Biomedical subjects

Lin Lin

Publications and source records attributed to Lin Lin.

6 recordsLinked to original sources

PubMed2026

Deciphering the effects of sulfonamide antibiotics on denitrification from a metagenomic perspective: Inhibition of nitrite reduction and succession patterns of functional microorganisms.

Limited research has thoroughly elucidated the impact mechanisms of antibiotics on the denitrification process at the genomic and gene levels, which has hindered the optimization and development of nitrogen removal technology for antibiotic-containing swine wastewater. Lab-scale sequencing batch reactors were constructed in this study to treat synthetic wastewater containing different sulfonamides and nitrate. Investigations were carried out on denitrification performance, microbial community diversity, denitrifier succession patterns, and functional gene distribution. The stress of sulfonamides inhibited the nitrite reduction process, transforming complete denitrification into partial denitrification and causing significant nitrite accumulation. The average nitrogen removal efficiency in the treatment groups decreased from 81.0% ± 2.2-40.1% ± 6.1%. Alicycliphilus and Thauera were identified as the key taxa, accounting for 32.2% and 16.9% of all potential denitrifying bacteria, respectively. Although metagenome-assembled genomes (MAGs) from Thauera were enriched with genes encoding nitrate reductases (nap, nar) and nitrite reductases (nir), this genus preferentially utilized nitrate as an electron acceptor, resulting in the preferential nitrate reduction and subsequent nitrite accumulation. In contrast, Alicycliphilus MAGs developed tolerance to the sulfonamides stress during later stages, with concomitant enrichment of associated functional genes. They replaced Thauera to reemerge as the dominant group, thereby restoring complete denitrification. This study provides new insights into the regulatory mechanisms governing complete versus partial denitrification in nitrogen removal from antibiotic-containing wastewater.

Denitrifier succession↗

PubMed2026

Inhibitory mechanism of phloretin on the AgrA LytTR domain-agr operon complex formation and its application in beef.

Staphylococcus aureus (S. aureus) represents a major foodborne pathogen whose enterotoxin production poses significant challenges to food safety due to its high environmental resistance and limited efficacy of conventional sterilization. Since the expression of enterotoxins is predominantly governed by the agr quorum sensing system, targeting this regulatory pathway has become a strategic choice for virulence control. This study elucidated the mechanism by which phloretin, a potential quorum sensing inhibitor, interferes with the agr system to attenuate virulence. To achieve this, the recombinant AgrA LytTR domain was expressed and purified, and its interaction with phloretin was characterized using thermal shift assays (TSA), electrophoretic mobility shift assays (EMSA), and molecular dynamics (MD) simulations. The results showed that phloretin specifically binds to the AgrA LytTR domain, enhancing its thermal stability and disrupting AgrA LytTR-agr operon binding by reducing the free energy of interaction between them, without causing significant structural rearrangement. Mechanistic analysis indicated that phloretin sterically hinders key β-sheet turn residues (HIS169, ASN201, ARG233), thereby impairing DNA recognition, downregulating RNAIII transcription, and inhibiting agr signaling. In cooked beef, phloretin significantly inhibited the secretion of enterotoxins and α-hemolysin, while delaying lipid oxidation and protein degradation, and maintaining the meat texture. These findings suggested that phloretin is a multifunctional substance with anti-virulence, antioxidant, and preservative properties, demonstrating its potential as a natural food preservative.

Phloretin↗

PubMed2026

Age-stratified associations of glycemia, blood pressure, and cholesterol with mortality in diabetes: A prospective cohort study.

BACKGROUND: Optimization of HbA1c, blood pressure and cholesterol, referred to as the "ABCs", is central to the management of diabetes. However, the age-specific associations of these factors with mortality in patients with diabetes remains unclear. METHODS: In this prospective cohort study, 43,732 Chinese adults aged ≥ 40 years with diabetes were included from the China Cardiometabolic Disease and Cancer Cohort (4C) Study. Participants were stratified by age (< 55, 55-<65, 65-<75, ≥ 75 years). Cox proportional hazards regression and Fine-Gray competing risk models were employed to estimate the associations of HbA1c, systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-C) with all-cause, cardiovascular, and non-cardiovascular mortality across age groups. Relative importance and population attributable fractions (PAFs) were computed for each metabolic factor. RESULTS: During a median follow-up of 10.1 years, 3,975 deaths were documented. Age significantly modified the associations of HbA1c, SBP, and LDL-C with all mortality outcomes (all P for interaction < 0.05). Among participants aged < 75 years, HbA1c showed graded positive associations with all-cause, cardiovascular, and non-cardiovascular mortality. The SBP thresholds associated with increased mortality risk were 140 mmHg in those aged < 65 years and 160 mmHg in those aged 65-<75 years. Among those aged ≥ 75 years, however, the patterns of these associations differed markedly. Elevated mortality risk was observed only at HbA1c ≥ 9%, with a hazard ratio (HR) of 1.51 (95% confidence interval [CI]: 1.19-1.91) for all-cause mortality and a subdistribution hazard ratio (SHR) of 1.70 (95% CI: 1.23-2.36) for cardiovascular mortality, while SBP showed no significant association with any mortality outcome in this age group. Moreover, LDL-C emerged as a significant risk factor for cardiovascular mortality. Compared with participants with LDL-C < 1.8 mmol/L, those with LDL-C of 1.8-<2.6 mmol/L exhibited a significantly higher risk (SHR: 1.86; 95% CI: 1.11-3.11). Additionally, LDL-C had the largest PAF for cardiovascular mortality (9.6%) within this age group. CONCLUSIONS: The impacts of ABC factors on mortality risk vary substantially by age among adults with diabetes. In patients aged ≥ 75 years, less stringent glycemic and blood pressure targets may be appropriate, whereas lipid management remains critically important for reducing cardiovascular mortality.

Humans↗

PubMed2026

Ameliorating Effects and Autonomic Mechanisms of Transcutaneous Auricular Vagus Nerve Stimulation on Abdominal Pain in Patients With Functional Dyspepsia and Irritable Bowel Syndrome.

BACKGROUND: Patients with functional dyspepsia (FD) and irritable bowel syndrome (IBS) often experience abdominal pain and reduced quality of life and need effective treatments. This exploratory study aimed to evaluate whether transcutaneous auricular vagus nerve stimulation (taVNS) could improve abdominal pain and quality of life in patients with FD and IBS, and whether the effects were mediated via the autonomic mechanisms. METHODS: A total of 64 patients with abdominal pain (43 FD and 21 IBS) with a pain score of 3 out of 10 or higher were randomized to receive 2 weeks of taVNS or sham-taVNS treatment. The primary outcome was numeric rating scale (NRS) for abdominal pain. The dyspeptic symptom scales (DSS), IBS symptom severity scale score (IBS-SSS), anxiety and depression scores, and the SF36 quality of life scale were assessed before and after the treatment. The electrocardiogram was also recorded for the assessment of autonomic function at baseline and after the treatment. KEY RESULTS: (1) taVNS reduced the abdominal pain score (p < 0.001 for both FD and IBS), the frequency of abdominal pain (p < 0.001 for both FD and IBS), and overall symptom scores in both FD patients and IBS patients (p < 0.001 for FD and IBS). There was no significant difference in the effect of taVNS on abdominal pain between FD and IBS patients. (2) taVNS improved quality of life compared with baseline in both FD and IBS patients. (3) taVNS decreased anxiety (p < 0.001) and depression (p < 0.001). (4) taVNS increased vagal activity. At the end of the taVNS treatment, the vagal activity was negatively correlated with the pain score (r = -0.491, p = 0.004). CONCLUSIONS: Non-invasive taVNS improves abdominal pain, quality of life, and anxiety and depression in patients with FD and patients with IBS, possibly attributed to the enhancement of vagal activity. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2400085697.

Humans↗

PubMed2025

Spatial-Temporal Diversity of Extrachromosomal DNA Shapes Urothelial Carcinoma Evolution and Tumor-Immune Microenvironment.

Extrachromosomal DNA (ecDNA) presents a promising target for cancer therapy; however, its spatial-temporal diversity and influence on tumor evolution and the immune microenvironment remain largely unclear. We apply computational methods to analyze ecDNA from whole-genome sequencing data of 595 urothelial carcinoma (UC) patients. We demonstrate that ecDNA drives clonal evolution through structural rearrangements during malignant transformation and recurrence of UC. This supports a model wherein tumors evolve via the selective expansion of ecDNA-bearing cells. Through multi-regional sampling of tumors, we demonstrate that ecDNA contributes to the evolution of multifocality and increased intratumoral heterogeneity. EcDNA is present in 36% of UC tumors and correlates with an immunosuppressive phenotype and poor prognosis. Single-cell RNA sequencing analyses reveal that ecDNA+ malignant cells exhibit diminished expression of major histocompatibility complex class I molecules, enabling them to evade T-cell immunity. Finally, we show that sequencing of urinary sediment-derived DNA has excellent specificity in detecting ecDNA.

Journal Article↗

PubMed2024

Ovarian tumor cells gain competitive advantage by actively reducing the cellular fitness of microenvironment cells.

Cell competition and fitness comparison between cancer and tumor microenvironment (TME) cells determine oncogenic fate. Our previous study established a role for human Flower isoforms as fitness fingerprints, where the expression of Flower Win isoforms in tumor cells leads to growth advantage over TME cells expressing Lose isoforms. Here we demonstrate that the expression of Flower Lose and reduced microenvironment fitness is not a pre-existing condition but, rather, a cancer-induced phenomenon. Cancer cells actively reduce TME fitness by the exosome-mediated release of a cancer-specific long non-coding RNA, Tu-Stroma, which controls the splicing of the Flower gene in the TME cells and expression of Flower Lose isoform, which leads to reduced fitness status. This mechanism controls cancer growth, metastasis and host survival in ovarian cancer. Targeting Flower protein with humanized monoclonal antibody (mAb) in mice significantly reduces cancer growth and metastasis and improves survival. Pre-treatment with Flower mAb protects intraperitoneal organs from developing lesions despite the presence of aggressive tumor cells.

Female↗