Histological Analysis Research Articles

Long-term therapeutic efficacy and safety profiles of hpCas13d RNA editing in treating early-onset hypertrophic cardiomyopathy

AimsThrough evolving a precise RNA nuclease, hpCas13d, we have successfully inhibited hypertrophic cardiomyopathy in a compound heterozygous model. However, further investigation is needed to assess the long-term therapeutic effects and safety profiles of hpCas13d treatment. Materials and methodsAAV-hpCas13d[RQ] was subcutaneously injected into neonatal Myh6RH/RQ mice. Sequential echocardiography analyses were conducted at 4 months and 12 months to evaluate the sustained therapeutic effects of hpCas13d. Electrocardiography was employed to assess cardiac arrhythmias, and mice were euthanized at 12 months. Quantification of Myh6RQ degradation induced by hpCas13d[RQ] was performed using digital droplet PCR and cDNA sequencing. Histological analysis, RNA sequencing, and proteomic analyses were utilized to examine the inhibitory effects on pathological phenotypes and downstream signaling pathways. Biodistribution, tissue damage, and host immune response to AAV-hpCas13d[RQ] were assessed to evaluate long-term safety profiles. Key findingsThe allele-specific RNA degradation persisted for 12 months in AAV-hpCas13d[RQ]-treated Myh6RH/RQ mice. Partial degradation of pathogenic Myh6RQ transcripts proved adequate for the long-term inhibition of cardiac hypertrophy, arrhythmias, fibrosis, and cellular apoptosis in Myh6RH/RQ mice. RNA sequencing and proteomic analyses revealed that hpCas13d[RQ] treatment impeded hypertrophy and fibrosis, mitochondrial dysfunction, and abnormalities in ion channels downstream of mutant Myh6. Prolonged treatment with AAV-hpCas13d from the neonatal stage did not induce significant tissue damage, liver toxicity, humoral responses, or cellular immune reactions against the AAV9 capsid and bacterial hpCas13d. SignificanceThese results underscore the promising translational potential of AAV-hpCas13d in treating cardiovascular diseases and advancing in vivo gene therapy.

Lapatinib-loaded reductive-responsive hyaluronic acid-cholesterol nanoparticles for inhibiting metastasis of uveal melanoma

Uveal melanoma (UM) is the most common intraocular primary malignancy in adults with highly metastatic characteristics. Currently, there are no effective therapies to prevent metastasis formation in UM, resulting in a poor prognosis. Herein, we report a novel lapatinib-loaded reductive-responsive nanoparticle platform prepared via the self-assembly of amphiphilic hyaluronic acid-cystamine-cholesteryl hemisuccinate conjugate to suppress the distant metastasis of UM. The platform can maintain a stable nanosphere structure in the physiological environment and effectively deliver the drug to UM tumor sites, enhancing intratumoral drug accumulation and penetration. Upon endocytosis, lapatinib-loaded nanoparticles rapidly disintegrate triggered by intracellular glutathione and release the payload, leading to considerable suppression of MuM-2B cell proliferation, invasion, and migration. Systemic administration of lapatinib-loaded nanoparticles into mice bearing lung metastases of UM resulted in significantly higher metastasis suppression compared to free lapatinib, with histological analyses indicating no detectable toxicity. This nanotherapeutic platform is expected to provide a promising approach for the safe and efficient prevention of metastasis in UM.

Neuroprotective and anti-inflammatory effects of the RIPK3 inhibitor GSK872 in an MPTP-induced mouse model of Parkinson’s disease

Parkinson's disease (PD) is a neurodegenerative disorder triggered by the loss of dopaminergic neurons in the substantia nigra (SN). Recent studies have demonstrated that necroptosis is involved in dopaminergic neuronal cell death and the resulting neuroinflammation. During the process of necroptosis, a necrosome complex is formed consisting of the proteins receptor-interacting protein kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL). Although the neuroprotective effects of the RIPK1-specific inhibitor necrostatin-1, as well as RIPK3 and MLKL knockout in mice, have been described, the effects of RIPK3 pharmacological inhibitors have not yet been reported in animal models of PD. In the present study, we investigated the neuroprotective effects of GSK872, a specific RIPK3 inhibitor, in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. GSK872 rescued MPTP-induced motor impairment and inhibited tyrosine hydroxylase-positive dopaminergic cell death in the SN and striatum. Additionally, GSK872 inhibited the MPTP-induced increase in the expression of p-RIPK3 and p-MLKL in both the dopaminergic neurons and microglia, as assessed by biochemical and histological analyses. GSK872 further inhibited microglial activation and the expression of inflammatory mediators including NLRP3, interleukin (IL)-1β, IL-6, tumor necrosis factor-alpha, and inducible nitric oxide synthase in the SN region of MPTP mice. Using in vitro experiments, we validated the effects of GSK872 on necroptosis in SH-SY5Y neuronal and BV2 microglial cells. Overall, our results suggest that GSK872 exerts neuroprotective and anti-inflammatory effects, and may thus have therapeutic potential for PD.

Complement factor H-related protein 5 alleviates joint inflammation and osteoclast differentiation by disrupting RANK-JNK signaling in collagen antibody-induced arthritis mouse model

BackgroundComplement Factor H-Related protein 5 (CFHR5) belongs to the factor H/CFHR family and regulates the complement system by modulating factor H’s inhibitory activity against C3b. Despite its known role, the impact of CFHR5 on autoimmune arthritis and its relationship to pathophysiological changes in arthritis and bone loss remain unclear. This study aimed to assess the effect of CFHR5 on aggressive osteoclast activity and arthritis using a murine model of collagen antibody-induced arthritis (CAIA). MethodsThe effect of recombinant CFHR5 protein (rCFHR5) on arthritis were evaluated in CAIA. The mice were divided into three group and intraperitoneally treated with rCFHR5, methotrexate (MTX) as positive control or PBS as negative control. In the CAIA mouse model, the rCFHR5-treated group significantly reduced the incidence and clinical arthritis equivalent to the MTX group. Clinical arthritis scores, incidence and body weight were measured, and histological analysis of ankle joints was performed by Hematoxylin and Eosin (H&E) and Safranin O − Fast green (SOFG), Tartrate-resistant acid phosphatase (TRAP) staining and Immunohistochemistry. Moreover, to investigate the rCFHR5 role, we isolated murine osteoclast precursor cells (OCPs) from each group, induced osteoclasts with M−CSF and RANKL, and performed TRAP and F-actin staining. To verify the mechanism, mRNA and protein analyses were performed in OCPs. ResultsHistological examination of ankle joints revealed substantial reductions in synovial hyperplasia, bone marrow inflammation, bone erosion, cartilage destruction and TRAP-positive cells in the rCFHR5 group compared to the vehicle group. The ankle joints of the rCFHR5 group showed markedly decreased expression of proinflammatory cytokines (TNF-α, IL-1β and IL-6). Mechanically, treatment with rCFHR5 inhibited RANKL-mediated osteoclast differentiation from OCPs and disrupted the RANK-JNK signaling. These findings demonstrate that treatment with rCFHR5 attenuates joint inflammation and reduces osteoclast differentiation, indicating its potential anti-inflammatory effect in autoimmune arthritis models.

Lycium barbarum oligosaccharide-derived carbon quantum dots inhibit glial scar formation while promoting neuronal differentiation of neural stem cells

Overexpression of glial fibrillary acidic protein (GFAP) in activated astrocytes following spinal cord injury is closely associated with glial scar formation, which harms axonal regrowth. In this study, we prepared ultrasmall cationic carbon quantum dots (CQDs) via one-step hydrothermal carbonization. Lycium barbarum oligosaccharides were used as the carbon source for the first time, and polyetherimide (PEI) and ethylenediamine (ED) were used as cationic reagents. Interestingly, the resultant CQDs show the bioactivity of specifically inhibiting GFAP protein expression, while promoting neuronal marker expression in neural stem cells (NSCs). Furthermore, CQDs together with NSCs can remarkably improve the motor activity of animals after implantation into the transection lesion of the rat spinal cord. Histological analysis confirmed that CQDs can enhance neuronal differentiation of NSCs while inhibiting glial scar formation in vivo. Altogether, this study represents the first report of producing CQDs from oligosaccharides and investigating their impact on NSCs differentiation, thus providing a paradigm for exploring the bioactivity of quantum dots.

A putative new Besnoitia species in the southern black-eared opossum Didelphis aurita

Besnoitia spp. are cyst-forming coccidian parasites with a broad host range, infecting various wild and domestic animal species. Northamerican opossums (Didelphis virginiana) are severely affected by the infection with B. darlingi. This study presents a case of infection with Besnoitia in a road-killed female southern black-eared opossum (Didelphis aurita) in Misiones, Argentina. Many 0.5 to 1 mm cysts were observed in several muscles and visceral organs and were microscopically identified in skeletal muscles, tongue, and heart. Histological analysis disclosed multiple spherical cysts with a myriad of bradyzoites like-cells and a well-defined cyst wall. A small number of degenerate and ruptured cysts, surrounded by mild to moderate inflammation were observed. Genomic DNA from an individual cyst and muscle was extracted and ITS1 marker and 18S rRNA gene fragments from sarcocystid protozoa were successfully amplified by PCR and sequenced. The 18S sequence exhibited 100% identity with sequences of B. darlingi and B. oryctofelisi. Comparison of the complete ITS1 sequence (259 bp) revealed an identity of 99.2% with B. oryctofelisi and 97.7% with B. darlingi. This result together with the phylogeny positioning, suggest that the Besnoitia sp. in the present case differ from B. darlingi, being closely related with B. oryctofelisi.

Loss of MMP9 disturbs cranial suture fusion via suppressing cell proliferation, chondrogenesis and osteogenesis in mice

Cranial sutures function as growth centers for calvarial bones. Abnormal suture closure will cause permanent cranium deformities. MMP9 is a member of the gelatinases that degrades components of the extracellular matrix. MMP9 has been reported to regulate bone development and remodeling. However, the function of MMP9 in cranial suture development is still unknown. Here, we identified that the expression of Mmp9 was specifically elevated during fusion of posterior frontal (PF) suture compared with other patent sutures in mice. Interestingly, inhibition of MMP9 ex vivo or knockout of Mmp9 in mice (Mmp9-/-) disturbed the fusion of PF suture. Histological analysis showed that knockout of Mmp9 resulted in wider distance between osteogenic fronts, suppressed cell condensation and endocranial bone formation in PF suture. Proliferation, chondrogenesis and osteogenesis of suture cells were decreased in Mmp9-/- mice, leading to the PF suture defects. Moreover, transcriptome analysis of PF suture revealed upregulated ribosome biogenesis and downregulated IGF signaling associated with abnormal closure of PF suture in Mmp9-/- mice. Inhibition of the ribosome biogenesis partially rescued PF suture defects caused by Mmp9 knockout. Altogether, these results indicate that MMP9 is critical for the fusion of cranial sutures, thus suggesting MMP9 as a potential therapeutic target for cranial suture diseases.

Implementation of biotechnological techniques for the propagation and introduction of Trichosanthes kirilowii Maxim

Trichosanthes kirilowii Maxim. is classified among the 50 most important medicinal plants used in traditional Asian medicine. This species is endemic and reproduction from seeds in the conditions of Central Europe is inefficient. The present study focused on the implementation of effective propagation of T. kirilowii, including standardisation of seed germination conditions, reproduction of the plant based on micropropagation, and introduction to field conditions. Four types of explants were tested on six types of media in various variants of culture conditions. Additionally, anatomical and histological analyses of specimens obtained through the in vitro cultivation were carried out, with particular emphasis on the site of initiation of aboveground and underground shoots. Microscopic analyses showed that the T. kirilowii shoots and roots obtained in the in vitro culture formed in the process of organogenesis via direct regeneration. Even though the callus did not participate in the regeneration of the entire plant, the micropropagation protocol proposed in the study was efficient: 6–8 shoots were obtained from 1 explant. The entire micropropagation process from the explant to an adult individual growing in the ground lasted 122 days. The protocol for T. kirilowii micropropagation in vitro cultures provides a fast, efficient, and robust approach to propagation of this species. The biotechnological applications in the reproduction of T. kirilowii will help not only to increase the number of daughter plants but also to multiply individuals of the appropriate sex, which will increase the probability of production of fruits in this dioecious species.

Silver Nanoparticles and L-Cysteine Composite Redresses Carbon Tetrachloride-Induced Hepatotoxicity in Swiss Albino Rats.

l-cysteine is a versatile amino acid that plays a pivotal role in synthesizing critical molecules, enzymatic catalysis, regulation, and electron transport. It also has tremendous potential to act as an adjuvant for enhancing the biological efficacy of various nanoparticles in vivo. The current study is aimed to evaluate the protective efficacy of silver nanoparticles (AgNPs) decorated with l-cysteine in carbon tetrachloride (CCl4)-induced hepatotoxicity in the Swiss albino rats as an animal model. The rats were divided into four treatment groups: Group 1 (control without any treatments), Group 2 treated with AgNPs and l-cysteine composite (5 mg/kg body weight on every third day), Group 3 (single dose of 1 mL/kg CCl4), and Group 4 treated with AgNPs-l-cysteine composite in the rats pre-administered with CCl4. After treatment for a month, the rats were killed, and their liver and blood samples were subjected to biochemical analysis and histological examination.: Group 2 showed all the parameters comparable to control Group 1. On the contrary, CCl4-treated, Group 3 rats showed abnormally raised liver function markers (AST and ALT) and liver toxicity markers (GGT, LDH, and total bilirubin) concomitant with disturbed oxidative stress parameters (GSH and MDA) compared to the control. However, Group 4 rats demonstrated a significant recovery from CCl4-induced biochemical alteration in the animals as compared to Group 3. In addition, the biochemical measurements were harmonious with the histological analysis of the liver sections of the treated rats. Hence, the proposed AgNPs-l-cysteine composite is a potent hepato-protecting agent in vivo that can be employed in regulating CCl4-induced hepatotoxicity or any drug or potential pharmaceutical compound exerting similar toxicity.

Zang Siwei Qingfei Mixture Alleviates Inflammatory Response to Attenuate Acute Lung Injury by the ACE2/NF-κB Signaling Pathway in Mice.

Acute lung injury (ALI) is a serious lung disease characterized by acute and severe inflammation. Upregulation of ACE2 and inhibition of the NF-κB signaling pathway attenuate LPS-induced ALI. To explore whether Zang Siwei Qingfei Mixture inhibits the development of ALI through the ACE2/NF-κB signaling pathway. Alveolar type II epithelial cells (AEC II) were identified by immunofluorescence staining and flow cytometry. C57BL/6J mice were treated with LPS to establish an ALI model. Cell viability was assessed using CCK8 assays. The levels of ACE, ACE2, p-p38/p38, p- ERK1/2/ERK1/2, p-JNK/JNK, p-IκBα/IκB-α, p-NF-κBp65 were analyzed by Western blotting. ELISA was applied to detect the levels of TNF-a, IL-6, AGT, and Ang1-7. HE staining was used to observe lung injury. The mRNA expression of ACE, ACE2, and Mas was measured by RTqPCR. AEC II cells were successfully isolated. Treatment with Zang Siwei Qingfei mixture resulted in a decrease in ACE, p-p38/p38, p-ERK1/2/ERK1/2, p-JNK/JNK, p-IκBα/IκB-α, p- NF-κBp65 levels, while increasing ACE2 levels. Zang Siwei Qingfei mixture also led to a reduction in TNF-α, IL6, and AGT levels, while increasing Ang1-7 level. Histological analysis showed that Zang Siwei Qingfei Mixture treatment improved the alveolar structure of ALI mice and reduced inflammatory infiltration. The pretreatment with MLN-4760, an ACE2 inhibitor, resulted in opposite effects compared to Zang Siwei Qingfei Mixture treatment. Zang Siwei Qingfei mixture attenuates ALI by regulating the ACE2/NF-κB signaling pathway in mice. This study provides a theoretical foundation for the development of improved ALI treatments.

Potential blood pressure regulatory effect of low molecular weight α-chymotrypsin extract and its peptides from Stichopus japonicus: Peptide-ACE interaction study via in silico molecular docking

Hypertension is a significant risk factor for cardiovascular disease and heart damage. Stichopus japonicus (S. japonicus) is a red sea cucumber with antioxidant and anti-hypertensive activities. However, its anti-hypertensive mechanism remains unclear. In this study, we evaluated the inhibitory effects of angiotensin-converting enzyme (ACE) of α-chymotrypsin-assisted hydrolysate of S. japonicus (α-chy) and its ultrafiltrate fractions (>10 kDa [α-chy-I], 5–10 kDa [α-chy-II], and <5 kDa [α-chy-III]). Low molecular α-chy-III exerted excellent ACE inhibitory and anti-hypertensive activities in spontaneously hypertensive rats (SHR). Moreover, α-chy-III significantly reduced the systolic and diastolic blood pressure by modulating the serum angiotensin and ACE levels. Histological analysis revealed that α-chy-III markedly protected the aorta, heart, and kidney tissues of SHR from hypertension-induced tissue damage.Taken together, our findings highlight the potential of α-chy-III as a functional food ingredient for the treatment of hypertension and its comorbidities.

Effect of dietary replacement of fish meal by poultry by-product meal on the growth and hepatic health in loach (Paramisgurnus dabryanus)

Our objective was to systematically evaluate the impact of substituting fish meal (FM) with poultry by-product meal (PBM) in fish feed on the growth and hepatic health of loach. Six diets with different levels of PBM (0%-PBM0, 10%-PBM10, 30%-PBM30, 50%-PBM50, 70%-PBM70 and 90%-PBM90 were formulated. After 8 weeks feeding trial, the highest weight gain (WG) was observed in 55% PBM replacement ratio. Meanwhile, the lowest feed conversion ratio (FCR) were observed in 41.56% PBM replacement ratio. In addition, dietary PBM induced hepatic oxidative stress including increasing the activity of aminotransferase from PBM0 to PBM50 group, whereas the activity of those enzymes was decreased from PBM50 to PBM90 group. Meanwhile, histological analysis showed that the lipid vacuoles in the liver were increased from PBM0 to PBM50 group, then decreased from PBM50 to PBM90 group (P< 0.05). Moreover, primary bile acid biosynthesis was the only one pathway enriched in top 20 significant pathways by transcriptomic and metabolomic analysis. Specifically, the key bile acid synthesis gene CYP7a1 was down-regulated, while CYP7b1 evinced an up-regulated pattern in PBM50 group compared to PBM0 group. In short, the PBM replacement ratio of up to 50% in diets was appropriate for rearing loach, while higher PBM replacement ratio resulted in extremely oxidative stress in the liver.

Novel Approach to Fat Reduction: A Phase I Study Evaluating Safety and Tolerability of STP705 in Abdominoplasty

Background: RNAi therapeutics are a rapidly developing technology with broad medical applications predicated on reducing the expression of genes with key links to disease pathogenesis. The TGF-β1/Smad3 and COX-2 signaling pathways are strongly implicated in obesity and type 2 diabetes. Reducing the expression of TGF-β1 and COX-2 may have benefits in fat reduction procedures. The aim of this study was to assess the safety and tolerability of STP705 (a TGF-β1/COX-2 siRNA complex in a polypeptide nanoparticle vehicle) injections in persons undergoing abdominoplasty. A secondary aim was to make initial histologic observations on the efficacy of STP705 injections in inducing adipocyte apoptosis for the purpose of focal fat reduction. Methods: The study treatment consisted of 3 rounds of treatment with 7 subcutaneous abdominal injections of STP705 or placebo. Eight female subjects aged 18-65 years received 120 μg, 240 μg, or 360 μg STP705 in 0.5 or 1.0 ml doses (per injection) or an equivalent amount of placebo injected randomly across seven 1 cm2 areas. Treatments were administered 28 days apart with follow-ups occurring at 2 and 7 days’ post-procedure. Tissue samples from each of the 7 injection sites were harvested from total abdominoplasty excisional specimens obtained 28 days after the final injection. Safety assessments were conducted, including physical examination, clinical laboratory tests, electrocardiograms, evaluation of local skin reactions (LSRs), and collection of adverse events (AEs). Lipolytic and inflammatory effects of STP705 were assessed by blinded histologic analysis of harvested tissue samples. Results: There were no clinically significant changes in clinical labs, vital signs, or ECGs. The incidence of LSRs was low throughout the study. There were 3 moderate AEs deemed likely to be related to STP705 injection; none required intervention, and all resolved without dose modification. Histology revealed marginally dose-dependent tissue response with adipocyte destruction and fat remodeling. Conclusion: In general, STP705 was well tolerated at all concentrations and volumes studied. STP705 demonstrated excellent safety, and initial histologic analysis is suggestive of its efficacy in adipocyte destruction. The lack of cutaneous side effects with STP705 injection is an advantage over current treatments for similar indications.

Sea food by-products valorization for biomedical applications: evaluation of their wound regeneration capabilities in an Ex vivo skin model

IntroductionThe skin is often exposed to harmful stimuli that might compromise its integrity and functionality. After an injury, the skin has a limited capability to restore its complex structure, and in the case of severe skin damage, surgical operations and rapid application of wound dressings are often required to promote optimal wound healing. Nowadays, collagen-based biomaterials are widely used in combination with bioactive molecules able to prevent excessive inflammation and possible infections. In line with a circular economy and blue biotechnology approach, it was recently demonstrated that both collagen and bioactive molecules (i.e., antioxidant compounds) can be sustainably obtained from sea food by-products and effectively used for biomaterial development. Herein, we describe and compare the application of two marine collagen-based wound dressings (CBWDs), produced with materials obtained from sea urchin food waste, for the treatment of skin lesions in a wound healing organ culture (WHOC) model.MethodsThe ex vivo WHOC model was set up starting from rat skin explants and the induced lesions were assigned into three different groups: control (CTRL) group, not treated, marine collagen wound dressing (MCWD) group, and antioxidants-enriched marine collagen wound dressing (A-MCWD) group. After 5 and 10 days, specimens were examined for organ maintenance and assessed for the healing process.ResultsImmunohistochemical results showed that both CBWDs were similarly successful in prolonging skin repair, preserving the epidermal barrier up to 5 days under static culture conditions. Histological and gene expression analysis highlighted that the A-MCWD might support and accelerate skin wound healing by exerting antioxidant activity and counteracting inflammation.DiscussionOverall, these findings underline the potential of sea urchin food waste as a novel resource for the development of functional medical devices for the treatment of skin wounds.

QuPath Edu and OpenMicroanatomy: Open‐source virtual microscopy tools for medical education

AbstractVirtual microscopy is becoming increasingly common in both medical education and routine clinical practice. Virtual microscopy software is typically designed either for (1) training students in anatomy, histology, and histopathology, or (2) quantitative analysis—but not both simultaneously. QuPath is one of the most widely used software applications for histopathology image analysis in research and provides a comprehensive set of computational tools to evaluate histology slides. We have enhanced QuPath by developing a new extension, QuPath Edu, which adapts the software to function as an intuitive microanatomy learning environment. Additionally, we have created an entirely new, complementary software platform called OpenMicroanatomy, which provides an alternative way to access QuPath Edu teaching content through a web interface. These tools have been used in teaching of first year medical and dentistry students at the University of Oulu Medical Faculty, and we conducted a user survey for the Class of 2023 to assess the usability and student experience. In general, the introduced annotation and quiz features were appreciated by the students and the system usability of OpenMicroanatomy was considered excellent (SUS score 84.8). Together, these freely available tools enable teachers to develop and deploy innovative training material for anatomy, histopathology, quantitative analysis, and artificial intelligence in a wide range of contexts. This unique combination can provide the next generation of students with essential multidisciplinary skills.

Study the role of xanthine oxidase inhibitor, allopurinol in experimentally induced steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a chronic liver disease which can lead to cirrhosis and hepatic failure. It is observed in patients with both type 1 and type 2 diabetes mellitus (T1DM, T2DM). Allopurinol, a xanthine oxidase inhibitor that is widely used in clinical practice, has been demonstrated to reduce hepatic oxidative stress and attenuate acute liver injury which may be through activation of antioxidant pathways. This work aimed at investigating the role of Allopurinol (ALP) in attenuation of type 1 diabetes associated with Nonalcoholic fatty liver disease (NAFLD) and exploring the possible molecular mechanism by which ALP attenuates NASH in type 1 diabetes. Forty-five adult male albino rats were included in the study. They were randomly allocated to 3 equal groups: group I (control), Group II (diabetic animals), Group III (diabetic animals with allopurinol treatment). At the end of this experimental study measurements of serum glucose, ALT, AST, cholesterol, triglyceride, serum levels of uric acid, malondialdehyde (MDA), serum superoxide dismutase (SOD) were done. Histological analysis of liver tissue to diagnose steatohepatitis and gene expression of nuclear factor-erythroid-2- related factor-2 (Nrf2) &amp; TNFα were done. Diabetic rates treated with allopurinol (group III) showed decrease in serum levels of ALT, AST, cholesterol, uric acid and MDA compared to diabetic rat group. As regards TNF, gene expression was significantly decreased in group III compared to group II. This study also demonstrated that Nrf2α was significantly increased in group III compared to group II. Allopurinol also, ameliorated the histopathological changes observed in group II. In conclusion, allopurinol treatment increases the Nrf2 gene expression in the liver of STZ-induced diabetic rats and ameliorates steatohepatitis through modulation of TNF-α gene expression. Allopurinol could be a candidate for prevention or treatment of NAFLD.

EP300‐interacting inhibitor of differentiation 3 is required for spermatogenesis in mice

AbstractBackgroundMammalian spermatogenesis is a highly complex process of cell proliferation, meiosis, and differentiation. A series of genes are expressed in an orderly and precise manner to ensure spermatogenesis, with chromatin undergoing intricate changes throughout. EP300‐interacting inhibitor of differentiation 3 (Eid3) is a testis‐enriched gene, but its role in male reproduction remains unclear.ObjectiveTo investigate the role of EID3 in male spermatogenesis and explore the potential underlying mechanism.Materials and MethodsWe generated Eid3 knockout mouse model using the CRISPR‐Cas9 system. We measured the expression of EID3 in mouse tissues and testicular cell populations by qRT‐PCR and western blot. Histological analysis, including hematoxylin and eosin (H&amp;E) and periodic acid‐Schiff (PAS) staining, together with computer‐assisted sperm analysis (CASA), were performed to evaluate the effect of EID3 on spermatogenesis in mice. Light and ultrastructural microscopy were used to evaluate the morphology and structure of the Eid3−/− spermatozoa. We used western blot and immunofluorescence to further analyze the function of EID3 in spermiogenesis.ResultsEid3−/− mouse showed a significant decrease in sperm count, motility, and morphology. Loss of EID3 impaired the normal meiotic process and induced apoptosis of abnormally developing spermatocytes, ultimately resulting in the decrease of sperm cell number. Additionally, EID3 deficiency led to a decrease in histone acetylation levels in spermatids, impaired histone‐to‐protamine transition and chromatin condensation process, and ultimately resulted in abnormal sperm morphology.Discussion and ConclusionsThis study confirms for the first time that EID3 is crucial for meiosis and chromatin condensation during spermatogenesis, and EID3 deficiency leads to a significant decrease in sperm parameters. Given the high expression paradigm of Eid3 in human testis, EID3 likely plays a role in human reproduction. Future research could provide a new target for the clinical diagnosis and treatment of male infertility.

Abstract C014: Degradation of extracellular trap DNA sustains anti-tumor immune responses in breast cancer

Abstract Increased extracellular DNA (exDNA) levels in the blood are a hallmark of metastatic cancer, arising from tumor lysis, apoptosis, necrosis, and neutrophil extracellular traps (NETs) released by tumor-expanded neutrophils. NETs, web-like chromatin structures extruded by neutrophils to trap pathogens, are highly immunogenic due to their DNA and histone content and their persistent interaction with dendritic cells. Tumor cells can also release extracellular traps. In myeloid leukemia, blasts release nuclear content via traps to activate coagulation or sustain myeloproliferation. Extracellular traps have been found in NPM1 mutant AML patients, with mutant NPM co-localizing with histones along exDNA traps. Forcing trap extrusion in NPM mutant leukemia cells has been used to create dendritic cell-based vaccines that break tolerance against NPMc antigens. This suggests that NETs in the tumor microenvironment (TME) may promote tolerance, with breaking tolerance requiring consistent NET formation and dendritic cell interaction. NETs are also seen in solid tumors, such as triple-negative breast cancer (TNBC), where they aid in cancer cell migration, invasion, and awakening of circulating tumor cells. However, the capacity of tumor cells to directly extrude DNA traps is not fully understood. To investigate this, various human and murine breast cancer cell lines were seeded on poly-D-lysine coated slides, stained with DAPI and Sytoxgreen, and observed via confocal microscopy. Tumor cells extruded DNA traps within 4 hours without stimuli. Notably, trap extrusion correlated with cell line aggressiveness and was abolished by DNase, indicating dsDNA composition. The absence of traps in 24-hour cultures suggests DNA extrusion may help rare tumor cells survive and proliferate. In line, DNase treatment reduced tumor proliferation and increased apoptosis. To assess the significance of DNA traps in vivo, BALB/c mice were injected with the highly metastatic 4T1 clone 5 breast cancer model, with or without DNase treatment, and monitored starting 5 days post-injection and weekly until day 28. Histological analysis at the injection site 5 days post-injection showed that DNase treatment reduced both local trap formation and tumor cell proliferation, as indicated by BrdU incorporation. Moreover, immunohistochemistry revealed that in DNase-treated mice, initial tumor growth was followed by complete tumor regression, accompanied by local and systemic CD8 T cell activation. Correspondingly, although a few metastases were detectable at day 14 in DNase-treated mice, no metastases were observed by day 28. Although it remains unclear whether tumor-derived or immune cell-derived traps are most relevant in our model, the results demonstrate that their presence in the TME promotes tolerance despite the inherent immune adjuvant properties of the traps. This suggests that DNase treatment could be particularly effective in combating early tumor development or relapse when used as part of a combination therapy designed to sustain anti-tumor immune responses. Citation Format: Sabina Sangaletti, Paola Portararo, Laura Botti, Valeria Cancila, Claudio Tripodo, Mario P. Colombo, Claudia Chiodoni. Degradation of extracellular trap DNA sustains anti-tumor immune responses in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C014.

Abstract B044: Spatial transcriptomics reveals a distinct B cell signature in the dormant prostate cancer bone microenvironment

Abstract Background &amp; Objective: Prostate cancer (PCa) cells frequently disseminate to bone where they can remain dormant for extended periods. The precise cellular and molecular mechanisms responsible remain largely unknown. The advent of spatial transcriptomics provides a unique opportunity to study key bone microenvironment-dormant PCa cell interactions in situ. Here, we developed a novel immunocompetent in vivo model of PCa dormancy in bone and employed the technology to address this major gap in knowledge. Methods: We established an in vitro protocol to induce dormancy in multiple PCa cell lines, including the C57BL/6 murine PCa cell line, RM1. Isogenic active and dormant PCA cells underwent bulk RNA Seq. We used an intra- iliac artery (IIA) approach to allow niche-specific seeding of dormant PCa within the bone. Spatial transcriptomics (10X Visium) was performed on tissue sections and R packages (Seurat &amp; CellChat) were used for data analysis. Results: We validated in vitro PCa dormancy via cell cycle analysis, membrane dye retention and ERK/p38 ratio. RNASeq analysis of dormant PCa cells (vs. active) revealed upregulation of immunomodulatory genes such as, GDF15, BDNF, A2M, VGF, NLRP1, and CD55. C57BL/6 immunocompetent mice were inoculated with active or dormant RM1 cells via IIA. Majority of active RM1 mice reached endpoint within 15 days. In contrast, mice bearing dormant RM1 (D-RM1) had extended survival and were removed from study after 30 days. Histological analysis revealed solitary D-RM1 (panCK+/Ki67-/CC3-) on endosteal surfaces compared to macrometastases (high Ki67+) in the active RM1 group. Using IIA PBS injected tumor naïve bones as a control, we applied spatial transcriptomics (10X Visium) to interrogate the microenvironment surrounding active and dormant RM1 PCa cells. Bioinformatic analyses demonstrated higher expression of B cell markers (CD19, CD79a, CD79b, Ighm, and Pax5) and enhanced B cell activation/antigen phagocytosis signature in the D- RM1 group compared to other groups. We validated the presence of CD19 B-cells in proximity to the D-RM1 cells in subsequent tissue sections. In contrast, B cells were located less frequently and to the periphery of active RM1 metastases. Inference analysis using CellChat also identified a significant and distinct signaling pattern between CD55 and CD97 in the B cell enriched clusters in D-RM1 group. CD55/CD97 interaction is a noted mediator of B cell homing. These data suggest a potential role for distinct populations of B cells during the establishment of PCa dormancy in bone. Conclusion: Spatial transcriptomic analysis of the dormant PCa bone microenvironment reveals an enrichment of CD19+ B cells with a distinct signaling pattern. Given their known roles in immune tolerance we posit that infiltrating B cells may play a role in protecting and sustaining newly disseminated dormant PCa cells from immune mediated elimination. Citation Format: Mostafa M. Nasr, Ryan T. Bishop, Haley du Bois, Tao Li, Jeremy S. Frieling, Conor C. Lynch. Spatial transcriptomics reveals a distinct B cell signature in the dormant prostate cancer bone microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B044.

Abstract C035: Spatially limited stroma-mediated resistance potentiates targeted therapy resistance through an integration of multiple juxtacrine and paracrine mechanisms

Abstract Despite the ability to induce strong clinical responses, therapies that target mutational drivers of oncogenic signaling are not curative in advanced cancers, as a subset of cancer cells is capable of surviving therapy and evolving resistance. While therapy resistance is commonly viewed as a cell-intrinsic phenomenon, multiple factors produced by tumors can also confer strong therapy resistance. In contrast to the detailed elucidation of molecular mediators of cell-intrinsic and stroma-mediated (SM) resistance, the relative importance of cell-intrinsic and SM resistance to in vivo therapeutic responses remains poorly defined. To address this gap of knowledge, we used a well-characterized experimental model of ALK+ lung cancer H3122 cell line that exemplifies a duality observed across common models of targetable cancers. Under standard stroma-free in vitro cultures, H3122 cells can survive under therapeutically relevant concentrations of ALK inhibitors (ALKi), eventually acquiring cell-intrinsic therapy resistance. At the same time, co-culture with stromal fibroblasts drastically reduces the sensitivity of H3122 cells to ALKi, indicating the relevance of SM resistance. To understand the impact of SM resistance on in vivo responses, we sought to identify the mechanism(s) responsible for the therapy-protective effects of stromal fibroblasts, subsequently interrogating the impact of the disruption of this mechanism on in vivo therapeutic responses. Our in vitro studies with a large panel of primary stromal fibroblast isolates identified the HGF-cMET axis as the major mechanism responsible for ALKi desensitization. Surprisingly, xenograft validation studies demonstrated a weak effect of HGF-cMET modulation. Histological analyses of tumor tissues revealed that this relative weakness is attributable to a strong, spatially limited HGF-independent component of SM resistance. Mechanistic follow-up demonstrated that the HGF-independent component of SM resistance integrates the effect of multiple well-known juxtacrine and paracrine-acting mechanisms. Whereas the multifactorial nature of stroma-mediated resistance prevented a clear assessment of its relative contribution to in vivo therapy responses, our spatial analyses indicate that SM resistance dominates the ability of tumors to avoid therapeutic elimination. Surprisingly, we found that SM resistance was also a substantial contributor to tumor relapse, indicating that in vivo therapy resistance can integrate both cell-intrinsic and cell-extrinsic effects. This duality of therapy resistance and the multifactorial underpinning of both cell-intrinsic and stroma-mediated resistance present a challenge to therapeutic strategies focused on identifying and targeting specific resistance mechanisms. Our studies suggest that this limitation can be overcome by shifting the therapeutic focus towards shared orthogonal therapeutic sensitivities of tumor cells within residual disease. Citation Format: Bina Desai, Tatiana Miti, Sandhya Prabhakaran, Daria Miroshnychenko, Menkara Henry, Viktoriya Marusyk, Chandler Gatenbee, Marilyn Bui, Jacob Scott, Philipp M. Altrock, Eric Haura, Alexander R.A. Anderson, David Basanta, Andriy Marusyk. Spatially limited stroma-mediated resistance potentiates targeted therapy resistance through an integration of multiple juxtacrine and paracrine mechanisms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C035.