scholarly journals Intravital microscopy imaging of kidney injury and regeneration

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yue Liu ◽  
Zongjin Li
Keyword(s):  
Cell Fate ◽  
Intravital Microscopy ◽  
Single Cells ◽  
Elevated Serum ◽  
Kidney Injury ◽  
Lineage Tracing ◽  
Tissue Slices ◽  
Microscopy Imaging ◽  
Two Photon Microscopy ◽  
Nitrogen Levels

AbstractAcute kidney injury (AKI) is a common clinical symptom, which is mainly manifested by elevated serum creatinine and blood urea nitrogen levels. When AKI is not repaired in time, the patient is prone to develop chronic kidney disease (CKD). The kidney is composed of more than 30 different cells, and its structure is complex. It is extremely challenging to understand the lineage relationships and cell fate of these cells in the process of kidney injury and regeneration. Since the 20th century, lineage tracing technology has provided an important mean for studying organ development, tissue damage repair, and the differentiation and fate of single cells. However, traditional lineage tracing methods rely on sacrificing animals to make tissue slices and then take snapshots with conventional imaging tools to obtain interesting information. This method cannot achieve dynamic and continuous monitoring of cell actions on living animals. As a kind of intravital microscopy (IVM), two-photon microscopy (TPM) has successfully solved the above problems. Because TPM has the ability to penetrate deep tissues and can achieve imaging at the single cell level, lineage tracing technology with TPM is gradually becoming popular. In this review, we provided the key technical elements of lineage tracing, and how to use intravital imaging technology to visualize and quantify the fate of renal cells.

scholarly journals In vivo two-photon microscopy reveals the contribution of Sox9+ cell to kidney regeneration in a mouse model with extracellular vesicle treatment

2020 ◽  
Vol 295 (34) ◽  
pp. 12203-12213 ◽  
Author(s):  
Kaiyue Zhang ◽  
Shang Chen ◽  
Huimin Sun ◽  
Lina Wang ◽  
Huifang Li ◽  
...  
Keyword(s):  
Mouse Model ◽  
Kidney Injury ◽  
Extracellular Vesicle ◽  
Lineage Tracing ◽  
Abdominal Imaging ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Activation Mechanisms ◽  
Renal Regeneration

Mesenchymal stem cell (MSC)–derived extracellular vesicles (EVs) have been shown to stimulate regeneration in the treatment of kidney injury. Renal regeneration is also thought to be stimulated by the activation of Sox9+ cells. However, whether and how the activation mechanisms underlying EV treatment and Sox9+ cell–dependent regeneration intersect is unclear. We reasoned that a high-resolution imaging platform in living animals could help to untangle this system. To test this idea, we first applied EVs derived from human placenta–derived MSCs (hP-MSCs) to a Sox9-CreERT2; R26mTmG transgenic mouse model of acute kidney injury (AKI). Then, we developed an abdominal imaging window in the mouse and tracked the Sox9+ cells in the inducible Sox9-Cre transgenic mice via in vivo lineage tracing with two-photon intravital microscopy. Our results demonstrated that EVs can travel to the injured kidneys post intravenous injection as visualized by Gaussia luciferase imaging and markedly increase the activation of Sox9+ cells. Moreover, the two-photon living imaging of lineage-labeled Sox9+ cells showed that the EVs promoted the expansion of Sox9+ cells in kidneys post AKI. Histological staining results confirmed that the descendants of Sox9+ cells contributed to nephric tubule regeneration which significantly ameliorated the renal function after AKI. In summary, intravital lineage tracing with two-photon microscopy through an embedded abdominal imaging window provides a practical strategy to investigate the beneficial functions and to clarify the mechanisms of regenerative therapies in AKI.

Use of Flexible Materials with a Novel Pressure Driven Equibiaxial Cell Stretching Device for Mechanical Stimulation of Single Mammalian Cells

2003 ◽  
Vol 773 ◽  
Author(s):  
James D. Kubicek ◽  
Stephanie Brelsford ◽  
Philip R. LeDuc
Keyword(s):  
Cell Fate ◽  
Mechanical Stimulation ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Single Cells ◽  
Complex Nature ◽  
Cellular Behavior ◽  
Cell Stretching ◽  
Stimulation Of ◽  
Pressure Driven

AbstractMechanical stimulation of single cells has been shown to affect cellular behavior from the molecular scale to ultimate cell fate including apoptosis and proliferation. In this, the ability to control the spatiotemporal application of force on cells through their extracellular matrix connections is critical to understand the cellular response of mechanotransduction. Here, we develop and utilize a novel pressure-driven equibiaxial cell stretching device (PECS) combined with an elastomeric material to control specifically the mechanical stimulation on single cells. Cells were cultured on silicone membranes coated with molecular matrices and then a uniform pressure was introduced to the opposite surface of the membrane to stretch single cells equibiaxially. This allowed us to apply mechanical deformation to investigate the complex nature of cell shape and structure. These results will enhance our knowledge of cellular and molecular function as well as provide insights into fields including biomechanics, tissue engineering, and drug discovery.

scholarly journals Taking a Step Back: Insights into the Mechanisms Regulating Gut Epithelial Dedifferentiation

2021 ◽  
Vol 22 (13) ◽  
pp. 7043
Author(s):  
Shaida Ouladan ◽  
Alex Gregorieff
Keyword(s):  
Cell Fate ◽  
Hormonal Regulation ◽  
Transcriptional Profiling ◽  
Cell Types ◽  
Lineage Tracing ◽  
Intestinal Stem Cells ◽  
Physical Damage ◽  
Epithelial Regeneration ◽  
Gut Epithelium ◽  
Stem Cell Populations

Despite the environmental constraints imposed upon the intestinal epithelium, this tissue must perform essential functions such as nutrient absorption and hormonal regulation, while also acting as a critical barrier to the outside world. These functions depend on a variety of specialized cell types that are constantly renewed by a rapidly proliferating population of intestinal stem cells (ISCs) residing at the base of the crypts of Lieberkühn. The niche components and signals regulating crypt morphogenesis and maintenance of homeostatic ISCs have been intensely studied over the last decades. Increasingly, however, researchers are turning their attention to unraveling the mechanisms driving gut epithelial regeneration due to physical damage or infection. It is now well established that injury to the gut barrier triggers major cell fate changes, demonstrating the highly plastic nature of the gut epithelium. In particular, lineage tracing and transcriptional profiling experiments have uncovered several injury-induced stem-cell populations and molecular markers of the regenerative state. Despite the progress achieved in recent years, several questions remain unresolved, particularly regarding the mechanisms driving dedifferentiation of the gut epithelium. In this review, we summarize the latest studies, primarily from murine models, that define the regenerative processes governing the gut epithelium and discuss areas that will require more in-depth investigation.

scholarly journals Coronary blood vessels from distinct origins converge to equivalent states during mouse and human development

2021 ◽  
Author(s):  
Ragini S Phansalkar ◽  
Josephine Krieger ◽  
Mingming Zhao ◽  
Sai Saroja Kolluru ◽  
Robert C Jones ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Cell Fate ◽  
Adult Mouse ◽  
Coronary Vessels ◽  
Lineage Tracing ◽  
Specific Gene ◽  
Cell Type ◽  
Functional Differences ◽  
Coronary Blood Vessels ◽  
Two Populations

Most cell fate trajectories during development follow a diverging, tree-like branching pattern, but the opposite can occur when distinct progenitors contribute to the same cell type. During this convergent differentiation, it is unknown if cells "remember" their origins transcriptionally or whether this influences cell behavior. Most coronary blood vessels of the heart develop from two different progenitor sources-the endocardium (Endo) and sinus venosus (SV)-but whether transcriptional or functional differences related to origin are retained is unknown. We addressed this by combining lineage tracing with single-cell RNA sequencing (scRNAseq) in embryonic and adult mouse hearts. Shortly after coronary development begins, capillary ECs transcriptionally segregated into two states that retained progenitor-specific gene expression. Later in development, when the coronary vasculature is well-established but still remodeling, capillary ECs again segregated into two populations, but transcriptional differences were related to tissue localization rather than lineage. Specifically, ECs in the heart septum expressed genes indicative of increased local hypoxia and decreased blood flow. Adult capillary ECs were more homogeneous and lacked indications of either lineage or location. In agreement, SV- and Endo-derived ECs in adult hearts displayed similar responses to injury. Finally, scRNAseq of developing human coronary vessels indicated that the human heart followed similar principles. Thus, over the course of development, transcriptional heterogeneity in coronary ECs is first influenced by lineage, then by location, until heterogeneity disappears in the homeostatic adult heart. These results highlight the plasticity of ECs during development, and the validity of the mouse as a model for human coronary development.

scholarly journals Quinine-Induced Thrombotic Microangiopathy (Q-TMA): Frequency, Presenting Features, Outcomes

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1381-1381 ◽  
Author(s):  
Evaren E Page ◽  
Sara K. Vesely ◽  
James N. George
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Conflicts Of Interest ◽  
Elevated Serum ◽  
Kidney Injury ◽  
Long Term Outcome ◽  
Presenting Symptoms ◽  
Immune Mediated ◽  
Organ Systems ◽  
History Of

Abstract Q-TMA is an acute, severe, immune-mediated, drug-induced disorder. Q-TMA is suspected when symptoms suddenly begin within hours following quinine (Q) exposure. Diagnosis of Q-TMA is established by the history of recurrent acute symptoms following recurrent Q exposures and/or by documentation of Q-dependent antibodies reactive with platelets and/or neutrophils. The Oklahoma TTP-HUS Registry enrolls all patients for whom plasma exchange (PEX) is requested for suspected TTP or HUS. Since 1995, when routine measurement of ADAMTS13 activity began, the Registry has diagnosed 78 patients with acquired TTP (ADAMTS13 <10%). During this time we have also diagnosed 17 patients with Q-TMA; 2 additional patients were diagnosed before 1995. Seventeen of these 19 patients were tested for Q-dependent antibodies; all were positive. Nine patients had a history of recurrent acute symptoms with recurrent Q exposure, including the 2 patients not tested for Q-dependent antibodies. Q exposure was a pill in 18 patients, tonic water in one. Remarkably, 18 patients were women; all 19 patients were white. Common presenting symptoms were fever, chills, nausea and vomiting. No patients had focal neurologic abnormalities. All patients had microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and acute kidney injury. Eight patients had elevated serum alanine aminotransferase (231-1345 U/L). Three patients had neutropenia (absolute neutrophil counts, 184-486). Two patients had coagulation abnormalities suggesting disseminated coagulation (DIC). One patient died from complications of the central venous catheter insertion, performed for PEX and dialysis; all other patients recovered normal platelet counts. Three of the 18 surviving patients had end-stage renal disease (2 had kidney transplants). The median estimated glomerular filtration rate (GFR) for the other 15 patients, at 2.7-19.2 years (median, 10.2) after recovery, was 36 ml/min (range, 19-98). Only two patients had normal GFR (≥90 ml/min). Eleven patients had chronic kidney disease, defined by GFR <60 ml/min. Seven of 18 patients have died 4.1-12.7 years (median, 7.8) following recovery at ages 59-87 years. Conclusion. Quinine can cause severe immune-mediated toxicities involving multiple organ systems (Am J Hematol 2016; 91: 461). Q-TMA is an acute disorder causing severe kidney injury and, in some patients, also liver toxicity, neutropenia, and/or DIC. Q-TMA is not rare. During 20 years, we enrolled 17 Q-TMA patients compared to 78 patients with acquired TTP. Chronic kidney disease is a common long-term outcome. Explicit questions are required to discover the association of systemic symptoms with quinine ingestion. Table Table. Disclosures No relevant conflicts of interest to declare.

scholarly journals Generative modeling of single-cell population time series for inferring cell differentiation landscapes

2020 ◽  
Author(s):  
Grace H.T. Yeo ◽  
Sachit D. Saksena ◽  
David K. Gifford
Keyword(s):  
Gene Expression ◽  
Time Series ◽  
Cell Differentiation ◽  
Single Cell ◽  
Cell Fate ◽  
Lineage Tracing ◽  
Model Framework ◽  
Modeling Framework ◽  
Generative Modeling ◽  
Model Complex

SummaryExisting computational methods that use single-cell RNA-sequencing for cell fate prediction either summarize observations of cell states and their couplings without modeling the underlying differentiation process, or are limited in their capacity to model complex differentiation landscapes. Thus, contemporary methods cannot predict how cells evolve stochastically and in physical time from an arbitrary starting expression state, nor can they model the cell fate consequences of gene expression perturbations. We introduce PRESCIENT (Potential eneRgy undErlying Single Cell gradIENTs), a generative modeling framework that learns an underlying differentiation landscape from single-cell time-series gene expression data. Our generative model framework provides insight into the process of differentiation and can simulate differentiation trajectories for arbitrary gene expression progenitor states. We validate our method on a recently published experimental lineage tracing dataset that provides observed trajectories. We show that this model is able to predict the fate biases of progenitor cells in neutrophil/macrophage lineages when accounting for cell proliferation, improving upon the best-performing existing method. We also show how a model can predict trajectories for cells not found in the model’s training set, including cells in which genes or sets of genes have been perturbed. PRESCIENT is able to accommodate complex perturbations of multiple genes, at different time points and from different starting cell populations. PRESCIENT models are able to recover the expected effects of known modulators of cell fate in hematopoiesis and pancreatic β cell differentiation.

scholarly journals Leveraging high-powered RNA-Seq datasets to improve inference of regulatory activity in single-cell RNA-Seq data

2019 ◽  
Author(s):  
Ning Wang ◽  
Andrew E. Teschendorff
Keyword(s):  
Transcription Factors ◽  
Single Cell ◽  
Cell Fate ◽  
Regulatory Networks ◽  
Large Scale ◽  
Single Cells ◽  
Differential Expression Analysis ◽  
Dropout Rate ◽  
Rna Seq ◽  
Regulatory Activity

AbstractInferring the activity of transcription factors in single cells is a key task to improve our understanding of development and complex genetic diseases. This task is, however, challenging due to the relatively large dropout rate and noisy nature of single-cell RNA-Seq data. Here we present a novel statistical inference framework called SCIRA (Single Cell Inference of Regulatory Activity), which leverages the power of large-scale bulk RNA-Seq datasets to infer high-quality tissue-specific regulatory networks, from which regulatory activity estimates in single cells can be subsequently obtained. We show that SCIRA can correctly infer regulatory activity of transcription factors affected by high technical dropouts. In particular, SCIRA can improve sensitivity by as much as 70% compared to differential expression analysis and current state-of-the-art methods. Importantly, SCIRA can reveal novel regulators of cell-fate in tissue-development, even for cell-types that only make up 5% of the tissue, and can identify key novel tumor suppressor genes in cancer at single cell resolution. In summary, SCIRA will be an invaluable tool for single-cell studies aiming to accurately map activity patterns of key transcription factors during development, and how these are altered in disease.

scholarly journals Attenuation of Circulating Trimethylamine N-Oxide Prevents the Progression of Cardiac and Renal Dysfunction in a Rat Model of Chronic Cardiorenal Syndrome

2021 ◽  
Vol 12 ◽  
Author(s):  
Deling Zou ◽  
Yanyu Li ◽  
Guangping Sun
Keyword(s):  
Gene Expression ◽  
Renal Dysfunction ◽  
Treatment Options ◽  
Elevated Serum ◽  
Kidney Injury ◽  
Cardiorenal Syndrome ◽  
Current Treatment ◽  
Sprague Dawley ◽  
Kidney Injury Molecule 1 ◽  
And Control

Chronic heart failure (HF) frequently causes progressive decline in kidney function, known as cardiorenal syndrome-2 (CRS2). Current treatment options for CRS2 remain unacceptably limited. Trimethylamine-N-oxide (TMAO), a metabolite of gut microbiota, has recently been implicated in the pathogenesis of both HF and chronic kidney disease. Here we examined whether circulating TMAO is elevated in CRS2 and if so, whether attenuation of circulating TMAO would ameliorate the progression of CRS2. Sprague-Dawley rats underwent surgery for myocardial infarction (MI) or sham (week 0) followed by subtotal (5/6) nephrectomy (STNx) or sham at week 4 to induce CRS2 or control. At week 6, MI + STNx rats and control rats received vehicle or 1.0% 3,3-Dimethyl-1-butanol (DMB, a TMAO inhibitor) treatment for 8 weeks. Compared with control rats, MI + STNx rats exhibited elevated serum TMAO at week 6, which was increased further at week 14 but was attenuated by DMB treatment. MI + STNx rats showed cardiac dysfunction as assessed by echocardiography and renal dysfunction as evidenced by increased serum creatinine and urinary kidney injury molecule-1 and decreased creatinine clearance at week 6. The cardiac and renal dysfunction in MI + STNx rats was exacerbated at week 14 but was prevented by DMB treatment. Molecular and histological studies revealed myocyte hypertrophy and increases in interstitial myocardial fibrosis and gene expression of pro-hypertrophic and pro-fibrotic markers in both heart and kidney at week 14, which were accompanied by elevated gene expression of proinflammatory cytokines. The changes in molecular and histological parameters observed in MI + STNx rats were significantly reduced by DMB treatment. These findings suggest that rats with CRS2 have elevated circulating TMAO, which is associated with the exacerbation of cardiac and renal dysfunction. Attenuation of circulating TMAO can ameliorate cardiac and renal injury and prevents the progression of CRS2.

scholarly journals Immunoglobulin A Nephropathy as the First Clinical Presentation of Wilson Disease: A Case Report and Literature Review

2021 ◽  
Author(s):  
Yong-Zhe Zhang ◽  
Geng Jian ◽  
Ping He ◽  
Rui Yu ◽  
Mi Tian ◽  
...  
Keyword(s):  
Renal Function ◽  
Iga Nephropathy ◽  
Wilson Disease ◽  
Genetic Disorder ◽  
Immunoglobulin A ◽  
Elevated Serum ◽  
Clinical Manifestations ◽  
Kidney Injury ◽  
Copper Metabolism ◽  
Normal Liver

Abstract Background: Wilson disease (WD) is a rare genetic disorder of copper metabolism. The difference in copper tissue accumulation lead to various clinical manifestations, including some atypical presentations. The complex clinical picture makes it easy to miss and misdiagnose, even delay the best chance for treatment. Case presentation: A 26-year-old male patient who had nephritis-range proteinuria and elevated serum creatinine. The renal pathology indicated Immunoglobulin A (IgA) nephropathy and tubular injury which was inconsistent with glomerular lesions. Cirrhosis was also detected by imaging examination. Considering both kidney injury and liver damage, WD was suspected. According to further detected results of abnormal copper metabolism, corneal Kayser-Fleischer rings(K-F rings), and genetic disorder of ATP7B gene, he was finally diagnosed as a case of WD.The patient was given oral penicillamine and zinc sulfate daily and he was also prescribed losartan to control proteinuria on the premise of monitoring renal function and blood pressure. During the 2 years follow-up, the patient’s 24h uric cooper dropped to normal. The sign of tremor hands disappeared. The Urine protein and renal function keep stable. The patient had normal liver function and maintained good quality of daily life. Conclusions: In some cases, IgA nephropathy patients with suspicious and unexplained neurological and liver symptoms cannot be ignored. They may eventually be diagnosed with WD.

scholarly journals A novel Axin2 knock-in mouse model for visualization and lineage tracing of WNT/CTNNB1 responsive cells

2020 ◽  
Author(s):  
Anoeska Agatha Alida van de Moosdijk ◽  
Yorick Bernardus Cornelis van de Grift ◽  
Saskia Madelon Ada de Man ◽  
Amber Lisanne Zeeman ◽  
Renée van Amerongen
Keyword(s):  
Cell Fate ◽  
Mouse Strain ◽  
Critical Role ◽  
Lineage Tracing ◽  
Fluorescent Reporter ◽  
Cell Fate Decisions ◽  
Stem Cell Maintenance ◽  
Signaling Dynamics ◽  
Before And After

AbstractWnt signal transduction controls tissue morphogenesis, maintenance and regeneration in all multicellular animals. In mammals, the WNT/CTNNB1 (Wnt/β-catenin) pathway controls cell proliferation and cell fate decisions before and after birth. It plays a critical role at multiple stages of embryonic development, but also governs stem cell maintenance and homeostasis in adult tissues. However, it remains challenging to monitor endogenous WNT/CTNNB1 signaling dynamics in vivo. Here we report the generation and characterization of a new knock-in mouse strain that doubles as a fluorescent reporter and lineage tracing driver for WNT/CTNNB1 responsive cells. We introduced a multi-cistronic targeting cassette at the 3’ end of the universal WNT/CTNNB1 target gene Axin2. The resulting knock-in allele expresses a bright fluorescent reporter (3xNLS-SGFP2) and a doxycycline-inducible driver for lineage tracing (rtTA3). We show that the Axin2P2A-rtTA3-T2A-3xNLS-SGFP2 strain labels WNT/CTNNB1 cells at multiple anatomical sites during different stages of embryonic and postnatal development. It faithfully reports the subtle and dynamic changes in physiological WNT/CTNNB1 signaling activity that occur in vivo. We expect this mouse strain to be a useful resource for biologists who want to track and trace the location and developmental fate of WNT/CTNNB1 responsive stem cells in different contexts.Abstract Figure

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