ObjectiveTo compare the histological staining performance of four various tissue fixatives, including a self-developed fixative, for preparing paraffin sections of rat eyeball tissue. MethodsTwenty 5-week-old male Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=5 per group). After anesthesia by intraperitoneal injection of Zoletil™ 50 at a dose of 45 mg/kg body weight, the rats were euthanized by exsanguination via the abdominal aorta. Bilateral eyeballs were carefully extracted intact and fixed for 72 h in 10% formaldehyde fixative, glutaraldehyde-formaldehyde mixed fixative, Davidson's fixative, and self-developed fixative, respectively. After fixation, the eyeballs were longitudinally sectioned along the optic nerve, with the portions containing the optic nerve preserved. The tissues were then dehydrated, embedded, and sectioned. Following hematoxylin and eosin (HE) staining, histological staining quality was compared among ocular structures including the cornea, lens, and retina. ResultsThe overall appearance of rat eyeballs showed marked shrinkage in the 10% formaldehyde group and the glutaraldehyde-formaldehyde group, whereas the eye morphology remained round and intact in the modified Davidson's fixative group and self-developed fixative group. The corneal stroma exhibited obvious rupture, and the cells were arranged in folded arrangement in the modified Davidson's fixative group, 10% formaldehyde group, and self-developed fixative group. In contrast, the corneal cells in the glutaraldehyde-formaldehyde group were neatly arranged, showing no rupture or folding, and exhibited clear staining, indicating the highest quality of corneal sectioning among all groups. In the 10% formaldehyde group, cracks were observed in the equatorial and cortical regions of the lens, but the lens fiber structure remained intact. The lenses in the modified Davidson's fixative group showed extensive rupture and detachment. The glutaraldehyde-formaldehyde group displayed only slight cracks at the equator. In the self-developed fixative group, mild red folding was limited to the peripheral lens region, with the remaining structures intact and unbroken. These findings indicated that the glutaraldehyde-formaldehyde and self-developed fixative groups achieved the best lens sectioning quality. The retina was severely detached from the choroid/sclera layer, with extensive rupture of each cellular layer in the 10% formaldehyde fixative group. In the glutaraldehyde-formaldehyde group, partial detachment between the retina and choroid/sclera was observed. The outer plexiform layer and nerve fiber layer showed separation with edema, while the cells in all layers were neatly arranged. In both the Davidson's fixative and the self-developed fixative groups, the retina remained intact without rupture, and no structural separation was observed in any layer. Both demonstrated advantages in preserving the integrity and orderly arrangement of all retinal layers; however, the self-developed fixative group exhibited greater contrast. ConclusionThe choice of fixative significantly affects the morphological preservation of various structures in the rat eye. The self-developed fixative demonstrates the best overall performance in maintaining overall eye morphology, the structural integrity of the lens, and retinal adhesion. For studies focusing solely on the corneal structure, the glutaraldehyde-formaldehyde mixed fixative is recommended. The 10% formaldehyde fixative exhibits unsatisfactory fixation effects for all the aforementioned ocular structures and is not recommended for detailed morphological studies of eyeball tissues.

FH-deficient renal cell carcinoma(FH-dRCC) is a rare and highly aggressive subtype of renal cell carcinoma. This tumor is often associated with hereditary leiomyomatosis and renal cell carcinoma(HLRCC) syndrome. Its pathogenesis involves biallelic inactivation of the FH gene, leading to the accumulation of fumarate, which disrupts cellular metabolic balance and DNA repair processes, thereby driving tumorigenesis. This paper reports a patient with FH-dRCC. The patient underwent radical nephrectomy but experienced early postoperative recurrence and liver metastasis. Despite multiple lines of systemic therapy, including targeted and combination immunotherapy, which initially achieved radiographic response, the patient eventually died as the disease progressed with extensive metastases. This case highlights the highly aggressive nature of FH-dRCC, its propensity for early recurrence and metastasis, and the limited duration of response to current systemic therapies. There is a clinical need for enhanced early detection and active exploration of more effective combination treatment strategies.

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome, caused by germline pathogenic variants in the DNA mismatch repair (MMR) system. Beyond colorectal and endometrial cancers, the spectrum of tumor associated with LS has expanded to the urological system. Upper urinary tract urothelial carcinoma (UTUC) represents the most frequent LS-associated urological cancer and is typically characterized by microsatellite instability-high/mismatch repair-deficient(MSI-H/dMMR) status and high tumor mutational burden (TMB), showing a high sensitivity to immunotherapy. Bladder and prostate cancers also show increased incidence among specific LS genotypes. In recent years, the integration of multi-omics analyses, liquid biopsy, artificial intelligence, and disease risk prediction models has advanced understanding of LS-associated urological tumors in terms of molecular mechanisms, early detection, and precision therapy. Immune checkpoint inhibitors demonstrate remarkable efficacy, particularly in dMMR/MSI-H UTUC. Future efforts should focus on establishing systematic screening strategies, optimizing individualized treatment, and conducting multicenter prospective studies to improve early diagnosis and clinical outcomes in high-risk populations. This review summarizes recent research progress on urological tumors associated with LS to enhance clinical understanding of the disease.

BACKGROUND:It was found that the ligands and receptors of Notch are both cell membrane surface proteins,which are important proteins to mediate intercellular communication,and the Notch signaling pathway plays a crucial regulatory role in the proliferation and differentiation of mesenchymal stem cells. OBJECTIVE:To review the regulatory mechanism of the Notch signaling pathway on the proliferation and differentiation of mesenchymal stem cells,summarize and clarify the research advance in how the Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells,and provide theoretical support for the future use of stem cells to treat various related diseases. METHODS:By using the computer,the first author searched the relevant studies involving Notch signaling pathway regulation of mesenchymal stem cell proliferation and differentiation on CNKI,Wanfang,VIP,PubMed,Web of Science,and Nature databases with Chinese search terms"mesenchymal stem cells,Notch,Notch signaling pathway,proliferation,differentiation"and the English search terms"mesenchymal stem cells,MSC,Notch,Notch signaling pathway,proliferation,differentiation".Part of the literature was searched in combination with the literature tracing method.Finally,87 articles were included in the review analysis. RESULTS AND CONCLUSION:(1)Notch signaling pathway is a conserved signaling pathway in multicellular organisms,which plays an important role in regulating cell differentiation,proliferation,apoptosis,and the cell cycle by mediating communication between neighboring cells through receptor-ligand binding.(2)Mesenchymal stem cells are a class of adult stem cells with self-proliferative and multi-directional differentiation potential,which can be regulated by external signaling pathways to affect their proliferation and differentiation.Notch signaling pathway,as one of them,when Notch ligands are activated,the Notch proteins will undergo two protein hydrolysis cleavages to release Notch intracellular structural domain NICD,which then enters the nucleus and thus promotes the transcription of target genes to regulate the proliferation and differentiation of mesenchymal stem cells from different sources,such as bone marrow,adipose,and umbilical cord.However,the specific mechanisms that regulate the proliferation and differentiation of mesenchymal stem cells from different tissue sources of the same species are different.(3)The Notch signaling pathway can regulate the differentiation of mesenchymal stem cells into different target cells,but due to different target cells,the expression levels of receptors or ligands in the Notch signaling pathway vary.(4)Clinical targeting of the Notch signaling pathway to promote mesenchymal stem cells for the treatment of various refractory diseases,such as aplastic anemia,severe joint injuries,ischemic strokes,and myocardial infarctions,has a promising application.(5)By exploring the Notch signaling pathway via regulating the expression levels of its receptors and ligands in bone marrow mesenchymal stem cells from rat,mouse,and human,it can be found that the Notch signaling pathway expression levels in the proliferation and differentiation of mesenchymal stem cells from different species origins are also different.(6)The role of mesenchymal stem cells in tissue engineering has been gradually highlighted due to their advantages of safety,low immune rejection,and wide therapeutic prospects.The Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells with a wide range of influencing factors,and subsequent studies should further optimize the influencing factor variables and explore the standardized studies of regulating the proliferation and differentiation of mesenchymal stem cells.

Objective To investigate the factors influencing the prognosis of complex intracranial aneurysms treated with pipeline flow-directed device(PED)and to develop a nomogram prediction model.Methods The clinical data of a total of 98 patients with complex intracranial aneurysm,who were admitted to the Anyue County People's Hospital or the Second Affiliated Hospital of Guilin Medical College of China from January 2021 to April 2023 to receive PED treatment,were retrospectively analyzed.The influencing factors that might affect the prognosis of patients with complex intracranial aneurysm were collected.According to the modified Rankin Scale(mRS)score,the patients were divided into good prognosis group(being defined as mRS ≤2 points)and poor prognosis group(being defined as mRS＞2 points).The clinical data were compared between the two groups,and a nomogram model was established and validated.Results In the 98 patients,poor prognosis was seen in 10(10.20％).The differences in age,history of hypertension,history of diabetes mellitus,clopidogrel resistance,Fisher classification,repeated aneurysm rupture,aneurysm location,aneurysm size,aneurysm neck,multiple lesions,and Hunt-Hess grade on admission between good prognosis group and poor prognosis group were statistically significant(all P＜0.05).Multivariate analysis revealed that history of hypertension,clopidogrel resistance,repeated aneurysm rupture,aneurysm location,multiple lesions,and Hunt-Hess grade were the independent factors influencing the prognosis of patients with complex intracranial aneurysm after receiving PED treatment.The AUC of the nomogram model in predicting the prognosis of PED for complex intracranial aneurysms was 0.849(95％CI=0.758-0.939).The predicted curves of the model group and validation group were basically fitted to the standard curves.The results of the decision curve analysis showed that the net benefit to patients was greater than 0 when the probability threshold of the nomogram model for predicting a poor prognosis of PED for complex intracranial aneurysms was 0.10-0.90.Conclusion The factors causing poor prognosis of PED for complex intracranial aneurysms mainly include history of hypertension,clopidogrel resistance,repeated aneurysm rupture,etc.The nomogram model established in this study can predict the risk of poor prognosis in patients with complicated intracranial aneurysm after receiving PED treatment.

Objective:To study the value of urine-based multi-dimensional bioinformatics evaluation model (utLIFE model) in early diagnosis and postoperative monitoring of upper urinary tract urothelial carcinoma (UTUC).Methods:Morning urine samples of patients clinically diagnosed with UTUC without bladder cancer from Peking University First Hospital from August 2022 to October 2022 were collected. Urine samples were collected before and after surgery, and DNA was extracted for gene sequencing. The utLIFE model previously constructed by our center was used to calculate the score, based on 155 gene mutation sites and copy number variation, and the score ≥60 was defined as utLIFE positive. The sensitivity of utLIFE model in diagnosis of UTUC was analyzed with postoperative pathology as the gold standard. The utLIFE scores before and after operation were also compared.Results:A total of 53 patients were included in this study, all of whom were confirmed as UTUC by postoperative pathology. The median age of patients was 66 (59, 72) years. Twenty-four cases (45.3%) of UTUC tumors were located in the renal pelvis, 26 cases (49.1%) were located in the ureter, and 2 cases (5.7%)involved both ureter and renal pelvis. There were 27 patients (50.9%) at T 1stage and 26 patients (49.1%) at ≥T 2 stage. Preoperative utLIFE score of 53 patients was 79 (70, 84). The sensitivity of preoperative utLIFE diagnosis of UTUC was 96.2% (51/53). utLIFE showed similar high sensitivity in T 1 stage and ≥T 2 stage [100.0% (27/27) vs. 92.3% (24/26), P=0.236], in N 0 and ≥N 1 stage [ 95.0% (38/40) vs. 100.0% (5/5), P=1.000]. In addition, the sensitivity of preoperative utLIFE was higher than that of urine cytology [ 95.2% (20/21) vs. 23.8% (5/21). P<0.001], fluorescence in situ hybridization (FISH) [ 92.6% (25/27) vs. 55.5% (15/27), P=0.004] and ureteroscopy [ 86.7% (13/15) vs. 60.0% (9/15), P=1.000]. A total of 45 patients postoperative utLIFE samples were collected, and the postoperative utLIFE score was significantly lower than that of preoperative [ 36 (18, 61) vs. 79 (70, 84), P<0.001]. Conclusions:utLIFE, as a non-invasive urine DNA bioinformatics assessment model, is significantly superior to cytology and FISH in early detection and has high sensitivity in diagnosis of UTUC, and can reflect perioperative minimal residual disease levels.

Inflammation-driven endothelial dysfunction is the major initiating factor in atherosclerosis, while the underlying mechanism remains elusive. Here, we report that the non-canonical stimulator of interferon genes (STING)-PKR-like ER kinase (PERK) pathway was significantly activated in both human and mice atherosclerotic arteries. Typically, STING activation leads to the activation of interferon regulatory factor 3 (IRF3) and nuclear factor-kappa B (NF-κB)/p65, thereby facilitating IFN signals and inflammation. In contrast, our study reveals the activated non-canonical STING-PERK pathway increases scaffold protein bromodomain protein 4 (BRD4) expression, which encourages the formation of super-enhancers on the proximal promoter regions of the proinflammatory cytokines, thereby enabling the transactivation of these cytokines by integrating activated IRF3 and NF-κB via a condensation process. Endothelium-specific STING and BRD4 deficiency significantly decreased the plaque area and inflammation. Mechanistically, this pathway is triggered by leaked mitochondrial DNA (mtDNA) via mitochondrial permeability transition pore (mPTP), formed by voltage-dependent anion channel 1 (VDAC1) oligomer interaction with oxidized mtDNA upon cholesterol oxidation stimulation. Especially, compared to macrophages, endothelial STING activation plays a more pronounced role in atherosclerosis. We propose a non-canonical STING-PERK pathway-dependent epigenetic paradigm in atherosclerosis that integrates IRF3, NF-κB and BRD4 in inflammatory responses, which provides emerging therapeutic modalities for vascular endothelial dysfunction.

Although somatic cells can be reprogrammed to pluripotent stem cells (PSCs) with pure chemicals, authentic pluripotency of chemically induced pluripotent stem cells (CiPSCs) has never been achieved through tetraploid complementation assay. Spontaneous reprogramming of spermatogonial stem cells (SSCs) was another non-transgenic way to obtain PSCs, but this process lacks mechanistic explanation. Here, we reconstructed the trajectory of mouse SSC reprogramming and developed a five-chemical combination, boosting the reprogramming efficiency by nearly 80- to 100-folds. More importantly, chemical induced germline-derived PSCs (5C-gPSCs), but not gPSCs and chemical induced pluripotent stem cells, had authentic pluripotency, as determined by tetraploid complementation. Mechanistically, SSCs traversed through an inverted pathway of in vivo germ cell development, exhibiting the expression signatures and DNA methylation dynamics from spermatogonia to primordial germ cells and further to epiblasts. Besides, SSC-specific imprinting control regions switched from biallelic methylated states to monoallelic methylated states by imprinting demethylation and then re-methylation on one of the two alleles in 5C-gPSCs, which was apparently distinct with the imprinting reprogramming in vivo as DNA methylation simultaneously occurred on both alleles. Our work sheds light on the unique regulatory network underpinning SSC reprogramming, providing insights to understand generic mechanisms for cell-fate decision and epigenetic-related disorders in regenerative medicine.
Male ; Mice ; Animals ; Cellular Reprogramming/genetics* ; Tetraploidy ; Pluripotent Stem Cells/metabolism* ; Induced Pluripotent Stem Cells/metabolism* ; DNA Methylation ; Spermatogonia/metabolism* ; Germ Cells/metabolism*

OBJECTIVE: To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley. METHODS: Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group. RESULTS: Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected. CONCLUSION The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Brain Ischemia ; Cerebral Infarction ; Reperfusion Injury ; Body Weight

Disturbance of macrophage-associated lipid metabolism plays a key role in atherosclerosis. Crosstalk between autophagy deficiency and inflammation response in foam cells (FCs) through epigenetic regulation is still poorly understood. Here, we demonstrate that in macrophages, oxidized low-density lipoprotein (ox-LDL) leads to abnormal crosstalk between autophagy and inflammation, thereby causing aberrant lipid metabolism mediated through a dysfunctional transcription factor EB (TFEB)-P300-bromodomain-containing protein 4 (BRD4) axis. ox-LDL led to macrophage autophagy deficiency along with TFEB cytoplasmic accumulation and increased reactive oxygen species generation. This activated P300 promoted BRD4 binding on the promoter regions of inflammatory genes, consequently contributing to inflammation with atherogenesis. Particularly, ox-LDL activated BRD4-dependent super-enhancer associated with liquid-liquid phase separation (LLPS) on the regulatory regions of inflammatory genes. Curcumin (Cur) prominently restored FCs autophagy by promoting TFEB nuclear translocation, optimizing lipid catabolism, and reducing inflammation. The consequences of P300 and BRD4 on super-enhancer formation and inflammatory response in FCs could be prevented by Cur. Furthermore, the anti-atherogenesis effect of Cur was inhibited by macrophage-specific Brd4 overexpression or Tfeb knock-out in Apoe knock-out mice via bone marrow transplantation. The findings identify a novel TFEB-P300-BRD4 axis and establish a new epigenetic paradigm by which Cur regulates autophagy, inhibits inflammation, and decreases lipid content.