Transplantation of bone marrow cells from miR150 knockout mice improves senescence-associated humoral immune dysfunction and arterial stiffness

NLRP3 inflammasome-mediated premature immunosenescence drives diabetic vascular aging dependent on the induction of perivascular adipose tissue dysfunction

AIMS

The vascular aging process accelerated by type 2 diabetes mellitus (T2DM) is responsible for the elevated risk of associated cardiovascular diseases. Metabolic disorder-induced immune senescence has been implicated in multi-organ/tissue damage. Herein, we sought to determine the role of immunosenescence in diabetic vascular aging and to investigate the underlying mechanisms.

METHODS AND RESULTS

Aging hallmarks of the immune system appear prior to the vasculature in streptozotocin (STZ)/high-fat diet (HFD)-induced T2DM mice or db/db mice. Transplantation of aged splenocytes or diabetic splenocytes into young mice triggered vascular senescence and injury compared with normal control splenocyte transfer. RNA sequencing profile and validation in immune tissues revealed that the toll-like receptor 4-nuclear factor-kappa B-NLRP3 axis might be the mediator of diabetic premature immunosenescence. The absence of Nlrp3 attenuated immune senescence and vascular aging during T2DM. Importantly, senescent immune cells, particularly T cells, provoked perivascular adipose tissue (PVAT) dysfunction and alternations in its secretome, which in turn impair vascular biology. In addition, senescent immune cells may uniquely affect vasoconstriction via influencing PVAT. Lastly, rapamycin alleviated diabetic immune senescence and vascular aging, which may be partly due to NLRP3 signalling inhibition.

CONCLUSION

These results indicated that NLRP3 inflammasome-mediated immunosenescence precedes and drives diabetic vascular aging. The contribution of senescent immune cells to vascular aging is a combined effect of their direct effects and induction of PVAT dysfunction, the latter of which can uniquely affect vasoconstriction. We further demonstrated that infiltration of senescent T cells in PVAT was increased and associated with PVAT secretome alterations. Our findings suggest that blocking the NLRP3 pathway may prevent early immunosenescence and thus mitigate diabetic vascular aging and damage, and targeting senescent T cells or PVAT might also be the potential therapeutic approach.

Decellularized adipose matrix hydrogel-based in situ delivery of antagomiR-150-5p for rat abdominal aortic aneurysm therapy

Abdominal aortic aneurysm (AAA) is a progressive aortic disease featured by inflammation, vascular smooth muscle cells (VSMCs) depletion, and elastin degradation. MicroRNAs were related to AAA formation, which bring the approach for precise and targeted drug therapy for AAA. We developed a new strategy based on decellularized adipose matrix (DAM) hydrogel immobilized on the adventitia to release antagomiR-150-5p for preventing the AAA development. In this study, Cacl2-induced and elastase-induced rat AAA models were established. We found that miR-150-5p was upregulated while Notch3 was downregulated in two rat AAA models. Then a mold was designed for shaping hydrogel for miR-150-5p delivery around the abdominal aorta. Interestingly, inhibition of miR-150-5p in AAA by local release of antagomiR-150-5p with DAM hydrogel significantly prevented aortic dilation and elastin degradation. Moreover, inflammatory cell infiltration, the expression of inflammatory cytokines (MCP-1, TNF-α, and NF-κB (p65)), and matrix metalloproteinases (MMP-2, MMP-9) were increased while Notch3 and α-SMA were decreased in rat AAA, which can be attenuated by antagomiR-150-5p treatment. In VSMCs with TNF-α stimulation, we further demonstrated that inhibition of miR-150-5p downregulated NF-κB (p65), MMP-2, and MMP-9 and upregulated elastin via Notch3. This work presents a translational potential strategy for AAA repair via DAM hydrogel sustained release of antagomiR-150-5p, and highlights the mechanism of miR-150-5p during AAA progression by regulating Notch3.

ACL injury management: a comprehensive review of novel biotherapeutics

The anterior cruciate ligament (ACL) is integral to the stability of the knee joint, serving to limit anterior tibial translation and regulate rotational movements. ACL injuries are among the most common and debilitating forms of knee trauma, often resulting in joint effusion, muscular atrophy, and diminished athletic capabilities. Despite the established efficacy of ACL reconstruction as the standard treatment, it is not uniformly successful. Consequently, there is a growing interest in novel biotherapeutic interventions as potential alternatives. This comprehensive review examines the latest advancements in ACL biotherapy, encompassing the application of hyaluronic acid, self-assembled short peptides, growth factors, stem cell therapy, gene therapy, platelet-rich plasma therapy, bone marrow aspirate concentrate cells, extracorporeal shock wave, electrical stimulation and cross bracing protocol. The collective aim of these innovative treatments is to facilitate the restoration of the ACL's native biological and biomechanical integrity, with the ultimate goal of enhancing clinical outcomes and the functional recovery of affected individuals.

TNFα Induces DNA and Histone Hypomethylation and Pulmonary Artery Smooth Muscle Cell Proliferation Partly via Excessive Superoxide Formation

Objective: The level of tumor necrosis factor-α (TNF-α) is upregulated during the development of pulmonary vascular remodeling and pulmonary hypertension. A hallmark of pulmonary arterial (PA) remodeling is the excessive proliferation of PA smooth muscle cells (PASMCs). The purpose of this study is to investigate whether TNF-α induces PASMC proliferation and explore the potential mechanisms. Methods: PASMCs were isolated from 8-week-old male Sprague-Dawley rats and treated with 0, 20, or 200 ng/mL TNF-α for 24 or 48 h. After treatment, cell number, superoxide production, histone acetylation, DNA methylation, and histone methylation were assessed. Results: TNF-α treatment increased NADPH oxidase activity, superoxide production, and cell numbers compared to untreated controls. TNF-α-induced PASMC proliferation was rescued by a superoxide dismutase mimetic tempol. TNF-α treatment did not affect histone acetylation at either dose but did significantly decrease DNA methylation. DNA methyltransferase 1 activity was unchanged by TNF-α treatment. Further investigation using QRT-RT-PCR revealed that GADD45-α, a potential mediator of DNA demethylation, was increased after TNF-α treatment. RNAi inhibition of GADD45-α alone increased DNA methylation. TNF-α impaired the epigenetic mechanism leading to DNA hypomethylation, which can be abolished by a superoxide scavenger tempol. TNF-α treatment also decreased H3-K4 methylation. TNF-α-induced PASMC proliferation may involve the H3-K4 demethylase enzyme, lysine-specific demethylase 1 (LSD1). Conclusions: TNF-α-induced PASMC proliferation may be partly associated with excessive superoxide formation and histone and DNA methylation.

KDM6A Demethylase Regulates Renal Sodium Excretion and Blood Pressure

BACKGROUND

KDM6A (Lysine-Specific Demethylase 6A) is a specific demethylase for histone 3 lysine (K) 27 trimethylation (H3K27me3). The purpose of this study is to investigate whether KDM6A in renal tubule cells plays a role in the regulation of kidney function and blood pressure.

METHODS

We first crossed Ksp-Cre+/- and KDM6Aflox/flox mice for generating inducible kidney-specific deletion of KDM6A gene.

RESULTS

Notably, conditional knockout of KDM6A gene in renal tubule cells (KDM6A-cKO) increased H3K27me3 levels which leads to a decrease in Na excretion and elevation of blood pressure. Further analysis showed that the expression of NKCC2 (Na-K-2Cl cotransporter 2) and NCC (Na-Cl cotransporters) was upregulated which contributes to impaired Na excretion in KDM6A-cKO mice. The expression of AQP2 (aquaporin 2) was also increased in KDM6A-cKO mice, which may facilitate water reabsorption in KDM6A-cKO mice. The expression of Klotho was downregulated while expression of aging markers including p53, p21, and p16 was upregulated in kidneys of KDM6A-cKO mice, indicating that deletion of KDM6A in the renal tubule cells promotes kidney aging. Interestingly, KDM6A-cKO mice developed salt-sensitive hypertension which can be rescued by treatment with Klotho. KDM6A deficiency induced salt-sensitive hypertension likely through downregulation of the Klotho/ERK (extracellular signal-regulated kinase) signaling and upregulation of the WNK (with-no-lysine kinase) signaling.

CONCLUSIONS

This study provides the first evidence that KDM6A plays an essential role in maintaining normal tubular function and blood pressure. Renal tubule cell specific KDM6A deficiency causes hypertension due to increased H3K27me3 levels and the resultant downregulation of Klotho gene expression which disrupts the Klotho/ERK/NCC/NKCC2 signaling.

Inhibition of miR-101-3p prevents human aortic valve interstitial cell calcification through regulation of CDH11/SOX9 expression

BACKGROUND

Calcific aortic valve disease (CAVD) is the second leading cause of adult heart diseases. The purpose of this study is to investigate whether miR-101-3p plays a role in the human aortic valve interstitial cells (HAVICs) calcification and the underlying mechanisms.

METHODS

Small RNA deep sequencing and qPCR analysis were used to determine changes in microRNA expression in calcified human aortic valves.

RESULTS

The data showed that miR-101-3p levels were increased in the calcified human aortic valves. Using cultured primary HAVICs, we demonstrated that the miR-101-3p mimic promoted calcification and upregulated the osteogenesis pathway, while anti-miR-101-3p inhibited osteogenic differentiation and prevented calcification in HAVICs treated with the osteogenic conditioned medium. Mechanistically, miR-101-3p directly targeted cadherin-11 (CDH11) and Sry-related high-mobility-group box 9 (SOX9), key factors in the regulation of chondrogenesis and osteogenesis. Both CDH11 and SOX9 expressions were downregulated in the calcified human HAVICs. Inhibition of miR-101-3p restored expression of CDH11, SOX9 and ASPN and prevented osteogenesis in HAVICs under the calcific condition.

CONCLUSION

miR-101-3p plays an important role in HAVIC calcification through regulation of CDH11/SOX9 expression. The finding is important as it reveals that miR-1013p may be a potential therapeutic target for calcific aortic valve disease.