Far-infrared irradiation attenuates vessel contraction by activating SERCA2 through disruption of SERCA2 and PLN interaction

by Yun-Jin Hwang, So-Young Park, Jung-Hyun Park, Du-Hyong Cho

Vascular smooth muscle cells (VSMCs) plays an important role in maintaining vascular function by responding to various vasoactive stimuli within blood vessels. Far-infrared (FIR) rays has been shown to possess a variety of physiological effects including vasodilation, while the underlying molecular mechanism remains elusive. Here, we explored the molecular mechanism by which FIR irradiation suppresses vascular contraction using rat VSMCs and aortas. FIR irradiation enhanced the transport of intracellular Ca²⁺ from the cytosol to the sarcoendoplasmic reticulum (SER) via activation of sarcoendoplasmic reticulum Ca²⁺-ATPase (SERCA), which accompanied a decrease in intracellular ATP levels. Pretreatment with thapsigargin (TG), a specific SERCA inhibitor, or knockdown of SERCA2 gene expression reversed FIR irradiation-induced translocation of Ca²⁺ into the SER. Notably, FIR irradiation promoted the dissociation of SERCA2 and phospholamban (PLN), an endogenous SERCA inhibitor, without altering their total protein expression levels. The array of effects elicited by FIR irradiation was not observed under hyperthermic conditions (39°C). Moreover, FIR irradiation, but not hyperthermal condition, decreased the phosphorylation of myosin light chain (MLC) at Ser19, which was restored by pretreatment with TG or the knockdown of SERCA2 gene expression. FIR irradiation attenuated phenylephrine-induced vessel contraction in endothelium-deprived rat aortas. Consistent with the in vitro results, the reduction in MLC phosphorylation caused by FIR irradiation was reversed following pretreatment with TG in isolated aortas. Additionally, FIR irradiation increased blood flow in the carotid arteries of mice. Collectively, these results suggest that FIR irradiation activates SERCA2 by promoting its dissociation from PLN, independent of hyperthermic effects. This activation lowers cytosolic Ca²⁺ and ATP levels, reducing MLC phosphorylation and vascular smooth muscle contraction. These findings provide scientific evidence for the therapeutic potential of FIR therapy in the treatment and prevention of arterial narrowing conditions such as pathological vasospasm, and peripheral artery disease.

Pharmacokinetic profiles of Moutan Cortex after single and repeated administration in a dinitrobenzene sulfonic acid-induced colitis model

by Jin-Hwa Kim, Ji-Soo Jeong, Jeong-Won Kim, Eun-Hye Chung, Su-Ha Lee, Je-Won Ko, Youn-Hwan Hwang, Tae-Won Kim

Moutan Cortex (MC), the dried root bark of Paeonia suffruticosa, is used in traditional Chinese and Korean medicine to treat enteritis for its anti-inflammatory properties. This study compared the pharmacokinetic (PK) profiles of paeonol and paeoniflorin in normal and dinitrobenzene sulfonic acid (DNBS)-induced colitis rats, and to determine how repeated low-dose MC [MC(L), 0.5 g/kg] or high-dose MC [MC(H), 2.5 g/kg] alters PK and disease severity. Using ultra-performance liquid chromatography–tandem mass spectrometry, we found that DNBS modestly increased paeonol AUC_last (NC: 247.8 ± 63.7 vs DNBS: 337.0 ± 120.8 hr*ng/mL) and decreased paeoniflorin (NC: 474.1 ± 11.7 vs DNBS: 463.7 ± 106.8 hr*ng/mL) compared to controls (ns). After repeated dosing, the maximum plasma concentration (C_max) of paeonol was higher in the MC(H) than that in the MC(L) group (MC(L): 63.81 ± 29.74 vs MC(H): 4221.5 ± 1579.2 ng/mL, p max in the MC(H) group was also higher than MC(L) group (MC(L): 60.5 ± 15.3 vs MC(H): 164.7 ± 74.7 ng/mL, p 

Comparative outcomes of swing segment revisions of radiocephalic arteriovenous fistula between endovascular and surgical approaches

by Suehyun Park, Sangho Lee, Hyeon Ju Kim, Hyung-Kee Kim, Seung Huh, Deokbi Hwang

Objective

Regarding revision of vascular access (VA), endovascular methods are commonly employed owing to their procedural simplicity, yet their durability remains uncertain. This study aimed to compare clinical outcomes of swing segment (SwS) revision of radiocephalic arteriovenous fistula (RC-AVF) between endovascular and surgical approaches.

Materials and methods

A retrospective cohort study comparing two groups was conducted at one tertiary hospital in South Korea. A total of 131 patients underwent endovascular or surgical revision of SwS in RC-AVF for the first time after AVF creation between 2016 and 2023. Endovascular and surgical revisions were performed in 114 and 17 patients, respectively (interposition, n = 10; patch angioplasty, n = 5; transposition, n = 1; proximalization, n = 1). Kaplan-Meier survival analysis was used to assess post-intervention primary patency (PP) and post-intervention secondary patency (SP). Multivariable Cox regression analysis was performed to adjust for potential confounders, and a subgroup analysis was conducted based on whether the SwS was in stenosis or occlusion.

Results

The median minimal diameter of SwS was 1.3 mm in the endovascular group and 1.4 mm in the surgical group, and the median lesion length was 2.5 cm and 4.0 cm, respectively. Twelve-month PP was 63.5% vs 73.7% (endo vs surgical, P = 0.79). While PP did not differ in the stenosis subgroup, the occlusion subgroup showed significantly higher PP after surgical revision (P = 0.002), with surgery associated with a markedly lower risk of loss of PP events (HR 0.073).

Conclusion

Surgical revision may be preferentially considered for long-segment occlusive lesions, given its superior early PP and the longer lesions typically associated with occlusions, whereas percutaneous transluminal angioplasty (PTA) remains appropriate for focal or stenotic lesions within the SwS. Consistent follow-up is essential to enable timely interventions, thereby maximizing the functionality of RC-AVF.