Adiponectin Alleviates Genioglossal Mitochondrial Dysfunction in Rats Exposed to Intermittent Hypoxia

Background

Genioglossal dysfunction is involved in the pathophysiology of obstructive sleep apnea hypoxia syndrome (OSAHS) characterized by nocturnal chronic intermittent hypoxia (CIH). The pathophysiology of genioglossal dysfunction and possible targeted pharmacotherapy for alleviation of genioglossal injury in CIH require further investigation.

Methodology/Principal Findings

Rats in the control group were exposed to normal air, while rats in the CIH group and CIH+adiponectin (AD) group were exposed to the same CIH condition (CIH 8 hr/day for 5 successive weeks). Furthermore, rats in CIH+AD group were administrated intravenous AD supplementation at the dosage of 10 µg, twice a week for 5 consecutive weeks. We found that CIH-induced genioglossus (GG) injury was correlated with mitochondrial dysfunction, reduction in the numbers of mitochondrias, impaired mitochondrial ultrastructure, and a reduction in type I fibers. Compared with the CIH group, impaired mitochondrial structure and function was significantly improved and a percentage of type I fiber was elevated in the CIH+AD group. Moreover, compared with the control group, the rats’ GG in the CIH group showed a significant decrease in phosphorylation of LKB1, AMPK, and PGC1-α, whereas there was significant rescue of such reduction in phosphorylation within the CIH+AD group.

Conclusions

CIH exposure reduces mitochondrial biogenesis and impairs mitochondrial function in GG, while AD supplementation increases mitochondrial contents and alleviates CIH-induced mitochondrial dysfunction possibly through the AMPK pathway.     

NF- kB 对低氧大鼠肺动脉平滑肌细胞ET- 1 表达的影响

目的：探讨核因子kB（NF—kB）对低氧大鼠肺动脉平滑肌细胞（PAMSC）内皮素-1（endothelin—1,ET—1）表达的影响。方法：分离培养大鼠肺动脉平滑肌细胞,分别在常氧和低氧条件下培养48小时。ELISA检测培养上清中ET—1含量,RT—PCR检测ET-1 mRNA表达。在培养液中加入NF—kB抑制剂PDTC,检测PASMCs ET—1表达的变化。Western blotting检测PASMCs IkB表达变化。结果：低氧培养能够诱导PASMCs表达ET—1。NF—kB抑制剂能够减少由于低氧引起的ET—1释放,IkB在低氧情况下表达明显减少。结论：ET-1低氧情况下在PAMCS表达明显增加。可能参与低氧所引起的肺动脉的病理过程。低氧所引起的ET—1表达增加可能通过NF—kB信号通路。     

间断低氧大鼠饲养舱的研制和初步应用

目的设计制造自动控制的长期间断低氧大鼠饲养舱,以建立符合睡眠呼吸暂停综合征（SAS）特征的大鼠模型。方法①由单片机自动控制,通过电磁阀控制供应各气体的流量,使饲养舱内的氧浓度能够在9%～21%的范围内快速地变化。②50只SD大鼠均分为五组,即间断低氧2周组（2H）和4周组（4H）、空气对照2周组（2C）和4周组（4C）及正常对照组（NC）。间断低氧组在密闭的舱中间断性地呼吸低氧气体,90s一次循环,每天8h,每周7d。对照组呼吸空气。结果通过单片机能自动调节医用氮气与氧气的输入,使舱内低氧时氧浓度在9.0%±1.5%,复氧时氧浓度在21.0%±0.5%。大鼠平均肺动脉压：2H组较2C组高18.71%,4H组较4C组高16.87%（P均〈0.05）;右心室收缩末期压及最大变化速率RVESP、RV＋dp/dt和RV-dp/dt：4H组较4C组分别高36.36%、56.35%和55.43%（P均〈0.01）,4H组比2H组分别高88.85%、19.49%和80.97%（P均〈0.01）;而2C组、4C组与NC组上述指标各组间均无显著性差异（P均〉0.05）。结论该大鼠饲养舱能自动、精确控制舱内氧浓度、循环时间,能复制出比较符合SAS病理生理变化特征的动物模型。     

Adaptation to Intermittent Hypoxia: Influence on the State of Endothelial Function

Human Physiology - This study involving ten apparently healthy male volunteers aged 19 to 31 years was aimed at establishing possible effects of a three-week course of normobaric intermittent...     

Intermittent Hypoxia Can Aggravate Motor Neuronal Loss and Cognitive Dysfunction in ALS Mice

Background

Patients with ALS may be exposed to variable degrees of chronic intermittent hypoxia. However, all previous experimental studies on the effects of hypoxia in ALS have only used a sustained hypoxia model and it is possible that chronic intermittent hypoxia exerts effects via a different molecular mechanism from that of sustained hypoxia. No study has yet shown that hypoxia (either chronic intermittent or sustained) can affect the loss of motor neurons or cognitive function in an in vivo model of ALS.

Objective

To evaluate the effects of chronic intermittent hypoxia on motor and cognitive function in ALS mice.

Methods

Sixteen ALS mice and 16 wild-type mice were divided into 2 groups and subjected to either chronic intermittent hypoxia or normoxia for 2 weeks. The effects of chronic intermittent hypoxia on ALS mice were evaluated using the rotarod, Y-maze, and wire-hanging tests. In addition, numbers of motor neurons in the ventral horn of the spinal cord were counted and western blot analyses were performed for markers of oxidative stress and inflammatory pathway activation.

Results

Compared to ALS mice kept in normoxic conditions, ALS mice that experienced chronic intermittent hypoxia had poorer motor learning on the rotarod test, poorer spatial memory on the Y-maze test, shorter wire hanging time, and fewer motor neurons in the ventral spinal cord. Compared to ALS-normoxic and wild-type mice, ALS mice that experienced chronic intermittent hypoxia had higher levels of oxidative stress and inflammation.

Conclusions

Chronic intermittent hypoxia can aggravate motor neuronal death, neuromuscular weakness, and probably cognitive dysfunction in ALS mice. The generation of oxidative stress with activation of inflammatory pathways may be associated with this mechanism. Our study will provide insight into the association of hypoxia with disease progression, and in turn, the rationale for an early non-invasive ventilation treatment in patients with ALS.     

Prenatal Hypoxia Is Associated with Long-Term Retinal Dysfunction in Rats

Background

Intra-uterine growth restriction (IUGR) has been associated with increased predisposition to age-related complications. We tested the hypothesis that rat offspring models of IUGR would exhibit exacerbated, age-related retinal dysfunction.

Methods

Female Sprague-Dawley rats (maintained at 11.5% O₂ from gestational day 15 to 21 to induce IUGR) and control offspring (maintained at 21% O₂ throughout pregnancy) had retinal function assessed at 2 months (young) and 14 months of age (aged) with electroretinogram (ERG) recordings. Retinal anatomy was assessed by immunofluorescence.

Results

Deficits in rod-driven retina function were observed in aged IUGR offspring, as evidenced by reduced amplitudes of dark-adapted mixed a-wave V_max (by 49.3%, P<0.01), b-wave V_max (by 42.1%, P<0.001) and dark-adapted peak oscillatory potentials (by 42.3%, P<0.01). In contrast to the rod-driven defects specific to aged IUGR offspring, light adapted ERG recordings revealed cone defects in young animals, that were stationary until old age. At 2 months, IUGR offspring had amplitude reductions for both b-wave (V_max by 46%, P<0.01) and peak oscillatory potential (V_max by 38%, P<0.05). Finally, defects in cone-driven responses were further confirmed by reduced maximal photopic flicker amplitudes at 2 (by 42%, P<0.001) and 14 months (by 34%, P = 0.06) and critical flicker fusion frequencies at 14 months (Control: 42±1 Hz, IUGR: 35±2 Hz, P<0.05). These functional changes were not paralleled by anatomical losses in IUGR offspring retinas.

Conclusions

These data support that the developing retina is sensitive to stressors, and that pathways governing cone- and rod-driven function differ in their susceptibilities. In the case of prenatal hypoxia, cone- and rod-driven dysfunction manifest at young and old ages, respectively. We must, therefore, take into account the specific impact that fetal programming might exert on age-related retinal dystrophies when considering related diagnoses and therapeutic applications.     

Gene Expression of ANP,BNP and ET-1 in the Heart of Rats during Pulmonary Embolism

Aims

Atrial natriuretic petide (ANP), brain natriuretic peptide (BNP) and endothelin-1 (ET-1) may reflect the severity of right ventricular dysfunction (RVD) in patients with pulmonary embolism (PE). The exact nature and source of BNP, ANP and ET-1 expression and secretion following PE has not previously been studied.

Methods and Results

Polystyrene microparticles were injected to induce PE in rats. Gene expression of BNP, ANP and ET-1 were determined in the 4 cardiac chambers by quantitative real time polymerase chain reaction (QPCR). Plasma levels of ANP, BNP, ET-1 and cardiac troponin I (TNI) were measured in plasma. PE dose-dependently increased gene expression of ANP and BNP in the right ventricle (RV) and increased gene expression of ANP in the right atrium (RA). In contrast PE dose-dependently decreased BNP gene expression in both the left ventricle (LV) and the left atrium (LA). Plasma levels of BNP, TNI and ET-1 levels dose-dependently increased with the degree of PE.

Conclusion

We found a close correlation between PE degree and gene-expression of ANP, and BNP in the cardiac chambers with a selective increase in the right chambers of the heart.The present data supports the idea of natriuretic peptides as valuable biomarkers of RVD in PE.     

Intermittent Hypobaric Hypoxia Preconditioning Induced Brain Ischemic Tolerance by Up-Regulating Glial Glutamate Transporter-1 in Rats

Several studies showed that the up-regulation of glial glutamate transporter-1 (GLT-1) participates in the acquisition of brain ischemic tolerance induced by cerebral ischemic preconditioning or ceftriaxone pretreatment in rats. To explore whether GLT-1 plays a role in the acquisition of brain ischemic tolerance induced by intermittent hypobaric hypoxia (IH) preconditioning (mimicking 5,000?m high-altitude, 6?h per day, once daily for 28?days), immunohistochemistry and western blot were used to observe the changes in the expression of GLT-1 protein in hippocampal CA1 subfield during the induction of brain ischemic tolerance by IH preconditioning, and the effect of dihydrokainate (DHK), an inhibitor of GLT-1, on the acquisition of brain ischemic tolerance in rats. The basal expression of GLT-1 protein in hippocampal CA1 subfield was significantly up-regulated by IH preconditioning, and at the same time astrocytes were activated by IH preconditioning, which appeared normal soma and aplenty slender processes. The GLT-1 expression was decreased at 7?days after 8-min global brain ischemia. When the rats were pretreated with the IH preconditioning before the global brain ischemia, the down-regulation of GLT-1 protein was prevented clearly. Neuropathological evaluation by thionin staining showed that 200?nmol DHK blocked the protective role of IH preconditioning against delayed neuronal death induced normally by 8-min global brain ischemia. Taken together, the up-regulation of GLT-1 protein participates in the acquisition of brain ischemic tolerance induced by IH preconditioning in rats.     

Expression of Erythropoietin mRNA in the Brainstem of Rats Adapted to Intermittent Hypoxia

We studied the content of mRNA of a glycoprotein, erythropoietin, in structures of the rat brainstem; the animals were adapted to intermittent hypoxia at different contents of oxygen in hypoxic gas mixtures (12 or 7% О₂, a 2-week-long course with five sessions per day). Under conditions of such adaptation, the content of erythropoietin in the brainstem demonstrated a clear trend toward a decrease after a course of moderate hypoxic trainings (12% О₂), and a more than twofold drop after a “stronger” course (7% О₂). We suppose that the decrease in the intensity of synthesis of this glycoprotein     

Sphingosine-1-Phosphate Signaling Regulates Myogenic Responsiveness in Human Resistance Arteries

We recently identified sphingosine-1-phosphate (S1P) signaling and the cystic fibrosis transmembrane conductance regulator (CFTR) as prominent regulators of myogenic responsiveness in rodent resistance arteries. However, since rodent models frequently exhibit limitations with respect to human applicability, translation is necessary to validate the relevance of this signaling network for clinical application. We therefore investigated the significance of these regulatory elements in human mesenteric and skeletal muscle resistance arteries. Mesenteric and skeletal muscle resistance arteries were isolated from patient tissue specimens collected during colonic or cardiac bypass surgery. Pressure myography assessments confirmed endothelial integrity, as well as stable phenylephrine and myogenic responses. Both human mesenteric and skeletal muscle resistance arteries (i) express critical S1P signaling elements, (ii) constrict in response to S1P and (iii) lose myogenic responsiveness following S1P receptor antagonism (JTE013). However, while human mesenteric arteries express CFTR, human skeletal muscle resistance arteries do not express detectable levels of CFTR protein. Consequently, modulating CFTR activity enhances myogenic responsiveness only in human mesenteric resistance arteries. We conclude that human mesenteric and skeletal muscle resistance arteries are a reliable and consistent model for translational studies. We demonstrate that the core elements of an S1P-dependent signaling network translate to human mesenteric resistance arteries. Clear species and vascular bed variations are evident, reinforcing the critical need for further translational study.     

Salt Loading in Canola Oil Fed SHRSP Rats Induces Endothelial Dysfunction

This study aimed to determine if 50 days of canola oil intake in the absence or presence of salt loading affects: (1) antioxidant and oxidative stress markers, (2) aortic mRNA of NADPH oxidase (NOX) subunits and superoxide dismutase (SOD) isoforms and (3) endothelial function in SHRSP rats. SHRSP rats were fed a diet containing 10 wt/wt% soybean oil or 10 wt/wt% canola oil, and given tap water or water containing 1% NaCl for 50 days. Without salt, canola oil significantly increased RBC SOD, plasma cholesterol and triglycerides, aortic p22^phox, NOX2 and CuZn-SOD mRNA, and decreased RBC glutathione peroxidase activity. With salt, canola oil reduced RBC SOD and catalase activity, LDL-C, and p22^phox mRNA compared with canola oil alone, whereas plasma malondialdehyde (MDA) was reduced and RBC MDA and LDL-C were higher. With salt, the canola oil group had significantly reduced endothelium-dependent vasodilating responses to ACh and contractile responses to norepinephrine compared with the canola oil group without salt and to the WKY rats. These results indicate that ingestion of canola oil increases O₂ ⁻ generation, and that canola oil ingestion in combination with salt leads to endothelial dysfunction in the SHRSP model.     

Endothelin-1-Mediated Mechanisms in the Carotid Body Modulates Cardiovascular Responses in Rats Exposed to Chronic Intermittent Hypoxia

Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea (OSA), is associated with hypertension. The increased of carotid body (CB) sensitivity due to enhanced sympathetic efferent may be mainly responsible for the elevation of blood pressure. Accordingly, we studied this effect of Endothelin-1 (ET-1)-induced CB chemosensory response to CIH, as a vasoactive peptide expressed in CB. The purpose of this study was to investigate the mean arterial blood pressure (MAP) and renal sympathetic nerve activity (RSNA) responses in CIH group by injecting ET-1 to directly stimulate CB chemoreceptor. Furthermore, whether ET receptor-mediated PKC and p³⁸MAPK signaling pathway was involved in CIH-induced CB activation was also studied. Male Sprague–Dawley rats were exposed to CIH (8 h/day for 3 weeks) and the MAP and RSNA were recorded in CIH rats and Sham rats. Our results demonstrated that ET-1-induced MAP and RSNA increase were mainly mediated by ET_A receptor activation in CB chemosensory after CIH exposure. Moreover, P³⁸MAPK and PKC signaling pathway might be involved in ET-1-induced increase of MAP and RSNA in CIH group, which provided a potential therapeutic target of OSA.

     

Endothelial Dysfunction and Metabolic Effects of Nitric Oxide in Humans

Shortage of nitric oxide (NO) is believed to be a key factor in the development of endothelial dysfunction. Metabolic effects of NO were analyzed in subjects with multiple metabolic disorders (essential arterial hypertension, platelet hyperaggregability, and hypercholesterolemia). Effects of the NO-inducing ₁-adrenoblocker nebivolol on the blood rheology and lipid profile were studied in pilots regularly exposed to factors of flying work contributing to the development of endotheliocyte dysfunction. The dynamics of spontaneous platelet aggregation in pilots with arterial hypertension suggested that nebivolol produced a statistically significant general effect on platelets, reducing their baseline activation by eliminating endothelial dysfunction. This NO-inducing drug has an antiatherosclerotic effect. Metabolic effects of NO are essential for normalizing endothelial functions because this messenger interacts with key reactions of the pathogenic cascade in the cardiovascular continuum.     

波动性高胰岛素对血管内皮细胞的凋亡的影响

目的:对比研究波动性高浓度胰岛素与恒定性高浓度胰岛素对体外培养的人脐静脉内皮细胞的凋亡的影响,从而探究波动性高浓度胰岛素血症在糖尿病动脉粥样硬化形成中的致病机制.方法:采用体外培养的人脐静脉内皮细胞为对象,研究波动性高胰岛素对血管内皮细胞的凋亡的影响.实验分为4组,即对照组(不含胰岛素)、正常浓度胰岛素组(含胰岛素1 nmol/L)、恒定性高胰岛素组(含胰岛素100nmol/L)与波动性高胰岛素组(含胰岛素1 nmol/L及含胰岛素100 nmol/L两种条件培养液,每8小时轮换一次),每间隔8小时更换新鲜条件培养液一次,一共作用72小时.应用AO-EB染色法与流式细胞仪检测内皮细胞凋亡.结果:1、胰岛素对内皮细胞凋亡的影响1.1经不同浓度的胰岛素作用72小时后,AO-EB检测结果显示:正常浓度胰岛素组的内皮细胞凋亡细胞数明显下降,为对照组的81%(p<0.001),而恒定性高胰岛素组与波动性高胰岛素组的内皮细胞凋亡细胞数明显上升,分别为对照组的1.53倍(p<0.001)与1.75倍(p<0.001),正常浓度胰岛素组的1.88倍(p<0.001)与2.15倍(p<0.001);且波动性高胰岛素组内皮细胞凋亡细胞数显著高于恒定性高胰岛素组(p<0.001).1.2经不同浓度的胰岛素作用72小时后,流式细胞仪检测结果显示:正常浓度胰岛素组的内皮细胞凋亡率明显下降,为对照组的81%(p<0.001),而恒定性高胰岛素组与波动性高胰岛素组的内皮细胞凋亡率出现明显上升,分别为对照组的1.11倍(p<0.01)与1.39倍(p<0.001),正常浓度胰岛素组的1.37倍(p<0.001)与1.72倍(p<0.001);且波动性高胰岛素组内皮细胞凋亡率显著高于恒定性高胰岛素组(p<0.001).结论:1、波动性高胰岛素相对于恒定性高胰岛素更能诱导人脐静脉内皮细胞的凋亡.     

Neuroprotective Role of Intermittent Hypobaric Hypoxia in Unpredictable Chronic Mild Stress Induced Depression in Rats

Hypoxic exposure results in several pathophysiological conditions associated with nervous system, these include acute and chronic mountain sickness, loss of memory, and high altitude cerebral edema. Previous reports have also suggested the role of hypoxia in pathogenesis of depression and related psychological conditions. On the other hand, sub lethal intermittent hypoxic exposure induces protection against future lethal hypoxia and may have beneficial effect. Therefore, the present study was designed to explore the neuroprotective role of intermittent hypobaric hypoxia (IHH) in Unpredictable Chronic Mild Stress (UCMS) induced depression like behaviour in rats. The IHH refers to the periodic exposures to hypoxic conditions interrupted by the normoxic or lesser hypoxic conditions. The current study examines the effect of IHH against UCMS induced depression, using elevated plus maze (EPM), open field test (OFT), force swim test (FST), as behavioural paradigm and related histological and molecular approaches. The data indicated the UCMS induced depression like behaviour as evident from decreased exploration activity in OFT with increased anxiety levels in EPM, and increased immobility time in the FST; whereas on providing the IHH (5000m altitude, 4hrs/day for two weeks) these behavioural changes were ameliorated. The morphological and molecular studies also validated the neuroprotective effect of IHH against UCMS induced neuronal loss and decreased neurogenesis. Here, we also explored the role of Brain-Derived Neurotrophic Factor (BDNF) in anticipatory action of IHH against detrimental effect of UCMS as upon blocking of BDNF-TrkB signalling the beneficial effect of IHH was nullified. Taken together, the findings of our study demonstrate that the intermittent hypoxia has a therapeutic potential similar to an antidepressant in animal model of depression and could be developed as a preventive therapeutic option against this pathophysiological state.     

亚急性轻度缺氧增加组胺刺激的肺动脉内皮细胞钙振荡频率

钙振荡 (calcium oscillation) 能以频率解码的形式调节基因转录,钙振荡的频率可反应基因转录的水平 . 为探索持续缺氧是强化还是钝化肺动脉内皮细胞对组胺的反应,研究了 24 h 亚急性轻度缺氧对组胺刺激的肺动脉内皮细胞钙振荡频率的影响,并探索了其机制 . 结果是： a. 24 h 亚急性轻度缺氧可显著增加组胺刺激的肺动脉内皮细胞钙振荡频率; b.NADPH 氧化酶抑制剂, diphenylene iodonium chloride (DPI , 10 μmol/L) 消除了组胺刺激的常氧和缺氧后肺动脉内皮细胞钙振荡; c. 黄嘌呤氧化酶抑制剂,别嘌呤醇 (oxypurinol , 100 μmol/L) 能显著降低组胺刺激的缺氧后肺动脉内皮细胞升高的钙振荡频率,但降低后的钙振荡频率仍高于常氧组,别嘌呤醇对组胺刺激的常氧组肺动脉内皮细胞钙振荡频率无显著影响 . 以上结果表明,在持续缺氧相关的肺疾患中,肺动脉内皮细胞对组胺反应的敏感性增加 . NADPH 氧化酶在组胺刺激的钙振荡的发生中发挥重要作用;黄嘌呤氧化酶的激活是缺氧引起组胺刺激的钙振荡频率增加的重要原因 .     

加兰他敏对间歇性低氧引起的认知损害的预防作用

目的：探究加兰他敏对间歇性低氧引起的认知损伤是否有保护作用,从而说明其对睡眠呼吸暂停综合症引起的认知损害是否有预防作用。方法：建立间歇低氧大鼠模型,行水迷宫试验检测行为功能变化,免疫组化检测海马神经元及胶质细胞数目的变化。结果：加兰他敏与间歇低氧模型纽相比,行水迷宫的平均逃避潜伏期缩短,游泳总距离减少;免疫组化的结果海马神经元的数目有所增加,胶质细胞的数目减少。结论：加兰他敏对间歇性低氧引起的认知损伤有明显的改善作用,可能与减少神经元的丢失及减少胶质细胞的再生有关。所以对于诊断了睡眠呼吸暂停综合征（ASA）的患者,如果同时合并其他痴呆的易感因素,可预防性应用加兰他敏.     

加兰他敏对间歇性低氧引起的认知损害的预防作用

目的:探究加兰他敏对间歇性低氧引起的认知损伤是否有保护作用,从而说明其对睡眠呼吸暂停综合症引起的认知损害是否有预防作用。方法:建立间歇低氧大鼠模型,行水迷宫试验检测行为功能变化,免疫组化检测海马神经元及胶质细胞数目的变化。结果:加兰他敏与间歇低氧模型组相比,行水迷宫的平均逃避潜伏期缩短,游泳总距离减少;免疫组化的结果海马神经元的数目有所增加,胶质细胞的数目减少。结论:加兰他敏对间歇性低氧引起的认知损伤有明显的改善作用,可能与减少神经元的丢失及减少胶质细胞的再生有关。所以对于诊断了睡眠呼吸暂停综合征(ASA)的患者,如果同时合并其他痴呆的易感因素,可预防性应用加兰他敏。     

Manganese Supplementation Reduces High Glucose-induced Monocyte Adhesion to Endothelial Cells and Endothelial Dysfunction in Zucker Diabetic Fatty Rats

Endothelial dysfunction is a hallmark of increased vascular inflammation, dyslipidemia, and the development of atherosclerosis in diabetes. Previous studies have reported lower levels of Mn²⁺ in the plasma and lymphocytes of diabetic patients and in the heart and aortic tissue of patients with atherosclerosis. This study examines the hypothesis that Mn²⁺ supplementation can reduce the markers/risk factors of endothelial dysfunction in type 2 diabetes. Human umbilical vein endothelial cells (HUVECs) were cultured with or without Mn²⁺ supplementation and then exposed to high glucose (HG, 25 mm) to mimic diabetic conditions. Mn²⁺ supplementation caused a reduction in monocyte adhesion to HUVECs treated with HG or MCP-1. Mn²⁺ also inhibited ROS levels, MCP-1 secretion, and ICAM-1 up-regulation in HUVECs treated with HG. Silencing studies using siRNA against MnSOD showed that similar results were observed in MnSOD knockdown HUVECs following Mn²⁺ supplementation, suggesting that the effect of manganese on monocyte adhesion to endothelial cells is mediated by ROS and ICAM-1, but not MnSOD. To validate the relevance of our findings in vivo, Zucker diabetic fatty rats were gavaged daily with water (placebo) or MnCl₂ (16 mg/kg of body weight) for 7 weeks. When compared with placebo, Mn²⁺-supplemented rats showed lower blood levels of ICAM-1 (17%, p < 0.04), cholesterol (25%, p < 0.05), and MCP-1 (28%, p = 0.25). These in vitro and in vivo studies demonstrate that Mn²⁺ supplementation can down-regulate ICAM-1 expression and ROS independently of MnSOD, leading to a decrease in monocyte adhesion to endothelial cells, and therefore can lower the risk of endothelial dysfunction in diabetes.