Magnesium Sulfate Mitigates the Progression of Monocrotaline Pulmonary Hypertension in Rats

Zinc attenuates monocrotaline-induced pulmonary hypertension in rats through upregulation of A20

Pulmonary hypertension (PH) is characterized by excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), in which inflammatory signaling caused by activation of the NF-κB pathway plays an important role. A20 is an important negative regulator of the NF-κB pathway, and zinc promotes the expression of A20 and exerts a protective effect against various diseases (e.g. COVID19) by inhibiting the inflammatory signaling. The role of A20 and intracellular zinc signaling in PH has been explored, but the extracellular zinc signaling is not well understood, and whether zinc has protective effects on PH is still elusive. Using inductively coupled plasma mass spectrometry (ICP-MS), we studied the alteration of trace elements during the progression of monocrotaline (MCT)-induced PH and found that serum zinc concentration was decreased with the onset of PH accompanied by abnormalities of other three elements, including copper, chromium, and magnesium. Zinc chloride injection with the dosage of 5 mg/kg intraperitoneally partially corrected this abnormality and inhibited the progression of PH. Zinc supplementation induced the expression of A20 in lung tissue and reduce the inflammatory responses. In vitro, zinc supplementation time-dependently upregulated the expression of A20 in PASMCs, therefore correcting the excessive proliferation and migration of cells caused by hypoxia. Using genetically encoded-FRET based zinc probe, we found that these effects of zinc ions are not achieved by entering cells, but most likely by activating cell surface zinc receptor (ZnR/GPR39). These results provide the first evidence of the effectiveness of zinc supplementation in the treatment of PH.

Magnesium Sulfate, Rosuvastatin, Sildenafil and Their Combination in Chronic Hypoxia-Induced Pulmonary Hypertension in Male Rats

Previous experimental findings have led to considerable interest in the beneficial effects on pulmonary hypertension (PH) produced by sildenafil and in the pleiotropic effects of rosuvastatin and their positive role in the process of pulmonary angiogenesis. However, magnesium sulfate, the most abundant intracellular cation, is essential in vascular endothelial functionality due to its anti-inflammatory and vasodilatory effects. Therefore, the present study aims to assess these treatment regimens and how they could potentially provide some additional benefits in PH therapy. Fourteen days after chronic-hypoxia PH was induced, rosuvastatin, sildenafil and magnesium sulfate were administered for an additional fourteen days to male Wistar rats. The Fulton Index, right ventricle (RV) anterior wall thickness, RV internal diameter and pulmonary arterial (PA) acceleration time/ejection time were evaluated, and another four biochemical parameters were calculated: brain natriuretic peptide, vascular endothelial growth factor, nitric oxide metabolites and endothelin 1. The present study demonstrates that sildenafil and rosuvastatin have modest effects in reducing RV hypertrophy and RV systolic pressure. The drug combination of sildenafil + rosuvastatin + magnesium sulfate recorded statistically very highly significant results on all parameters; through their positive synergistic effects on vascular endothelial function, oxidative stress and pathological RV remodeling, they attenuated PH in the chronic hypoxia pulmonary hypertension (CHPH) rat model.

Vasodilators for persistent pulmonary hypertension of the newborn: A network meta-analysis

OBJECTIVES

To compare the efficacy and safety of different vasodilators in the treatment of persistent pulmonary hypertension of the newborn (PPHN) by a Bayesian network meta-analysis.

METHODS

We searched databases (Cochrane, PubMed, Embase, and Web of Science) from January, 1990 up to December, 2023. Randomized controlled trials on the use of vasodilators in the treatment of PPHN. We extracted details of population, intervention, and outcome indicators. R and STATA software were used for data analysis. Sixteen articles were included, encompassing 776 neonates with PPHN. Among them, 12 articles were included in the quantitative analysis. The vasodilators included Sildenafil, Bosentan, Milrinone, Magnesium, Adenosine, and Tadalafil.

RESULTS

The Bayesian network meta-analysis results suggested that compared to placebo, Milrinone [OR = 0.125, 95% CI (0.0261, 0.562)], Sildenafil [OR = 0.144, 95% CI (0.0428, 0.420)], and Sildenafil_Milrinone [OR = 0.0575, 95% CI (0.00736, 0.364)] reduced the mortality, but the difference among the three was not significant. There was also no significant difference in the incidence of hypotension, the duration of mechanical ventilation, and the use of extracorporeal membrane oxygenation among the vasodilators. Compared to Bosentan, Adenosine was more effective in reducing the oxygenation index [MD = -12.78, 95% CI (-25.56, -0.03)], and Magnesium was less effective in reducing the oxygenation index than Sildenafil [MD = 5.19, 95% CI (1.23, 9.2)].

CONCLUSIONS

Milrinone, Sildenafil, and Sildenafil_Milrinone reduced the mortality of neonates with PPHN. More clinical trials are needed to verify the efficacy and safety of vasodilators in the treatment of PPHN.

The Recurring Word in the Scientific Articles about the Role of Mg in Living Systems Is "Key"

Magnesium (Mg) is a versatile element involved in all aspects of life on our planet [...].

Т1 mapping of rat lungs in 19 F MRI using octafluorocyclobutane

PURPOSE

To demonstrate the feasibility of using octafluorocyclobutane (OFCB, c-C₄ F₈ ) for T₁ mapping of lungs in ¹⁹ F MRI.

METHODS

The study was performed at 7 T in three healthy rats and three rats with pulmonary hypertension. To increase the sensitivity of ¹⁹ F MRI, a bent-shaped RF coil with periodic metal strips structure was used. The double flip angle method was used to calculate normalized transmitting RF field (B_1n ⁺ ) maps and for correcting T₁ maps built with the variable flip angle (VFA) method. The ultrashort TE pulse sequence was applied for acquiring MR images throughout the study.

RESULTS

The dependencies of OFCB relaxation times on its partial pressure in mixtures with oxygen, air, helium, and argon were obtained. T₁ of OFCB linearly depended on its partial pressure with the slope of about 0.35 ms/kPa in the case of free diffusion. RF field inhomogeneity leads to distortion of T₁ maps built with the VFA method, and therefore to high standard deviation of T₁ in these maps. To improve the accuracy of the T₁ maps, the B_1n ⁺ maps were applied for VFA correction. This contributed to a 2-3-fold decrease in the SD of T₁ values in the corresponding maps compared with T₁ maps calculated without the correction. Three-dimensional T₁ maps were obtained, and the mean T₁ in healthy rat lungs was 35 ± 10 ms, and in rat lungs with pulmonary hypertension - 41 ± 9 ms.

CONCLUSION

OFCB has a spin-rotational relaxation mechanism and can be used for ¹⁹ F T₁ mapping of lungs. The calculated OFCB maps captured ventilation defects induced by edema.

Attenuating effect of magnesium on pulmonary arterial calcification in rodent models of pulmonary hypertension

OBJECTIVE

Vascular calcification has been considered as a potential therapeutic target in pulmonary hypertension. Mg2+ has a protective role against calcification. This study aimed to investigate whether Mg2+ could alleviate pulmonary hypertension by reducing medial calcification of pulmonary arteries.

METHODS

Monocrotaline (MCT)-induced and chronic hypoxia-induced pulmonary hypertension rats were given an oral administration of 10% MgSO4 (10 ml/kg per day). Additionally, we administered Mg2+ in calcified pulmonary artery smooth muscle cells (PASMCs) after incubating with β-glycerophosphate (β-GP, 10 mmol/l).

RESULTS

In vivo, MCT-induced and chronic hypoxia-induced pulmonary hypertension indexes, including right ventricular systolic pressure, right ventricular mass index, and arterial wall thickness, as well as Alizarin Red S (ARS) staining-visualized calcium deposition, high calcium levels, and osteochondrogenic differentiation in pulmonary arteries, were mitigated by dietary Mg2+ intake. In vitro, β-GP-induced calcium-rich deposits stained by ARS, calcium content, as well as the detrimental effects of calcification to proliferation, migration, and resistance to apoptosis of PASMCs were alleviated by high Mg2+ but exacerbated by low Mg2+. Expression levels of mRNA and protein of β-GP-induced osteochondrogenic markers, RUNX Family Transcription Factor 2, and Msh Homeobox 2 were decreased by high Mg2+ but increased by low Mg2+; however, Mg2+ did not affect β-GP-induced expression of SRY-Box Transcription Factor 9. Moreover, mRNA expression and protein levels of β-GP-reduced calcification inhibitor, Matrix GLA protein was increased by high Mg2+ but decreased by low Mg2+.

CONCLUSION

Mg2+ supplement is a powerful strategy to treat pulmonary hypertension by mitigating pulmonary arterial calcification as the calcification triggered physiological and pathological changes to PASMCs.

Melatonin activates the Mst1-Nrf2 signaling to alleviate cardiac hypertrophy in pulmonary arterial hypertension

Among pulmonary arterial hypertension (PAH) patients, right ventricular (RV) functioning has been considered a major determining factor for cardiac capacity and survival. However, despite the recognition of the clinical importance for preserving RV functioning, no effective treatments are currently available for RV failure. This study aims to suggest one such possible treatment, through investigating the cardio-protective capabilities of the anti-oxidant, melatonin (Mel), for treating adverse RV remodeling in PAH, along with its underlying mechanisms. Arginine vasopressin induced neonatal rat cardiomyocyte hypertrophy in vitro; in vivo, PAH was induced in rats through intraperitoneal monocrotaline (MCT) injections, and Mel was administered intraperitoneally 24 h prior to MCT. Mel reduced rat cardiomyocyte hypertrophy and mitochondrial oxidative stress in vitro by activating the Mst1-Nrf2 pathway, which were all reversed upon siRNA knockdown of Mst1. Likewise, in vivo, Mel pre-treatment significantly ameliorated MCT-induced deterioration in cardiac function, RV hypertrophy, fibrosis and dilation. These beneficial effects were also associated with Mst1-Nrf2 pathway up regulation and its associated reduction in oxidative stress, as evidenced by the decrease in RV malondialdehyde content. Notably, results from Mel treatment were similar, or even superior, to those obtained from N-acetyl cysteine (NAC), which has already been-confirmed as an anti-oxidative treatment for PAH. By contrast, co-treatment with the Mst1 inhibitor XMU-MP-1 reversed all of those Mel-associated beneficial effects. Our findings thus identified Mel as a potent cardio-protective agent against the onset of maladaptive RV remodeling, through enhancement of the anti-oxidative response via Mst1-Nrf2 pathway activation.

Pirfenidone ameliorates pulmonary arterial pressure and neointimal remodeling in experimental pulmonary arterial hypertension by suppressing NLRP3 inflammasome activation

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by increased pulmonary arterial pressure, inflammation, and neointimal remodeling of pulmonary arterioles. Serum levels of interleukin (IL)-1β and IL-18 are elevated in PAH patients and may enhance proinflammatory neointimal remodeling. NLRP3 inflammasome activation induces cleavage of the cytokines IL-1β and IL-18, required for their secretion. Pirfenidone (PFD), an antifibrotic and anti-inflammatory drug, has been suggested to inhibit NLRP3 inflammasome activation. We hypothesized that PFD delays the progression of PAH by suppressing NLRP3 inflammasome activation. We assessed the effects of PFD treatment in a rat model for neointimal PAH induced by monocrotaline and aortocaval shunt using echocardiographic, hemodynamic, and vascular remodeling parameters. We measured inflammasome activation by NLRP3 immunostaining, Western blots for caspase-1, IL-1β, and IL-18 cleavage, and macrophage IL-1β secretion. PFD treatment ameliorated pulmonary arterial pressure, pulmonary vascular resistance, and pulmonary vascular remodeling in PAH rats. In PAH rats, immunostaining of NLRP3 in pulmonary arterioles and caspase-1, IL-1β, and IL-18 cleavage in lung homogenates were increased compared to controls, reflecting NLRP3 inflammasome activation in vivo. PFD decreased IL-1β and IL-18 cleavage, as well as macrophage IL-1β secretion in vitro. Our studies show that PFD ameliorates pulmonary hemodynamics and vascular remodeling in experimental PAH. Although PFD did not affect all NLRP3 inflammasome parameters, it decreased IL-1β and IL-18 cleavage, the products of NLRP3 inflammasome activation that are key to its downstream effects. Our findings thus suggest a therapeutic benefit of PFD in PAH via suppression of NLRP3 inflammasome activation.

Sex-Dependent Protective Effect of Combined Application of Solubilized Ubiquinol and Selenium on Monocrotaline-Induced Pulmonary Hypertension in Wistar Rats

Ubiquinol exhibits anti-inflammatory and antioxidant properties. Selenium is a part of a number of antioxidant enzymes. The monocrotaline inducible model of pulmonary hypertension used in this study includes pathological links that may act as an application for the use of ubiquinol with high bioavailability and selenium metabolic products. On day 1, male and female rats were subcutaneously injected with a water-alcohol solution of monocrotaline or only water-alcohol solution. On days 7 and 14, some animals were intravenously injected with either ubiquinol’s vehicle or solubilized ubiquinol, or orally with selenium powder daily, starting from day 7, or received both ubiquinol + selenium. Magnetic resonance imaging of the lungs was performed on day 20. Hemodynamic parameters and morphometry were measured on day 22. An increased right ventricle systolic pressure in relation to control was demonstrated in all groups of animals of both sexes, except the group of males receiving the combination of ubiquinol + selenium. The relative mass of the right ventricle did not differ from the control in all groups of males and females receiving either ubiquinol alone or the combination. Magnetic resonance imaging revealed impaired perfusion in almost all animals examined, but pulmonary fibrosis developed in only half of the animals in the ubiquinol group. Intravenous administration of ubiquinol has a protective effect on monocrotaline-induced pulmonary hypertension development resulting in reduced right ventricle hypertrophy, and lung mass. Ubiquinol + selenium administration resulted in a less severe increase in the right ventricle systolic pressure in male rats but not in females 3 weeks after the start of the experiment. This sex-dependent effect was not observed in the influence of ubiquinol alone.

Effects of Crocin on CCL2/CCR2 Inflammatory Pathway in Monocrotaline-Induced Pulmonary Arterial Hypertension Rats

Pulmonary arterial hypertension (PAH) is a malignant cardiopulmonary disease, in which pulmonary arterial remodeling is regarded as the prominent pathological feature. So far, the mechanism of PAH is still unclear, so its treatment remains a challenge. However, inflammation plays an important part in the occurrence and progression of PAH. It is well known that crocin has anti-inflammatory properties, so we investigated whether crocin could be a potential drug for the treatment of PAH rat models. Rats injected subcutaneously with monocrotaline (MCT) were treated with crocin via a gastric tube daily for four weeks. The results showed that crocin treatment significantly reduced the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) in the PAH rat models. Moreover, crocin treatment reduced the proliferation of pulmonary arteriole smooth muscle cells (PASMCs). In addition, crocin treatment not only relieved inflammatory cell infiltration and collagen fiber hyperplasia in the lung and right ventricle, but also decreased the expression of the CCL2/CCR2 inflammatory pathway in the lung of PAH rat models. Furthermore, crocin treatment reduced the inflammatory cytokines and oxidative stress responses. In summary, crocin may play a protective role in MCT-induced PAH rats by alleviating inflammatory response, improving pulmonary arterial remodeling, and preventing PAH. Therefore, crocin as a new treatment for PAH may be quite worthy of consideration.

Cannabinoids-A New Perspective in Adjuvant Therapy for Pulmonary Hypertension

Currently, no treatment can completely cure pulmonary hypertension (PH), which can lead to right ventricular failure and, consequently, death. Therefore, searching for new therapies remains important. Increased resistance in pulmonary circulation is mainly caused by the excessive contraction and proliferation of small pulmonary arteries. Cannabinoids, a group of lipophilic compounds that all interact with cannabinoid receptors, exert a pulmonary vasodilatory effect through several different mechanisms, including mechanisms that depend on vascular endothelium and/or receptor-based mechanisms, and may also have anti-proliferative and anti-inflammatory properties. The vasodilatory effect is important in regulating pulmonary resistance, which can improve patients’ quality of life. Moreover, experimental studies on the effects of cannabidiol (plant-derived, non-psychoactive cannabinoid) in animal PH models have shown that cannabidiol reduces right ventricular systolic pressure and excessive remodelling and decreases pulmonary vascular hypertrophy and pulmonary vascular resistance. Due to the potentially beneficial effects of cannabinoids on pulmonary circulation and PH, in this work, we review whether cannabinoids can be used as an adjunctive therapy for PH. However, clinical trials are still needed to recommend the use of cannabinoids in the treatment of PH.

Essential sufficiency of zinc, ω-3 polyunsaturated fatty acids, vitamin D and magnesium for prevention and treatment of COVID-19, diabetes, cardiovascular diseases, lung diseases and cancer

Despite the development of a number of vaccines for COVID-19, there remains a need for prevention and treatment of the virus SARS-CoV-2 and the ensuing disease COVID-19. This report discusses the key elements of SARS-CoV-2 and COVID-19 that can be readily treated: viral entry, the immune system and inflammation, and the cytokine storm. It is shown that the essential nutrients zinc, ω-3 polyunsaturated fatty acids (PUFAs), vitamin D and magnesium provide the ideal combination for prevention and treatment of COVID-19: prevention of SARS-CoV-2 entry to host cells, prevention of proliferation of SARS-CoV-2, inhibition of excessive inflammation, improved control of the regulation of the immune system, inhibition of the cytokine storm, and reduction in the effects of acute respiratory distress syndrome (ARDS) and associated non-communicable diseases. It is emphasized that the non-communicable diseases associated with COVID-19 are inherently more prevalent in the elderly than the young, and that the maintenance of sufficiency of zinc, ω-3 PUFAs, vitamin D and magnesium is essential for the elderly to prevent the occurrence of non-communicable diseases such as diabetes, cardiovascular diseases, lung diseases and cancer. Annual checking of levels of these essential nutrients is recommended for those over 65 years of age, together with appropriate adjustments in their intake, with these services and supplies being at government cost. The cost:benefit ratio would be huge as the cost of the nutrients and the testing of their levels would be very small compared with the cost savings of specialists and hospitalization.

Magnesium: The recent research and developments

Magnesium is the fourth most abundant mineral in the human body, which facilitates more than 300 enzymatic reactions. Magnesium is essential for nucleic material and protein synthesis, neuromuscular conduction, cardiac contractility, energy metabolism, and immune system function. Gastrointestinal system and kidneys closely regulate magnesium absorption and elimination to maintain adequate storage of magnesium. Magnesium deficiency has been linked to many diseases and poor health outcomes. Magnesium has also been proven to be an effective therapeutic agent in many diseases, such as bronchial asthma, cardiac arrhythmia, and pre-eclampsia.

Magnesium Supplementation Attenuates Pulmonary Hypertension via Regulation of Magnesium Transporters

Pulmonary hypertension (PH) is characterized by profound vascular remodeling and altered Ca²⁺ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Magnesium ion (Mg²⁺), a natural Ca²⁺ antagonist and a cofactor for numerous enzymes, is crucial for regulating diverse cellular functions, but its roles in PH remains unclear. Here, we examined the roles of Mg²⁺ and its transporters in PH development. Chronic hypoxia and monocrotaline induced significant PH in adult male rats. It was associated with a reduction of [Mg²⁺]_i in PASMCs, a significant increase in gene expressions of Cnnm2, Hip14, Hip14l, Magt1, Mmgt1, Mrs2, Nipa1, Nipa2, Slc41a1, Slc41a2 and Trpm7; upregulation of SLC41A1, SLC41A2, CNNM2, and TRPM7 proteins; and downregulation of SLC41A3 mRNA and protein. Mg²⁺ supplement attenuated pulmonary arterial pressure, right heart hypertrophy, and medial wall thickening of pulmonary arteries, and reversed the changes in the expression of Mg²⁺ transporters. Incubation of PASMCs with a high concentration of Mg²⁺ markedly inhibited PASMC proliferation and migration, and increased apoptosis, whereas a low level of Mg²⁺ produced the opposite effects. siRNA targeting Slc41a1/2, Cnnm2, and Trpm7 attenuated PASMC proliferation and migration, but promoted apoptosis; and Slc41a3 overexpression also caused similar effects. Moreover, siRNA targeting Slc41a1 or high [Mg²⁺] incubation inhibited hypoxia-induced upregulation and nuclear translocation of NFATc3 in PASMCs. The results, for the first time, provide the supportive evidence that Mg²⁺ transporters participate in the development of PH by modulating PASMC proliferation, migration, and apoptosis; and Mg²⁺ supplementation attenuates PH through regulation of Mg²⁺ transporters involving the NFATc3 signaling pathway.

Peptide-Based TNF-α-Binding Decoy Therapy Mitigates Lipopolysaccharide-Induced Liver Injury in Mice

A peptide named SEM18, possessing structural similarity to the binding site of tumor necrosis factor (TNF)-α to TNF receptor 1 (TNFR1), was designed. We investigated whether the SEM18 peptide can mitigate lipopolysaccharide (LPS)-induced liver injury in mice. Adult male Balb/cJ mice received LPS (15 mg/kg; LPS group) or LPS plus SEM18 (LSEM group). Control groups were run simultaneously. At 2 h after LPS, the first dose of SEM18 (0.3 mg/kg) was administered, followed by three supplemental doses of SEM18 (0.15 mg/kg, every 2 h). At 24 h after LPS, surviving mice were euthanized for analyses. Compared with the LPS group, binding of TNF-α to TNFR1 in liver tissues was significantly lower in the LSEM group (p < 0.001). Plasma concentrations of aspartate transaminase and alanine transaminase, as well as Suzuki’s scores (liver damage assessment), wet/dry weight ratios, levels of polymorphonuclear neutrophil infiltration, and levels of mitochondrial injury in liver tissues, of the LSEM group were significantly lower than in the LPS group (all p < 0.05). Levels of necroptosis, pyroptosis, apoptosis, and autophagy upregulation in liver tissues in the LSEM group were also significantly lower than in the LPS group (all p < 0.05). Notably, exogenous TNF-α counteracted these effects of SEM18. SEM18 peptide mitigates LPS-induced liver injury in mice.

Cannabidiol Ameliorates Monocrotaline-Induced Pulmonary Hypertension in Rats

Cannabidiol (CBD) is known for its vasorelaxant (including in the human pulmonary artery), anti-proliferative and anti-inflammatory properties. The aim of our study was to examine the potential preventive effect of chronic CBD administration (10 mg/kg/day for three weeks) on monocrotaline (MCT)-induced pulmonary hypertension (PH) rats. PH was connected with elevation of right ventricular systolic pressure; right ventricle hypertrophy; lung edema; pulmonary artery remodeling; enhancement of the vasoconstrictor and decreasing vasodilatory responses; increases in plasma concentrations of tissue plasminogen activator, plasminogen activator inhibitor type 1 and leukocyte count; and a decrease in blood oxygen saturation. CBD improved all abovementioned changes induced by PH except right ventricle hypertrophy and lung edema. In addition, CBD increased lung levels of some endocannabinoids (anandamide, N-arachidonoyl glycine, linolenoyl ethanolamide, palmitoleoyl ethanolamide and eicosapentaenoyl ethanolamide but not 2-arachidonoylglycerol). CBD did not affect the cardiopulmonary system of control rats or other parameters of blood morphology in PH. Our data suggest that CBD ameliorates MCT-induced PH in rats by improving endothelial efficiency and function, normalization of hemostatic alterations and reduction of enhanced leukocyte count determined in PH. In conclusion, CBD may be a safe, promising therapeutic or adjuvant therapy agent for the treatment of human pulmonary artery hypertension.