Stellate cells are the GABAergic inhibitory interneurons of the nervous system. Other cells, including the immune system, modulate their synthesis and activity. They are derived from progenitors located in the white matter of the postnatal cerebellum. In addition, the hepatic stellate cell plays a vital role in the regeneration of the liver.
They are derived from dividing progenitors in the white matter of the postnatal cerebellum.
Stellate cells are neurons in the central nervous system, including the cerebellum. They send inhibitory signals to Purkinje cells. The stellate cells is the most common inhibitory interneuron in the murine cerebellum.
During postnatal development, neuronal migration plays a vital role in forming a cerebellar circuit. In the murine cerebellum, UBCs and GCs are generated from the RL during the early postnatal period. These neurons migrate through the white matter of the cerebellum. As they move, they project directly onto GCs and the GC layer. The PCP, a multi-cell thick immature PC layer, forms during this period.
At the p0 stage, roundish amoeboid microglial cells are present in the developing white matter of the cerebellum. Later, these cells become oligodendrocytes and form a dense network within the IGL. Several GFAP-positive cells are also present in the nascent WM. However, these oligodendrocytes are oriented at right angles to the border of the IGL.
The density of MBP-positive oligodendrocytes increases throughout the cerebellum at p15. They are primarily present in the inner part of the IGL. GFAP-positive cells are also present within posterior lobules.
Activated hepatic stellate cells assist in liver regeneration.
Hepatic stellate cells (HSCs) play a central role in liver homeostasis and regeneration. They are resident fibroblast-like cells that produce an extracellular matrix and transdifferentiate into myofibroblasts. HPCs are also involved in fibrogenesis and inflammation. In addition, their activation promotes fibrosis in response to liver injury.
In acute liver failure, HSCs are overactivated. This may have contributed to a decreased regenerative capacity. However, their activation is also thought to assist liver regeneration during liver failure.
Several studies have explored the relationship between HSCs and liver injury. However, despite these findings, several questions remain about the relationship between hepatic progenitor cells and acute liver failure. For instance, there is no consensus on whether HSCs contribute to apoptosis or tumorigenesis in acute liver failure.
Recent studies have suggested that HSCs are more plastic than previously believed. As such, some of these cells can become progenitor cells and participate in the compensatory response to liver damage.
Hepatic stellate cells are located between sinusoidal endothelial cells and hepatocytes. They maintain liver homeostasis by secreting paracrine factors. The stellate cell’s phenotype changes rapidly in response to injury.
They are GABAergic inhibitory interneurons.
GABAergic interneurons are essential for the development of the neocortex. This group of cells is highly heterogeneous. Their physiological and morphological features differ from other neuronal types. They play a crucial role in the processing of auditory signals. It has been proposed that they provide feedforward inhibition, stabilization of neuronal firing responses, and tuning properties.
Small glycinergic cells, or “stellate cells,” are an essential subtype of inhibitory neurons in the VCN. These cells are multipolar and make local inhibitory synaptic contacts on principal cells in the VCN. In the sensory neocortex, they are mainly found in layer 2.
Small glycinergic cells have smaller somata and dendrites. They are also more branched at the dendrite ends. However, they show diverse responses to depolarizing solid current injections. ASC amplitudes follow an exponential relationship with the distance between the release site and the soma.
These neurons have been classified into L-stellate cells and D-stellate cells. The majority of glycinergic VCN cells are L-stellate. However, a minority of cells are D-stellate. Although these cell types are asymmetrical, they exhibit distinct electrophysiological, morphological, and histochemical features.
They interact with immune cells.
Hepatic stellate cells are primary ECM-producing cells in the liver. They are located between the sinusoidal endothelial cells and hepatic epithelial cells. These cells play an essential role in regulating liver regeneration. In addition, they may also control the morphogenesis of other cells in the liver.
Hepatic stellate cells are essential regulators of the proliferation of hepatoblast progenitor cells. Although the exact mechanism of action remains unclear, these cells have been implicated in developing HCC. Their interactions with other hepatic cells are likely reactivated after the liver responds to injury.
Stellate cells interact with hepatocytes, hematopoietic stem cells, and immune cells. This interaction has significant consequences for the body’s ability to heal itself.
Several pathways can mediate these interactions. One candidate involves the Wnt/b-catenin path. Another candidate consists of the neurotrophin receptor. Finally, there is evidence that hepatic stellate cells may produce angiogenic factors.
There are many gaps in our knowledge of stellate cell development and function. However, recent studies in cell culture systems have provided vital insights. Nevertheless, a significant challenge for researchers is studying stellate cells in vivo. To overcome this, creating stellate cell-specific gene knockouts could be helpful.
They can cause pericellular fibrosis.
Hepatic stellate cells (HSCs) play a significant role in the pathogenesis of hepatic fibrosis. They are essential in liver cell development and contribute to the homeostasis of hepatocytes. In addition, they produce extracellular matrix proteins, which contribute to the formation of fibrous scars.
These stellate cells are also involved in promoting parenchymal restitution after acute hepatic injury. However, the stellate cell response is not permanent. Instead, when hepatic injury resolves, HSCs become inactive. As a result, they undergo apoptosis. This is a significant event in hepatic fibrosis, which can progress to liver cirrhosis. Moreover, this major event is associated with a change in the balance between proliferation and apoptosis. Therefore, it is crucial to understand the etiology and pathophysiology of hepatic fibrosis and discover new therapeutic targets.
Activated hepatic stellate cells (aHSCs) are the primary source of extracellular matrix (ECM) production in liver fibrosis. During fibrogenesis, they produce abnormal levels of extracellular matrix proteins such as collagen and glycoproteins. The abnormal ECM composition also leads to a disruption in the typical architecture of the liver.