Up-regulation of Sirt1/miR-149-5p signaling may play a role in resveratrol induced protection against ischemia via p53 in rat brain

Micro-RNA(miRNA) are well studied small noncoding RNA, which plays a diverse role in the regulation of vital elements in cell survival and apoptosis. However, the functional significance of miRNAs after the pathogenesis of ischemic stroke remains unclear. The present study is designed to investigate the regulatory role of miR-149-5p on Sirtuin-1/p53 axis during ischemic-reperfusion-induced injury. Middle cerebral artery occlusion (MCAO) was performed by nylon monofilament for 60 min. Resveratrol was administered via intraperitoneal (IP) route, 30 min before the MCAO. Our study demonstrated that the miR-149-5p levels were markedly decreased at 24 h after ischemic-reperfusion (I/R) injury. Further, we observed decreased p53 protein expression and increased miR-149-5p activity on sirtuin1 (Sirt1) activation with resveratrol after 24 h following MCAO. Moreover, immunohistochemistry studies found that resveratrol treatment significantly decreased the immunoreactivity of p53 and caspase-3 on activation of Sirt1/miR149-5p axis. In conclusion, our findings suggest that miR-149-5p could play a regulatory role in neuronal cell death via Sirt1/p53 axis, which offers a new target for novel therapeutic interventions during acute ischemic stroke.

Microfluidic Model to Evaluate Astrocyte Activation in Penumbral Region following Ischemic Stroke

Stroke is one of the main causes of death in the US and post-stroke treatment options remain limited. Ischemic stroke is caused by a blood clot that compromises blood supply to the brain, rapidly leading to tissue death at the core of the infarcted area surrounded by a hypoxic and nutrient-starved region known as the penumbra. Recent evidence suggests that astrocytes in the penumbral region play a dual role in stroke response, promoting further neural and tissue damage or improving tissue repair depending on the microenvironment. Thus, astrocyte response in the hypoxic penumbra could promote tissue repair after stroke, salvaging neurons in the affected area and contributing to cognitive recovery. However, the complex microenvironment of ischemic stroke, characterized by gradients of hypoxia and nutrients, poses a unique challenge for traditional in vitro models, which in turn hinders the development of novel therapies. To address this challenge, we have developed a novel, polystyrene-based microfluidic device to model the necrotic and penumbral region induced by an ischemic stroke. We demonstrated that when subjected to hypoxia, and nutrient starvation, astrocytes within the penumbral region generated in the microdevice exhibited long-lasting, significantly altered signaling capacity including calcium signaling impairment.

Up-regulation of Sirtuin-1/autophagy signaling in human cerebral ischemia: possible role in caspase-3 mediated apoptosis

Aim

Autophagy is a catabolic process, which plays a pivotal role in neuronal homeostases. Sirtuin-1 (Sirt1, Silent information regulator family protein 1) is a protein deacetylase that is activated by nicotinamide adenine dinucleotide (NAD⁺), is also influenced by starvation and stress response similar to autophagy. Sirt1 is necessary for the induction of autophagy and is critical for neuronal survival in neurodegeneration. The present study investigates the role of Sirt1/autophagy signaling and its possible involvement in neuronal cell death in the brains of cerebral ischemia (CI) patients.

Patients and methods

Autopsied brain tissues from three healthy subjects and ten CI patients were obtained from National Institute of Mental Health and Neurosciences (NIMHANS); Bangalore, India. Western blotting and immunostaining were performed to assess the expression changes in Sirt1, autophagy mediators including Beclin-1, autophagy-related (Atg) proteins-3, 5, 7, 12-5, microtubule-associated protein-1A light chain3 (Lc3-I/II), and caspase-3 in stroke patients.

Results

Our study showed that, in stroke patients, expression of Sirt1, Beclin-1, Atg-3, 5, 7, 12-5, and Lc3-II/I were upregulated. Further, our immunohistochemistry results show increased immunoreactivity of Sirt1, Beclin-1, Atg-7, Lc3-I/II, and cleaved caspase-3 in stroke brains.

Conclusion

The present data suggesting a role for Sirt1/autophagy signaling in regulating neuronal cell survival in CI.

Notch Signaling Suppresses Melanoma Tumor Development in BRAF/Pten Mice

Both oncogenic and tumor suppressor roles have been assigned to Notch signaling in melanoma. In clinical trials, Notch inhibitors proved to be ineffective for melanoma treatment. Notch signaling has also been implicated in melanoma transdifferentiation, a prognostic feature in primary melanoma. In this study, we investigated the role of Notch signaling in melanoma tumor development and growth using the genetic model of mouse melanoma by crossing BRAFCA/+/Pten+/+/Tyr-CreER+ (B) and BRAFCA/+/Pten-/-/Tyr-CreER + (BP) mice with Notch1 or Notch2 floxed allele mice. The topical application of tamoxifen induced tumors in BP mice but not in B mice with or without the deletion of either Notch1 or Notch2. These data show that the loss of either Notch1 nor Notch2 can substitute the tumor suppressor function of Pten in BRAFV600E-induced melanomagenesis. However, in Pten-null background, the loss of either Notch1 or Notch2 appeared to accelerate BRAFV600E-induced tumor development, suggesting a tumor suppressor role for Notch1 and Notch2 in BRAFV600E/Pten-null driven melanomagenesis. Quantitative immunochemical analysis of a human cutaneous melanoma tissue microarray that consists of >100 primary tumors with complete clinical history showed a weak to moderate correlation between NOTCH protein levels and clinical and pathological parameters. Our data show that Notch signaling is involved during melanomagenesis and suggest that the identification of genes and signaling pathways downstream of Notch could help devise strategies for melanoma prevention.

Advances in Microengineered Platforms for Skin Research

The skin plays a critical role in human physiology, acting both as a barrier to environmental insults and as a window to environmental stimuli. Disruption of this homeostasis leads to numerous skin disorders. Human and animal skin differ significantly, limiting the translational potential of animal-based investigations to advance therapeutics to human skin diseases. Hence, there is a critical need for physiologically relevant human skin models to explore novel treatment strategies. Recent advances in microfluidic technologies now allow design and generation of organ-on-chip devices that mimic critical features of tissue architecture. Skin-on-a-chip and microfluidic platforms hold promise as useful models for diverse dermatology applications. Compared with traditional in vitro models, microfluidic platforms offer improved control of fluid flow, which in turn allows precise manipulation of cell and molecular distribution. These properties enable the generation of multilayered in vitro models that mimic human skin structure while simultaneously offering superior control over nutrient and drug distribution. Researchers have used microfluidic platforms for a variety of applications in skin research, including epidermal-dermal cellular crosstalk, cell migration, mechanobiology, microbiome-immune response interactions, vascular biology, and wound healing. In this review, we comprehensively review state-of-the-art microfluidic models for skin research. We discuss the challenges and promise of current skin-on-a-chip technologies and provide a roadmap for future research in this active field.

A Comprehensive Review of Cardiovascular Disease Management: Cardiac Biomarkers, Imaging Modalities, Pharmacotherapy, Surgical Interventions, and Herbal Remedies

Cardiovascular diseases (CVDs) continue to be a major global health concern, representing a leading cause of morbidity and mortality. This review provides a comprehensive examination of CVDs, encompassing their pathophysiology, diagnostic biomarkers, advanced imaging techniques, pharmacological treatments, surgical interventions, and the emerging role of herbal remedies. The review covers various cardiovascular conditions such as coronary artery disease, atherosclerosis, peripheral artery disease, deep vein thrombosis, pulmonary embolism, cardiomyopathy, rheumatic heart disease, hypertension, ischemic heart disease, heart failure, cerebrovascular diseases, and congenital heart defects. The review presents a wide range of cardiac biomarkers such as troponins, C-reactive protein, CKMB, BNP, NT-proBNP, galectin, adiponectin, IL-6, TNF-α, miRNAs, and oxylipins. Advanced molecular imaging techniques, including chest X-ray, ECG, ultrasound, CT, SPECT, PET, and MRI, have significantly enhanced our ability to visualize myocardial perfusion, plaque characterization, and cardiac function. Various synthetic drugs including statins, ACE inhibitors, ARBs, β-blockers, calcium channel blockers, antihypertensives, anticoagulants, and antiarrhythmics are fundamental in managing CVDs. Nonetheless, their side effects such as hepatic dysfunction, renal impairment, and bleeding risks necessitate careful monitoring and personalized treatment strategies. In addition to conventional therapies, herbal remedies have garnered attention for their potential cardiovascular benefits. Plant extracts and their bioactive compounds, such as flavonoids, phenolic acids, saponins, and alkaloids, offer promising cardioprotective effects and enhanced cardiovascular health. This review underscores the value of combining traditional and modern therapeutic approaches to improve cardiovascular outcomes. This review serves as a vital resource for researchers by integrating a broad spectrum of information on CVDs, diagnostic tools, imaging techniques, pharmacological treatments and their side effects, and the potential of herbal remedies.

Abstract B01: Microphysiological systems as a next-generation precision immunotherapy tool: From patient heterogeneity to memory-like natural killer cells

Immunotherapy is transforming cancer treatment for thousands of patients worldwide. However, treatment response relies on the patients’ immune system, eliciting heterogeneous results. Numerous parameters contribute to immunotherapy response, including tumor-intrinsic factors such as an immunosuppressive microenvironment characterized by nutrient depletion, acidic pH, or waste products; and tumor-extrinsic factors including genetic immunodeficiencies, or immunosuppressive disorders like HIV infection or organ transplant medication. Consequently, predicting response to immunotherapy remains challenging. Thus, we designed a microphysiological system (MPS) that allows us to incorporate these factors to evaluate patient-specific immunotherapy efficacy. We used our MPS to assess memory-like natural killer (mNK) cell efficacy against solid tumors, as well as evaluated NK cell exhaustion in a tumor-induced suppressive environment. Focusing upon head and neck squamous cell carcinoma (HNSCC), we evaluated risk/benefit ratios and mNK cell responses, including mNK cell extravasation; tumor penetration/killing; and synergy with therapeutic antibodies. We observed that the tumor-induced microenvironment led to gradual erosion of natural killer (NK) cells’ cytotoxicity and upregulation of exhaustion markers. Interestingly, NK cells exhibited a limited capacity to recover from tumor-induced exhaustion, and checkpoint inhibitors and immunomodulatory agents (e.g., PD-1, IDO-1 inhibitors) partially prevented NK cell exhaustion. We also infected T cells with HIV to evaluate whether immunocompromised patients would benefit from mNK cell therapy in the same fashion. In this context, mNK cells exhibited promising immunotherapeutic potential for these populations as they retained tumor killing capacity even in the absence of T cells; mNK cells exhibited extravasation and migration towards patient-derived tumor spheroids, suggesting that mNK cells alone are capable of extravasation. However, CD4 T cells enhanced mNK responses and elicited overexpression of NK survival and function-associated genes, suggesting that future guidelines for people living with HIV and cancer should consider the progression of the disease when considering mNK cell-based therapies. Our MPS may also help to identify CD4 T cell-secreted factors with therapeutic potential to increase mNK cell responses, which could be provided ex vivo in immunocompromised patients. In summary, MPSs offer a precision tool to assess treatment responses in a patient-specific fashion and may help identify next-generation immunotherapies for hitherto excluded cohorts.

Citation Format: Catherine A McBain, Mehtab A Farooqui, María Virumbrales-Muñoz, Cristina Sanchez-de-Diego, Sireesh Kumar Teertam, Rebecca Schmitz, Melissa Skala, David J Beebe, Jose M Ayuso. Microphysiological systems as a next-generation precision immunotherapy tool: From patient heterogeneity to memory-like natural killer cells [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B01.

Cardiovascular Biomarkers: Tools for Precision Diagnosis and Prognosis

The present study provides a detailed review of cardiovascular biomarkers critical for the diagnosis, prognosis, and pathophysiology of cardiovascular diseases, the leading cause of global morbidity and mortality. These biomarkers aid in detecting disease onset, progression, and therapeutic responses, providing insights into molecular mechanisms. Enzyme markers like AST, CK-MB, LDH, CA-III, and HBDH are pivotal for detecting myocardial injury during acute events. Protein markers such as CRP, H-FABP, and MPO shed light on inflammation and oxidative stress. Cardiac Troponins, the gold standard for myocardial infarction diagnosis, exhibit high specificity and sensitivity, while IMA and GPBB indicate ischemia and early myocardial damage. Peptide markers, including BNP and NT-proBNP, are crucial for heart failure diagnosis and management, reflecting ventricular stress and remodeling. Novel peptides like MR-proANP and MR-proADM aid in assessing disease severity. Lipid markers such as lipoprotein-associated phospholipase A2 and oxylipins provide insights into lipid metabolism and atherosclerosis. Inflammatory and stress-related biomarkers, including TNFα, IL-6, GDF-15, and Pentraxin 3, illuminate chronic inflammation in CVDs. Hormonal markers like copeptin and endothelin-1 highlight neurohormonal activation, while emerging markers such as ST2, galectin-3, PAPP-A, and TMAO elucidate fibrosis, remodeling, and metabolic dysregulation. The inclusion of microRNAs and long non-coding RNAs represents a breakthrough in biomarker research, offering sensitive tools for early detection, risk stratification, and therapeutic targeting. This review emphasizes the diagnostic and prognostic utility of these biomarkers, advancing cardiovascular care through personalized medicine.