Search Results (127)

Using the fly eye as a model system, we previously demonstrated that upregulation of the fly gene mask protects against FUS- and Tau-induced photoreceptor degeneration. Building upon this finding, we investigated whether the protective role of mask is conserved in mammals. To this end, we generated a transgenic mouse line carrying Cre-inducible ANKHD1, the human homolog of mask. Utilizing the TauP301S-PS19 mouse model for Tau-related dementia, we found that expressing ANKHD1 driven by CamK2a-Cre reduced hyperphosphorylated human Tau in 6-month-old mice. Additionally, ANKHD1 expression was associated with a trend toward reduced gliosis and preservation of the presynaptic marker Synaptophysin, suggesting a protective role of ANKHD1 against TauP301S-linked neuropathology. At 9 months of age, novel object recognition (NOR) testing revealed cognitive impairment in female, but not male, PS19 mice. Notably, co-expression of ANKHD1 restored cognitive performance in the affected female mice. Together, this study highlights the novel effect of ANKHD1 in counteracting the adverse effects induced by the mutant human Tau protein. This finding underscores ANKHD1’s potential as a unique therapeutic target for tauopathies. Full article

Background/Objectives: Environmental factors, including the differences in genotype-based housing (GbH), can act as confounding variables in studies using transgenic mouse models, potentially influencing experimental outcomes and limiting their reproducibility and translational value. Despite the widespread use of transgenic models in preclinical studies, the extent to which housing conditions can affect the behavioral and molecular parameters of interest remains poorly understood. This study aims to investigate how different GbH conditions influence visuo-spatial memory and gene expression in the A53T mouse model (JAX006823) of Parkinson’s disease (PD) during the pre-motor phase. Methods: A53T+ transgenic male mice and their non-transgenic littermates (A53T−) were housed in either mixed-genotype (MGH) or single-genotype (SGH) environments from postnatal day (PND) 30, with C57BL/6J mice serving as the controls. A behavioral assessment using the Novel Object Recognition and Object Location Tests was conducted at PND 180, followed by a qPCR analysis of Iba1, Gfapα, Bdnf, Tnfα, Il-1β, and Il-6 expression in the medial prefrontal cortex and the hippocampus. Results: The variations in GbH influenced behavior and mRNA expression differently in the A53T+ and A53T− animals. Specifically, the A53T− mice in SGH environments displayed behavioral and molecular profiles similar to the C57BL/6J controls, while the same was not evident in the MGH environments. In the A53T+ mice, the mRNA expression of Iba1, Gfapα, Bdnf, and Tnfα was sensitive to variations in GbH, while memory impairment was not. Conclusions: This study highlights the importance of considering environmental factors in studies using transgenic animal models. The obtained data suggests that GbH can influence the parameters of interest in preclinical research, implicating the need for the optimization of future study designs. Full article

Background: Heart failure (HF) is associated with an increased risk of cognitive impairment and hippocampal dysfunction, yet the underlying molecular mechanisms remain poorly understood. This study aims to investigate the role of microRNA (miRNA) networks in hippocampus-dependent memory recovery in a mouse model of HF. Methods: CaMKIIδC transgenic (TG) mice, a model for HF, were used to assess hippocampal function at 3 and 6 months of age. Memory performance was evaluated using hippocampus-dependent behavioral tasks. Small RNA sequencing was performed to analyze hippocampal miRNA expression profiles across both time points. Bioinformatic analyses identified miRNAs that potentially regulate genes previously implicated in HF-induced cognitive impairment. Results: We have previously shown that at 3 months of age, CaMKIIδC TG mice exhibited significant memory deficits associated with dysregulated hippocampal gene expression. In this study, we showed that these impairments, memory impairment and hippocampal gene expression, were no longer detectable at 6 months, despite persistent cardiac dysfunction. However, small RNA sequencing revealed a dynamic shift in hippocampal miRNA expression, identifying 27 miRNAs as “compensatory miRs” that targeted 73% of the transcripts dysregulated at 3 months but reinstated by 6 months. Notably, miR-181a-5p emerged as a central regulatory hub, with its downregulation coinciding with restored memory function. Conclusions: These findings suggest that miRNA networks contribute to the restoration of hippocampal function in HF despite continued cardiac pathology and provide an important compensatory mechanism towards memory impairment. A better understanding of these compensatory miRNA mechanisms may provide novel therapeutic targets for managing HF-related cognitive dysfunction. Full article

The Na,K-ATPase is a heterodimeric ion pump consisting of various combinations of a catalytic α-subunit (α1, α2, α3, or α4, encoded by ATP1A1–ATP1A4) and a β-subunit (β1, β2, or β3, encoded by ATP1B1–ATP1B3). We have previously shown that Atp1b2 knock-out (ko) mice exhibit rapid photoreceptor cell degeneration, whereas Atp1b2^Atp1b1 knock-in (ki) mice, which express the β1-subunit instead of the β2-subunit under regulatory elements of the Atp1b2 gene, exhibit slowly progressive retinal dystrophy. Here, we performed a detailed analysis of the retinal phenotype of the Atp1b2^Atp1b1 ki mouse. We found that the number of cone photoreceptor cells in the mutant retinas was significantly reduced by postnatal day 28. The retinas of 4-month-old mice were almost devoid of cones. The early onset and rapid loss of cones was followed by a slowly progressive degeneration of rods. Other retinal cell types were unaffected. Nonradioactive in situ hybridization and immunohistochemistry revealed that wild-type photoreceptors expressed β3 and high levels of β2, while Atp1b2^Atp1b1 ki photoreceptor cells expressed β3 and low levels of transgenic β1. Additionally, levels of retinoschisin, a secreted retina-specific protein that interacts directly with the β2-subunit, were greatly reduced in mutant retinas. The results demonstrate that the β1-subunit can functionally compensate, at least in part, for the absence of the β2-subunit. The results also show that cones are more susceptible to Na,K-ATPase dysfunction than rods. Taken together, the present study identifies the Atp1b2^Atp1b1 ki mutant as a novel animal model of an early-onset and rapidly progressive cone–rod dystrophy. Full article

Background: Myeloid-derived suppressor cells (MDSCs) contribute to immune suppression observed in chronic lymphocytic leukemia (CLL). MDSCs are immature myeloid cells that are hijacked during development and further reprogrammed by the tumor microenvironment (TME) to harbor immune-suppressive properties and inhibit T-cell functions. Bromodomain and extraterminal domain (BET) proteins, including BRD4, are epigenetic modulators that regulate genes implicated in CLL pathogenesis and TME interactions. Previously, we investigated how the novel BET inhibitor OPN-51107 (OPN5) prevents CLL disease expansion, modulates T-cell immune function, and alters gene expression related to MDSCs. In turn, we hypothesize that BET proteins such as BRD4 regulate MDSC functions, and subsequent pharmacological inhibition of BRD4 will alleviate MDSC-mediated immune suppression in CLL. Methods: Utilizing the Eµ-TCL1 mouse model of CLL, we evaluated BRD4 protein expression in MDSCs derived from the bone marrow of transgenic and age-matched wild-type (WT) mice. We then investigated the ex vivo functionality of OPN5-treated MDSCs, expanded from Eµ-TCL1 and WT bone marrow in MDSC-supportive medium. Finally, we conducted an in vivo study utilizing the Eµ-TCL1 adoptive transfer mouse model to determine the in vivo effects of OPN5 on MDSCs and other immune populations. Results: Through the course of this study, we found that MDSCs isolated from Eμ-TCL1 mice upregulate BRD4 expression and are more immune-suppressive than their WT counterparts. Furthermore, we demonstrated ex vivo OPN5 treatment reverses the immune-suppressive capacity of MDSCs isolated from leukemic mice, evident via enhanced T-cell proliferation and IFNγ production. Finally, we showed in vivo OPN5 treatment slows CLL disease progression and modulates immune cell populations, including MDSCs. Conclusions: Altogether, these data support BET inhibition as a useful therapeutic approach to reverse MDSC-mediated immune suppression in CLL. Full article

This study investigates the role of p38 mitogen-activated protein kinase (MAPK) activation in dorsal root ganglion (DRG) neurons in the development and progression of chemotherapy-induced peripheral neuropathy (CIPN). This research evaluates whether inhibiting activation of p38 MAPK could reduce neuropathic outcomes in a transgenic breast cancer mouse model (C3TAg) and wild-type mice (FVB/N) treated with cisplatin. Cisplatin treatment stimulated p38 MAPK phosphorylation and nuclear translocation in DRG neurons. Neflamapimod, a specific inhibitor of p38 MAPK alpha (p38α), proven to be safe in clinical trials, inhibited neuronal cisplatin-induced p38 MAPK phosphorylation in vitro and in vivo. Neflamapimod also reduced cisplatin-induced oxidative stress, mitochondrial dysfunction, and cleaved caspase-3 expression in DRG neurons in vitro, protecting neuronal integrity and preventing axonal damage. Functionally, neflamapimod improved mechanical and musculoskeletal hyperalgesia, and cold sensitivity in cisplatin-treated mice, reversing neuropathic pain and neurotoxicity. This study identifies p38 MAPK activation as a critical driver of CIPN and highlights its potential as a therapeutic target for CIPN. Targeting p38 MAPK activation with neflamapimod offers a promising strategy to mitigate neurotoxicity and hyperalgesia without exacerbating cancer progression, positioning it as a novel intervention for CIPN. Full article

Alzheimer’s disease is characterized by two key neuropathological lesions: amyloid plaques composed of amyloid β and neurofibrillary tangles formed by hyperphosphorylated tau. Amyloid β is produced through successive cleavages of amyloid precursor protein (APP) via the amyloidogenic pathway. While increasing evidence suggests that APP plays critical roles in neuronal function and that its proteolytic derivative, sAPPα, has neurotrophic effects, the impact of APP deletion on both amyloid and tau pathologies remains poorly understood. Here, we introduce a novel transgenic mouse model, 5xFAD×Tg30XAPP-/-, in which murine APP is deleted in the presence of both amyloid and tau pathologies. Using this innovative model, we demonstrate for the first time that deletion of APP exacerbates tau aggregation, amyloid deposition, and gliosis compared to control 5xFAD×Tg30 mice. This study provides the first in vivo evidence that APP deletion has profound and detrimental effects on both amyloid and tau pathologies in a transgenic model of Alzheimer’s disease, highlighting the previously unappreciated role of APP in the regulation of these neurodegenerative processes. Full article

Alzheimer’s disease (AD) remains a leading cause of cognitive decline and mortality worldwide, characterized by neurodegeneration, synaptic deficiencies, and neuroinflammation. Despite advancements in early detection, diagnosis, and treatment, AD presents substantial challenges due to its complex pathology, heterogeneity, and the limited efficacy of current therapies. Consequently, there is a pressing need for novel therapeutic agents to target the multifaceted aspects of AD pathology, enhance current treatments, and minimize adverse effects. AdipoRon, an adiponectin receptor agonist, has garnered interest for its potential neuroprotective effects, including reducing neuroinflammation, improving mitochondrial function, and mitigating tau hyperphosphorylation. This review aimed to evaluate the effects of AdipoRon-based adiponectin replacement therapy against AD, using a comprehensive approach grounded in the PICO framework—Population, Intervention, Comparison, and Outcomes. A total of six studies were reviewed, including in vitro and in vivo investigations examining AdipoRon’s impact on various AD models. These studies involved different cell lines and transgenic mouse models, assessing various outcomes such as cognitive function, neuroinflammation, tau phosphorylation, synaptic deficiencies, and relevant molecular pathways. By synthesizing data from these studies, our review thoroughly explains AdipoRon’s neuroprotective effects, mechanisms of action, and potential as a therapeutic agent for AD. This analysis aims to highlight the current state of knowledge, identify gaps in the research, and suggest directions for future studies and clinical applications. Full article

Obsessive–compulsive disorder (OCD) is a prevalent, chronic, and severe neuropsychiatric disorder that leads to illness-related disability. Despite the availability of several treatments, many OCD patients respond inadequately, because the underlying neural mechanisms remain unclear, necessitating the establishment of many animal models, particularly mouse models, to elucidate disease mechanisms and therapeutic strategies better. Although the development of animal models is ongoing, there remain many comprehensive summaries and updates in recent research, hampering efforts to develop novel treatments and enhance existing interventions. This review summarizes the phenotypes of several commonly used models and mechanistic insights from transgenic models of OCD, such as knockout mouse models. In addition, we present the advantages and limitations of these models and discuss their future in helping further understand the pathophysiology and advanced treatment. Here, we highlight current frontline treatment approaches for OCD, including neuromodulation and surgical interventions, and propose potential future directions. By studying gene mutations and observing phenotypes from available OCD animal models, researchers have classified the molecular signatures of each model reminiscent of changes in brain areas and neural pathways, with the hope of guiding the future selection of the most appropriate models for specific research in the OCD field. Full article

A notion of the continuous production of amyloid-β (Aβ) via the proteolysis of Aβ-protein-precursor (AβPP) in Alzheimer’s disease (AD)-affected neurons constitutes both a cornerstone and an article of faith in the Alzheimer’s research field. The present Perspective challenges this assumption. It analyses the relevant empirical data and reaches an unexpected conclusion, namely that in AD-afflicted neurons, the production of AβPP-derived Aβ is either discontinued or severely suppressed, a concept that, if proven, would fundamentally change our understanding of the disease. This suppression, effectively self-suppression, occurs in the context of the global inhibition of the cellular cap-dependent protein synthesis as a consequence of the neuronal integrated stress response (ISR) elicited by AβPP-derived intraneuronal Aβ (iAβ; hence self-suppression) upon reaching certain levels. Concurrently with the suppression of the AβPP proteolytic pathway, the neuronal ISR activates in human neurons, but not in mouse neurons, the powerful AD-driving pathway generating the C99 fragment of AβPP independently of AβPP. The present study describes molecular mechanisms potentially involved in these phenomena, propounds novel approaches to generate transgenic animal models of AD, advocates for the utilization of human neuronal cells-based models of the disease, makes verifiable predictions, suggests experiments designed to validate the proposed concept, and considers its potential research and therapeutic implications. Remarkably, it opens up the possibility that the conventional production of AβPP, BACE enzymes, and γ-secretase components is also suppressed under the neuronal ISR conditions in AD-affected neurons, resulting in the dyshomeostasis of AβPP. It follows that whereas conventional AD is triggered by AβPP-derived iAβ accumulated to the ISR-eliciting levels, the disease, in its both conventional and unconventional (triggered by the neuronal ISR-eliciting stressors distinct from iAβ) forms, is driven not (or not only) by iAβ produced in the AβPP-independent pathway, as we proposed previously, but mainly, possibly exclusively, by the C99 fragment generated independently of AβPP and not cleaved at the γ-site due to the neuronal ISR-caused deficiency of γ-secretase (apparently, the AD-driving “substance X” predicted in our previous study), a paradigm consistent with a dictum by George Perry that Aβ is “central but not causative” in AD. The proposed therapeutic strategies would not only deplete the driver of the disease and abrogate the AβPP-independent production of C99 but also reverse the neuronal ISR and ameliorate the AβPP dyshomeostasis, a potentially significant contributor to AD pathology. Full article

Cancer cachexia (CC) continues to challenge clinicians by massively impairing patients’ prognosis, mobility, and quality of life through skeletal muscle wasting. CC also includes cardiac cachexia as characterized by atrophy, compromised metabolism, innervation and function of the myocardium through factors awaiting clarification for therapeutic targeting. Because monoamine oxidase-A (MAO-A) is a myocardial source of H₂O₂ and implicated in myofibrillar protein catabolism and heart failure, we presently studied myocardial MAO-A expression, inflammatory cells, and capillarization together with transcripts of pro-inflammatory, -angiogenic, -apoptotic, and -proteolytic signals (by qRT-PCR) in a 3x-transgenic (LSL-Kras^G12D/+; LSL-TrP53^R172H/+; Pdx1-Cre) mouse model of orthotopic pancreatic ductal adenoarcinoma (PDAC) compared to wild-type (WT) mice. Moreover, we evaluated the effect of MAO-A inhibition by application of harmine hydrochloride (HH, 8 weeks, i.p., no sham control) on PDAC-related myocardial alterations. Myocardial MAO-A protein content was significantly increased (1.69-fold) in PDAC compared to WT mice. PDAC was associated with an increased percentage of atrogin-1+ (p < 0.001), IL-1β+ (p < 0.01), COX2+ (p < 0.001), and CD68+ (p > 0.05) cells and enhanced transcripts of pro-inflammatory IL-1β (2.47-fold), COX2 (1.53-fold), TNF (1.87-fold), and SOCS3 (1.64-fold). Moreover, PDAC was associated with a reduction in capillary density (−17%, p < 0.05) and transcripts of KDR (0.46-fold) but not of VEGFA, Notch1, or Notch3. Importantly, HH treatment largely reversed the PDAC-related increases in atrogin-1+, IL-1β+, and TNF+ cell fraction as well as in COX2, IL-1β, TNF, and SOCS3 transcripts, whereas capillary density and KDR transcripts failed to improve. In mice with PDAC, increased myocardial pro-atrophic/-inflammatory signals are attributable to increased expression of MAO-A, because they are significantly improved with MAO-A inhibition as a potential novel therapeutic option. The PDAC-related loss in myocardial capillary density may be due to other mechanisms awaiting evaluation with consideration of cardiomyocyte size, cardiac function and physical activity. Full article

Chlamydia trachomatis remains a major global health problem with increasing infection rates, requiring innovative vaccine solutions. Modified Vaccinia Virus Ankara (MVA) is a well-established, safe and highly immunogenic vaccine vector, making it a promising candidate for C. trachomatis vaccine development. In this study, we evaluated two novel MVA-based recombinant vaccines expressing spCTH522 and CTH522:B7 antigens. Our results show that while both vaccines induced CD4⁺ T-cell responses in C57BL/6J mice, they failed to generate antigen-specific systemic CD8⁺ T cells. Only the membrane-anchored CTH522 elicited strong IgG2b and IgG2c antibody responses. In an HLA transgenic mouse model, both recombinant MVAs induced Th1-directed CD4⁺ T cell and multifunctional CD8⁺ T cells, while only the CTH522:B7 vaccine generated antibody responses, underscoring the importance of antigen localization. Collectively, our data indicate that distinct antigen formulations can induce different immune responses depending on the mouse strain used. This research contributes to the development of effective vaccines by highlighting the importance of careful antigen design and the selection of appropriate animal models to study specific vaccine-induced immune responses. Future studies should investigate whether these immune responses provide protection in humans and should explore different routes of immunization, including mucosal and systemic immunization. Full article

Trinucleotide repeat (TNR) expansion is the cause of over 40 neurodegenerative diseases, including Huntington’s disease and Friedreich’s ataxia (FRDA). There are no effective treatments for these diseases due to the poor understanding of molecular mechanisms underlying somatic TNR expansion and contraction in neural systems. We and others have found that DNA base excision repair (BER) actively modulates TNR instability, shedding light on the development of effective treatments for the diseases by contracting expanded repeats through DNA repair. In this study, temozolomide (TMZ) was employed as a model DNA base damaging agent to reveal the mechanisms of the BER pathway in modulating GAA repeat instability at the frataxin (FXN) gene in FRDA neural cells and transgenic mouse mice. We found that TMZ induced large GAA repeat contraction in FRDA mouse brain tissue, neurons, and FRDA iPSC-differentiated neural cells, increasing frataxin protein levels in FRDA mouse brain and neural cells. Surprisingly, we found that TMZ could also inhibit H3K9 methyltransferases, leading to open chromatin and increasing ssDNA breaks and recruitment of the key BER enzyme, pol β, on the repeats in FRDA neural cells. We further demonstrated that the H3K9 methyltransferase inhibitor BIX01294 also induced the contraction of the expanded repeats and increased frataxin protein in FRDA neural cells by opening the chromatin and increasing the endogenous ssDNA breaks and recruitment of pol β on the repeats. Our study provides new mechanistic insight illustrating that inhibition of H3K9 methylation can crosstalk with BER to induce GAA repeat contraction in FRDA. Our results will open a new avenue for developing novel gene therapy by targeting histone methylation and the BER pathway for repeat expansion diseases. Full article

Rapidly proliferative processes in mammalian tissues including tumorigenesis and embryogenesis rely on the glycolytic pathway for energy and biosynthetic precursors. The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3) plays an important regulatory role in glycolysis by activating the key rate-limiting glycolytic enzyme, 6-phosphofructo-1-kinase (PFK-1). We have previously determined that decreased PFKFB3 expression reduced glycolysis and growth in transformed cells in vitro and suppressed xenograft growth in vivo. In earlier studies, we created a constitutive knockout mouse to interrogate the function of PFKFB3 in vivo but failed to generate homozygous offspring due to the requirement for PFKFB3 for embryogenesis. We have now developed a novel transgenic mouse model that exhibits inducible homozygous pan-tissue Pfkfb3 gene deletion (Pfkfb3^fl/fl). We have induced Pfkfb3 genomic deletion in these mice and found that it effectively decreased PFKFB3 expression and activity. To evaluate the functional consequences of Pfkfb3 deletion in vivo, we crossed Cre-bearing Pfkfb3^fl/fl mice with oncogene-driven tumor models and found that Pfkfb3 deletion markedly decreased their glucose uptake and growth. In summary, our studies reveal a critical regulatory function for PFKFB3 in glycolysis and tumorigenesis in vivo and characterize an effective and powerful model for further investigation of its role in multiple biological processes. Full article

Bladder cancer (BC) is the fourth most common cancer in men, with a poor patient prognosis for advanced disease. The poor survival of patients with muscle-invasive bladder cancer (MIBC) and metastatic status emphasizes the urgent need to develop new therapies. Lacking in the field of BC is the availability of relevant advanced BC mouse models, especially metastatic ones, that accurately recapitulate the complexities of human pathology to test and study new therapeutic strategies. Addressing this need, we developed a traceable mouse model of BC that expresses tumor-associated antigens within the context of advanced muscle-invasive BC. This novel system was achieved through the deletion of the tp53 and pten genes, alongside the incorporation of the fusion construct of Firefly luciferase (Luc) and the SIYRYYGL (SIY) T-cell antigen. We validate that the presence of the transgene did not impact on the development of the tumors while allowing us to measure tumor progression by bioluminescence. We show that the transgene did not influence the composition of the immune tumor microenvironment. More importantly, we report that this model was unresponsive to anti-PD-1 treatment, as in the majority of patients with BC. We also develop a new model based on the orthotopic injection of BC clonal cell lines derived from our first model. We demonstrate that this new model invades the muscle layer and has a metastasis development rate of 83%. The advantage of this model is that we can visualize tumor growth and metastasis development in vivo. These mouse models’ characteristics, displaying many similarities with the human pathology, provide a valuable tool for tracking tumor progression, metastasis spread in vivo, and treatment resistance, as well as exploring fundamental and translational aspects of BC biology. This work contributes to the improvement in the landscape of mouse models of advanced BC for testing new therapeutic strategies. Full article