Biomedical subjects

Lanlan Li

Publications and source records attributed to Lanlan Li.

3 recordsLinked to original sources

PubMed2026

Subcellular sirtuin signaling networks: pivotal regulators of cardiovascular homeostasis and remodeling.

Sirtuins represent a family of highly conserved enzymes, initially identified as Silent Information Regulator 2 (Sir2) in yeast, where they serve as fundamental determinants of longevity. Overexpression of Sir2 in yeast significantly extends lifespan, while its deletion leads to shortened longevity. In mammals, sirtuins (SIRT1-7) represent a conserved family of NAD+-dependent deacylases with diverse catalytic activities. While most members primarily function as deacetylases, SIRT4 exhibits mono-ADP-ribosylation activity, and SIRT5 uniquely targets negatively charged acyl groups, including lysine succinylation, malonylation, and glutarylation. These enzymes act as critical intracellular sensors and regulators widely distributed across diverse tissues. By targeting a broad array of protein substrates, they regulate core biological processes-including genomic stability, metabolism, inflammation, and stress responses. As cardiovascular diseases (CVDs) remain the primary cause of global mortality, driven by complex pathologies such as chronic inflammation and metabolic dysregulation, the sirtuin network has emerged as an indispensable regulator of cardiovascular health. This review systematically elucidates the pivotal roles of sirtuins in cardiovascular homeostasis. We provide an in-depth, subcellular perspective on how nuclear, cytoplasmic, and mitochondrial sirtuins synergistically protect against cardiovascular remodeling, atherosclerosis (AS), and heart failure (HF). Particular emphasis is placed on the molecular mechanisms modulating macrophage polarization and the mitigation of vascular inflammation via the NF-κB signaling pathway. Furthermore, we assess the therapeutic promise of caloric restriction (CR) and pharmacological activators, incorporating recent human clinical evidence. We propose a framework matching sirtuin-based interventions to disease tempo, advocating isoform and compartment-specific strategies for acute and chronic CVDs.

Sirtuins↗

PubMed2026

Investigating the causal role of smoking in gout: A triangulation approach combining NHANES data, genetic correlation, and Mendelian randomization.

The relationship between smoking and the development of gout is not well understood. To address this, we adopted a triangulation framework that integrates observational analysis, genetic correlation estimation, and two-sample Mendelian randomization (MR) to examine whether smoking confers a causal risk for gout. We first performed a cross-sectional analysis using information for 13,626 participants from the National Health and Nutrition Examination Survey between 2013 and 2018. The association of smoking with gout was subsequently assessed through logistic regression models. We next investigated the extent of shared genetic factors between smoking phenotypes and gout. We were able to demonstrate this using the linkage disequilibrium score regression applied to genome-wide association study data of European ancestry. Finally, to verify the causality of our relationship, we carried out a two-sample MR analysis. We selected the inverse-variance weighted (IVW) method and confirmed the consistency of using the IVW method with other statistical methods, including weighted median, weighted mode, and simple mode, as well as MR-Egger regression. We performed sensitivity analyses to investigate the heterogeneity of the hypothesis and stability of the data. Our findings based on National Health and Nutrition Examination Survey data reveal that there is a strong positive association between smoking and the risk of gout (odds ratio [OR] = 1.94, 95% confidence interval [CI] = 1.48-2.55, P < .001). This association persisted after confounding adjustments (OR = 1.41, 95% CI = 1.04-1.91, P = .027). In the subgroup analyses, former smokers and current smokers of 10 to 20 cigarettes per day had a substantially increased risk. Post-linkage disequilibrium score regression analysis revealed that the significantly positive genetic correlations of smoking initiation and lifetime smoking index with gout risk were both significantly positive. Additional evidence for causality is presented by MR. Genetic prediction of smoking initiation statistically increases gout risk (IVW OR = 1.55, 95% CI = 1.26-1.90, P = 3.17 × 10-5). A much stronger association is evident for lifetime smoking index (IVW OR = 1.99, 95% CI = 1.44-2.76, P = 3.24 × 10-5). These findings are the same with or without heterogeneity by sensitivity analysis. In light of our integrated analysis, smoking is a causative factor for gout. This suggests that public health interventions like anti-smoking campaigns might reduce gout incidence.

Humans↗

PubMed2026

Effects of acute hypoxia followed by reoxygenation on intestinal histomorphology, oxidative stress and hypoxia signaling biomarkers, and microbiota in pikeperch (Sander lucioperca).

In aquatic environments, natural and anthropogenic factors commonly reduce dissolved oxygen (DO) and trigger hypoxia, which threatens the health and survival of aquatic organisms. As an important economic fish species in China, pikeperch (Sander lucioperca) is extremely sensitive to hypoxia. However, there are relatively few reports on how hypoxia and reoxygenation affect its intestinal physiology and microbial community. Three treatment groups were set for pikeperch: normoxia (DO = 8.5 ± 0.5 mg/L), 48 h hypoxia (DO = 2.5 ± 0.1 mg/L), and reoxygenation (48 h hypoxia followed by 6 h reoxygenation at normal DO), to evaluate alterations in intestinal histopathology, tight junction gene expression, oxidative stress, hypoxia signaling molecules and intestinal microbiota composition. The results showed that hypoxia significantly decreased muscularis thickness by approximately 32.5% and reduced the expression of tight junction genes (Occludin, Claudin2, and ZO-2). Moreover, hypoxia significantly increased oxidative stress index levels (GSH-Px, CAT, and MDA), markedly upregulated the expression of Bax, Caspase3, and HIF-1α, while significantly downregulating the expression of Bcl-2, Egln1, and Egln2. Notably, reoxygenation elicited partial compensatory effects against these hypoxia-induced changes. 16S rRNA sequencing analysis revealed that hypoxic stress altered the intestinal microbial community composition of pikeperch and increased its diversity. In the hypoxia group, the abundance of the phylum Bacillota, along with the genera Halomonas and Acinetobacter, was significantly elevated, whereas in the reoxygenation group, the genus Lactobacillus increased approximately 180-fold. The results indicated that hypoxia caused intestinal oxidative damage, cell apoptosis, and intestinal microbiota dysbiosis in pikeperch, while short-term reoxygenation achieved partial recovery from these hypoxia-triggered intestinal injuries. The present research provides valuable references for in-depth exploration of the molecular mechanisms behind the response of pikeperch to acute hypoxia and reoxygenation stress, while also offering a novel perspective to understand the mechanism by which hypoxia impacts intestinal health in fish.

Animals↗