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Biomedical subjects

Lu Fang

Publications and source records attributed to Lu Fang.

11 recordsLinked to original sources

High-frequency contralesional dorsal premotor cortex and low-frequency contralesional primary motor cortex rTMS in subacute stroke with severe upper limb impairment: comparable motor outcomes and differential regional degree centrality changes.

BACKGROUND: The contralesional dorsal premotor cortex has been proposed as a potential neuromodulatory target for patients with severe upper limb impairment due to subacute ischemic stroke. This proof-of-concept study aimed to compare behavioral outcomes and resting-state neuroimaging findings between high-frequency repetitive transcranial magnetic stimulation (rTMS) over the contralesional dorsal premotor cortex and guideline-supported low-frequency stimulation over the contralesional primary motor cortex. METHODS: In this randomized trial, 46 patients with severe upper limb impairment in the subacute stage after ischemic stroke were randomly assigned to receive either high-frequency rTMS over the contralesional dorsal premotor cortex or low-frequency rTMS over the contralesional primary motor cortex. Low-frequency stimulation over the contralesional primary motor cortex served as an evidence-supported active comparator for poststroke upper limb motor recovery. Stimulation was administered five times per week for two weeks using magnetic resonance imaging-guided neuronavigation. All participants received concurrent standard rehabilitation therapy. The primary outcome was the Fugl-Meyer Assessment for Upper Extremity. Secondary outcomes included the Arm Subscore of the Motricity Index, the Hong Kong version of the Functional Test for the Hemiplegic Upper Extremity, the Modified Barthel Index, and resting-state functional magnetic resonance imaging-derived degree centrality. RESULTS: Both groups showed significant improvements in the primary and secondary behavioral measures (p&#x202f;<&#x202f;0.01), with no significant between-group differences in the magnitude of change (p&#x202f;>&#x202f;0.05). In neuroimaging analyses, patients receiving high-frequency rTMS over the contralesional dorsal premotor cortex showed significantly greater degree centrality changes in the ipsilesional middle occipital gyrus, contralesional medial superior frontal gyrus, and contralesional middle frontal gyrus than those receiving low-frequency rTMS over the contralesional primary motor cortex (p&#x202f;<&#x202f;0.05). Within the high-frequency stimulation group, degree centrality changes in the ipsilesional middle occipital gyrus were positively correlated with improvements in the Fugl-Meyer Assessment for Upper Extremity (r&#x202f;=&#x202f;0.619, false discovery rate-corrected p&#x202f;=&#x202f;0.018). CONCLUSIONS: High-frequency rTMS over the contralesional dorsal premotor cortex produced behavioral improvements comparable to guideline-supported low-frequency rTMS over the contralesional primary motor cortex, without establishing superiority or formal non-inferiority. Exploratory neuroimaging analyses showed greater degree centrality changes in the ipsilesional middle occipital gyrus after high-frequency premotor stimulation, and these changes correlated with upper-limb motor improvement. These findings support further investigation of contralesional dorsal premotor cortex-targeted high-frequency rTMS for severe subacute post-stroke upper limb impairment. REGISTRATION: URL: http://www.chictr.org.cn; Unique identifier: ChiCTR2000038049.

Humans↗

Uncovering parental exposure risks of TCPP: Impaired development and metabolic homeostasis in zebrafish offspring.

As brominated flame retardants are phased out, tris (1&#x2011;chloro-2-propyl) phosphate (TCPP), a phosphorus-based flame retardant, has emerged as a prominent detectable flame retardant in the environment. However, TCPP has been found to exhibit endocrine-disrupting effects on organisms, raising significant safety concerns. In our study, we utilized the zebrafish model to explore the toxic effects of parental TCPP exposure on offspring and uncover its regulatory mechanisms through metabolomics analysis. Moreover, the impact on the nervous system and lipid metabolism was examined through behavioral analysis and specific staining. Our findings demonstrated that both embryonic and parental TCPP exposure induced developmental disorders in larvae, along with decreased locomotor activity and disordered lipid metabolism homeostasis. Parental exposure to TCPP, exhibiting stronger developmental toxicity than direct embryonic exposure, notably led to reductions in crucial energy substrates such as amino acids and carbohydrates. Meanwhile, embryonic TCPP exposure primarily affected the endogenous lipid-related metabolites including phospholipids, lipid-soluble vitamins, steroids and fatty acids, promoting lipid accumulation in larval liver and subcutaneous tissue. What's more, continuously parental and embryonic exposure showed the most pronounced effects on zebrafish development and metabolic regulation. Our study highlights the risk posed by parental exposure to TCPP on offspring zebrafish, underscoring the need for comprehensive consideration of the impact from parental exposure in pollutants regulation.

Animals↗

Relaxin antagonizes hypertrophy and apoptosis in neonatal rat cardiomyocytes.

The pregnancy hormone relaxin has recently been shown to be cardio-protective. Despite its well-established antifibrotic actions in the heart, the effects of relaxin on cardiomyocytes (CM) remain to be determined. We investigated effects of isoform 2 of the human relaxin (H2-relaxin) on CM hypertrophy and apoptosis. In cultured neonatal rat CM, phenylephrine (50 microM) and cardiac fibroblast-conditioned medium were used respectively to induce CM hypertrophy. The degree of hypertrophy was indicated by increased cell size, protein synthesis and gene expression of atrial natriuretic peptide. Although H2-relaxin (16.7 nM) alone failed to suppress hypertrophy induced by phenylephrine, it repressed the cardiac fibroblast-conditioned medium-induced increase in protein synthesis by 24% (P<0.05) and reversed the increase in cell size (P<0.001) and atrial natriuretic peptide expression (P<0.01). We further studied the effect of H2-relaxin on CM apoptosis induced by H2O2 (200 microM). Studies of DNA laddering and nuclear staining demonstrated that H2-relaxin treatment reduced H2O2-induced DNA fragmentation. Real-time PCR and Western blot analysis revealed a significant increase in the Bcl2/Bax ratio in H2-relaxin-treated CM. Further analysis showed that activation of Akt (1.8-fold, P<0.001) and ERK (2.0-fold, P<0.01) were involved in the antiapoptotic action of H2-relaxin in CM, and that Gi/o coupling of relaxin receptors was associated with the H2-relaxin-induced Akt activation in CM. In conclusion, these results extend our current knowledge of the cardiac actions of relaxin by demonstrating that H2-relaxin indirectly inhibits CM hypertrophy and directly protects CM from apoptosis.

Animals↗

Sex dimorphism in cardiac pathophysiology: experimental findings, hormonal mechanisms, and molecular mechanisms.

The higher cardiovascular risk in men and post-menopausal women implies a protective action of estrogen. A large number of experimental studies have provided strong support to this concept. However, the recent clinical trials with negative outcomes regarding hormone replacement therapy call for "post hoc" reassessment of existing information, models, and research strategies as well as a summary of recent findings. Sex steroid hormones, in particular estrogen, regulate numerous processes that are related to the development and progression of cardiovascular disease through a variety of signaling pathways. Use of genetically modified models has resulted in interesting information on diverse actions mediated by steroid receptors. By focusing on experimental findings, we have reviewed hormonal, cellular, and signaling mechanisms responsible for sex dimorphism and actions of hormone replacement therapy and addressed current limitations and future directions of experimental research.

Animals↗

Anti-hepatitis activities in the broth of Ganoderma lucidum supplemented with a Chinese herbal medicine.

The anti-hepatitis B virus activity and hepatoprotective activity of a liquid fermentation broth of Ganoderma lucidum were investigated. The cultured broth was supplemented with aqueous extract of Radix Sophorae flavescentis, a kind of Chinese herbal medicine. Our results indicated that the cultured broth had effects of anti-hepatitis B virus activity in vitro and protected mice from liver damage in vivo. Our results also indicated that the co-fermentation broth of Ganoderma lucidum in the presence of aqueous extract of Radix Sophorae flavescentis has better medicinal effects than simply mixing these two ingredients together, suggesting a potential novel way to prepare Chinese herbal mixtures.

Animals↗

Statin-inhibited endothelial permeability could be associated with its effect on PECAM-1 in endothelial cells.

UNLABELLED: The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are known to inhibit leukocyte recruitment to endothelium but the mechanism is less understood. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is an endothelial junction protein involved in leukocyte diapedesis. We hypothesize that in endothelial cells, statins may well recruit PECAM-1 to exert their inhibitory effect on leukocyte trans-endothelial migration (TEM). In lovastatin-treated resting human umbilical vein endothelial cells (HUVECs), increased levels of mRNA and protein of PECAM-1 as well as its bio-synthesis (all approximately 2-fold) were observed by real-time PCR, Western blotting and 35S-labeled methionine incorporation assay, respectively. Moreover, in lovastatin treated resting cells as well as TNF-alpha activated endothelial cells, unanimously decreased Triton X-100 insoluble and soluble PECAM-1 ratio was observed. Such changes were accompanied by decreased TEM of U-937 cells (a promonocyte cell line). All lovastatin's effects were abrogated by mevalonic acid. In resting HUVECs, geranylgeranyl pyrophosphate (GGPP), but not farnesyl pyrophosphate (FPP) (both are isoprenoid intermediates in the cholesterol biosynthesis pathway) compromised the effect of lovastatin on PECAM-1 expression, whereas C3 toxin, an inhibitor of small G proteins, exerted statin-like effect. CONCLUSION: Statin-reduced endothelial permeability could be attributed to altered intracellular distribution of PECAM-1 in endothelial cells. We speculate that lovastatin regulates PECAM-1 expression in HUVECs through the mevalonate-GGPP pathway by inhibiting of Rho small GTPase.

Cells, Cultured↗

Association of Leu125Val polymorphism of platelet endothelial cell adhesion molecule-1 (PECAM-1) gene & soluble level of PECAM-1 with coronary artery disease in Asian Indians.

BACKGROUND & OBJECTIVES: Platelet endothelial cell adhesion molecule-1 (PECAM-1) plays a key role in the transendothelial migration of circulating leukocytes (diapedesis) during vascular inflammation. We hypothesized that genetic variation and the level of soluble PECAM-1 could be associated with the development of atherosclerosis and conducted a study on gene polymorphisms of PECAM-1 and soluble PECAM-1 levels in Asian Indian patients with coronary artery disease (CAD) in Singapore. METHODS: Of the 137 angiographically confirmed patients (> or =70% stenosis) of CAD and 110 controls in Asian Indian population, two single nucleotide polymorphisms (SNPs) of PECAM-1 gene, C+373G (Leu125Val) at exon 3 and G+1688A (Ser563Asn) at exon 8 were analyzed by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) strategy. In addition, plasma soluble PECAM-1, P-selection and lipid profile were measured. Chi- square test and student t test were adopted to compare categorical and continuous variables, respectively. RESULTS: A significant decrease in C allele frequency but increase in G allele frequency of the Leu125Val (C/G) polymorphism were observed in CAD patients as compared with controls (0.54/0.46 vs 0.663/0.337 respectively, P=0.008). Alteration in genotype distributions (CC, CG and GG) of the Leu125Val polymorphism between CAD patients and controls (P=0.009) was also significant. A similar trend was observed on the allele frequencies (G/A) and genotype distributions of Ser563Asn (G/A) polymorphism, though the difference did not reach significance. On the other hand, plasma level of soluble PECAM-1 (sPECAM-1) was markedly elevated in CAD patients (P=0.006), and associated with soluble P-selectin and lipid profiles. INTERPRETATION & CONCLUSION: Our study showed that Leu125Val polymorphism of PECAM-1 gene and elevated soluble PECAM-1 were related to severe coronary artery stenosis in CAD patients of Asian Indian origin in Singapore. Our data also suggest that PECAM-1 plays an important role in the development of atherosclerosis.

Base Sequence↗

Identification of a novel transcript of human PECAM-1 and its role in the transendothelial migration of monocytes and Ca2+ mobilization.

Platelet-endothelial cell adhesion molecule-1 (PECAM-1) is an integral component of endothelial cells and has been implicated in the transendothelial migration (TEM) of circulating leukocytes mediated by its 1st and 2nd extracellular immunoglobulin (Ig)-like domains and regulation of intracellular Ca(2+) homeostasis with its 6th domain. Up-to-date, little is known about the role of the 5th extracellular (Ig)-like domain. We have discovered a novel human PECAM-1 transcript missing the entire 7th exon, which encodes the 5th extracellular (Ig)-like domain of PECAM-1. A synthetic peptide with sequence homology to the 5th domain of PECAM-1 (JHS-7 peptide) and a corresponding polyclonal antibody (JHS-7 Ab) were prepared and their potential role in transendothelial migration and Ca(2+) influx was measured. The JHS-7 peptide and the antibody exerted a dose dependent decrease (50-80%) in the transendothelial migration of freshly isolated human monocytes and a promonocytic cell line (U-937) in resting HUVECs and HUVECs activated with tumor necrosis factor-alpha. This was accompanied by an increase in Ca(2+) influx and decrease in refilling of the intracellular Ca(2+) stores in HUVECs. In summary, we have identified a novel PECAM-1 transcript (Deltaexon 7) and shown that the 5th (Ig)-like domain of PECAM-1 plays a role in monocyte TEM and Ca(2+) homeostasis.

Amino Acid Sequence↗

Platelet-endothelial cell adhesion molecule-1 gene polymorphism and its soluble level are associated with severe coronary artery stenosis in Chinese Singaporean.

OBJECTIVES: Platelet-endothelial cell adhesion molecule-1 (PECAM-1) mediates the transendothelial migration of circulating leukocytes, a characteristic change in vascular inflammation leading to atherosclerotic plaque development. We hypothesized that genetic variation and soluble level of PECAM-1 could be associated with coronary artery disease (CAD). DESIGN AND METHODS: We analyzed two single nucleotide polymorphisms (SNPs) of PECAM-1 gene C+373G (Leu125Val) at exon 3, which encodes the first extracellular (Ig)-like domain that mediates the homophilic binding of PECAM-1, and G+1688A (Ser563Asn) at exon 8 in 144 angiographically documented (> or =70% stenosis) patients with CAD and 150 age- and sex-matched controls in the Chinese population in Singapore, using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy. Level of plasma soluble PECAM-1 (sPECAM-1) was measured by ELISA. RESULTS: The Leu125Val polymorphism was associated with CAD (P < 0.01). Also, the level of sPECAM-1 is was found to be elevated in CAD patients (P = 0.005). Moreover, subjects with the homozygous GG genotype of the Leu125Val polymorphism had higher sPECAM-1 levels (P = 0.005). The level of sPECAM-1 was further correlated to soluble platelet selectin (sP-selectin, also measured by ELISA), platelet count, and total white blood cell count (WBC), suggesting that platelets are a major source of sPECAM-1 and platelet activation and inflammation may contribute to PECAM-1 elevations in CAD patients. CONCLUSION: The Leu125Val polymorphism of PECAM-1 and the level of sPECAM-1 are associated with CAD in Chinese in Singapore. The level of sPECAM-1 is also associated with platelet activation and inflammation and correlated to the Leu125Val polymorphism. Our data suggest that PECAM-1 plays an important role in the development of atherosclerosis.

Arteriosclerosis↗

Markers of low-grade inflammation and soluble cell adhesion molecules in Chinese patients with coronary artery disease.

BACKGROUND: Inflammation plays an important role in atherosclerosis. Markers of low-grade chronic inflammation, such as C-reactive protein (CRP) and soluble cell adhesion molecules (sCAMs), have been associated with coronary artery disease (CAD). OBJECTIVE: To evaluate the significance of inflammatory markers as novel risk factors for CAD in the Chinese population. METHODS: High-sensitivity CRP (hs-CRP); sCAMs, including vascular cell adhesion molecule-1 (sVCAM-1), intercellular cell adhesion molecule-1 (sICAM-1), P-selectin (sP-selectin) and E-selectin (sE-selectin); and white blood cell (WBC) count were measured in 170 angiographically defined CAD patients (70% or greater stenosis affecting at least one vessel) and 177 healthy control subjects in the Chinese population in Singapore. RESULTS: The levels of hs-CRP, sVCAM-1 and sP-selectin, and the WBC count were higher in CAD patients than in control subjects (P<0.001, P<0.05, P<0.05 and P<0.001, respectively). There were no significant differences in the levels of sICAM-1 and sE-selectin between the two groups. Patients with unstable angina or myocardial infarction had higher levels of hs-CRP, and higher WBC and monocyte counts than those with stable angina or atypical chest pain (all P<0.05). The level of sP-selectin in patients with multivessel disease was higher than in those with single-vessel disease (P<0.05). Overall, the levels of hs-CRP and sCAMs showed a significant correlation with the lipid profile and the WBC count. CONCLUSIONS: The present study suggests that inflammatory markers, including hs-CRP and WBC count, together with sP-selectin and sVCAM-1, could serve as markers of atherogenesis in Chinese patients with CAD, with potential diagnostic and therapeutic implications.

Aged↗