Search Results (35)

Alzheimer’s disease (AD) is a neurodegenerative disorder defined not only by amyloid-β plaques and tau pathology but also by several interacting processes that drive disease progression. These include neuroinflammation, neuronal cell death, synaptic dysfunction, blood–brain barrier (BBB) breakdown, and myelin and axonal damage. Together, they lead to neuronal loss and cognitive decline. In this review, we present a cell-centered framework linking these processes with key molecular markers. Neuroinflammation is driven by activated microglia and astrocytes and is associated with markers such as Iba1, CD68, GFAP, and C3, along with cytokines including IL-1β and TNF-α. Neuronal cell death occurs through apoptosis, ferroptosis, pyroptosis, and necroptosis, with markers such as caspase-3, GPX4, GSDMD, and MLKL. Synaptic dysfunction is reflected by reduced synaptic proteins, including synaptophysin and PSD-95. BBB breakdown increases permeability and reduces clearance of toxic molecules. Myelin and axonal damage, associated with MBP and NfL, disrupt neural connectivity. These processes are dynamically interconnected and may contribute differently across disease stages. This integrated cell-centered and systems-level framework provides insight into AD progression while highlighting potential biomarkers and therapeutic targets for diagnosis, disease monitoring, and therapeutic intervention. Full article

Soft tissue sarcomas (STS) are locally invasive and aggressive tumors that occur spontaneously in humans, dogs, and cats. High-intensity focused ultrasound (HIFU) is a non-invasive ablation technology that has been explored in canine but not feline STS. The objective of this pilot study was to determine the in vivo safety and feasibility of HIFU ablation for feline STS and to investigate the impact of HIFU on the acute immunological response. Client-owned cats diagnosed with spontaneous STS were recruited. Computed tomography (CT) scans of the chest, abdomen, and tumor were performed prior to treatment for staging and treatment planning. A commercially available HIFU unit (Echopulse, Theraclion, Malakoff, France) was used to target portions of solid tumors before standard-of-care surgical resection. Ablation efficacy and local immunological response were characterized using histopathological and immunohistochemical assessments. Acute safety was monitored with physical examinations, owner reports, and CBC/serum biochemistry. Multiplex serum cytokine levels were used to evaluate the systemic immune response. A total of three cats diagnosed with STS were recruited and treated. No significant adverse events attributed to HIFU treatment were noted in this pilot study. In treated areas, hemorrhage as well as coagulative and lytic necrosis were observed microscopically and were more extensive than in untreated tissues. There was a statistically significant difference in the level of serum MCP-1 after HIFU treatment, but no significant changes in any other analytes. No differences in the infiltration of CD3-, CD79a-, or IBA1-positive cells were noted between treated and untreated samples. Overall, findings suggested that HIFU may offer a viable alternative to conventional therapies for feline STS, with pilot results showing effective tumor ablation in cats with STS without significant adverse events. Some preliminary evidence of immunomodulation following treatment was observed, but HIFU as an immunotherapeutic treatment option needs to be further investigated. Full article

Background/Objectives: Maresin-1 (MaR1), a specialized pro-resolving mediator (SPM) derived from omega-3 fatty acids, has demonstrated potent anti-inflammatory and pro-resolving properties. However, its effects on depression-like behaviors and the associated dynamics of neuroinflammation, particularly in the context of chronic stress, are not yet fully understood. This study aimed to investigate the therapeutic potential of MaR1 in a chronic unpredictable stress (CUS) model and to monitor its dynamic effects on neuroimmune activity using longitudinal in vivo imaging. Methods: Adolescent male C57BL/6J mice were subjected to a 5-week CUS protocol. Mice exhibiting stable anhedonia were randomized to receive intraperitoneal injections of either MaR1 (5 µg/kg) or vehicle every other day for 4 weeks. During this period, CUS procedures were maintained. Depression-like behaviors were assessed using the sucrose preference test (SPT), tail suspension test (TST), and open field test (OFT). Dynamic changes in neuroinflammation were monitored via longitudinal [18F]DPA-714 positron emission tomography (PET) scans at baseline and after 2 and 4 weeks of treatment. Ex vivo analyses included immunofluorescence quantification of hippocampal microglia (ionized calcium-binding adaptor molecule 1, Iba1), astrocytes (glial fibrillary acidic protein, GFAP), and 18 kDa translocator protein (TSPO) co-expression, alongside quantitative polymerase chain reaction (qPCR) and Western blotting for inflammatory markers (IL-1β, IL-4, TSPO). Results: MaR1 treatment selectively alleviated depression-like behaviors, significantly reversing CUS-induced anhedonia in the SPT and improving locomotor activity, while its effect on despair-like behavior (TST) was not statistically significant. Longitudinal PET imaging revealed a biphasic neuroimmune response, characterized by an initial increase in [18F]DPA-714 standardized uptake value (SUV) at 2 weeks, followed by a return toward baseline at 4 weeks. Histologically, MaR1 reversed CUS-induced hippocampal microglial loss, resulting in a rebound of microglial numbers, and normalized astrocytic activation. At the molecular level, MaR1 dynamically modulated cytokine expression, culminating in a significant upregulation of the pro-resolving marker IL-4 and TSPO at 4 weeks. Conclusions: These findings indicate that Maresin-1 treatment is associated with behavioral improvement and dynamic modulation of glial activity and TSPO PET signals in the hippocampus. This study highlights the value of TSPO PET imaging for monitoring dynamic glial changes during therapeutic intervention and provides supportive evidence for targeting neuroimmune pathways in depression. Full article

The southern region of Kazakhstan represents the northernmost boundary of the natural habitat of five wild almond species, among which Amygdalus communis L. is of particular interest due to a range of favorable traits for use in breeding programs and cultivation in the region. The current distribution range of common almond growth was clarified using GPS to determine precise coordinates, and a schematic map was developed. Monitoring revealed a significant reduction in population size. In the surveyed areas, 54 trees were selected and described. Seed material was collected from 34 genotypes and characterized according to a descriptor. Genotypes A3, A8, and A15 were identified as having favorable trait combinations. To restore populations and preserve the gene pool of Amygdalus communis L., a method of clonal micropropagation was employed. The composition of the nutrient medium was optimized for establishment, multiplication, and rhizogenesis. It was determined that Murashige and Skoog (MS) medium without phytohormones is effective for in vitro establishment (70% regeneration rate). For multiplication, MS medium with 0.5 mg/L BAP (6-benzylaminopurine) was used (with a multiplication rate of 3.5 per explant). For rhizogenesis, MS medium with 0.5 mg/L BAP, 0.02 mg/L gibberellic acid (GA), and 0.1 mg/L IBA (indole-3-butyric acid) was used. A total of 340 clonal Amygdalus communis L. plants with closed root systems were grown for field collection. The research results can be applied for the restoration, propagation, and conservation of populations both in vitro and in situ, as well as for the inclusion of selected high-performing genotypes in breeding programs. Full article

This study investigated how propagation systems, growth regulators, and hormone formulations interactively affect the rooting and subsequent growth of rosemary (Salvia rosmarinus Spenn) cuttings. A three factorial (3 × 2 × 7) experiment was conducted under a fully controlled greenhouse environment, incorporating three soilless propagation systems (mist, float, aeroponics), two rooting hormone formulations (powder and gel-based IBA), and two growth regulators (paclobutrazol and daminozide) at three concentrations each. Significant differences (p < 0.001) were found in shoot height, root length, and number of lateral roots. The float system combined with powder hormone and no retardants achieved the highest shoot height (mean = 16.7 cm), while aeroponics with powder hormone and daminozide 1000 ppm promoted the greatest root branching (mean = 12.2 lateral roots per cutting). Root length was maximized (mean = 15.9 cm) under float systems with daminozide 1000 ppm. High doses of both growth regulators negatively affected all parameters across systems. Post-transplantation monitoring confirmed that cuttings from float and mist systems treated with powder hormone and low or no growth retardants exhibited superior establishment and net growth over 60 days. These findings demonstrate the critical importance of pairing hormone type, regulator concentration, and propagation system, providing actionable protocols for nursery managers aiming to enhance Salvia rosmarinus propagation in commercial practice. Full article

Huntington’s disease is a progressive, untreatable neurodegenerative disorder caused by a mutation in the Huntingtin gene. Next to neurodegeneration, altered immune activation is involved in disease progression. Since central nervous system inflammation and dysfunction of immune cells are recognized as driving characteristics, immunomodulation might represent an additional therapeutic strategy. Short-chain fatty acids were known to have immunomodulatory effects in neuroinflammatory diseases, such as multiple sclerosis. In this study, R6/2 mice were treated daily with 150 mM propionate. Survival range, body weight, and motor abilities were monitored. In striatal and cortical samples, neuronal survival was analyzed by immunofluorescence staining of NeuN-positive cells and expression levels of BDNF mRNA by real-time polymerase chain reaction. As inflammatory marker TNFα mRNA and IL-6 mRNA were quantified by rtPCR, iNOS-expressing cells were counted in immunologically stained brain slides. Microglial activation was evaluated by immunofluorescent staining of IBA1-positive cells and total IBA1 protein by Western Blot, in addition, SPI1 mRNA expression was quantified by rtPCR. Except for clasping behavior, propionate treatment did neither improve the clinical course nor mediated neuronal protection in R6/2 mice. Yet there was a mild anti-inflammatory effect in the CNS, with (i) reduction in SPI1-mRNA levels, (ii) reduced iNOS positive cells in the motor cortex, and (iii) normalized TNFα-mRNA in the motor cortex of propionate-treated R6/2 mice. Thus, Short-chain fatty acids, as an environmental factor in the diet, may slightly alleviate symptoms by down-regulating inflammatory factors in the central nervous system. However, they cannot prevent clinical disease progression or neuronal loss. Full article

The present study sets out to examine the status of sympatric populations of south polar (Catharacta maccormicki) (SPSs) and brown skuas (Catharacta antarctica) (BSs) at two sites on King George Island, Antarctica. The study sites were designated as Important Bird and Biodiversity Areas (IBAs) and were monitored for three (for Point Hennequin (PH)) and four (for West Admiralty Bay (WAB)) consecutive breeding seasons, concluding with the 2023/24 season. The most recently reported data from these areas are from the 2004/05 season, and the data presented herein allow both areas to be assessed in the context of their IBA and Antarctic Specially Protected Area values. The mean number of total pairs for the investigated seasons for WAB was 67 ± 7, while for PH, it was 157 ± 18. The number of pairs of SPSs at PH and WAB justifies the positive evaluation of the areas as IBAs based on global designation criterion A4 proposed jointly by BirdLife International and the Scientific Committee on Antarctic Research (SCAR). PH is of particular interest, as it has been determined that at least 2.3% of the global population of SPSs, estimated by BirdLife International to be between 6000 and 15,000 adult individuals, breeds at this site. The expansion of both IBA boundaries is also recommended based on this study. Full article

Glioblastoma (GB) is one of the most aggressive and treatment-resistant cancers due to its complex tumor microenvironment (TME). We previously showed that GB progression is dependent on the aberrant induction of chaperone-mediated autophagy (CMA) in pericytes (PCs), which promotes TME immunosuppression through the PC secretome. The secretion of extracellular matrix (ECM) proteins with anti-tumor (Lumican) and pro-tumoral (Osteopontin, OPN) properties was shown to be dependent on the regulation of GB-induced CMA in PCs. As biomarkers are rarely studied in TME, in this work, we aimed to validate Lumican and OPN as prognostic markers in the perivascular areas of the peritumoral niche of a cohort of GB patients. Previously, we had validated their expression in GB xenografted mice presenting GB infiltration (OPN) or GB elimination (Lumican) dependent on competent or deficient CMA PCs, respectively. Then, patient sample classification by GB infiltration into the peritumoral brain parenchyma was related to GB-induced CMA in microvasculature PCs, analyzing the expression of the lysosomal receptor, LAMP-2A. Our results revealed a correlation between GB-induced CMA activity in peritumoral PCs and GB patients’ outcomes, identifying three degrees of severity. The perivascular expression of both immune activation markers, Iba1 and CD68, was related to CMA-dependent PC immune function and determined as useful for efficient GB prognosis. Lumican expression was identified in perivascular areas of patients with less severe outcome and partially co-localizing with PCs presenting low CMA activity, while OPN was primarily found in perivascular areas of patients with poor outcome and partially co-localizing with PCs presenting high CMA activity. Importantly, we found sex differences in the incidence of middle-aged patients, being significantly higher in men but with worse prognosis in women. Our results confirmed that Lumican and OPN in perivascular areas of the GB peritumoral niche are effective predictive biomarkers for evaluating prognosis and monitoring possible therapeutic immune responses dependent on PCs in tumor progression. Full article

Agunmu (ground herbal medicine) is a form of West African traditional medicine consisting of a cocktail of herbs. The goal of this study is to evaluate a formulation of Agunmu made from M. indica, A. repens, E. chlorantha, A. boonei, and B. ferruginea, sold in the open market and commonly used for the treatment of malaria by the locals, for its antimalarial effects and to determine the active principles that may contribute to the antimalarial effect. The ethanolic extract obtained from this formulation (Ag-Iba) was analyzed, using TLC, LC-MS, and Tandem-MS techniques, to determine its phytochemical properties. The extract was tested in vitro against representative bacteria strains, cancer and normal human cell lines, and susceptible (D6) and resistant (W2) Plasmodium falciparum. In subsequent in vivo experiments, graded doses of the extract were used to treat mice infected with chloroquine-susceptible (NK-65) and chloroquine-resistant (ANKA) strains of Plasmodium berghei. Bacteria growth was monitored with a disc diffusion assay, cancer cell viability was determined with MTS assay, and percentage parasitemia and parasite clearance were determined by microscopy. Bound heme content, host mitochondria permeability transition (mPT) pore opening, F₀F₁-ATPase, and lipid peroxidation were determined via spectrophotometry. Indices of oxidative stress, anti-oxidant activities, toxicity, cell death, and inflammatory responses were obtained using biochemical and ELISA techniques. The histology of the liver and spleen was performed using the standard method. We elucidated the structures of the critical active principles in the extract to be flavonoids: kaempferol, quercetin, myricetin, and their glycosides with little or no detectable levels of the toxic Aristolochic acids that are found in Aristolochia repens, one of the components of the formulation. The extract also showed anti-plasmodial activity in in vitro and in vivo models. Furthermore, the extract dose-dependently decreased mitochondrial dysfunction, cell death, and inflammatory and oxidative damage but increased antioxidant potentials. Presumably, the active principles in the extract work as a combinatorial therapy to elicit potent antimalarial activity. Overall, our study unraveled the active components from a commercial herbal formulation that could be reformulated for antimalarial therapy. Full article

Optimal veterinary care of managed elephant populations is vital due to the continued decline of wild populations. Appropriate health monitoring and accurate disease diagnosis include hematologic evaluation. Elephant hematology is distinctive in that elephants have high percentages of monocytes in health. Elephant monocytes also have unusual morphology, a feature shared with manatees and rock hyraxes. Manual white blood cell counting is used for elephant hematology, as analyzers are generally inaccurate. The aims of this study were to evaluate basic cell isolation and functional testing protocols for use in elephant monocyte research, and to test several available antibodies via flow cytometry for use in elephant monocyte identification. Peripheral blood samples from five Asian elephants (Elephas maximus) were used. Methods for monocyte isolation and evaluation of phagocytic function were established. Putative lymphocyte and monocyte populations were identified using a scatter on flow cytometry. Antibodies against CD11b, CD11c, CD14, and ionized calcium-binding adapter molecule 1 (IBA1) were tested, with IBA1 showing the highest apparent diagnostic utility in labeling monocytes. Combined flow cytometric scatter and IBA1 positivity appear to identify Asian elephant monocytes. These data provide a methodologic basis for further investigation into elephant monocyte function and immune response to infection. Full article

Galanthamine is an immensely valuable alkaloid exhibiting anti-cancer and antiviral activity. The cultivation of plant tissues in in vitro conditions is a good source for the synthesis and enrichment of secondary metabolites of commercial interest. In this study, the Amaryllidaceae alkaloid galanthamine was quantified in three Zephyranthes species, such as Zephyranthes candida, Zephyranthes grandiflora, and Zephyranthes citrina, and the impact of the methyl jasmonate (MJ) signaling molecule on galanthamine accumulation was monitored in in vitro-derived plant tissues. This is the first ever study of the MJ-regulated accumulation of galanthamine in in vitro-grown Zephyranthes tissues. Shoot regeneration was obtained in all three Zephyranthes species on Murashige and Skoog (MS) medium containing 2.0 mgL⁻¹ benzylaminopurine (BAP) + 0.5 mgL⁻¹ naphthalene acetic acid (NAA). The regenerated shoots were rooted on a medium containing 2.0 mgL⁻¹ indole butyric acid (IBA). A GC-MS study of Zephyranthes extracts revealed the presence of 34 phyto-compounds of varied levels with therapeutic activities against diseases. The galanthamine content was quantified in plant parts of the three Zephyranthes species using high-performance thin layer chromatography (HPTLC); the maximum was found in Z. candida bulb (2.41 µg g⁻¹ dry wt.), followed by Z. grandiflora (2.13 µg g⁻¹ dry wt.), and then Z. citrina (2.02 µg g⁻¹ dry wt.). The galanthamine content showed bulb > leaf > root source order. The in vitro-generated plantlets were treated with different MJ concentrations, and the galanthamine yield was measured in bulb, leaf, and root tissues. The highest galanthamine content was recorded in bulbs of Z. candida (3.97 µg g⁻¹ dry wt.) treated with 150 µM MJ, showing an increase of 64.73% compared to the control. This accumulation may be attributed to MJ-induced stress, highlighting the potential commercial synthesis of galanthamine in vitro. Full article

The experiment was conducted to investigate the potential effects of steviol glycosides on growth performance, rumen fermentation processes, and microbial diversity in Hu sheep. A single-factor design was used for the trial. Twenty healthy weaned Hu lambs, possessing comparable body weights averaging 18.31 ± 1.24 kg, were randomly allocated into two distinct groups: the control group (CON) and the experimental group (STE), with each comprising 10 lambs. The CON was fed the basal diet, and the STE was supplemented with 0.07% steviol glycosides based on the basal diet. During the experimental period, variations in body weight and feed intake were closely monitored and recorded. After feeding for 90 d, blood was collected to determine blood biochemical indices, and rumen fluid samples were gathered for an in-depth analysis of rumen fermentation parameters and microbial diversity. The outcomes revealed no statistically significant differences in growth performance or serum biochemical indices between the two groups (p > 0.05). Rumen pH in STE and CON was within the normal range. The rumen ammonia nitrogen (NH₃-N) and acetic acid (AA) content of STE decreased significantly compared with CON (p < 0.05). No significant variations were observed in the levels of other volatile fatty acids (VFAs) between the two groups (p > 0.05). The rumen microbial OTUs count, as well as the Shannon, Simpson, Chao1, and Ace indices, were notably lower in the STE group compared to the CON group (p < 0.05). Additionally, at the phylum level, the relative abundance of Firmicutes, Bacteroidetes, and Proteobacteria collectively accounted for over 97% of the total phylum composition. In comparison to the CON group, the STE group exhibited an increase in the relative abundance of Proteobacteria (p < 0.05), accompanied by a significant reduction in the relative abundance of Patescibacteria and Desulfobacteria (p < 0.05). At the genus level, there was a notable increase in the relative abundance of Prevotella_7 and Succinivibrionaceae_UCG_001 in the STE group, whereas the relative abundance of Rikenellaceae_RC9_gut_group significantly decreased (p < 0.05). According to the correlation analysis between rumen microflora and VFAs, the relative abundance of Succinivibrionaceae_UCG_001 displayed a significant negative correlation with AA (p < 0.05), whereas Lactobacillus exhibited a notable positive correlation with isobutyric acid (IBA) (p < 0.05). In summary, steviol glycosides had no significant effect on the production performance and blood biochemical indexes of Hu sheep. Steviol glycosides can improve rumen fermentation parameters and rumen microflora structure of Hu sheep and have a certain effect on rumen microbial diversity and composition. Full article

The present study examined how P2X7 receptor knockout (KO) modulates central post-stroke pain (CPSP) induced by lesions of the ventrobasal complex (VBC) of the thalamus in behaviors, molecular levels, and electrical recording tests. Following the experimental procedure, the wild-type and P2X7 receptor KO mice were injected with 10 mU/0.2 μL type IV collagenase in the VBC of the thalamus to induce an animal model of stroke-like thalamic hemorrhage. Behavioral data showed that the CPSP group induced thermal and mechanical pain. The P2X7 receptor KO group showed reduced thermal and mechanical pain responses compared to the CPSP group. Molecular assessments revealed that the CPSP group had lower expression of NeuN and KCC2 and higher expression of GFAP, IBA1, and BDNF. The P2X7 KO group showed lower expression of GFAP, IBA1, and BDNF but nonsignificant differences in KCC2 expression than the CPSP group. The expression of NKCC1, GABAa receptor, and TrkB did not differ significantly between the control, CPSP, and P2X7 receptor KO groups. Muscimol, a GABAa agonist, application increased multiunit numbers for monitoring many neurons and [Cl⁻] outflux in the cytosol in the CPSP group, while P2X7 receptor KO reduced multiunit activity and increased [Cl⁻] influx compared to the CPSP group. P2X4 receptor expression was significantly decreased in the 100 kDa but not the 50 kDa site in the P2X7 receptor KO group. Altogether, the P2X7 hypothesis of CPSP was proposed, wherein P2X7 receptor KO altered the CPSP pain responses, numbers of astrocytes and microglia, CSD amplitude of the anterior cingulate cortex and the medial dorsal thalamus, BDNF expression, [Cl⁻] influx, and P2X4 expression in 100 kDa with P2X7 receptors. The present findings have implications for the clinical treatment of CPSP symptoms. Full article

Background: Alzheimer’s disease (AD) presents a significant global health concern, characterized by neurodegeneration and cognitive decline. Neuroinflammation is a crucial factor in AD development and progression, yet effective pharmacotherapy remains elusive. Sulforaphane (SFN), derived from cruciferous vegetables and mainly from broccoli, has shown a promising effect via in vitro and in vivo studies as a potential treatment for AD. This study aims to investigate the possible prophylactic mechanisms of SFN against prefrontal cortex (PFC)-related recognition memory impairment induced by lipopolysaccharide (LPS) administration. Methodology: Thirty-six Swiss (SWR/J) mice weighing 18–25 g were divided into three groups (n = 12 per group): a control group (vehicle), an LPS group (0.75 mg/kg of LPS), and an LPS + SFN group (25 mg/kg of SFN). The total duration of the study was 3 weeks, during which mice underwent treatments for the initial 2 weeks, with daily monitoring of body weight and temperature. Behavioral assessments via novel object recognition (NOR) and temporal order recognition (TOR) tasks were conducted in the final week of the study. Inflammatory markers (IL-6 and TNF), antioxidant enzymes (SOD, GSH, and CAT), and pro-oxidant (MDA) level, in addition to acetylcholine esterase (AChE) activity and active (caspase-3) and phosphorylated (AMPK) levels, were evaluated. Further, PFC neuronal degeneration, Aβ content, and microglial activation were also examined using H&E, Congo red staining, and Iba1 immunohistochemistry, respectively. Results: SFN pretreatment significantly improved recognition memory performance during the NOR and TOR tests. Moreover, SFN was protected from neuroinflammation and oxidative stress as well as neurodegeneration, Aβ accumulation, and microglial hyperactivity. Conclusion: The obtained results suggested that SFN has a potential protective property to mitigate the behavioral and biochemical impairments induced by chronic LPS administration and suggested to be via an AMPK/caspase-3-dependent manner. Full article

Background: The translocator protein (TSPO) has been proven to have great potential as a target for the positron emission tomography (PET) imaging of glioblastoma. However, there is an ongoing debate about the potential various sources of the TSPO PET signal. This work investigates the impact of the inoculation-driven immune response on the PET signal in experimental orthotopic glioblastoma. Methods: Serial [¹⁸F]GE-180 and O-(2-[¹⁸F]fluoroethyl)-L-tyrosine ([¹⁸F]FET) PET scans were performed at day 7/8 and day 14/15 after the inoculation of GL261 mouse glioblastoma cells (n = 24) or saline (sham, n = 6) into the right striatum of immunocompetent C57BL/6 mice. An additional n = 25 sham mice underwent [¹⁸F]GE-180 PET and/or autoradiography (ARG) at days 7, 14, 21, 28, 35, 50 and 90 in order to monitor potential reactive processes that were solely related to the inoculation procedure. In vivo imaging results were directly compared to tissue-based analyses including ARG and immunohistochemistry. Results: We found that the inoculation process represents an immunogenic event, which significantly contributes to TSPO radioligand uptake. [¹⁸F]GE-180 uptake in GL261-bearing mice surpassed [¹⁸F]FET uptake both in the extent and the intensity, e.g., mean target-to-background ratio (TBR_mean) in PET at day 7/8: 1.22 for [¹⁸F]GE-180 vs. 1.04 for [¹⁸F]FET, p < 0.001. Sham mice showed increased [¹⁸F]GE-180 uptake at the inoculation channel, which, however, continuously decreased over time (e.g., TBR_mean in PET: 1.20 at day 7 vs. 1.09 at day 35, p = 0.04). At the inoculation channel, the percentage of TSPO/IBA1 co-staining decreased, whereas TSPO/GFAP (glial fibrillary acidic protein) co-staining increased over time (p < 0.001). Conclusion: We identify the inoculation-driven immune response to be a relevant contributor to the PET signal and add a new aspect to consider for planning PET imaging studies in orthotopic glioblastoma models. Full article