with honeycomb titanium plate(titanium plate group),including 11 males and 9 females,aged from 23 to 65 years old with an average of(47.40±12.58)years old;12 patients on the left side,8 patients on the right side;11 patients with type Ⅲ,3 patients with type Ⅳ,and 6 patients with type Ⅴ according to Rockwood classification.Twenty patients were fixed with clavicular hook plate(clavicular hook group),including 8 males and 12 females,aged from 24 to 65 years old with an average of(48.40±12.08)years old;12 patients on the left side,8 patients on the right side;10 patients with type Ⅲ,2 patients with type Ⅳ,and 8 patients with type V according to Rockwood classifica-tion.Operative time,incision length,intraoperative blood loss,hospital stay,visual analogue scale(VAS)and Constant-Murley score of shoulder joint function were compared between two groups.Anteroposterior radiographs of the affected shoulder joint were recorded before,immediately and 6 months after surgery,and the coracoclavicular distance was measured and compared.Results Both groups of patients were successfully completed operation without serious complications.All patients were fol-lowed up for 6 to 15 months with an average of(11.9±4.8)months.There were no incisional infection,internal plant fracture or failure,bone tunnel fracture and other complications occurred.The incision length of titanium plate group(35.90±3.14)mm was significantly shorter than that of clavicular hook group(49.30±3.79)mm(P<0.05).There were no significant difference in operative time,intraoperative blood loss and hospital stay between two groups(P>0.05).At 1 and 3 months after operation,VAS of titanium plate group was lower than that of clavicular hook group(P<0.05).Connstant-Murley scores in titanium plate group at 1,3 and 6 months after operation were(86.80±1.36),(91.60±2.32)and(94.90±2.22),respectively;and in clavicular hook group were(78.45±5.47),(85.55±2.01)and(90.25±1.92),which were higher than that of clavicular hook group(P<0.05).There was no significant difference in coracoclavicular distance between two groups immediately and 6 months after op-eration(P>0.05).Conclusion For the treatment of acute acromioclavicular joint dislocation,single small incision combined with honeycomb titanium plate have advantages of shorter incision,fast recovery of shoulder joint function without the second operation,and has good satisfaction of patient.
3.Clinical Characteristics of CD4-CD56+Blastic Plasmacytoid Dendritic Cell Neoplasm
He-Sheng HE ; Yuan-Feng WEI ; Xin-Yue JI ; You-Hai XU ; Yu-Qiong YANG ; Xiao-Ke JIN
Journal of Experimental Hematology 2024;32(2):588-594
Objective:To explore the clinical manifestations,pathological features,immunophenotype,as well as diagnosis,treatment and prognosis of patients with CD4-CD56+blastic plasmacytoid dendritic cell neoplasm(BPDCN),in order to further understand the rare disease.Methods:The clinical data,laboratory examinations and treatment regimens of two patients with CD4-CD56+BPDCN in the First Affiliated Hospital of Wannan Medical College were retrospectively analyzed.Results:The two patients were both elderly males with tumor involved in skin,bone marrow,lymph nodes,etc.Immunohistochemical results of skin lesions showed that both CD56 and CD123 were positive,while CD4,CD34,TdT,CD3,CD20,MPO and EBER were negative.Flow cytometry of bone marrow demonstrated that CD56,CD123,and CD304 were all positive,while specific immune markers of myeloid and lymphoid were negative.Two patients were initially very sensitive to acute lymphoblastic leukemia or lymphomatoid chemotherapy regimens,but prone to rapid relapse.The overall survival of both patients was 36 months and 4 months,respectively.Conclusion:CD4-CD56+BPDCN is very rare and easily misdiagnosed as other hematological tumors with poor prognosis.Acute lymphoblastic leukemia or lymphomatoid therapy should be used first to improve the poor prognosis.
5.Exploring lncRNA Expression Patterns in Patients With Hypertrophied Ligamentum Flavum
Junling CHEN ; Guibin ZHONG ; Manle QIU ; Wei KE ; Jingsong XUE ; Jianwei CHEN
Neurospine 2024;21(1):330-341
Objective:
Hypertrophy ligamentum flavum (LFH) is a common cause of lumbar spinal stenosis, resulting in significant disability and morbidity. Although long noncoding RNAs (lncRNAs) have been associated with various biological processes and disorders, their involvement in LFH remains not fully understood.
Methods:
Human ligamentum flavum samples were analyzed using lncRNA sequencing followed by validation through quantitative real-time polymerase chain reaction. To explore the potential biological functions of differentially expressed lncRNA-associated genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. We also studied the impact of lncRNA PARD3-AS1 on the progression of LFH in vitro.
Results:
In the LFH tissues when compared to that in the nonhypertrophic ligamentum flavum (LFN) tissues, a total of 1,091 lncRNAs exhibited differential expression, with 645 upregulated and 446 downregulated. Based on GO analysis, the differentially expressed transcripts primarily participated in metabolic processes, organelles, nuclear lumen, cytoplasm, protein binding, nucleic acid binding, and transcription factor activity. Moreover, KEGG pathway analysis indicated that the differentially expressed lncRNAs were associated with the hippo signaling pathway, nucleotide excision repair, and nuclear factor-kappa B signaling pathway. The expression of PARD3-AS1, RP11-430G17.3, RP1-193H18.3, and H19 was confirmed to be consistent with the sequencing analysis. Inhibition of PARD3-AS1 resulted in the suppression of fibrosis in LFH cells, whereas the overexpression of PARD3-AS1 promoted fibrosis in LFH cells in vitro.
Conclusion
This study identified distinct expression patterns of lncRNAs that are linked to LFH, providing insights into its underlying mechanisms and potential prognostic and therapeutic interventions. Notably, PARD3-AS1 appears to play a significant role in the pathophysiology of LFH.
6.Influence of the severity of diabetic retinopathy on three-dimensional choroidal vascularity index and its significance
Fengtao JI ; Hui WANG ; Yongrong LI ; Wei DAI ; Ke WEI ; Zhimin WANG ; Rongfeng LIAO
Chinese Journal of Experimental Ophthalmology 2024;42(8):736-743
Objective:To investigate the relationship between three-dimensional choroidal vascularity index (3D CVI) and the severity of diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA).Methods:A cross-sectional study was conducted.A total of 139 eyes of 139 subjects, including 115 eyes with diabetes mellitus and 24 control eyes without diabetes, were enrolled in the Second People's Hospital of Hefei from March to December 2022.DR was graded according to the standard seven-field ETDRS color fundus photographs.Eyes with diabetes mellitus were divided into non-DR (NDR) group (34 eyes), non-proliferative DR (NPDR) group (42 eyes), NPDR with diabetic macular edema (DME) group (21 eyes) and PDR group (18 eyes).3D CVI in central fovea 1 mm (C1) and parafoveal 3 mm (C3), choroidal vascular volume (CVV), and choroidal thickness were measured by SS-OCTA in the area of 3 mm×3 mm centered on the fovea using the built-in automated quantification software.Parafoveal region was divided into superior, inferior, temporal and nasal quadrants, and 3D CVI of the different quadrants was detected.3D CVI was defined as the ratio of CVV to total choroidal volume.The monocular data were analyzed to compare 3D CVI among the five groups, and multiple linear regression analysis was used to evaluate the influencing factors.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Second People's Hospital of Hefei, Hefei Hospital Affiliated to Anhui Medical University (No.2022064).All subjects were aware of the study purpose and agreed to participate the study.Results:There were significant differences in 3D CVI-C1 and 3D CVI-C3 among all groups ( F=3.103, 3.036, both at P<0.05).In PDR group, 3D CVI-C1 was lower than in non-DR group, and 3D CVI-C3 was lower than in control group and non-DR group, with statistically significant differences (all at P<0.05).There were significant differences in 3D CVI in the inferior and nasal quadrants among all groups ( F=2.714, 4.020, both at P<0.05).In PDR group, 3D CVI in the inferior quadrant was lower than that in non-DR group, and 3D CVI in nasal quadrant in PDR group was lower than that in control group, non-DR group, NPDR group and NPDR with DME group, with statistically significant differences (all at P<0.05).Multiple linear regression showed that after controlling for age, course of disease and glycosylated hemoglobin, the severity of DR was the influencing factor of 3D CVI in fovea and parafovea.PDR eyes had the greatest impact on 3D CVI in fovea and parafovea.Compared with non-DR eyes, there was a -0.019(95% CI: -0.031--0.007, P=0.003) decrease in central foveal 3D CVI and a -0.019(95% CI: -0.030--0.008, P=0.001) decrease in parafoveal 3D CVI in PDR eyes, followed by a 0.014(95% CI: -0.027-0.000, P=0.044) decrease in central foveal 3D CVI in NPDR with DME eyes. Conclusions:Macular foveal 3D CVI correlates with DR severity, and a decrease in 3D CVI of large vessels in the macular choroid may be a sensitive indicator of DR exacerbation.
7.Design,numerical simulation and experimental study of novel oxygenator
Ming-Hao YUE ; Shi-Yao ZHANG ; Ji-Nian LI ; Hui-Chao LIU ; Zi-Hua SU ; Ya-Wei WANG ; Zeng-Sheng CHEN ; Shi-Hang LIN ; Jin-Yu LI ; Ya-Ke CHENG ; Yong-Fei HU ; Cun-Ding JIA ; Ming-Zhou XU
Chinese Medical Equipment Journal 2024;45(3):23-28
Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]
9.Exploring lncRNA Expression Patterns in Patients With Hypertrophied Ligamentum Flavum
Junling CHEN ; Guibin ZHONG ; Manle QIU ; Wei KE ; Jingsong XUE ; Jianwei CHEN
Neurospine 2024;21(1):330-341
Objective:
Hypertrophy ligamentum flavum (LFH) is a common cause of lumbar spinal stenosis, resulting in significant disability and morbidity. Although long noncoding RNAs (lncRNAs) have been associated with various biological processes and disorders, their involvement in LFH remains not fully understood.
Methods:
Human ligamentum flavum samples were analyzed using lncRNA sequencing followed by validation through quantitative real-time polymerase chain reaction. To explore the potential biological functions of differentially expressed lncRNA-associated genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. We also studied the impact of lncRNA PARD3-AS1 on the progression of LFH in vitro.
Results:
In the LFH tissues when compared to that in the nonhypertrophic ligamentum flavum (LFN) tissues, a total of 1,091 lncRNAs exhibited differential expression, with 645 upregulated and 446 downregulated. Based on GO analysis, the differentially expressed transcripts primarily participated in metabolic processes, organelles, nuclear lumen, cytoplasm, protein binding, nucleic acid binding, and transcription factor activity. Moreover, KEGG pathway analysis indicated that the differentially expressed lncRNAs were associated with the hippo signaling pathway, nucleotide excision repair, and nuclear factor-kappa B signaling pathway. The expression of PARD3-AS1, RP11-430G17.3, RP1-193H18.3, and H19 was confirmed to be consistent with the sequencing analysis. Inhibition of PARD3-AS1 resulted in the suppression of fibrosis in LFH cells, whereas the overexpression of PARD3-AS1 promoted fibrosis in LFH cells in vitro.
Conclusion
This study identified distinct expression patterns of lncRNAs that are linked to LFH, providing insights into its underlying mechanisms and potential prognostic and therapeutic interventions. Notably, PARD3-AS1 appears to play a significant role in the pathophysiology of LFH.

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