Journal of Molecular Pathology

Periodontal disease remains a significant global health concern, characterized by complex host–pathogen interactions leading to tissue destruction. This review explored the role of pattern recognition receptors (PRRs) in the pathogenesis of periodontal disease, synthesizing current knowledge on their molecular mechanisms and potential as therapeutic targets. We examined the diverse family of PRRs, focusing on toll-like receptors (TLRs) and NOD-like receptors (NLRs), elucidating their activation by periodontal pathogens and subsequent downstream signaling cascades. This review highlights the intricate interplay between PRR-mediated pathways, including NF-κB and MAPK signaling, and their impact on inflammatory responses and bone metabolism in periodontal tissues. We discussed the emerging concept of PRR crosstalk and its implications for periodontal homeostasis and disease progression. Furthermore, this review addressed the potential of PRR-targeted therapies, exploring both challenges and opportunities in translating molecular insights into clinical applications. By providing an overview of PRRs in periodontal health and disease, this review aims to stimulate future research directions and inform the development of novel diagnostic and therapeutic strategies in periodontology. Full article

Birt–Hogg–Dubé syndrome (BHDS) is an autosomal dominant disease characterized by skin, lung, and renal manifestations. This syndrome is caused by a germline mutation in the FLCN gene, which leads to disruption in multiple downstream pathways. Renal cell carcinomas are one of the serious clinical manifestations of the disease, which usually presents as bilateral and multiple tumors. Morphologically, most of these tumors are classified as hybrid oncocytic tumors. Recent advances in molecular techniques have shed light on the pathogenesis of these renal tumors. In this review, we evaluate and summarize the current knowledge of BHDS, pathologic changes, and its molecular basis with the focus on the renal hybrid oncocytic tumor (HOT), their pathogenesis, and molecular underpinning. Full article

The rising global incidence of uterine cancer has been linked to the escalating prevalence of obesity. Obesity results in insulin resistance which alters the IGF system, thereby driving cancer progression via increased cell proliferation and the inhibition of apoptosis, although the precise mechanisms remain unclear. In a previous study, we compared the levels of IGF1 and IGF2 between fifty endometrial cancer patients (study group) and fifty age-matched non-cancer patients with benign gynaecological conditions (control group), identifying a correlation with menopause. Building on these data, we now report that IGF levels in pre-menopausal women were significantly lower in the study group compared to the control group, a pattern not observed in post-menopausal women. We undertook the receiver operating characteristic (ROC) curve analysis for calculating the potential of IGF1 and IGF2 to effectively distinguish pre-menopausal women with endometrial cancer from those without it. For pre-menopausal women, the area under ROC curve values were 0.966 for IGF1 and 0.955 for IGF2, both with significant p-values, indicating that IGF1 and IGF2 levels have the potential to be diagnostic biomarkers for distinguishing pre-menopausal women with endometrial cancer from those without it. In summary, our findings emphasise the importance of considering menopausal status in the context of IGF level assessments and suggest that IGF1 and IGF2 could play a crucial role in the early diagnosis of endometrial cancer in pre-menopausal women. Full article

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by symmetrical joint inflammation, cartilage degradation, and bone erosion. This review explores the multifaceted aspects of RA pathogenesis, focusing on the dynamic interplay between innate and adaptive immune responses, genetic predisposition, and environmental triggers. The development of RA involves genetic susceptibility and trigger events such as infections, trauma, smoking, obesity, and microbiome alterations, fostering autoimmune reactions and tissue/organ destruction. The innate immune response, including toll-like receptor activation and synovial fibroblasts’ roles, contributes to the acceleration of inflammatory processes in joint tissues. Monocytes and macrophages organize and sustain chronic joint inflammation, leading to tissue damage and bone resorption, while highlighting the significance of CD14 and CD16 subsets in RA pathogenesis. In the adaptive immune response, aberrant activation and proliferation of CD4+ T cells and the role of regulatory T cells in maintaining immune tolerance are discussed. Target cytokines like TNF-α, IL-6, IL-1, IL-17, and BAFF, as well as chemokines such as CCL2, CXCL10, CCL5, and CXCL12, have emerged as critical components in managing chronic inflammation and joint damage in RA. This comprehensive overview provides insights into the pathophysiology of RA and potential therapeutic avenues, emphasizing the importance of understanding these complex immunological and genetic mechanisms for developing more effective treatment strategies. Full article

The extracellular matrix is an organized three-dimensional network of protein-based molecules and other macromolecules that provide structural and biochemical support to tissues. Depending on its biochemical and structural properties, the extracellular matrix influences cell adhesion and signal transduction and, in general, can influence cell differentiation and proliferation through specific mechanisms of chemical and mechanical sensing. The development of body tissues during ontogenesis is accompanied by changes not only in cells but also in the composition and properties of the extracellular matrix. Similarly, tumor development in carcinogenesis is accompanied by a continuous change in the properties of the extracellular matrix of tumor cells, called ‘oncomatrix’, as the tumor matures, from the development of the primary focus to the stage of metastasis. In this paper, the characteristics of the composition and properties of the extracellular matrix of tumor tissues are considered, as well as changes to the composition and properties of the matrix during the evolution of the tumor and metastasis. The extracellular matrix patterns of tumor tissues can be used as biomarkers of oncological diseases as well as potential targets for promising anti-tumor therapies. Full article

Aggressive B-cell lymphoma encompasses Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and, as per the 2016 WHO classification, high-grade B-cell lymphoma (HGBL) not otherwise specified (NOS) and HGBL double/triple hit (DH/TH). However, the diagnostic distinction of HGBL from BL and DLBCL is difficult by means of histology/immunostaining in a substantial number of patients. This study aimed to improve subtyping by the identification of molecular features of aggressive B-cell lymphomas, with a specific focus on HGBL. To this end, we performed a comprehensive gene expression and mutational pattern analysis as well as the detection of B-cell clonality of 34 cases diagnosed with BL (n = 4), DLBCL (n = 16), HGBL DH (n = 8), and HGBL NOS (n = 6). Three distinct molecular subgroups were identified based on gene expression, primarily influenced by MYC expression/translocation and cell proliferation. In HGBL, compared to BL, there was an upregulation of PRKAR2B and TERT. HGBL DH exhibited elevated expression of GAMT and SMIM14, while HGBL NOS showed increased expression of MIR155HG and LZTS1. Our gene mutation analysis revealed MYC, ARID1A, BCL2, KMT2D, and PIM1 as the most affected genes in B-cell lymphoma, with BCL2 and CREBBP predominant in HGBL DH, and MYC and PIM1 in HGBL NOS. Clonality analysis of immunoglobulin heavy and light chain rearrangements did not show distinguishable V- or J-usage between the diagnostic subgroups. Full article

Primary endometrial serous carcinoma, known for its aggressive nature and poor prognosis, shares similarities with breast and gastric cancers in terms of potential HER2 overexpression as a therapeutic target. Assessing HER expression is complicated by tumor heterogeneity and discrepancies between primary and metastatic sites. In this study, we retrospectively analyzed HER amplification and expression in 16 pairs of primary endometrial serous carcinoma resections and corresponding metastases. HER2 status was determined using immunohistochemistry (IHC), with criteria based on the percentage and intensity of tumor cell staining. Confirmatory techniques, such as dual in situ hybridization (DISH) and fluorescence in situ hybridization (FISH), were also employed. This study reports on the concordance rates and the presence and pattern of HER2 heterogeneity. Our results showed an 87.5% concordance rate in HER2 amplification status between primary and metastatic sites, with 33% of cases scored as 2+ being amplified. Heterogeneity was observed in 100% of amplified cases and 95% of non-amplified cases on in situ testing, with variations in heterogeneity patterns between techniques. In conclusion, our findings emphasize the importance of testing both primary and metastatic sites or recurrences, with a concordance rate of 87.5%. In addition, a review of the literature and combining the results showed a concordance rate of up to 68%. The presence and pattern of heterogeneity, particularly in cases of mosaic or clustered heterogeneity in the primary tumor, may serve as reliable indicators of concordance, predicting a non-amplified HER2 status in corresponding metastases. Full article

Cardiovascular diseases (CVDs) significantly exacerbate the severity and mortality of COVID-19. We aimed to investigate whether GWAS-significant SNPs correlate with CVDs in severe COVID-19 patients. DNA samples from 199 patients with severe COVID-19 hospitalized in intensive care units were genotyped using probe-based PCR for 10 GWAS SNPs previously implicated in severe COVID-19 outcomes. SNPs rs17713054 SLC6A20-LZTFL1 (risk allele A, OR = 2.14, 95% CI 1.06–4.36, p = 0.03), rs12610495 DPP9 (risk allele G, OR = 1.69, 95% CI 1.02–2.81, p = 0.04), and rs7949972 ELF5 (risk allele T, OR = 2.57, 95% CI 1.43–4.61, p = 0.0009) were associated with increased risk of coronary artery disease (CAD). SNPs rs7949972 ELF5 (OR = 2.67, 95% CI 1.38–5.19, p = 0.003) and rs61882275 ELF5 (risk allele A, OR = 1.98, 95% CI 1.14–3.45, p = 0.01) were linked to a higher risk of cerebral stroke (CS). No associations were observed with AH. Bioinformatics analysis revealed the involvement of GWAS-significant loci in atherosclerosis, inflammation, oxidative stress, angiogenesis, and apoptosis, which provides evidence of their role in the molecular mechanisms of CVDs. This study provides novel insights into the associations between GWAS-identified SNPs and the risk of CAD and CS. Full article

Background: Alcohol-related brain degeneration (ARBD) is associated with cognitive–motor impairments that can progress to disability and dementia. White matter (WM) is prominently targeted in ARBD due to chronic neurotoxic and degenerative effects on oligodendrocytes and myelin. Early detection and monitoring of WM pathology in ARBD could lead to therapeutic interventions. Objective: This study examines the potential utility of a non-invasive strategy for detecting WM ARBD using exosomes isolated from serum. Comparative analyses were made with paired tissue (Tx) and membrane vesicles (MVs) from the temporal lobe (TL). Methods: Long Evans rats were fed for 8 weeks with isocaloric liquid diets containing 37% or 0% caloric ethanol (n = 8/group). TL-Tx, TL-MVs, and serum exosomes (S-EVs) were used to examine ethanol’s effects on oligodendrocyte glycoprotein, astrocyte, and oxidative stress markers. Results: Ethanol significantly decreased the TL-Tx expression of platelet-derived growth factor receptor alpha (PDGFRA), 2′,3′-cyclic nucleotide 3′ phosphodiesterase (CNPase), proteolipid protein (PLP), myelin oligodendrocyte glycoprotein (MOG), glial fibrillary acidic protein (GFAP), and 8-OHdG, whereas in the TL-MVs, ethanol increased CNPase, PDGFRA, and 8-OHdG, but decreased MOG and GFAP concordantly with TL-Tx. Ethanol modulated the S-EV expression by reducing PLP, nestin, GFAP, and 4-hydroxynonenal (HNE). Conclusion: Chronic ethanol exposures differentially alter the expression of oligodendrocyte/myelin, astrocyte, and oxidative stress markers in the brain, brain MVs, and S-EVs. However, directionally concordant effects across all three compartments were limited. Future studies should advance these efforts by characterizing the relationship between ABRD and molecular pathological changes in brain WM-specific exosomes in serum. Full article

Diabetic Nephropathy (DN) stands as a primary cause of end-stage renal disease and its etiology remains unclear. Thus, this study aims to construct a genetic panel with potential biomarkers linked to the inflammatory pathway of DN associated with the pathology’s susceptibility. Through a systematic review and meta-analysis, we selected observational studies in English, Portuguese, and Spanish, selected from the PubMed, SCOPUS, Virtual Health Library, Web of Science, and EMBASE databases. Additionally, a protein–protein interaction network was constructed to list hub genes, with differential expression analysis by microarray of kidneys with DN from the GSE30529 database to further refine results. Seventy-two articles were included, and 54 polymorphisms in 37 genes were associated with the inflammatory pathway of DN. Meta-analysis indicated a higher risk of complication associated with SNPs 59029 G/A, −511 C/T, VNTR 86 bp, −308 G/A, and −1031 T/C. Bioinformatics analyses identified differentially expressed hub genes, underscoring the scarcity of studies on CCL2 and VEGF-A genes in relation to DN. This study highlighted the intrinsic relationship between inflammatory activity in the etiology and progression of DN, enabling the effective application of precision medicine in diabetic patients for potential prognosis of the complications and contributing to cost reduction in the public health system. Full article

Cathelicidins (human LL-37 and rat CRAMP) are multifunctional peptides involved in various cardiovascular conditions. This review integrates the recent findings about the functional involvement of LL-37/CRAMP across atherosclerosis, acute coronary syndrome, myocardial infarction, heart failure, diabetic cardiomyopathy, and platelet aggregation/thrombosis. In atherosclerosis, LL-37 interacts with scavenger receptors to modulate lipid metabolism and binds with mitochondrial DNA and lipoproteins. In acute coronary syndrome, LL-37 influences T cell responses and mitigates calcification within atherosclerotic plaques. During myocardial infarction and ischaemia/reperfusion injury, LL-37/CRAMP exhibits dual roles: protecting against myocardial damage through the AKT and ERK1/2 signalling pathways, while exacerbating inflammation via TLR4 and NLRP3 inflammasome activation. In heart failure, LL-37/CRAMP attenuates hypertrophy and fibrosis via NF-κB inhibition and the activation of the IGFR1/PI3K/AKT and TLR9/AMPK pathways. Moreover, in diabetic cardiomyopathy, these peptides alleviate oxidative stress and fibrosis by inhibiting TGFβ/Smad and AMPK/mTOR signalling and provide anti-inflammatory effects by reducing NF-κB nuclear translocation and NLRP3 inflammasome formation. LL-37/CRAMP also modulates platelet aggregation and thrombosis through the FPR2 and GPVI receptors, impacting apoptosis, autophagy, and other critical cellular processes. This comprehensive overview underscores LL-37/CRAMP as a promising therapeutic target in cardiovascular diseases, necessitating further elucidation of its intricate signalling networks and biological effects for clinical translation. Full article

ALK is related to poor survival in neuroblastoma patients. We investigated the prognostic relevance of ALK mRNA expression and the relationship with ALK immunohistochemical expression, histological subtype and ALK aberrations. Whole transcriptome sequencing data were available from 54 patients. Overall survival (OS) and event-free survival (EFS) were estimated with Kaplan–Meier’s methodology. ALK protein expression was analyzed by immunohistochemistry. ALK aberrations were detected using whole exome sequencing, single nucleotide polymorphism array, next generation sequencing and/or fluorescence in situ hybridization. OS was 74.8% and EFS was 60%. ALK mRNA expression was not associated with OS (HR 1.127, 95% CI (0.812–1.854), p = 0.331) and adjusted EFS (HR 1.134, 95% CI (0.783–1.644), p = 0.505), but was associated with histological subtype (OR 1.914, 95% CI (1.083–3.382), p = 0.025) and ALK protein expression (negative versus weak: OR 2.829, 95% CI (1.290–6.204), p = 0.009) (negative versus moderate/strong: OR 2.934, 95% CI (0.889–9.679), p = 0.077). ALK mutated tumors had significantly higher ALK mRNA expression than non-mutated tumors (p < 0.001). MYCN-amplified neuroblastomas have higher MYCN mRNA expression (p ≤ 0.001), but not ALK mRNA expression (p = 0.553). ALK mRNA expression is higher in ALK mutated neuroblastomas and is associated with poorer differentiation degree and higher protein expression. ALK mRNA expression is not significantly associated with OS and EFS. Full article

Mucosa-associated lymphoid tissue (MALT) lymphomas are slow-growing B-cell lymphomas mainly diagnosed in the stomach and termed gastric MALT lymphoma (G-MALT). Despite histological evaluation, immunostaining, and additional B-cell clonality analysis by fragment analysis, a clear-cut diagnosis is not feasible in all cases, especially for clinical follow-up of patients after treatment. We examined clonally rearranged immunoglobulin heavy- and light-chain gene sequences of 36 genomic DNA samples from six different patients obtained at different time points over the course of several years using the Oncomine^TM B-cell receptor pan-clonality next-generation sequencing (NGS) assay. Each case consisted of samples diagnosed with G-MALT and samples without evidence of lymphoma, based on histological examinations. We show a robust correlation (100%) of the results between the applied NGS method and histology-diagnosed G-MALT-positive patients. We also detected malignant clonotypes in samples where histology assessment failed to provide clear evidence of G-MALT (15 out of 19 samples). Furthermore, this method revealed malignant clonotypes much earlier in the disease course, with NGS of the immunoglobulin light chain being crucial in complementing immunoglobulin heavy-chain analysis. Hence, the value of NGS in routine lymphoma diagnostics is greatly significant and can be explored in order to provide better diagnoses and proffer the early detection of lymphoma relapse. Full article

Characterizing changes in beta cell function during prolonged hyperinsulinemia and dietary stress is important to study to prevent diseases like metabolic dysfunction-associated steatotic liver disease and insulin resistance. This research investigates how a moderate sucrose (MS) diet affects insulin resistance and β-cell mass in two rat strains: LEW.1WR1 and Wistar Furth (WF). LEW.1WR1 rats seem to be sensitive to beta cell disruptions as weanlings. Twenty-one male LEW.1WR1 rats and sixteen male WF rats were studied over 18 weeks. The rats were divided into groups and given either the control or MS diet. Their body weight was monitored twice a week. Insulin tolerance tests (ITTs) and fasting blood glucose measurements were taken at intervals. Urine samples were analyzed to assess metabolic shifts, and pancreas tissue was examined to evaluate changes in β-cell mass. The LEW.1WR1 rats became overweight and showed higher insulin resistance than the WF rats. Both strains of rats on the MS diet displayed changes in urine metabolite profiles in terms of levels of lactic acid and alanine. This study highlights the impact or lack thereof of a moderate sucrose diet on body mass, insulin resistance, and β-cell mass, with notable effects observed specifically in LEW.1WR1 rats. These findings contribute to our understanding of how dietary sugar intake can affect metabolism when observed in models sensitive to metabolic defects. Full article

DICER1 syndrome, a rare autosomal dominant genetic disorder, stems from mutations in the DICER1 gene, disrupting RNA interference and leading to various tumors. These tumors, affecting organs like the lung, kidney, ovaries, and brain, pose diagnostic challenges due to diverse presentations. Understanding DICER1-associated tumors, including pleuropulmonary blastoma, ovarian Sertoli–Leydig cell tumors, and others, is vital for early detection and management. Surgical resection, chemotherapy, and targeted therapies are primary treatment modalities, with genetic counseling playing a crucial role. Multidisciplinary care is essential for optimal management, offering hope for improved outcomes in affected individuals. Full article

Iatrogenic amyloidosis results from medical therapeutic interventions, leading to the misfolding and aggregation of proteins into amyloid fibrils or to their direct deposition in different tissues. This review aims to provide a comprehensive overview of the iatrogenic amyloidosis pathology, underlying the possible molecular mechanisms, associated pathological manifestations, and clinical implications within modern medicine. By conducting a systematic analysis of the current literature, this paper highlights the diverse instances of iatrogenic amyloidosis triggered by medical procedures such as dialysis, organ and tissue transplantation, and therapeutic drugs. Exploring the intricate molecular pathways and contributing factors involved in protein misfolding and amyloidogenesis, and uncovering the pathological consequences observed in various tissues and organs, allows us to establish appropriate nomenclature and to gain a more profound understanding of the condition, working towards improved medical interventions and treatments. Full article

Over the past decade, molecular cytopathology has emerged as a relevant area of modern pathology. Notably, in patients with advanced-stage cancer, cytological samples could be the only material available for diagnosis and molecular biomarker testing to identify patients suitable for targeted therapies. As a result, the contemporary cytopathologist’s role extends beyond morphological assessments to include critical skills such as evaluating the adequacy of the cytological samples and managing these specimens for molecular testing. This case collection can be a valuable source of insight, especially for young pathologists, who should learn to combine the opportunities offered by molecular biology with the basis of morphological evaluation. Full article