Search Results (15,726)

The regulated formation and resolution of R-loops is a natural process in physiological gene expression. Defects in R-loop metabolism can lead to DNA replication stress, which is associated with a variety of diseases and, ultimately, with cancer. The proteins PARP1, DIDO3, and DHX9 are important players in R-loop regulation. We previously described the interaction between DIDO3 and DHX9. Here, we show that, in mouse embryonic fibroblasts, the three proteins are physically linked and dependent on PARP1 activity. The C-terminal truncation of DIDO3 leads to the impairment of this interaction; concomitantly, the cells show increased replication stress and senescence. DIDO3 truncation also renders the cells partially resistant to in vitro oncogenic transformation, an effect that can be reversed by immortalization. We propose that PARP1, DIDO3, and DHX9 proteins form a ternary complex that regulates R-loop metabolism, preventing DNA replication stress and subsequent senescence. Full article

Hydrogen sulfide (H₂S) belongs to the family of gasotransmitters and can modulate a myriad of biological signaling pathways. Among others, its cardioprotective effects, through antioxidant, anti-inflammatory, anti-fibrotic, and proangiogenic activities, are well-documented in experimental studies. Cardiorespiratory failure, predominantly cardiomyopathy, is a life-threatening complication that is the number one cause of death in patients with Duchenne muscular dystrophy (DMD). Although recent data suggest the role of H₂S in ameliorating muscle wasting in murine and Caenorhabditis elegans models of DMD, possible cardioprotective effects have not yet been addressed. In this review, we summarize the current understanding of the role of H₂S in animal models of cardiac dysfunctions and cardiac cells. We highlight that DMD may be amenable to H₂S supplementation, and we suggest H₂S as a possible factor regulating DMD-associated cardiomyopathy. Full article

Cardiovascular disease (CVD) remains an important comorbidity in people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Our previous studies performed in the Canadian HIV/Aging Cohort Study (CHACS) (>40 years-old; Framingham Risk Score (FRS) > 5%) revealed a 2–3-fold increase in non-calcified coronary artery atherosclerosis (CAA) plaque burden, measured by computed tomography angiography scan (CTAScan) as the total (TPV) and low attenuated plaque volume (LAPV), in ART-treated PLWH (HIV+) versus uninfected controls (HIV−). In an effort to identify novel correlates of subclinical CAA, markers of intestinal damage (sCD14, LBP, FABP2); cell trafficking/inflammation (CCL20, CX3CL1, MIF, CCL25); subsets of Th17-polarized and regulatory (Tregs) CD4⁺ T-cells, classical/intermediate/non-classical monocytes, and myeloid/plasmacytoid dendritic cells were studied in relationship with HIV and TPV/LAPV status. The TPV detection/values coincided with higher plasma sCD14, FABP2, CCL20, MIF, CX3CL1, and triglyceride levels; lower Th17/Treg ratios; and classical monocyte expansion. Among HIV⁺, TPV⁺ versus TPV⁻ exhibited lower Th17 frequencies, reduced Th17/Treg ratios, higher frequencies of non-classical CCR9^lowHLADR^high monocytes, and increased plasma fibrinogen levels. Finally, Th17/Treg ratios and non-classical CCR9^lowHLADR^high monocyte frequencies remained associated with TPV/LAPV after adjusting for FRS and HIV/ART duration in a logistic regression model. These findings point to Th17 paucity and non-classical monocyte abundance as novel immunological correlates of subclinical CAA that may fuel the CVD risk in ART-treated PLWH. Full article

The skin is constantly exposed to a range of environmental stressors, including ultraviolet (UV) radiation, which can cause damage to the skin. Repairing UV-damaged skin has been a major focus of research in recent years. The therapeutic potential of human umbilical cord mesenchymal stem cells (HUCMSCs) exhibits anti-photoaging properties. In this study, we developed a strategy for concentrating an HUCMSC supernatant, and examined the protective effects of CHS on UVB exposure in vitro and in vivo. Our results demonstrate that CHS repairs UVB exposure by promoting cell viability and migration and reducing senescent and apoptosis cells. We further found that the photoprotective effect of CHS is due to autophagy activation. Moreover, CHS reduces wrinkles and senescent cells, increases collagen expression, and improves immune function in UVB exposure-induced skin damage. In summary, our study provides a new approach for repairing cell damage, and suggests that CHS might be a potential candidate for preventing UVB-induced skin photodamage. Full article

The close cooperation between breast cancer and cancer-associated adipose tissue (CAAT) shapes the malignant phenotype, but the role of mitochondrial metabolic reprogramming and obesity in breast cancer remains undecided, especially in premenopausal women. Here, we examined mitochondrial metabolic dynamics in paired biopsies of malignant versus benign breast tumor tissue and CAAT in normal-weight and overweight/obese premenopausal women. Lower protein level of pyruvate dehydrogenase and citrate synthase in malignant tumor tissue indicated decreased carbon flux from glucose into the Krebs cycle, whereas the trend was just the opposite in malignant CAAT. Simultaneously, stimulated lipolysis in CAAT of obese women was followed by upregulated β-oxidation, as well as fatty acid synthesis enzymes in both tumor tissue and CAAT of women with malignant tumors, corroborating their physical association. Further, protein level of electron transport chain complexes was generally increased in tumor tissue and CAAT from women with malignant tumors, respective to obesity. Preserved mitochondrial structure in malignant tumor tissue was also observed. However, mitochondrial DNA copy number and protein levels of PGC-1α were dependent on both malignancy and obesity in tumor tissue and CAAT. In conclusion, metabolic cooperation between breast cancer and CAAT in premenopausal women involves obesity-related, synchronized changes in mitochondrial metabolism. Full article

Using an original methodological and technical approach, we studied the real-time dynamics of radial water transfer in roots and transpiration rate in intact maize plants in response to water stress. It was shown that the response of maize plants to water stress, induced by 10% PEG 6000, was accompanied by changes in the intensity and redistribution of water transfer along different pathways of radial water transport in the roots. It was shown that during the first minutes of water stress impact, the intensity of transcellular and symplastic water transport in the roots decreased with a parallel short-term increase in the transpiration rate in leaves and, presumably, in apoplastic transport in roots. Further, after a decrease in transpiration rate, the intensity of transcellular and symplastic water transport was restored to approximately the initial values and was accompanied by parallel upregulation of some PIP aquaporin genes in roots and leaves, changes in aquaporin localization in root tissues, and changes in xylem sap pH. Under water stress conditions, cell-to-cell water transport in roots becomes dominant, and aquaporins contribute to the simultaneous regulation of water transport in roots and shoots under water stress. Full article

Equine metabolic syndrome (EMS) is a significant global health concern in veterinary medicine. There is increasing interest in utilizing molecular agents to modulate hepatocyte function for potential clinical applications. Recent studies have shown promising results in inhibiting protein tyrosine phosphatase (PTP1B) to maintain cell function in various models. In this study, we investigated the effects of the inhibitor Trodusquemine (MSI-1436) on equine hepatic progenitor cells (HPCs) under lipotoxic conditions. We examined proliferative activity, glucose uptake, and mitochondrial morphogenesis. Our study found that MSI-1436 promotes HPC entry into the cell cycle and protects them from palmitate-induced apoptosis by regulating mitochondrial dynamics and biogenesis. MSI-1436 also increases glucose uptake and protects HPCs from palmitate-induced stress by reorganizing the cells’ morphological architecture. Furthermore, our findings suggest that MSI-1436 enhances 2-NBDG uptake by increasing the expression of SIRT1, which is associated with liver insulin sensitivity. It also promotes mitochondrial dynamics by modulating mitochondria quantity and morphotype as well as increasing the expression of PINK1, MFN1, and MFN2. Our study provides evidence that MSI-1436 has a positive impact on equine hepatic progenitor cells, indicating its potential therapeutic value in treating EMS and insulin dysregulation. Full article

Internal circadian clocks coordinate 24 h rhythms in behavior and physiology. Many immune functions show daily oscillations, and cellular circadian clocks can impact immune functions and disease outcome. Inflammation may disrupt circadian clocks in peripheral tissues and innate immune cells. However, it remains elusive if chronic inflammation impacts adaptive immune cell clock, e.g., in CD4+ and CD8+ T lymphocytes. We studied this in the experimental autoimmune encephalomyelitis (EAE), a mouse model for multiple sclerosis, as an established experimental paradigm for chronic inflammation. We analyzed splenic T cell circadian clock and immune gene expression rhythms in mice with late-stage EAE, CFA/PTx-treated, and untreated mice. In both treatment groups, clock gene expression rhythms were altered with differential effects for baseline expression and peak phase compared with control mice. Most immune cell marker genes tested in this study did not show circadian oscillations in either of the three groups, but time-of-day- independent alterations were observed in EAE and CFA/PTx compared to control mice. Notably, T cell effects were likely independent of central clock function as circadian behavioral rhythms in EAE mice remained intact. Together, chronic inflammation induced by CFA/PTx treatment and EAE immunization has lasting effects on circadian rhythms in peripheral immune cells. Full article

The blood–brain barrier (BBB) is a fundamental structure that protects the composition of the brain by determining which ions, metabolites, and nutrients are allowed to enter the brain from the blood or to leave it towards the circulation. The BBB is structurally composed of a layer of brain capillary endothelial cells (BCECs) bound to each other through tight junctions (TJs). However, its development as well as maintenance and properties are controlled by the other brain cells that contact the BCECs: pericytes, glial cells, and even neurons themselves. Astrocytes seem, in particular, to have a very important role in determining and controlling most properties of the BBB. Here, we will focus on these latter cells, since the comprehension of their roles in brain physiology has been continuously expanding, even including the ability to participate in neurotransmission and in complex functions such as learning and memory. Accordingly, pathological conditions that alter astrocytic functions can alter the BBB’s integrity, thus compromising many brain activities. In this review, we will also refer to different kinds of in vitro BBB models used to study the BBB’s properties, evidencing its modifications under pathological conditions. Full article

Besides visceral heterotaxia, Pkd1l1 null mouse embryos exhibit general edema and perinatal lethality. In humans, congenital chylothorax (CCT) is a frequent cause of fetal hydrops. In 2021, Correa and colleagues reported ultrarare compound heterozygous variants in PKD1L1 exhibiting in two consecutive fetuses with severe hydrops, implicating a direct role of PKD1L1 in fetal hydrops formation. Here, we performed an exome survey and identified ultrarare compound heterozygous variants in PKD1L1 in two of the five case–parent trios with CCT. In one family, the affected carried the ultrarare missense variants c.1543G>A(p.Gly515Arg) and c.3845T>A(p.Val1282Glu). In the other family, the affected carried the ultrarare loss-of-function variant (LoF) c.863delA(p.Asn288Thrfs*3) and the ultrarare missense variant c.6549G>T(p.Gln2183His). Investigation of the variants’ impact on PKD1L1 protein localization suggests the missense variants cause protein dysfunction and the LoF variant causes protein mislocalization. Further analysis of Pkd1l1 mutant mouse embryos revealed about 20% of Pkd1l1^−/− embryos display general edema and pleural effusion at 14.5 dpc. Immunofluorescence staining at 14.5 dpc in Pkd1l1^−/− embryos displayed both normal and massively altered lymphatic vessel morphologies. Together, our studies suggest the implication of PKD1L1 in congenital lymphatic anomalies, including CCTs. Full article

Traumatic Brain Injury (TBI) represents a significant health concern, necessitating advanced therapeutic interventions. This detailed review explores the critical roles of astrocytes, key cellular constituents of the central nervous system (CNS), in both the pathophysiology and possible rehabilitation of TBI. Following injury, astrocytes exhibit reactive transformations, differentiating into pro-inflammatory (A1) and neuroprotective (A2) phenotypes. This paper elucidates the interactions of astrocytes with neurons, their role in neuroinflammation, and the potential for their therapeutic exploitation. Emphasized strategies encompass the utilization of endocannabinoid and calcium signaling pathways, hormone-based treatments like 17β-estradiol, biological therapies employing anti-HBGB1 monoclonal antibodies, gene therapy targeting Connexin 43, and the innovative technique of astrocyte transplantation as a means to repair damaged neural tissues. Full article

Orthodontic tooth movement (OTM) is thought to be impeded by bisphosphonate (BP) therapy, mainly due to increased osteoclast apoptosis and changes in the periodontal ligament (PdL), a connecting tissue between the alveolar bone and teeth. PdL cells, mainly fibroblasts (PdLFs), are crucial regulators in OTM by modulating force-induced local inflammatory processes. Recently, we identified the TGF-β/BMP superfamily member GDF15 as an important modulator in OTM, promoting the pro-inflammatory mechanoresponses of PdLFs. The precise impact of the highly potent BP zoledronate (ZOL) on the mechanofunctionality of PdLFs is still under-investigated. Therefore, the aim of this study was to further characterize the ZOL-induced changes in the initial inflammatory mechanoresponse of human PdLFs (hPdLFs) and to further clarify a potential interrelationship with GDF15 signaling. Thus, two-day in vitro treatment with 0.5 µM, 5 µM and 50 µM of ZOL altered the cellular properties of hPdLFs partially in a concentration-dependent manner. In particular, exposure to ZOL decreased their metabolic activity, the proliferation rate, detected using Ki-67 immunofluorescent staining, and survival, analyzed using trypan blue. An increasing occurrence of DNA strand breaks was observed using TUNEL and an activated DNA damage response was demonstrated using H2A.X (phosphoS139) staining. While the osteogenic differentiation of hPdLFs was unaffected by ZOL, increased cellular senescence was observed using enhanced p21^{Waf1/Cip1/Sdi1} and β-galactosidase staining. In addition, cytokine-encoding genes such as IL6, IL8, COX2 and GDF15, which are associated with a senescence-associated secretory phenotype, were up-regulated by ZOL. Subsequently, this change in the hPdLF phenotype promoted a hyperinflammatory response to applied compressive forces with an increased expression of the pro-inflammatory markers IL1β, IL6 and GDF15, as well as the activation of monocytic THP1 cells. GDF15 appeared to be particularly relevant to these changes, as siRNA-mediated down-regulation balanced these hyperinflammatory responses by reducing IL-1β and IL-6 expression (IL1B p-value < 0.0001; IL6 p-value < 0.001) and secretion (IL-1β p-value < 0.05; IL-6 p-value < 0.001), as well as immune cell activation (p-value < 0.0001). In addition, ZOL-related reduced RANKL/OPG values and inhibited osteoclast activation were enhanced in GDF15-deficient hPdLFs (both p-values < 0.0001; all statistical tests: one-way ANOVA, Tukey’s post hoc test). Thus, GDF15 may become a promising new target in the personalized orthodontic treatment of bisphosphonatepatients. Full article

This last decade, chimeric antigen receptor (CAR) T-cell therapy has become a real treatment option for patients with B-cell malignancies, while multiple efforts are being made to extend this therapy to other malignancies and broader patient populations. However, several limitations remain, including those associated with the time-consuming and highly personalized manufacturing of autologous CAR-Ts. Technologies to establish “off-the-shelf” allogeneic CAR-Ts with low alloreactivity are currently being developed, with a strong focus on gene-editing technologies. Although these technologies have many advantages, they have also strong limitations, including double-strand breaks in the DNA with multiple associated safety risks as well as the lack of modulation. As an alternative, non-gene-editing technologies provide an interesting approach to support the development of allogeneic CAR-Ts in the future, with possibilities of fine-tuning gene expression and easy development. Here, we will review the different ways allogeneic CAR-Ts can be manufactured and discuss which technologies are currently used. The biggest hurdles for successful therapy of allogeneic CAR-Ts will be summarized, and finally, an overview of the current clinical evidence for allogeneic CAR-Ts in comparison to its autologous counterpart will be given. Full article