The broad role of Nkx3.2 in the development of the zebrafish axial skeleton

The transcription factor Nkx3.2 (Bapx1) is an important chondrocyte maturation inhibitor. Previous Nkx3.2 knockdown and overexpression studies in non-mammalian gnathostomes have focused on its role in primary jaw joint development, while the function of this gene in broader skeletal development is not fully described. We generated a mutant allele of nkx3.2 in zebrafish with CRISPR/Cas9 and applied a range of techniques to characterize skeletal phenotypes at developmental stages from larva to adult, revealing loss of the jaw joint, fusions in bones of the occiput, morphological changes in the Weberian apparatus, and the loss or deformation of bony elements derived from basiventral cartilages of the vertebrae. Axial phenotypes are reminiscent of Nkx3.2 knockout in mammals, suggesting that the function of this gene in axial skeletal development is ancestral to osteichthyans. Our results highlight the broad role of nkx3.2 in zebrafish skeletal development and its context-specific functions in different skeletal elements.

Download Full-text

The Broad Role of Nkx3.2 in the Development of the Zebrafish Axial Skeleton

10.1101/2020.12.30.424496 ◽

2020 ◽

Author(s):

Laura Waldmann ◽

Jake Leyhr ◽

Hanqing Zhang ◽

Caroline Öhman-Mägi ◽

Amin Allalou ◽

...

Keyword(s):

Developmental Stages ◽

Skeletal Development ◽

Axial Skeleton ◽

Joint Development ◽

Chondrocyte Maturation ◽

Maturation Inhibitor ◽

Jaw Joint ◽

Context Specific ◽

Broad Role

AbstractThe transcription factor Nkx3.2 (Bapx1) is an important chondrocyte maturation inhibitor. Previous Nkx3.2 knock-down and overexpression studies in non-mammalian gnathostomes have focused on its role in primary jaw joint development, while little is known about the function of this gene in broader skeletal development. We generated CRISPR/Cas9 knockout of nkx3.2 in zebrafish and applied a range of techniques to characterize skeletal phenotypes at developmental stages from larva to adult, revealing fusions in bones of the occiput, the loss or deformation of bony elements derived from basiventral cartilages of the vertebrae, and an increased length of the proximal radials of the dorsal and anal fins. These phenotypes are reminiscent of Nkx3.2 knockout phenotypes in mammals, suggesting that the function of this gene in axial skeletal development is ancestral to osteichthyans. Our results highlight the broad role of nkx3.2 in zebrafish skeletal development and its context-specific functions in different skeletal elements.

Download Full-text

The role of Gdf5 in the development of the zebrafish fin endoskeleton

10.1101/2021.01.31.428959 ◽

2021 ◽

Author(s):

Laura Waldmann ◽

Jake Leyhr ◽

Hanqing Zhang ◽

Amin Allalou ◽

Caroline Öhman-Mägi ◽

...

Keyword(s):

Transforming Growth Factor Beta ◽

Transforming Growth Factor ◽

Developmental Stages ◽

Appendicular Skeleton ◽

Pectoral Fins ◽

Vertebrate Limb ◽

Jaw Joint ◽

Median Fins ◽

Human And Mouse

AbstractBackgroundThe development of the vertebrate limb skeleton requires a complex interaction of multiple factors to facilitate correct shaping and positioning of bones and joints. Growth and differentiation factor 5 (Gdf5), a member of the transforming growth factor-beta family (TGF-β) is involved in patterning appendicular skeletal elements including joints. Expression of gdf5 in zebrafish has been detected within the first pharyngeal arch jaw joint, fin mesenchyme condensations and segmentation zones in median fins, however little is known about the functional role of Gdf5 outside of Amniota.ResultsWe generated CRISPR/Cas9 knockout of gdf5 in zebrafish and analysed the resulting phenotype at different developmental stages. Homozygous gdf5 mutant zebrafish displayed changes in segmentation of the endoskeletal disc and, in consequence, loss of posterior radials in the pectoral fins. Mutant fish also displayed affected organisation and length of skeletal elements in the median fins, however joint formation and mineralisation process seemed unaffected.ConclusionsOur study demonstrates the importance of Gdf5 for the paired and median fin endoskeleton development in zebrafish and reveals that the severity of the effect increases from anterior to posterior side of the elements. Our findings are consistent with phenotypes observed in human and mouse appendicular skeleton in response to Gdf5 knockout, suggesting a broadly conserved role for Gdf5 in Osteichthyes.

Download Full-text

Skeletal defects in VEGF120/120 mice reveal multiple roles for VEGF in skeletogenesis

Development ◽

10.1242/dev.129.8.1893 ◽

2002 ◽

Vol 129 (8) ◽

pp. 1893-1904 ◽

Cited By ~ 14

Author(s):

Elazar Zelzer ◽

William McLean ◽

Yin-Shan Ng ◽

Naomi Fukai ◽

Anthony M. Reginato ◽

...

Keyword(s):

Blood Vessels ◽

Skeletal Development ◽

Surrounding Tissue ◽

Ossification Center ◽

Direct Role ◽

Osteoblastic Activity ◽

Chondrocyte Maturation ◽

Skeletal Defects

Angiogenesis is an essential component of skeletal development and VEGF signaling plays an important if not pivotal role in this process. Previous attempts to examine the roles of VEGF in vivo have been largely unsuccessful because deletion of even one VEGF allele leads to embryonic lethality before skeletal development is initiated. The availability of mice expressing only the VEGF120 isoform (which do survive to term) has offered an opportunity to explore the function of VEGF during embryonic skeletal development. Our study of these mice provides new in vivo evidence for multiple important roles of VEGF in both endochondral and intramembranous bone formation, as well as some insights into isoform-specific functions. There are two key differences in vascularization of developing bones between wild-type and VEGF120/120 mice. VEGF120/120 mice have not only a delayed recruitment of blood vessels into the perichondrium but also show delayed invasion of vessels into the primary ossification center, demonstrating a significant role of VEGF at both an early and late stage of cartilage vascularization. These findings are the basis for a two-step model of VEGF-controlled vascularization of the developing skeleton, a hypothesis that is supported by the new finding that VEGF is expressed robustly in the perichondrium and surrounding tissue of cartilage templates of future bones well before blood vessels appear in these regions. We also describe new in vivo evidence for a possible role of VEGF in chondrocyte maturation, and document that VEGF has a direct role in regulating osteoblastic activity based on in vivo evidence and organ culture experiments.

Download Full-text

Role of endocannabinoid CB1 receptors in Streptozotocin-induced uninephrectomised Wistar rats in diabetic nephropathy

Beni-Suef University Journal of Basic and Applied Sciences ◽

10.1186/s43088-021-00121-y ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Jayarami Reddy Medapati ◽

Deepthi Rapaka ◽

Veera Raghavulu Bitra ◽

Santhosh Kumar Ranajit ◽

Girija Sankar Guntuku ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Transforming Growth Factor Beta ◽

Transforming Growth Factor ◽

Morphological Changes ◽

Serum Levels ◽

Cb1 Receptors ◽

Protective Effects ◽

Renal Hypertrophy ◽

Necrosis Factor Alpha

Abstract Background The endocannabinoid CB1 receptor is known to have protective effects in kidney disease. The aim of the present study is to evaluate the potential agonistic and antagonistic actions and to determine the renoprotective potential of CB1 receptors in diabetic nephropathy. The present work investigates the possible role of CB1 receptors in the pathogenesis of diabetes-induced nephropathy. Streptozotocin (STZ) (55 mg/kg, i.p., once) is administered to uninephrectomised rats for induction of experimental diabetes mellitus. The CB1 agonist (oleamide) and CB1 antagonist (AM6545) treatment were initiated in diabetic rats after 1 week of STZ administration and were given for 24 weeks. Results The progress in diabetic nephropathy is estimated biochemically by measuring serum creatinine (1.28±0.03) (p < 0.005), blood urea nitrogen (67.6± 2.10) (p < 0.001), urinary microprotein (74.62± 3.47) (p < 0.005) and urinary albuminuria (28.31±1.17) (p < 0.0001). Renal inflammation was assessed by estimating serum levels of tumor necrosis factor alpha (75.69±1.51) (p < 0.001) and transforming growth factor beta (8.73±0.31) (p < 0.001). Renal morphological changes were assessed by estimating renal hypertrophy (7.38± 0.26) (p < 0.005) and renal collagen content (10.42± 0.48) (p < 0.001). Conclusions From the above findings, it can be said that diabetes-induced nephropathy may be associated with overexpression of CB1 receptors and blockade of CB1 receptors might be beneficial in ameliorating the diabetes-induced nephropathy. Graphical abstract

Download Full-text

Crayfish hemocytes develop along the granular cell lineage

Scientific Reports ◽

10.1038/s41598-021-92473-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Fang Li ◽

Zaichao Zheng ◽

Hongyu Li ◽

Rongrong Fu ◽

Limei Xu ◽

...

Keyword(s):

Developmental Stages ◽

Cell Lineage ◽

Granular Cell ◽

Marker Genes ◽

Hematopoietic Tissue ◽

Differentiated Cells ◽

Stage Of Development ◽

Almost All ◽

Relationship Of

AbstractDespite the central role of hemocytes in crustacean immunity, the process of hemocyte differentiation and maturation remains unclear. In some decapods, it has been proposed that the two main types of hemocytes, granular cells (GCs) and semigranular cells (SGCs), differentiate along separate lineages. However, our current findings challenge this model. By tracking newly produced hemocytes and transplanted cells, we demonstrate that almost all the circulating hemocytes of crayfish belong to the GC lineage. SGCs and GCs may represent hemocytes of different developmental stages rather than two types of fully differentiated cells. Hemocyte precursors produced by progenitor cells differentiate in the hematopoietic tissue (HPT) for 3 ~ 4 days. Immature hemocytes are released from HPT in the form of SGCs and take 1 ~ 3 months to mature in the circulation. GCs represent the terminal stage of development. They can survive for as long as 2 months. The changes in the expression pattern of marker genes during GC differentiation support our conclusions. Further analysis of hemocyte phagocytosis indicates the existence of functionally different subpopulations. These findings may reshape our understanding of crustacean hematopoiesis and may lead to reconsideration of the roles and relationship of circulating hemocytes.

Download Full-text

Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

Endocrine Reviews ◽

10.1210/er.2015-1106 ◽

2016 ◽

Vol 37 (2) ◽

pp. 135-187 ◽

Cited By ~ 150

Author(s):

J. H. Duncan Bassett ◽

Graham R. Williams

Keyword(s):

Thyroid Hormones ◽

Skeletal Development ◽

Bone Maintenance

Download Full-text

Evolution and expansion of the RUNX2 QA repeat corresponds with the emergence of vertebrate complexity

Communications Biology ◽

10.1038/s42003-020-01501-3 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Axel H. Newton ◽

Andrew J. Pask

Keyword(s):

Natural Variation ◽

Skeletal Development ◽

Skull Shape ◽

Morphological Novelty ◽

Transactivation Potential ◽

Repeat Domain ◽

Related Transcription Factor ◽

Mammalian Skull ◽

Evolutionary Tuning

AbstractRunt-related transcription factor 2 (RUNX2) is critical for the development of the vertebrate bony skeleton. Unlike other RUNX family members, RUNX2 possesses a variable poly-glutamine, poly-alanine (QA) repeat domain. Natural variation within this repeat is able to alter the transactivation potential of RUNX2, acting as an evolutionary ‘tuning knob’ suggested to influence mammalian skull shape. However, the broader role of the RUNX2 QA repeat throughout vertebrate evolution is unknown. In this perspective, we examine the role of the RUNX2 QA repeat during skeletal development and discuss how its emergence and expansion may have facilitated the evolution of morphological novelty in vertebrates.

Download Full-text

Tissue Ki67 proliferative index expression and pathological changes in hemodialysis arteriovenous fistulae: Preliminary single-center results

The Journal of Vascular Access ◽

10.1177/11297298211015495 ◽

2021 ◽

pp. 112972982110154

Author(s):

Raffaella Mauro ◽

Cristina Rocchi ◽

Francesco Vasuri ◽

Alessia Pini ◽

Anna Laura Croci Chiocchini ◽

...

Keyword(s):

Morphological Changes ◽

Hot Spot ◽

Wall Thickening ◽

Proliferating Cells ◽

Ki 67 ◽

Group A ◽

The Mean ◽

Set Up ◽

Group B

Background: Arteriovenous fistula (AVF) for hemodialysis integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes. Aim of this study is to determine the role of Ki67, a well-established proliferative marker, related to AVF, and its relationship with time-dependent histological morphologic changes. Materials and methods: All patients were enrolled in 1 year and stratified in two groups: (A) pre-dialysis patients submitted to first AVF and (B) patients submitted to revision of AVF. Morphological changes: neo-angiogenesis (NAG), myointimal thickening (MIT), inflammatory infiltrate (IT), and aneurysmatic fistula degeneration (AD). The time of AVF creation was recorded. A biopsy of native vein in Group A and of arterialized vein in Group B was submitted to histological and immunohistochemical (IHC) analysis. IHC for Ki67 was automatically performed in all specimens. Ki67 immunoreactivity was assessed as the mean number of positive cells on several high-power fields, counted in the hot spots. Results: A total of 138 patients were enrolled, 69 (50.0%) Group A and 69 (50.0%) Group B. No NAG or MIT were found in Group A. Seven (10.1%) Group A veins showed a mild MIT. Analyzing the Group B, a moderate-to-severe MIT was present in 35 (50.7%), IT in 19 (27.5%), NAG in 37 (53.6%); AD was present in 10 (14.5%). All AVF of Group B with the exception of one (1.4%) showed a positivity for Ki67, with a mean of 12.31 ± 13.79 positive cells/hot spot (range 0–65). Ki67-immunoreactive cells had a subendothelial localization in 23 (33.3%) cases, a myointimal localization in SMC in 35 (50.7%) cases. The number of positive cells was significantly correlated with subendothelial localization of Ki67 ( p = 0.001) and with NA ( p = 0.001). Conclusions: Native veins do not contain cycling cells. In contrast, vascular cell proliferation starts immediately after AVF creation and persists independently of the time the fistula is set up. The amount of proliferating cells is significantly associated with MIT and subendothelial localization of Ki67-immunoreactive cells, thus suggesting a role of Ki-67 index in predicting AVF failure.

Download Full-text

The Neuroinflammatory Role of Pericytes in Epilepsy

Biomedicines ◽

10.3390/biomedicines9070759 ◽

2021 ◽

Vol 9 (7) ◽

pp. 759

Author(s):

Gaku Yamanaka ◽

Fuyuko Takata ◽

Yasufumi Kataoka ◽

Kanako Kanou ◽

Shinichiro Morichi ◽

...

Keyword(s):

Proinflammatory Cytokines ◽

Current Knowledge ◽

Morphological Changes ◽

Cell Damage ◽

Neurovascular Unit ◽

Experimental Studies ◽

Intractable Epilepsy ◽

In Vivo Studies

Pericytes are a component of the blood–brain barrier (BBB) neurovascular unit, in which they play a crucial role in BBB integrity and are also implicated in neuroinflammation. The association between pericytes, BBB dysfunction, and the pathophysiology of epilepsy has been investigated, and links between epilepsy and pericytes have been identified. Here, we review current knowledge about the role of pericytes in epilepsy. Clinical evidence has shown an accumulation of pericytes with altered morphology in the cerebral vascular territories of patients with intractable epilepsy. In vitro, proinflammatory cytokines, including IL-1β, TNFα, and IL-6, cause morphological changes in human-derived pericytes, where IL-6 leads to cell damage. Experimental studies using epileptic animal models have shown that cerebrovascular pericytes undergo redistribution and remodeling, potentially contributing to BBB permeability. These series of pericyte-related modifications are promoted by proinflammatory cytokines, of which the most pronounced alterations are caused by IL-1β, a cytokine involved in the pathogenesis of epilepsy. Furthermore, the pericyte-glial scarring process in leaky capillaries was detected in the hippocampus during seizure progression. In addition, pericytes respond more sensitively to proinflammatory cytokines than microglia and can also activate microglia. Thus, pericytes may function as sensors of the inflammatory response. Finally, both in vitro and in vivo studies have highlighted the potential of pericytes as a therapeutic target for seizure disorders.

Download Full-text

Epigenetic transgenerational inheritance, Gametogenesis and Germline Development

Biology of Reproduction ◽

10.1093/biolre/ioab085 ◽

2021 ◽

Author(s):

Millissia Ben Maamar ◽

Eric E Nilsson ◽

Michael K Skinner

Keyword(s):

Developmental Biology ◽

Environmental Factors ◽

Biological System ◽

Developmental Stages ◽

Primordial Germ Cell ◽

Cell Types ◽

Transgenerational Inheritance ◽

Germline Development ◽

Current Review

Abstract One of the most important developing cell types in any biological system is the gamete (sperm and egg). The transmission of phenotypes and optimally adapted physiology to subsequent generations is in large part controlled by gametogenesis. In contrast to genetics, the environment actively regulates epigenetics to impact the physiology and phenotype of cellular and biological systems. The integration of epigenetics and genetics is critical for all developmental biology systems at the cellular and organism level. The current review is focused on the role of epigenetics during gametogenesis for both the spermatogenesis system in the male and oogenesis system in the female. The developmental stages from the initial primordial germ cell through gametogenesis to the mature sperm and egg are presented. How environmental factors can influence the epigenetics of gametogenesis to impact the epigenetic transgenerational inheritance of phenotypic and physiological change in subsequent generations is reviewed.

Download Full-text