Studies Of Human Tissue Research Articles

An analysis of RNA quality metrics in human brain tissue.

Human brain tissue studies have historically used a range of metrics to assess RNA quality. However, few large-scale cross-comparisons of pre-sequencing quality metrics with RNA-seq quality have been published. Here, we analyze how well metrics gathered before RNA sequencing (post-mortem interval (PMI) and RNA integrity number RIN) relate to analyses of RNA quality after sequencing (Percent of counts in Top Ten genes (PTT), 5' bias, and 3' bias) as well as with individual gene counts across the transcriptome. We conduct this analysis across four different human cortical brain tissue collections sequenced with varying library preparation protocols. PMI and RIN have a low inverse correlation, and both PMI and RIN show consistent and opposing correlations with PTT. Unlike PMI, RIN shows strong consistent correlations with measurements of 3' and 5' bias, and RIN also correlates with 3,933 genes across datasets, in comparison to 138 genes for PMI. Neuronal and immune response genes correlate positively and negatively with RIN respectively, suggesting that different gene sets have divergent relationships with RIN in brain tissue. In summary, these analyses suggest that conventional metrics of RNA quality have varying degrees of value, and that PMI has an overall minimal but reproducible effect on RNA quality.

An emerging multi-omic understanding of the genetics of opioid addiction.

Opioid misuse, addiction, and associated overdose deaths remain global public health crises. Despite the tremendous need for pharmacological treatments, current options are limited in number, use, and effectiveness. Fundamental leaps forward in our understanding of the biology driving opioid addiction are needed to guide development of more effective medication-assisted therapies. This Review focuses on the omics-identified biological features associated with opioid addiction. Recent GWAS have begun to identify robust genetic associations, including variants in OPRM1, FURIN, and the gene cluster SCAI/PPP6C/RABEPK. An increasing number of omics studies of postmortem human brain tissue examining biological features (e.g., histone modification and gene expression) across different brain regions have identified broad gene dysregulation associated with overdose death among opioid misusers. Drawn together by meta-analysis and multi-omic systems biology, and informed by model organism studies, key biological pathways enriched for opioid addiction-associated genes are emerging, which include specific receptors (e.g., GABAB receptors, GPCR, and Trk) linked to signaling pathways (e.g., Trk, ERK/MAPK, orexin) that are associated with synaptic plasticity and neuronal signaling. Studies leveraging the agnostic discovery power of omics and placing it within the context of functional neurobiology will propel us toward much-needed, field-changing breakthroughs, including identification of actionable targets for drug development to treat this devastating brain disease.

Alternative Splicing of the Last TKFC Intron Yields Transcripts Differentially Expressed in Human Tissues That Code In Vitro for a Protein Devoid of Triokinase and FMN Cyclase Activity.

The 18-exon human TKFC gene codes for dual-activity triokinase and FMN cyclase (TKFC) in an ORF, spanning from exon 2 to exon 18. In addition to TKFC-coding transcripts (classified as tkfc type by their intron-17 splice), databases contain evidence for alternative TKFC transcripts, but none of them has been expressed, studied, and reported in the literature. A novel full-ORF transcript was cloned from brain cDNA and sequenced (accession no. DQ344550). It results from an alternative 3' splice-site in intron 17. The cloned cDNA contains an ORF also spanning from exon 2 to exon 18 of the TKFC gene but with a 56-nt insertion between exons 17 and 18 (classified as tkfc_ins56 type). This insertion introduces an in-frame stop, and the resulting ORF codes for a shorter TKFC variant, which, after expression, is enzymatically inactive. TKFC intron-17 splicing was found to be differentially expressed in human tissues. In a multiple-tissue northern blot using oligonucleotide probes, the liver showed a strong expression of the tkfc-like splice of intron 17, and the heart preferentially expressed the tkfc_ins56-like splice. Through a comparison to global expression data from massive-expression studies of human tissues, it was inferred that the intestine preferentially expresses TKFC transcripts that contain neither of those splices. An analysis of transcript levels quantified by RNA-Seq in the GTEX database revealed an exception to this picture due to the occurrence of a non-coding short transcript with a tkfc-like splice. Altogether, the results support the occurrence of potentially relevant transcript variants of the TKFC gene, differentially expressed in human tissues. (This work is dedicated in memoriam to Professor Antonio Sillero, 1938-2024, for his lifelong mentoring and his pioneering work on triokinase).

Microglial process convergence onto injured axonal swellings, a human postmortem brain tissue study

Traumatic brain injury (TBI) affects millions globally, with a majority of TBI cases being classified as mild, in which diffuse pathologies prevail. Two of the pathological hallmarks of TBI are diffuse axonal injury (DAI) and microglial activation. While progress has been made investigating the breadth of TBI-induced axonal injury and microglial changes in rodents, the neuroinflammatory progression and interaction between microglia and injured axons in humans is less well understood. Our group previously investigated microglial process convergence (MPC), in which processes of non-phagocytic microglia directly contact injured proximal axonal swellings, in rats and micropigs acutely following TBI. These studies demonstrated that MPC occurred on injured axons in the micropig, but not in the rat, following diffuse TBI. While it has been shown that microglia co-exist and interact with injured axons in humans post-TBI, the occurrence of MPC has not been quantitatively measured in the human brain. Therefore, in the current study we sought to validate our pig findings in human postmortem tissue. We investigated MPC onto injured axonal swellings and intact myelinated fibers in cases from individuals with confirmed DAI and control human brain tissue using multiplex immunofluorescent histochemistry. We found an increase in MPC onto injured axonal swellings, consistent with our previous findings in micropigs, indicating that MPC is a clinically relevant phenomenon that warrants further investigation.

Pathophysiological insights into HFpEF from studies of human cardiac tissue.

Heart failure with preserved ejection fraction (HFpEF) is a major, worldwide health-care problem. Few therapies for HFpEF exist because the pathophysiology of this condition is poorly defined and, increasingly, postulated to be diverse. Although perturbations in other organs contribute to the clinical profile in HFpEF, altered cardiac structure, function or both are the primary causes of this heart failure syndrome. Therefore, studying myocardial tissue is fundamental to improve pathophysiological insights and therapeutic discovery in HFpEF. Most studies of myocardial changes in HFpEF have relied on cardiac tissue from animal models without (or with limited) confirmatory studies in human cardiac tissue. Animal models of HFpEF have evolved based on theoretical HFpEF aetiologies, but these models might not reflect the complex pathophysiology of human HFpEF. The focus of this Review is the pathophysiological insights gained from studies of human HFpEF myocardium. We outline the rationale for these studies, the challenges and opportunities in obtaining myocardial tissue from patients with HFpEF and relevant comparator groups, the analytical approaches, the pathophysiological insights gained to date and the remaining knowledge gaps. Our objective is to provide a roadmap for future studies of cardiac tissue from diverse cohorts of patients with HFpEF, coupling discovery biology with measures to account for pathophysiological diversity.

Convergent alterations in the tumor microenvironment of MYC-driven human and murine prostate cancer

How prostate cancer cells and their precursors mediate changes in the tumor microenvironment (TME) to drive prostate cancer progression is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we perform extensive single-cell RNA-sequencing (scRNA-seq) and molecular pathology of the comparative biology between human prostate cancer and key stages in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues reveal that cancer cell-intrinsic activation of MYC signaling is a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Cell communication network and pathway analyses in GEMMs show that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogram the TME during carcinogenesis, leading to a convergence of cell state alterations in neighboring epithelial, immune, and fibroblast cell types that parallel key findings in human prostate cancer.

The Human Pancreas in Type 1 Diabetes: Lessons Learned from the Network of Pancreatic Organ Donors with Diabetes.

The Network for Pancreatic Organ Donors with Diabetes (nPOD) has helped shape the contemporary understanding of type 1 diabetes (T1D) pathogenesis in humans through the procurement, distribution to scientists, and collaborative study of human pancreata and disease-related tissues from organ donors with T1D and islet autoantibody positivity. Since its inception in 2007, nPOD has collected tissues from 600 donors, and these resources have been distributed across 22 countries to more than 290 projects, resulting in nearly 350 publications. Research projects supported by nPOD span the breadth of diabetes research, including studies on T1D immunology and β-cell biology, and have uniquely unveiled abnormalities in other pancreatic cell types. In this article, we will detail the history and programmatic features of nPOD, as well as highlight key scientific findings from nPOD studies. We will present our view for the future of nPOD and discuss how the success of the program has established a precedent whereby knowledge gaps in biomedical research can be addressed through the study of human tissues.

Microglial process convergence onto injured axonal swellings, a human postmortem brain tissue study.

Traumatic brain injury (TBI) affects millions globally, with a majority of TBI cases being classified as mild, in which diffuse pathologies prevail. Two of the pathological hallmarks of TBI are diffuse axonal injury and microglial activation. While progress has been made investigating the breadth of TBI-induced axonal injury and microglial changes in rodents, the neuroinflammatory progression and interaction between microglia and injured axons following brain injury in humans is less well understood. Our group previously investigated microglial process convergence (MPC), in which processes of non-phagocytic microglia directly contact injured proximal axonal segments, in rats and micropigs acutely following TBI. These studies demonstrated that MPC occurred on injured axons in the micropig, but not in the rat, following diffuse TBI. While it has been shown that microglia co-exist and interact with injured axons in humans post-TBI, the occurrence of MPC has not been quantitatively measured in the human brain. Therefore, in the current study we sought to validate our pig findings in human postmortem tissue. We investigated MPC onto injured axonal swellings and intact myelinated fibers in cases from individuals that sustained a TBI and control human brain tissue using multiplex immunofluorescent histochemistry. We found an increase in MPC onto injured axonal swellings, consistent with our previous findings in micropigs, indicating that MPC is a clinically relevant phenomenon that warrants further investigation.

DNA methylation correlates of chronological age in diverse human tissue types

BackgroundWhile the association of chronological age with DNA methylation (DNAm) in whole blood has been extensively studied, the tissue-specificity of age-related DNAm changes remains an active area of research. Studies investigating the association of age with DNAm in tissues such as brain, skin, immune cells, fat, and liver have identified tissue-specific and non-specific effects, thus, motivating additional studies of diverse human tissue and cell types.ResultsHere, we performed an epigenome-wide association study, leveraging DNAm data (Illumina EPIC array) from 961 tissue samples representing 9 tissue types (breast, lung, colon, ovary, prostate, skeletal muscle, testis, whole blood, and kidney) from the Genotype-Tissue Expression (GTEx) project. We identified age-associated CpG sites (false discovery rate < 0.05) in 8 tissues (all except skeletal muscle, n = 47). This included 162,002 unique hypermethylated and 90,626 hypomethylated CpG sites across all tissue types, with 130,137 (80%) hypermethylated CpGs and 74,703 (82%) hypomethylated CpG sites observed in a single tissue type. While the majority of age-associated CpG sites appeared tissue-specific, the patterns of enrichment among genomic features, such as chromatin states and CpG islands, were similar across most tissues, suggesting common mechanisms underlying cellular aging. Consistent with previous findings, we observed that hypermethylated CpG sites are enriched in regions with repressed polycomb signatures and CpG islands, while hypomethylated CpG sites preferentially occurred in non-CpG islands and enhancers. To gain insights into the functional effects of age-related DNAm changes, we assessed the correlation between DNAm and local gene expression changes to identify age-related expression quantitative trait methylation (age-eQTMs). We identified several age-eQTMs present in multiple tissue-types, including in the CDKN2A, HENMT1, and VCWE regions.ConclusionOverall, our findings will aid future efforts to develop biomarkers of aging and understand mechanisms of aging in diverse human tissue types.

Multi-Omics Analysis of Primary Prostate Cancer Datasets Reveals Novel Biomarkers.

Prostate cancer (PCa) ranks second in cancer-related deaths in men. Current screenings used in the diagnosis are not sufficient enough in the early stages therefore, more diagnostic biomarker studies are needed. We performed a meta-analysis on the biomarker potential of miRNAs, mRNAs, and methylation for the early stages of PCa by searching available microarrays from the GEO dataset for PCa tissue and benign prostatic hyperplasia (BPH) or normal adjacent to PCa. Target genes of miRNAs were determined using the miRWalk and miRDB datasets. The results were visualized using network analysis. qPCR quantification of potential miRNA and genes was performed in human prostate epithelial cell line (RWPE-1) and human prostate carcinoma epithelial cell line (22RV1). Our meta-analysis of potential biomarkers for the diagnosis of PCa identified several candidates. It was shown that miR-7-5p is overexpressed. CAMKK2, TMEM97 expression were upregulated and CLIP1 expression was downregulated and these genes were shown to be targets of miR-7-5p. CAMKK2, TMEM97, and CLIP1 genes were found to be hypermethylated. Although the changes in the expression levels of miR-7-5p and CAMKK2, TMEM97, and CLIP1 in the two cell lines used in our study were not consistent with the significant expression differences observed in the meta-analysis, our meta-analysis results would be promising in human prostate tissue or different human tumor cell line studies. This highlights the importance of our meta-analysis results in prostate cancer biomarker research, given the difficulty of experimental validation of our large-scale data meta-analysis results using a specific cell line.

What Makes It Tick: Exploring the Mechanisms of Post-treatment Lyme Disease Syndrome.

Post-treatment Lyme disease syndrome (PTLDS), which may also be referred to incorrectly as "chronic Lyme disease," is defined by the Infectious Diseases Society of America (IDSA) as the presence of fatigue, pain, and/or cognitive complaints with the functional impact that persists for more than six months after completing treatment for Lyme disease (LD). These symptoms occur in 10%-20% of patients previously diagnosed with LD caused by the bacteria Borrelia burgdorferi and appropriately treated with a course of antibiotics. The symptoms of PTLDS can be easily overlooked or misdiagnosed as a psychiatric manifestation in geographic locations that rarely see LD. In contrast, geographic locations with a higher prevalence of LD may be more aware of PTLDS symptoms and have higher clinical suspicion leading to this diagnosis. The pathophysiology behind the persistent symptoms some people experience from a primary infection is still largely unknown. Some mechanisms that have been proposed include permanent tissue damage and inflammation, immune system dysfunction, autoimmune response, co-infection, and even persistent infection refractory to treatment. We propose that ongoing PTLDS symptoms seem to be related to an autoimmune response to the tissue damage and inflammation caused by the viable or nonviable spirochete pathogen. At this point, PTLDS is diagnosed clinically as no quantifiable methods are available from laboratory or tissue diagnostics as of 2024. Similar pathophysiological features of PTLDS are seen in diseases such as COVID-19 or chronic fatigue syndrome (CFS). More effective diagnostic approaches might include further studies looking at a possible connection in the genomes of individuals developing PTLDS, quantifiable biomarkers, common inflammatory markers/pathways, and careful histopathological studies of human tissues.

Distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas

BackgroundExpression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed description of the distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas. MethodsWe collected healthy samples from cadavers (n = 4) and visceral surgery (n = 4) to investigate the respective expression profiles using immunohistochemical tracing with knockout-validated antibodies. ResultsTRPC3- and TRPC6-proteins were detected in different pancreatic structures including acinar cells, as well as epithelial ductal cells from intercalate, intralobular, and interlobular ducts. Respective connective tissue layers appeared unstained. Endocrine islets of Langerhans were clearly and homogenously immunolabeled by the anti-TRPC3 and anti-TRPC6 antibodies. Insular α, β, γ, and δ cells were conclusively stained, although no secure differentiation of cell types was performed. ConclusionsDue to aforementioned antibody specificity verification, protein expression in the immunolabeled localizations can be accepted. Our study in human tissue supports previous investigations especially with respect to acinar and insular α and β cells, while other localizations are here reported for the first time to express TRPC3 and TRPC6, ultimately warranting further research.

Pathogenic PHIP Variants are Variably Associated With CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) represent the most common cause of chronic kidney disease in children. Although only 20% of cases can be genetically explained, the majority remain without an identified underlying etiology. The neurodevelopmental disorder Chung-Jansen syndrome (CHUJANS) is caused by haploinsufficiency of Pleckstrin homology domain-interacting protein (PHIP) and was previously associated with genital malformations. Anecdotal coincidence of CHUJANS and CAKUT prompted us to investigate whether urorenal malformations are part of the phenotypic spectrum of CHUJANS. Analysis of existing CHUJANS and CAKUT cohorts, consulting matchmaking platforms, and systematic literature review to look for additional patients with both CHUJANS and CAKUT. Prenatal expression studies in murine and human renal tissues to investigate the role for PHIP in kidney development. We identified 4 novel and 8 published cases, indicating variable expressivity with a urorenogenital trait frequency of 5% to 35%. The prenatal expression studies supported a role for PHIP in normal kidney and urinary tract development. Pathogenic PHIP gene variants should be considered as causative in patients with syndromal CAKUT. Conversely, patients with CHUJANS should be clinically evaluated for urorenogenital manifestations. Because neurodevelopmental disorders are often associated with kidney phenotypes, an interdisciplinary re-evaluation offers promise in identifying incompletely penetrant kidney associations and uncovering novel molecular mechanisms of disturbed nephrogenesis.

In Situ Loading and Time-Resolved Synchrotron-Based Phase Contrast Tomography for the Mechanical Investigation of Connective Knee Tissues: A Proof-of-Concept Study.

Articular cartilage and meniscus transfer and distribute mechanical loads in the knee joint. Degeneration of these connective tissues occurs during the progression of knee osteoarthritis, which affects their composition, microstructure, and mechanical properties. A deeper understanding of disease progression can be obtained by studying them simultaneously. Time-resolved synchrotron-based X-ray phase-contrast tomography (SR-PhC-µCT) allows to capture the tissue dynamics. This proof-of-concept study presents a rheometer setup for simultaneous in situ unconfined compression and SR-PhC-µCT of connective knee tissues. The microstructural response of bovine cartilage (n = 16) and meniscus (n = 4) samples under axial continuously increased strain, or two steps of 15% strain (stress-relaxation) is studied. The chondrocyte distribution in cartilage and the collagen fiber orientation in the meniscus are assessed. Variations in chondrocyte density reveal an increase in the top 40% of the sample during loading, compared to the lower half. Meniscus collagen fibers reorient perpendicular to the loading direction during compression and partially redisperse during relaxation. Radiation damage, image repeatability, and image quality assessments show little to no effects on the results. In conclusion, this approach is highly promising for future studies of human knee tissues to understand their microstructure, mechanical response, and progression in degenerative diseases.

Abstract 1532: Improved reproducibility in multiplex immunofluorescence analysis of the tumor microenvironment using a novel quenching solution

Abstract Formalin-fixed, paraffin-embedded (FFPE) tissues are commonly used in histopathology because the fixed tissues are stable and easy to store. In the context of immunofluorescence detection, however, endogenous autofluorescence of FFPE tissues can significantly reduce or mask immunofluorescent signals. The autofluorescence of FFPE tissues is caused by a variety of factors, including the presence of endogenous fluorophores, tissue fixation, and processing. While there are several methods that can be used to quench autofluorescence in FFPE tissues, chemical quenchers, which absorb or scatter light, are most frequently used for multiplex IF. Examples of chemical quenchers commonly used in manual multiplex staining include Sudan Black B and TrueBlack; however, these are not chemically compatible for use on automated platforms such as the Leica Biosystems BOND RX. Due to the need for increased throughput and decreased hands-on time, automation has risen in popularity versus manual staining, leading to a need for a versatile quenching solution compatible with automation. Here we demonstrate that NovaPlex Quenching Solution (NPQS), a novel proprietary quenching agent, reduces the background caused by autofluorescence and enhances the signal of the Cell IDx UltraPlex multiplex immunofluorescent (mxIF) assay across tissue types. Qualitative studies showed a decrease in autofluorescent signal in FFPE mouse spleen stained with antibodies against B220/Foxp3/CD3e, suggesting the utility of NPQS in mouse models of cancer and immunity. Similarly, nonspecific background was decreased across FFPE human tissue types, including lung adenocarcinoma stained for CD8/Foxp3/CD3e/CD4 and tonsil stained for CD8/Foxp3/PD-1/CD4. Further statistical studies in FFPE human tonsil tissue stained with CD8/Foxp3/PD-1/CD4 showed there was no significant decrease in dye intensity across all four markers and channels, resulting in a significant increase in signal-to-noise ratio for both CD8 at 490nm and PD-1 at 650nm (p&amp;lt;0.05). These experiments using Cell IDx/LBS UltraPlex mxIF technology demonstrate an effective method to improve the signal-to-noise ratios of fluorophores without reducing signal intensity from any of the target proteins in these parallel multiplex immunofluorescent assays. Citation Format: Matt Levin, Jack Heath, April Schrank-Hacker, Shelby Dunn, Minh-Chau Vu, Imane Hamza, David Schwartz. Improved reproducibility in multiplex immunofluorescence analysis of the tumor microenvironment using a novel quenching solution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1532.

Abstract IA013: Unique metabolic changes in Lynch syndrome-associated endometrial cancer

Abstract Lynch syndrome-associated endometrial cancers (ECs) are defined by germline mutations in DNA mismatch repair genes, including MSH2, MSH6, PMS2, and MLH1. Lynch syndrome (LS) tumors have received increased attention in the therapeutic context as these tumors are microsatellite instable and often reflect increased immune cell infiltration and enhanced response to immunotherapy. However, relatively little attention has been paid to pathogenesis of LS ECs. Women with LS represent an at-risk population who could benefit from cancer interception strategies due to a 60% cumulative lifetime risk of developing EC. We developed a mouse model of MSH2 loss targeted to the uterus to evaluate EC pathogenesis, with the goal of elucidating mechanisms that alter disease penetrance for women with hereditary risk for EC development. Our Progesterone Receptor-Cre Msh2f lox/flox mice (abbreviated Msh2KO) develop ECs that closely mimic human EC. Whole transcriptome profiling of Msh2KO EC and Msh2KO normal endometrium compared to wild-type endometrium identified “Mitochondrial dysfunction” as a significantly altered pathway in Msh2 deficiency, prompting our in-depth evaluation of mitochondrial alterations in Msh2KO mice, MSH2-deficient cell lines, and LS-associated EC patient specimens. We will discuss the impact of MSH2 deficiency across multiple measures of mitochondrial content, integrity, function, and metabolomic analyses in ECs using preclinical models and human tissue studies. Overall, our studies reveal that MSH2-deficient EC is characterized by mitochondrial DNA damage, mitochondrial content reduction, and decreased mitochondrial function. In addition, decreased mitochondrial respiration for energy production facilitates metabolic reprogramming toward glycolysis. We are conducting further studies to define mechanisms underlying mitochondrial defects due to MSH2 loss and opportunities for intervention. Mitochondrial and metabolic aberrations could serve as novel biomarkers for EC development and targets for cancer prevention in women with LS. Citation Format: Melinda S. Yates. Unique metabolic changes in Lynch syndrome-associated endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr IA013.

Web-based multi-omics integration using the Analyst software suite.

The growing number of multi-omics studies demands clear conceptual workflows coupled with easy-to-use software tools to facilitate data analysis and interpretation. This protocol covers three key components involved in multi-omics analysis, including single-omics data analysis, knowledge-driven integration using biological networks and data-driven integration through joint dimensionality reduction. Using the dataset from a recent multi-omics study of human pancreatic islet tissue and plasma samples, the first section introduces how to perform transcriptomics/proteomics data analysis using ExpressAnalyst and lipidomics data analysis using MetaboAnalyst. On the basis of significant features detected in these workflows, the second section demonstrates how to perform knowledge-driven integration using OmicsNet. The last section illustrates how to perform data-driven integration from the normalized omics data and metadata using OmicsAnalyst. The complete protocol can be executed in ~2 h. Compared with other available options for multi-omics integration, the Analyst software suite described in this protocol enables researchers to perform a wide range of omics data analysis tasks via a user-friendly web interface.

(069) Markers of Neovascularization and Neurogenesis May Change After Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction

Abstract Introduction Low-intensity extracorporeal shockwave therapy (LiESWT) is thought to treat erectile dysfunction (ED) but the mechanism remains elusive. It is believed that LiESWT may work by stimulating neovascularization and nerve regeneration as demonstrated in animal models by histologically increased angiogenesis-related growth factors and neuronal factors including vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), neuronal NOS (nNOS) and brain derived-neurotropic factor (BDNF). Given its prolific use, a thorough understanding of the mechanism of action of this therapy at a cellular level is critical prior to recommendation of this therapy on a larger scale. Objective Objective data post LiESWT is sparse. In this study, we aimed to determine whether markers for neovascularization and nerve regeneration can be detected in the serum of penile tissue in men following LiESWT treatment. We hypothesized that LiESWT results in appreciable increases in vascular and neuronal factors post therapy. Methods Patients were prospectively enrolled in a clinical trial of LiESWT for ED. Patients received 12 bi-weekly LiESWT treatments of 0.2mJ/mm2 at 5Hz, 1500 shocks delivered per treatment, with follow up at 1-2 weeks, 4-6 weeks, 3 months and 6 months post-treatment. Cavernosal penile blood samples were obtained prior to treatment and at each visit post-treatment. The concentrations of eNOS, nNOS, VEGF, and BDNF in penile plasma samples were measured using Enzyme-Linked Immunosorbent Assay (ELISA) with specific commercial kits, following the protocols provided by the manufacturer. Results Twenty-five patients completed all five study visits. Mean patient age was 63. Mean baseline IIEF-EF score prior to treatment was 14.24 (±1.21). At the time of data analysis, plasma samples from 9 men were analyzed for BDNF, eNOS, and nNOS levels using the ELISA assay, and samples from all 25 men were analyzed for VEGF. BDNF levels demonstrated a sustained decrease after the first treatment (P = 0.0001, Figure 1A). Levels of eNOS were noted to trend upward, but no significant changes in eNOS, nNOS or VEGF levels were noted. Conclusions To our knowledge, this is the first study in human tissues to attempt to quantify objective measures of neurogenesis and neovascularization in penile tissue following LiESWT for ED. Though our N is small, our results suggest that LiESWT may decrease BDNF levels after initial LiESWT treatment while VEGF, eNOS and nNOS levels remain unchanged. The clinical significance of these findings is currently unknown, as our findings are not consistent with histological studies in animals which demonstrate upregulation of these markers in penile tissues. However, we believe this represents a promising first step in attempting to understand the effect of LiESWT at a tissue level in men undergoing LiESWT. Disclosure No.

Development of a cost-effective compact diode-laser-based photoacoustic sensing instrument for breast tissue diagnosis.

The photoacoustic (PA) technique, a noninvasive pump-probe technique, has found interesting applications in biomedical tissue diagnosis over the last decade. To take it a step further to clinical applications, the PA technique needs to be designed as an instrument focusing on a compact design, reducing the cost, and quickly providing a quantitative diagnosis. This work presents a design and characterization of a cost-effective, compact PA sensing instrument for biomedical tissue diagnosis. A compact laser diode case design is developed to house several laser diodes for PA excitation, and a pulsed current supply unit is also developed in-house to power the laser diodes to generate a 25ns current pulse at a frequency of 20kHz. After PA experimental data acquisition, the signal's frequency spectra were calculated to characterize the tissue quantitatively and correlated with their mechanobiological properties. The corresponding dominant frequency peak in the PA spectral response (PASR) study was low in the fibrofatty normal breast tissue , compared to the dominant frequency peak of in the fibrocystic disease tissue, which had increased glandular and stromal elements, thereby increased tissue density. The histopathological findings correlated with the PASR results, and the fibrocystic breast disease tissue exhibited a higher dominant frequency peak and energy compared to the normal breast tissue. We experimented with an in vitro PASR study of fibrocystic human breast tissues and successfully differentiated different tissue types using quantitative spectral parameters peak frequency, mean frequency, and spectral energy. This gives the potential to take this technique further for cost-effective and quick clinical applications.

The CALIPR framework for highly accelerated myelin water imaging with improved precision and sensitivity.

Quantitative magnetic resonance imaging (MRI) techniques are powerful tools for the study of human tissue, but, in practice, their utility has been limited by lengthy acquisition times. Here, we introduce the Constrained, Adaptive, Low-dimensional, Intrinsically Precise Reconstruction (CALIPR) framework in the context of myelin water imaging (MWI); a quantitative MRI technique generally regarded as the most rigorous approach for noninvasive, in vivo measurement of myelin content. The CALIPR framework exploits data redundancy to recover high-quality images from a small fraction of an imaging dataset, which allowed MWI to be acquired with a previously unattainable sequence (fully sampled acquisition 2 hours:57 min:20 s) in 7 min:26 s (4.2% of the dataset, acceleration factor 23.9). CALIPR quantitative metrics had excellent precision (myelin water fraction mean coefficient of variation 3.2% for the brain and 3.0% for the spinal cord) and markedly increased sensitivity to demyelinating disease pathology compared to a current, widely used technique. The CALIPR framework facilitates drastically improved MWI and could be similarly transformative for other quantitative MRI applications.