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Rufy4, a protein belonging to the RUN and FYVE domain-containing protein family, participates in various cellular processes such as autophagy and intracellular trafficking. However, its role in osteoclast-mediated bone resorption remains uncertain. In this study, we investigated the expression and role of the Rufy4 gene in osteoclasts using small interfering RNA (siRNA) transfection and gene overexpression systems. Our findings revealed a significant increase in Rufy4 expression during osteoclast differentiation. Silencing Rufy4 enhanced osteoclast differentiation, intracellular cathepsin K levels, and formation of axial protrusive structures but suppressed bone resorption. Conversely, overexpressing wild-type Rufy4 in osteoclasts hindered differentiation while promoting podosome formation and bone resorption. Similarly, overexpression of a Rufy4 variant lacking the RUN domain mimics the effects of Rufy4 knockdown, significantly increasing intracellular cathepsin K levels, promoting osteoclastogenesis, and elongated axial protrusions formation, yet inhibiting bone resorption. These findings indicate that Rufy4 plays a critical role in osteoclast differentiation and bone resorption by regulating the cytoskeletal organization through its RUN domain. Our study provides new insights into the molecular mechanisms governing osteoclast activity and underscores Rufy4's potential as a novel therapeutic target for bone disorders characterized by excessive bone resorption.

17β-estradiol plays a crucial role in regulating cellular processes in both reproductive and non-reproductive tissues, including the thyroid gland. It modulates oxidative stress and contributes to sexual dimorphism in thyroid diseases, with ROS production, particularly H₂O₂, generated by NOX/DUOX enzymes. This study aimed to investigate the effects of 17β-estradiol (10 nM or 100 nM) on the expression of NOX/DUOX, thyroid-specific genes, and endoplasmic reticulum (ER) stress-related genes in male and female porcine thyroid follicular cells. Expression of the studied genes was evaluated by RT-PCR before and after treatment with 17β-estradiol alone or with the addition of NOX4 inhibitor (GKT-136901). Additionally, the level of ROS was measured by flow cytometry analysis. Our results show that 17β-estradiol significantly upregulates thyroid-specific genes, particularly TPO, and stimulates NOX/DUOX expression, affecting the redox state of thyroid cells. It also stimulates ER stress-related genes such as CHOP. In conclusion, estrogen excess may contribute to thyroid disease development via such possible mechanisms as the upregulation of key thyroid-specific genes, particularly TPO, and of genes involved in the cellular response to ER stress, especially CHOP, as well as by the stimulation of the NOX/DUOX system with consequent ROS overproduction. These mechanisms may play a certain role in the higher prevalence of thyroid diseases in women.

Chikungunya virus (CHIKV) infection is characterized by febrile illness, severe joint pain, myalgia, and cardiovascular complications. Given that CHIKV stimulates reactive oxygen species (ROS) and pro- and anti-inflammatory cytokines, events that disrupt vascular homeostasis, we hypothesized that CHIKV induces arterial dysfunction by directly impacting redox-related mechanisms in vascular cells. Wild-type (WT) and iNOS knockout (iNOS^-/-) mice were administered either CHIKV (1.0 × 10⁶ PFU/µL) or Mock vehicle via the intracaudal route. In vivo, CHIKV infection induced vascular dysfunction (assessed by a wire myograph), decreased systolic blood pressure (tail-cuff plethysmography), increased IL-6 and IFN-γ, but not TNF-α levels (determined by ELISA), and increased protein content by Western blot. Marked contractile hyporesponsiveness to phenylephrine was observed 48 h post-infection, which was restored by endothelium removal. L-NAME, 1400W, Tiron, and iNOS gene deletion prevented phenylephrine hyporesponsiveness. CHIKV infection increased vascular nitrite concentration (Griess reaction) and superoxide anion (O₂^•-) generation (lucigenin chemiluminescence), and decreased hydrogen peroxide (H₂O₂, by Amplex Red) levels 48 h post-infection, alongside increased TBARS levels. In vitro, CHIKV infected endothelial cells (EA.hy926) and upregulated ICAM-1 and iNOS protein expression (determined by Western blot). These data support the conclusion that CHIKV-induced alterations in vascular ROS/NF-kB/iNOS/NO signaling potentially contribute to cardiovascular events associated with Chikungunya infection.

The development of novel tools to tackle viral processes has become a central focus in global health, during the COVID-19 pandemic. The spike protein is currently one of the main SARS-CoV-2 targets, owing to its key roles in infectivity and virion formation. In this context, exploring innovative strategies to block the activity of essential factors of SARS-CoV-2, such as spike proteins, will strengthen the capacity to respond to current and future threats. In the present work, we developed and tested novel bispecific molecules that encompass: (i) oligonucleotide aptamers S901 and S702, which bind to the spike protein through its S1 domain, and (ii) hydrophobic tags, such as adamantane and tert-butyl-carbamate-based ligands. Hydrophobic tags have the capacity to trigger the degradation of targets recruited in the context of a proteolytic chimera by activating quality control pathways. We observed that S901-adamantyl conjugates promote the degradation of the S1 spike domain, stably expressed in human cells by genomic insertion. These results highlight the suitability of aptamers as target-recognition molecules and the robustness of protein quality control pathways triggered by hydrophobic signals, and place aptamer-Hytacs as promising tools for counteracting coronavirus progression in human cells.

Background: Hypertension is a major cause of mortality worldwide. The kidneys play a crucial role in regulating blood pressure and fluid volume. The relationship between the kidneys and hypertension is complex, involving factors such as the renin-angiotensin system, oxidative stress, and inflammation. This study aims to assess the levels of inflammatory markers, oxidative stress, and metabolic factors in the kidneys, focusing on their potential role in early renal damage and their association with the development of hypertension. Methods: This study was designed to compare the levels of selected inflammatory markers, e.g., interleukins, tumor necrosis factor-α (TNF-α), transforming growth factor, and serine/threonine-protein (mTOR); oxidative stress markers such as malondialdehyde, sulfhydryl group, and glucose (GLC); and metabolic markers among other enzymes, such as alanine transaminase (ALT), aspartate transaminase (AST), hexokinase II (HK-II), and hypoxia-inducible factor-1α (HIF-1α), as well as creatinine in the kidneys of spontaneously hypertensive rats (SHR/NCrl, n = 12) and Wistar Kyoto rats (WKY/NCrl, n = 12). Both juvenile (5 weeks old) and maturing (10 weeks old) specimens were examined using spectrophotometric methods, e.g., ELISA. Results: Juvenile SHRs exhibited reduced renal levels of all studied cytokines and chemokines, with lower oxidative stress and deficits in the mTOR and HK-II levels compared to the age-matched WKYs. Maturing SHRs showed increased renal levels of interleukin-1β (IL-1β), IL-6, IL-18, and TNF-α, alongside elevated carbonyl stress and increased HIF-1α as opposed to their control peers. The levels of all other studied markers were normalized in these animals, except for ALT (increased), ALP, and GLC (both reduced). Conclusions: This study underscores the significant impact of inflammatory, oxidative stress, and metabolic marker changes on renal function. Juvenile SHRs display lower marker levels, indicating an immature immune response and potential subclinical kidney damage that may contribute to hypertension development. In contrast, mature SHRs exhibit chronic inflammation, oxidative dysregulation, and metabolic disturbances, suggesting cellular damage. These changes create a feedback loop that worsens kidney function and accelerates hypertension progression, highlighting the kidneys' crucial role in both initiating and exacerbating this condition.

Cobalt toxicity is difficult to detect and therefore often underdiagnosed. The aim of this study was to explore the pathophysiology of cobalt-induced oxidative stress in the brain and its impact on structure and function. Thirty-five wild-type C57B16 mice received intraperitoneal cobalt chloride injections: a single high dose with evaluations at 24, 48, and 72 h (n = 5, each) or daily low doses for 28 (n = 5) or 56 days (n = 15). A part of the 56-day group also received minocycline (n = 5), while 10 mice served as controls. Behavioral changes were evaluated, and cobalt levels in tissues were measured with particle-induced X-ray emission. Brain sections underwent magnetic resonance imaging (MRI), electron microscopy, and histological, immunohistochemical, and molecular analyses. High-dose cobalt caused transient illness, whereas chronic daily low-dose administration led to long-term elevations in cobalt levels accompanied by brain inflammation. Significant neurodegeneration was evidenced by demyelination, increased blood-brain barrier permeability, and mitochondrial dysfunction. Treated mice exhibited extended latency periods in the Morris water maze test and heightened anxiety in the open field test. Minocycline partially mitigated brain injury. The observed signs of neurodegeneration were dose- and time-dependent. The neurotoxicity after acute exposure was reversible, but the neurological and functional changes following chronic cobalt administration were not.

Background: ST-elevation myocardial infarction (STEMI) and Takotsubo syndrome (TS) are two distinct cardiac conditions that both result in sudden loss of cardiac dysfunction and that are difficult to distinguish clinically. This study compared plasma protein changes in 24 women with STEMI and 12 women with TS in the acute phase (days 0-3 post symptom onset) and the stabilization phase (days 7, 14, and 30) to examine the molecular differences between these conditions.

Methods: Plasma proteins from STEMI and TS patients were extracted during the acute and stabilization phases and analyzed via quantitative proteomics. Differential expression and functional significance were assessed. Data are accessible on ProteomeXchange, ID PXD051367.

Results: During the acute phase, STEMI patients showed higher levels of myocardial inflammation and tissue damage proteins compared to TS patients, along with reduced tissue repair and anti-inflammatory proteins. In the stabilization phase, STEMI patients exhibited ongoing inflammation and disrupted lipid metabolism. Notably, ADIPOQ was consistently downregulated in STEMI patients in both phases. When comparing the acute to the stabilization phase, STEMI patients showed increased inflammatory proteins and decreased structural proteins. Conversely, TS patients showed increased proteins involved in inflammation and the regulatory response to counter excessive inflammation. Consistent protein changes between the acute and stabilization phases in both conditions, such as SAA2, CRP, SAA1, LBP, FGL1, AGT, MAN1A1, APOA4, COMP, and PCOLCE, suggest shared underlying pathophysiological mechanisms.

Conclusions: This study presents protein changes in women with STEMI or TS and identifies ADIPOQ, SAA2, CRP, SAA1, LBP, FGL1, AGT, MAN1A1, APOA4, COMP, and PCOLCE as candidates for further exploration in both therapeutic and diagnostic contexts.

There are currently no effective treatments for retinal pigment epithelial (RPE) cell loss in atrophic AMD (aAMD). However, our research on Prominin-1 (Prom1), a known structural protein in photoreceptors (PRs), has revealed its distinct role in RPE and offers promising insights. While pathogenic Prom1 mutations have been linked to macular diseases with RPE atrophy, the broader physiological impact of dysfunctional Prom1 in RPE loss is unclear. We have shown that Prom1 plays a crucial role in regulating autophagy and cellular homeostasis in human and mouse RPE (mRPE) cells in vitro. Nevertheless, a comprehensive understanding of its in vivo expression and function in mRPE remains to be elucidated. To characterize Prom1 expression in RPE in situ, we used RNAscope assays and immunogold electron microscopy (EM). Our use of chromogenic and fluorescent RNAscope assays in albino and C57BL/6J mouse retinal sections has revealed Prom1 mRNA expression in perinuclear regions in mRPE in situ. Immunogold EM imaging showed Prom1 expression in RPE cytoplasm and mitochondria. To confirm Prom1 expression in RPE, we interrogated human RPE single-cell RNA-sequencing datasets using an online resource, Spectacle. Our analysis showed Prom1 expression in human RPE. To investigate Prom1's function in RPE homeostasis, we performed RPE-specific Prom1 knockdown (KD) using subretinal injections of AAV2/1.CMV.saCas9.U6.Prom1gRNA in male and female mice. Our data show that RPE-specific Prom1-KD in vivo resulted in abnormal RPE morphology, subretinal fluid accumulation, and secondary PR loss. These changes were associated with patchy RPE cell death and reduced a-wave amplitude, indicating retinal degeneration. Our findings underscore the central role of Prom1 in cell-autonomous mRPE homeostasis. The implications of Prom1-KD causing aAMD-like RPE defects and retinal degeneration in a mouse model are significant and could lead to novel treatments for aAMD.

Developmental and Epileptic Encephalopathies (DEEs) represent a clinically and genetically heterogeneous group of rare and severe epilepsies. DEEs commonly begin early in infancy with frequent seizures of various types associated with intellectual disability and leading to a neurodevelopmental delay or regression. Disease-causing genomic variants have been identified in numerous genes and are implicated in over 100 types of DEEs. In this context, genes encoding voltage-gated ion channels (VGCs) play a significant role, and part of the large phenotypic variability observed in DEE patients carrying VGC mutations could be explained by the presence of genetic modifier alleles that can compensate for these mutations. This review will focus on the current knowledge of the compensatory effect of DEE-associated voltage-gated ion channels and their therapeutic implications in DEE. We will enter into detailed considerations regarding the sodium channels SCN1A, SCN2A, and SCN8A; the potassium channels KCNA1, KCNQ2, and KCNT1; and the calcium channels CACNA1A and CACNA1G.

The onset of SARS-CoV-2 infection in 2019 sparked a global COVID-19 pandemic. This infection is marked by a significant rise in both viral and host kinase activity. Our primary objective was to identify a pivotal host kinase essential for COVID-19 infection and the associated phenomenon of the cytokine storm, which may lead to long-term COVID-19 complications irrespective of viral genetic variations. To achieve this, our study tracked kinase phosphorylation dynamics in RAW264.7 macrophages following SPIKE transfection over time. Among the kinases surveyed, p70S6K (RPS6KB1) exhibited a 3.5-fold increase in phosphorylation at S418. This significant change prompted the selection of p70S6K for in silico investigation, utilizing its structure bound to M2698 (PDB: 7N93). M2698, an oral dual Akt/p70S6K inhibitor with an IC₅₀ of 1.1 nM, exhibited psychosis side effects in phase I clinical trials, potentially linked to its interaction with Akt2. Our secondary objective was to discover a small-molecule analogue of M2698 that exhibits a distinct binding preference for p70S6K over Akt2 through computational modeling and analysis. The in silico part of our project began with validating the prediction accuracy of the docking algorithm, followed by an OCA analysis pinpointing specific atoms on M2698 that could be modified to enhance selectivity. Subsequently, our investigation led to the identification of an analog of M2698, designated as S34, that showed a superior docking score towards p70S6K compared to Akt2. To further assess the stability of S34 in its protein-ligand (PL) complexes with p70S6K and Akt2, MD simulations were conducted. These simulations suggest that S34, on average, forms two hydrogen bond interactions with p70S6K, whereas it only forms one hydrogen bond interaction with Akt2. This difference in hydrogen bond interactions likely contributed to the observed larger root mean square deviation (RMSD) of 0.3 nm in the S34-Akt2 complex, compared to 0.1 nm in the S34-p70S6K complex. Additionally, we calculated free binding energy to predict the strength of the binding interactions of S34 to p70S6K and Akt2, which showed ~2-fold favorable binding affinity of S34 in the p70S6K binding pocket compared to that in the Akt2 binding pocket. These observations may suggest that the S34-p70S6K complex is more stable than the S34-Akt2 complex. Our work focused on identifying a host kinase target and predicting the binding affinity of a novel small molecule to accelerate the development of effective treatments. The wet bench results specifically highlight p70S6K as a compelling anti-COVID-19 target. Meanwhile, our in silico investigations address the known off-target effects associated with M2698 by identifying a close analog called S34. In conclusion, this study presents novel and intriguing findings that could potentially lead to clinical applications with further investigations.