IL-33 Is Involved in the Anti-Inflammatory Effects of Butyrate and Propionate on TNFα-Activated Endothelial Cells

Short-chain fatty acids (e.g., butyrate and propionate) are able to diminish endothelial cell activation. The aim of this study was to investigate whether intracellular IL-33 mediates the effects of butyrate and propionate on TNFα-induced IL-8 production and vascular cell adhesion molecule-1 (VCAM-1) expression. In addition, it was investigated whether regulating NF-κB and MAPK signaling pathways are involved. Intracellular IL-33 was measured in human endothelial cells (HUVECs) pre-incubated for 24 h with butyrate (0.1 mM or 5 mM), propionate (0.3 mM or 10 mM), or trichostatin A (TSA, 0.5 μM) prior to TNFα (1 ng/mL) stimulation (24 h). The effects of butyrate, propionate, and TSA on TNFα-induced IL-8, vascular cell adhesion molecule-1 (VCAM-1), NF-κB, and MAPK signaling pathways in normal HUVECs and IL-33 siRNA (siIL-33)-transfected HUVECs were compared to study the role of IL-33 in the protective effects of butyrate and propionate. Endogenous IL-33 was highly expressed in the perinuclear in HUVECs, which was significantly reduced by TNFα stimulation. The TNFα-induced reduction in IL-33 was prevented by pre-incubation with butyrate or propionate. Butyrate (0.1 mM), propionate (0.3 mM), and TSA inhibited the IL-8 production and activation of NF-κB. Interestingly, this effect was not observed in siIL-33-transfected HUVECs. The effects of butyrate (5 mM), propionate (10 mM), and TSA (0.5 μM) on VCAM-1 expression and activation of MAPK signaling pathways were not affected by siIL-33 transfection. In conclusion, we showed that the inhibitory effects of butyrate and propionate on TNFα-induced IL-8 production were mediated by the HDACs/IL-33/NF-κB pathway, while their effects on VCAM-1 expression might be associated with the HDACs/MAPK signaling pathway, independently of IL-33.     

Pulmonary Vascular Complications in Hereditary Hemorrhagic Telangiectasia and the Underlying Pathophysiology

In this review, we discuss the role of transforming growth factor-beta (TGF-β) in the development of pulmonary vascular disease (PVD), both pulmonary arteriovenous malformations (AVM) and pulmonary hypertension (PH), in hereditary hemorrhagic telangiectasia (HHT). HHT or Rendu-Osler-Weber disease is an autosomal dominant genetic disorder with an estimated prevalence of 1 in 5000 persons and characterized by epistaxis, telangiectasia and AVMs in more than 80% of cases, HHT is caused by a mutation in the ENG gene on chromosome 9 encoding for the protein endoglin or activin receptor-like kinase 1 (ACVRL1) gene on chromosome 12 encoding for the protein ALK-1, resulting in HHT type 1 or HHT type 2, respectively. A third disease-causing mutation has been found in the SMAD-4 gene, causing a combination of HHT and juvenile polyposis coli. All three genes play a role in the TGF-β signaling pathway that is essential in angiogenesis where it plays a pivotal role in neoangiogenesis, vessel maturation and stabilization. PH is characterized by elevated mean pulmonary arterial pressure caused by a variety of different underlying pathologies. HHT carries an additional increased risk of PH because of high cardiac output as a result of anemia and shunting through hepatic AVMs, or development of pulmonary arterial hypertension due to interference of the TGF-β pathway. HHT in combination with PH is associated with a worse prognosis due to right-sided cardiac failure. The treatment of PVD in HHT includes medical or interventional therapy.     

4-Hydroxyphenylacetic Acid Attenuated Inflammation and Edema via Suppressing HIF-1α in Seawater Aspiration-Induced Lung Injury in Rats

4-Hydroxyphenylacetic acid (4-HPA) is an active component of Chinese herb Aster tataricus which had been widely used in China for the treatment of pulmonary diseases. The aim of this study is to investigate the effect of 4-HPA on seawater aspiration-induced lung injury. Pulmonary inflammation and edema were assessed by enzyme-linked immunosorbent assay (ELISA), bronchoalveolar lavage fluid (BALF) white cell count, Evans blue dye analysis, wet to dry weight ratios, and histology study. Hypoxia-inducible factor-1α (HIF-1α) siRNA and permeability assay were used to study the effect of 4-HPA on the production of inflammatory cytokines and monolayer permeability in vitro. The results showed that 4-HPA reduced seawater instillation-induced mortality in rats. In lung tissues, 4-HPA attenuated hypoxia, inflammation, vascular leak, and edema, and decreased HIF-1α protein level. In primary rat alveolar epithelial cells (AEC), 4-HPA decreased hypertonicity- and hypoxia-induced HIF-1α protein levels through inhibiting the activations of protein translational regulators and via promoting HIF-1α protein degradation. In addition, 4-HPA lowered inflammatory cytokines levels through suppressing hypertonicity- and hypoxia-induced HIF-1α in NR8383 macrophages. Moreover, 4-HPA decreased monolayer permeability through suppressing hypertonicity and hypoxia-induced HIF-1α, which was mediated by inhibiting vascular endothelial growth factor (VEGF) in rat lung microvascular endothelial cell line (RLMVEC). In conclusion, 4-HPA attenuated inflammation and edema through suppressing hypertonic and hypoxic induction of HIF-1α in seawater aspiration-induced lung injury in rats.     

Butyrate Protects Pancreatic Beta Cells from Cytokine-Induced Dysfunction

Pancreatic beta cell dysfunction caused by metabolic and inflammatory stress contributes to the development of type 2 diabetes (T2D). Butyrate, produced by the gut microbiota, has shown beneficial effects on glucose metabolism in animals and humans and may directly affect beta cell function, but the mechanisms are poorly described. The aim of this study was to investigate the effect of butyrate on cytokine-induced beta cell dysfunction in vitro. Mouse islets, rat INS-1E, and human EndoC-βH1 beta cells were exposed long-term to non-cytotoxic concentrations of cytokines and/or butyrate to resemble the slow onset of inflammation in T2D. Beta cell function was assessed by glucose-stimulated insulin secretion (GSIS), gene expression by qPCR and RNA-sequencing, and proliferation by incorporation of EdU into newly synthesized DNA. Butyrate protected beta cells from cytokine-induced impairment of GSIS and insulin content in the three beta cell models. Beta cell proliferation was reduced by both cytokines and butyrate. Expressions of the beta cell specific genes Ins, MafA, and Ucn3 reduced by the cytokine IL-1β were not affected by butyrate. In contrast, butyrate upregulated the expression of secretion/transport-related genes and downregulated inflammatory genes induced by IL-1β in mouse islets. In summary, butyrate prevents pro-inflammatory cytokine-induced beta cell dysfunction.     

Adenylate Kinase 4—A Key Regulator of Proliferation and Metabolic Shift in Human Pulmonary Arterial Smooth Muscle Cells via Akt and HIF-1α Signaling Pathways

Increased proliferation of pulmonary arterial smooth muscle cells (PASMCs) in response to chronic hypoxia contributes to pulmonary vascular remodeling in pulmonary hypertension (PH). PH shares numerous similarities with cancer, including a metabolic shift towards glycolysis. In lung cancer, adenylate kinase 4 (AK4) promotes metabolic reprogramming and metastasis. Against this background, we show that AK4 regulates cell proliferation and energy metabolism of primary human PASMCs. We demonstrate that chronic hypoxia upregulates AK4 in PASMCs in a hypoxia-inducible factor-1α (HIF-1α)-dependent manner. RNA interference of AK4 decreases the viability and proliferation of PASMCs under both normoxia and chronic hypoxia. AK4 silencing in PASMCs augments mitochondrial respiration and reduces glycolytic metabolism. The observed effects are associated with reduced levels of phosphorylated protein kinase B (Akt) as well as HIF-1α, indicating the existence of an AK4-HIF-1α feedforward loop in hypoxic PASMCs. Finally, we show that AK4 levels are elevated in pulmonary vessels from patients with idiopathic pulmonary arterial hypertension (IPAH), and AK4 silencing decreases glycolytic metabolism of IPAH-PASMCs. We conclude that AK4 is a new metabolic regulator in PASMCs interacting with HIF-1α and Akt signaling pathways to drive the pro-proliferative and glycolytic phenotype of PH.     

SOD2 Activity Is not Impacted by Hyperoxia in Murine Neonatal Pulmonary Artery Smooth Muscle Cells and Mice

Pulmonary hypertension (PH) complicates bronchopulmonary dysplasia (BPD) in 25% of infants. Superoxide dismutase 2 (SOD2) is an endogenous mitochondrial antioxidant, and overexpression protects against acute lung injury in adult mice. Little is known about SOD2 in neonatal lung disease and PH. C57Bl/6 mice and isogenic SOD2+/+ and SOD2−/+ mice were placed in room air (control) or 75% O₂ (chronic hyperoxia, CH) for 14 days. Right ventricular hypertrophy (RVH) was assessed by Fulton’s index. Medial wall thickness (MWT) and alveolar area were assessed on formalin fixed lung sections. Pulmonary artery smooth muscle cells (PASMC) were placed in 21% or 95% O₂ for 24 h. Lung and PASMC protein were analyzed for SOD2 expression and activity. Oxidative stress was measured with a mitochondrially-targeted sensor, mitoRoGFP. CH lungs have increased SOD2 expression, but unchanged activity. SOD2−/+ PASMC have decreased expression and activity at baseline, but increased SOD2 expression in hyperoxia. Hyperoxia increased mitochondrial ROS in SOD2+/+ and SOD2−/+ PASMC. SOD2+/+ and SOD2−/+ CH pups induced SOD2 expression, but not activity, and developed equivalent increases in RVH, MWT, and alveolar area. Since SOD2−/+ mice develop equivalent disease, this suggests other antioxidant systems may compensate for partial SOD2 expression and activity in the neonatal period during hyperoxia-induced oxidative stress.     

Anti-Inflammatory Effect of Allicin Associated with Fibrosis in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling. Recent evidence supports that inflammation plays a key role in triggering and maintaining pulmonary vascular remodeling. Recent studies have shown that garlic extract has protective effects in PAH, but the precise role of allicin, a compound derived from garlic, is unknown. Thus, we used allicin to evaluate its effects on inflammation and fibrosis in PAH. Male Wistar rats were divided into three groups: control (CON), monocrotaline (60 mg/kg) (MCT), and MCT plus allicin (16 mg/kg/oral gavage) (MCT + A). Right ventricle (RV) hypertrophy and pulmonary arterial medial wall thickness were determined. IL-1β, IL-6, TNF-α, NFκB p65, Iκβ, TGF-β, and α-SMA were determined by Western blot analysis. In addition, TNF-α and TGF-β were determined by immunohistochemistry, and miR-21-5p and mRNA expressions of Cd68, Bmpr2, and Smad5 were determined by RT-qPCR. Results: Allicin prevented increases in vessel wall thickness due to TNF-α, IL-6, IL-1β, and Cd68 in the lung. In addition, TGF-β, α-SMA, and fibrosis were lower in the MCT + A group compared with the MCT group. In the RV, allicin prevented increases in TNF-α, IL-6, and TGF-β. These observations suggest that, through the modulation of proinflammatory and profibrotic markers in the lung and heart, allicin delays the progression of PAH.     

Butyrate and the Fine-Tuning of Colonic Homeostasis: Implication for Inflammatory Bowel Diseases

This review describes current evidence supporting butyrate impact in the homeostatic regulation of the digestive ecosystem in health and inflammatory bowel diseases (IBDs). Butyrate is mainly produced by bacteria from the Firmicutes phylum. It stimulates mature colonocytes and inhibits undifferentiated malignant and stem cells. Butyrate oxidation in mature colonocytes (1) produces 70–80% of their energetic requirements, (2) prevents stem cell inhibition by limiting butyrate access to crypts, and (3) consumes oxygen, generating hypoxia and maintaining luminal anaerobiosis favorable to the microbiota. Butyrate stimulates the aryl hydrocarbon receptor (AhR), the GPR41 and GPR109A receptors, and inhibits HDAC in different cell types, thus stabilizing the gut barrier function and decreasing inflammatory processes. However, some studies indicate contrary effects according to butyrate concentrations. IBD patients exhibit a lower abundance of butyrate-producing bacteria and butyrate content. Additionally, colonocyte butyrate oxidation is depressed in these subjects, lowering luminal anaerobiosis and facilitating the expansion of Enterobacteriaceae that contribute to inflammation. Accordingly, gut dysbiosis and decreased barrier function in IBD seems to be secondary to the impaired mitochondrial disturbance in colonic epithelial cells.     

Effect of δ-Opioid Receptor Activation on BDNF-TrkB vs. TNF-α in the Mouse Cortex Exposed to Prolonged Hypoxia

We investigated whether δ-opioid receptor (DOR)-induced neuroprotection involves the brain-derived neurotrophic factor (BDNF) pathway. We studied the effect of DOR activation on the expression of BDNF and other proteins in the cortex of C57BL/6 mice exposed to hypoxia (10% of oxygen) for 1–10 days. The results showed that: (1) 1-day hypoxia had no appreciable effect on BDNF expression, while 3- and 10-day hypoxia progressively decreased BDNF expression, resulting in 37.3% reduction (p < 0.05) after 10-day exposure; (2) DOR activation with UFP-512 (1 mg/kg, i.p., daily) partially reversed the hypoxia-induced reduction of BDNF expression in the 3- or 10-day exposed cortex; (3) DOR activation partially reversed the hypoxia-induced reduction in functional TrkB (140-kDa) and attenuated hypoxia-induced increase in truncated TrkB (90-kDa) in the 3- or 10-day hypoxic cortex; and (4) prolonged hypoxia (10 days) significantly increased TNF-α level and decreased CD11b expression in the cortex, which was completely reversed following DOR activation; and (5) there was no significant change in pCREB and pATF-1 levels in the hypoxic cortex. We conclude that prolonged hypoxia down-regulates BDNF-TrkB signaling leading to an increase in TNF-α in the cortex, while DOR activation up-regulates BDNF-TrkB signaling thereby decreasing TNF-α levels in the hypoxic cortex.     

Inhibition of Histone Deacetylase by Butyrate Protects Rat Liver from Ischemic Reperfusion Injury

We showed previously that pretreatment of butyrate, which is an endogenous histone deacetylase (HDAC) inhibitor normally fermented from undigested fiber by intestinal microflora, seriously alleviated ischemia reperfusion (I/R)-induced liver injury by inhibiting the nuclear factor κB (NF-κB) pathway. The goal of this study was to investigate the effect of butyrate administrated at the onset of ischemia for HDAC inhibition in hepatic I/R injury. Sprague Dawley rats were subjected to warm ischemia for 60 min followed by 6 and 24 h of reperfusion. Butyrate was administrated at the onset of ischemia. Liver injury was evaluated by serum levels of aminotransferase, inflammatory factors, and histopathology. The levels of acetylated histone H3 and expression of heat shock protein (Hsp) 70 were measured by Western blot. After reperfusion, the levels of acetylated histone H3 significantly decreased. Butyrate treatment markedly prevented the reduction of acetylated histone H3 and upregulated the expression of Hsp70, thereby reducing liver injury. Our study demonstrated that I/R resulted in marked reduction of histone acetylation; butyrate exerted a great hepatoprotective effect through HDAC inhibition and Hsp70 induction.     

Yohimbine,an α2-Adrenoceptor Antagonist,Suppresses PDGF-BB-Stimulated Vascular Smooth Muscle Cell Proliferation by Downregulating the PLCγ1 Signaling Pathway

Yohimbine (YOH) has antiproliferative effects against breast cancer and pancreatic cancer; however, its effects on vascular proliferative diseases such as atherosclerosis remain unknown. Accordingly, we investigated the inhibitory mechanisms of YOH in vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor (PDGF)-BB, a major mitogenic factor in vascular diseases. YOH (5–20 μM) suppressed PDGF-BB-stimulated a mouse VSMC line (MOVAS-1 cell) proliferation without inducing cytotoxicity. YOH also exhibited antimigratory effects and downregulated matrix metalloproteinase-2 and -9 expression in PDGF-BB-stimulated MOVAS-1 cells. It also promoted cell cycle arrest in the initial gap/first gap phase by upregulating p27Kip1 and p53 expression and reducing cyclin-dependent kinase 2 and proliferating cell nuclear antigen expression. We noted phospholipase C-γ1 (PLCγ1) but not ERK1/2, AKT, or p38 kinase phosphorylation attenuation in YOH-modulated PDGF-BB-propagated signaling pathways in the MOVAS-1 cells. Furthermore, YOH still inhibited PDGF-BB-induced cell proliferation and PLCγ1 phosphorylation in MOVAS-1 cells with α2B-adrenergic receptor knockdown. YOH (5 and 10 mg/kg) substantially suppressed neointimal hyperplasia in mice subjected to CCA ligation for 21 days. Overall, our results reveal that YOH attenuates PDGF-BB-stimulated VSMC proliferation and migration by downregulating a α2B-adrenergic receptor–independent PLCγ1 pathway and reduces neointimal formation in vivo. Therefore, YOH has potential for repurposing for treating atherosclerosis and other vascular proliferative diseases.     

Natural Compound Resveratrol Attenuates TNF-Alpha-Induced Vascular Dysfunction in Mice and Human Endothelial Cells: The Involvement of the NF-κB Signaling Pathway

Resveratrol, a natural compound in grapes and red wine, has drawn attention due to potential cardiovascular-related health benefits. However, its effect on vascular inflammation at physiologically achievable concentrations is largely unknown. In this study, resveratrol in concentrations as low as 1 μm suppressed TNF-α-induced monocyte adhesion to human EA.hy926 endothelial cells (ECs), a key event in the initiation and development of atherosclerosis. Low concentrations of resveratrol (0.25–2 μm) also significantly attenuated TNF-α-stimulated mRNA expressions of MCP-1/CCL2 and ICAM-1, which are vital mediators of EC-monocyte adhesion molecules and cytokines for cardiovascular plaque formation. Additionally, resveratrol diminished TNF-α-induced IκB-α degradation and subsequent nuclear translocation of NF-κB p65 in ECs. In the animal study, resveratrol supplementation in diet significantly diminished TNF-α-induced increases in circulating levels of adhesion molecules and cytokines, monocyte adhesion to mouse aortic ECs, F4/80-positive macrophages and VCAM-1 expression in mice aortas and restored the disruption in aortic elastin fiber caused by TNF-α treatment. The animal study also confirmed that resveratrol blocks the activation of NF-κB In Vivo. In conclusion, resveratrol at physiologically achievable concentrations displayed protective effects against TNF-α-induced vascular endothelial inflammation in vitro and In Vivo. The ability of resveratrol in reducing inflammation may be associated with its role as a down-regulator of the NF-κB pathway.     

Impaired Butyrate Induced Regulation of T Cell Surface Expression of CTLA-4 in Patients with Ulcerative Colitis

Patients with ulcerative colitis (UC) have reduced intestinal levels of short-chain fatty acids (SCFAs), including butyrate, which are important regulators of host–microbiota crosstalk. The aim was therefore to determine effects of butyrate on blood and intestinal T cells from patients with active UC. T cells from UC patients and healthy subjects were polyclonally stimulated together with SCFAs and proliferation, activation, cytokine secretion, and surface expression of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) were analyzed. Butyrate induced comparable, dose dependent inhibition of activation and proliferation in blood T cells and activation in intestinal T cells from UC patients and healthy subjects. However, surface expression of the inhibitory molecule CTLA-4 on stimulated blood and intestinal T cells was impaired in UC patients and was not restored following butyrate treatment. Furthermore, unlike intestinal T cells from healthy subjects, butyrate was unable to downregulate secretion of interferon gamma (IFNγ), interleukin (IL)-4, IL-17A, and IL-10 in UC patients. Although seemingly normal inhibitory effects on T cell activation and proliferation, butyrate has an impaired ability to reduce cytokine secretion and induce surface expression of CTLA-4 in T cells from UC patients with active disease. Overall, these observations indicate a dysfunction in butyrate induced immune regulation linked to CTLA-4 signaling in T cells from UC patients during a flare.     

Hypoxia-Induced Collagen Synthesis of Human Lung Fibroblasts by Activating the Angiotensin System

The exact molecular mechanism that mediates hypoxia-induced pulmonary fibrosis needs to be further clarified. The aim of this study was to explore the effect and underlying mechanism of angiotensin II (Ang II) on collagen synthesis in hypoxic human lung fibroblast (HLF) cells. The HLF-1 cell line was used for in vitro studies. Angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1R) and angiotensin II type 2 receptor (AT2R) expression levels in human lung fibroblasts were analysed using real-time polymerase chain reaction (RT-PCR) after hypoxic treatment. Additionally, the collagen type I (Col-I), AT1R and nuclear factor κappaB (NF-κB) protein expression levels were detected using Western blot analysis, and NF-κB nuclear translocation was measured using immunofluorescence localization analysis. Ang II levels in HLF-1 cells were measured with an enzyme-linked immunosorbent assay (ELISA). We found that hypoxia increased Col-I mRNA and protein expression in HLF-1 cells, and this effect could be inhibited by an AT1R or AT2R inhibitor. The levels of NF-κB, RAS components and Ang II production in HLF-1 cells were significantly increased after the hypoxia exposure. Hypoxia or Ang II increased NF-κB-p50 protein expression in HLF-1 cells, and the special effect could be inhibited by telmisartan (TST), an AT1R inhibitor, and partially inhibited by PD123319, an AT2R inhibitor. Importantly, hypoxia-induced NF-κB nuclear translocation could be nearly completely inhibited by an AT1R or AT2R inhibitor. Furthermore pyrrolidine dithiocarbamate (PDTC), a NF-κB blocker, abolished the expression of hypoxia-induced AT1R and Col-I in HLF-1 cells. Our results indicate that Ang II-mediated NF-κB signalling via ATR is involved in hypoxia-induced collagen synthesis in human lung fibroblasts.     

Nox2 Upregulation and p38α MAPK Activation in Right Ventricular Hypertrophy of Rats Exposed to Long-Term Chronic Intermittent Hypobaric Hypoxia

One of the consequences of high altitude (hypobaric hypoxia) exposure is the development of right ventricular hypertrophy (RVH). One particular type of exposure is long-term chronic intermittent hypobaric hypoxia (CIH); the molecular alterations in RVH in this particular condition are less known. Studies show an important role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex-induced oxidative stress and protein kinase activation in different models of cardiac hypertrophy. The aim was to determine the oxidative level, NADPH oxidase expression and MAPK activation in rats with RVH induced by CIH. Male Wistar rats were randomly subjected to CIH (2 days hypoxia/2 days normoxia; n = 10) and normoxia (NX; n = 10) for 30 days. Hypoxia was simulated with a hypobaric chamber. Measurements in the RV included the following: hypertrophy, Nox2, Nox4, p22phox, LOX-1 and HIF-1α expression, lipid peroxidation and H₂O₂ concentration, and p38α and Akt activation. All CIH rats developed RVH and showed an upregulation of LOX-1, Nox2 and p22phox and an increase in lipid peroxidation, HIF-1α stabilization and p38α activation. Rats with long-term CIH-induced RVH clearly showed Nox2, p22phox and LOX-1 upregulation and increased lipid peroxidation, HIF-1α stabilization and p38α activation. Therefore, these molecules may be considered new targets in CIH-induced RVH.     

COVID-19: Immunohistochemical Analysis of TGF-β Signaling Pathways in Pulmonary Fibrosis

Acute respiratory distress syndrome (ARDS) followed by repair with lung remodeling is observed in COVID-19. These findings can lead to pulmonary terminal fibrosis, a form of irreversible sequelae. There is evidence that TGF-β is intimately involved in the fibrogenic process. When activated, TGF-β promotes the differentiation of fibroblasts into myofibroblasts and regulates the remodeling of the extracellular matrix (ECM). In this sense, the present study evaluated the histopathological features and immunohistochemical biomarkers (ACE-2, AKT-1, Caveolin-1, CD44v6, IL-4, MMP-9, α-SMA, Sphingosine-1, and TGF-β1 tissue expression) involved in the TGF-β1 signaling pathways and pulmonary fibrosis. The study consisted of 24 paraffin lung samples from patients who died of COVID-19 (COVID-19 group), compared to 10 lung samples from patients who died of H1N1pdm09 (H1N1 group) and 11 lung samples from patients who died of different causes, with no lung injury (CONTROL group). In addition to the presence of alveolar septal fibrosis, diffuse alveolar damage (DAD) was found to be significantly increased in the COVID-19 group, associated with a higher density of Collagen I (mature) and III (immature). There was also a significant increase observed in the immunoexpression of tissue biomarkers ACE-2, AKT-1, CD44v6, IL-4, MMP-9, α-SMA, Sphingosine-1, and TGF-β1 in the COVID-19 group. A significantly lower expression of Caveolin-1 was also found in this group. The results suggest the participation of TGF-β pathways in the development process of pulmonary fibrosis. Thus, it would be plausible to consider therapy with TGF-β inhibitors in those patients recovered from COVID-19 to mitigate a possible development of pulmonary fibrosis and its consequences for post-COVID-19 life quality.     

Immunosenescence in Aging-Related Vascular Dysfunction

The immunosenescence-related disproportion in T lymphocytes may have important consequences for endothelial dysfunction, which is a key event in vascular aging. The study was designed to assess the prognostic values of the inflammatory-immune profile to better predict and prevent vascular diseases associated with old age. Eighty individuals aged 70.9 ± 5.3 years were allocated to a low- (LGI) or high-grade inflammation (HGI) group based on CRP (<3 or ≥3 mg/L) as a conventional risk marker of cardiovascular diseases. Significant changes in inflammatory and endothelium-specific variables IL-1β, IL-6, TNFα, oxLDL, H₂O₂, NO, 3-nitrotyrosine, and endothelial progenitor cells (OR 7.61, 95% CI 2.56–29.05, p < 0.0001), confirmed their interplay in vascular inflammation. The flow-cytometry analysis demonstrated a high disproportion in T lymphocytes CD4⁺ and CD8⁺ between LGI and HGI groups. CRP was <3 mg/mL for the CD4/CD8 ratio within the reference values ≥ 1 or ≤2.5, unlike for the CD4/CD8 ratio < 1 and >2.5. The odds ratios for the distribution of CD4⁺ (OR 5.98, 95% CI 0.001–0.008, p < 0.001), CD8⁺ (OR 0.23, 95% CI 0.08–0.59, p < 0.01), and CD8CD45RO⁺ T naïve cells (OR 0.27, 95% CI 0.097–0.695, p < 0.01) and CD4/CD8 (OR 5.69, 95% CI 2.07–17.32, p < 0.001) indicated a potential diagnostic value of T lymphocytes for clinical prognosis in aging-related vascular dysfunction.     

The Effects of Insulin-Like Growth Factor I and BTP-2 on Acute Lung Injury

Acute lung injury (ALI) afflicts approximately 200,000 patients annually and has a 40% mortality rate. The COVID-19 pandemic has massively increased the rate of ALI incidence. The pathogenesis of ALI involves tissue damage from invading microbes and, in severe cases, the overexpression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). This study aimed to develop a therapy to normalize the excess production of inflammatory cytokines and promote tissue repair in the lipopolysaccharide (LPS)-induced ALI. Based on our previous studies, we tested the insulin-like growth factor I (IGF-I) and BTP-2 therapies. IGF-I was selected, because we and others have shown that elevated inflammatory cytokines suppress the expression of growth hormone receptors in the liver, leading to a decrease in the circulating IGF-I. IGF-I is a growth factor that increases vascular protection, enhances tissue repair, and decreases pro-inflammatory cytokines. It is also required to produce anti-inflammatory 1,25-dihydroxyvitamin D. BTP-2, an inhibitor of cytosolic calcium, was used to suppress the LPS-induced increase in cytosolic calcium, which otherwise leads to an increase in proinflammatory cytokines. We showed that LPS increased the expression of the primary inflammatory mediators such as toll like receptor-4 (TLR-4), IL-1β, interleukin-17 (IL-17), TNF-α, and interferon-γ (IFN-γ), which were normalized by the IGF-I + BTP-2 dual therapy in the lungs, along with improved vascular gene expression markers. The histologic lung injury score was markedly elevated by LPS and reduced to normal by the combination therapy. In conclusion, the LPS-induced increases in inflammatory cytokines, vascular injuries, and lung injuries were all improved by IGF-I + BTP-2 combination therapy.