Integumentary System - Gland Development - Revision history

Z8600021 at 04:14, 10 November 2019

2019-11-10T04:14:26Z

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			* '''Molecular dynamics of Dkk4 modulates Wnt action and regulates meibomian gland development'''{{#pmid:27864382\|PMID27864382}} "Secreted Dickkopf (Dkk) proteins are major {{Wnt}} pathway modulators during organ development. Dkk1 has been widely studied and acts as a general Wnt inhibitor. However, the molecular function of other Dkks remains largely unknown. Here, we show that Dkk4 selectively inhibits a subset of Wnts, but is further inactivated by proteolytic cleavage. Meibomian gland (MG) formation is employed as a model where Dkk4 and its Wnt targets are expressed. Skin-specific expression of Dkk4 arrests MG growth at early germ phase, which is similar to that observed in Eda-ablated Tabby mice. Consistent with transient Dkk4 action, intact Dkk4 inhibits MG extension but the cleaved form progressively increases during MG development with a concomitant upswing in Wnt activity. Furthermore, both Dkk4 and its receptor (and Wnt co-receptor) Lrp6 are direct Eda targets during MG induction. In cell and organotypic cultures, Dkk4 inhibition is eliminated by elevation of Lrp6. Also, Lrp6 upregulation restores MG formation in Tabby mice. Thus, the dynamic state of Dkk4 itself and its interaction with Lrp6 modulates Wnt function during MG development, with a novel limitation of Dkk4 action by proteolytic cleavage."

	* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''{{#pmid:25249463\|PMID25249463}} "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development {{#pmid:27414798\|PMID27414798}} )		* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''{{#pmid:25249463\|PMID25249463}} "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development {{#pmid:27414798\|PMID27414798}} )

Z8600021 at 04:10, 10 November 2019

2019-11-10T04:10:40Z

← Older revision		Revision as of 15:10, 10 November 2019
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	\| [[File:Mark_Hill.jpg\|90px\|left]] {{Most_Recent_Refs}}		\| [[File:Mark_Hill.jpg\|90px\|left]] {{Most_Recent_Refs}}

	Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Gland+Embryology ''Gland Embryology'']		Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Gland+Embryology ''Gland Embryology''] \| [http://www.ncbi.nlm.nih.gov/pubmed/?term=Integumentary+Gland+Development ''Integumentary Gland Development'']

	~~<pubmed limit=5>Gland Embryology</pubmed>~~

	~~<pubmed limit=5>Gland Development</pubmed>~~
	\|}		\|}
	== Textbooks ==		== Textbooks ==

Z8600021: Undo revision 389992 by Z8600021 (talk)

2019-11-10T04:09:45Z

Undo revision 389992 by Z8600021 (talk)

← Older revision		Revision as of 15:09, 10 November 2019
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	The {{mammary gland}} development is covered in detail on a separate notes page.		The {{mammary gland}} development is covered in detail on a separate notes page.

			\| [[File:Merocrine secretion animation.gif]]
	\| [[File:Apocrine secretion animation.gif]]		\| [[File:Apocrine secretion animation.gif]]
			\| [[File:Holocrine secretion animation.gif]]
	\|}		\|}

Z8600021: Undo revision 389994 by Z8600021 (talk)

2019-11-10T04:09:21Z

Undo revision 389994 by Z8600021 (talk)

← Older revision		Revision as of 15:09, 10 November 2019
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	The {{mammary gland}} development is covered in detail on a separate notes page.		The {{mammary gland}} development is covered in detail on a separate notes page.

	\| [[File:Apocrine secretion animation.gif~~\|200px~~]]		\| [[File:Apocrine secretion animation.gif]]
	\|}		\|}

Z8600021 at 04:08, 10 November 2019

2019-11-10T04:08:34Z

← Older revision		Revision as of 15:08, 10 November 2019
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	The {{mammary gland}} development is covered in detail on a separate notes page.		The {{mammary gland}} development is covered in detail on a separate notes page.

	\| [[File:Apocrine secretion animation.gif]]		\| [[File:Apocrine secretion animation.gif\|200px]]
	\|}		\|}

Z8600021 at 04:08, 10 November 2019

2019-11-10T04:08:14Z

← Older revision		Revision as of 15:08, 10 November 2019
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	The {{mammary gland}} development is covered in detail on a separate notes page.		The {{mammary gland}} development is covered in detail on a separate notes page.

	~~\| [[File:Merocrine secretion animation.gif]]~~
	\| [[File:Apocrine secretion animation.gif]]		\| [[File:Apocrine secretion animation.gif]]
	~~\| [[File:Holocrine secretion animation.gif]]~~
	\|}		\|}

Z8600021 at 04:07, 10 November 2019

2019-11-10T04:07:26Z

← Older revision		Revision as of 15:07, 10 November 2019
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	The {{mammary}} ~~gland~~ development is covered in detail on a separate notes page.		The {{mammary gland}} development is covered in detail on a separate notes page.

	\| [[File:Merocrine secretion animation.gif]]		\| [[File:Merocrine secretion animation.gif]]

Z8600021 at 03:45, 30 March 2019

2019-03-30T03:45:12Z

← Older revision		Revision as of 14:45, 30 March 2019
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	\| The secretory glands associated with the integumentary system have similar embryonic origins and mechanisms of development, though are specialised by their locations and secretions. A key process and feature of all gland development is an epithelial-mesenchymal interaction(s). Gland secretion can also be regulated by a number of different mechanisms, including endocrine changes postnatally at puberty and during pregnancy.		\| The secretory glands associated with the integumentary system have similar embryonic origins and mechanisms of development, though are specialised by their locations and secretions. A key process and feature of all gland development is an epithelial-mesenchymal interaction(s). Gland secretion can also be regulated by a number of different mechanisms, including endocrine changes postnatally at puberty and during pregnancy.

	The mammary gland development is covered in detail on a separate notes page.
			The {{mammary}} gland development is covered in detail on a separate notes page.

	\| [[File:Merocrine secretion animation.gif]]		\| [[File:Merocrine secretion animation.gif]]
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	'''Human Development''' (based upon data from{{#pmid:16879594\|PMID16879594}})		'''Human Development''' (based upon data from{{#pmid:16879594\|PMID16879594}})

	* Carnegie stage 16-18 - formation of the lacrimal lamina		* Carnegie stage {{CS16}} - {{CS18}} - formation of the lacrimal lamina
	* Carnegie stage 19-23 - formation of the lacrimal cord		* Carnegie stage {{CS19}} - {{CS23}} - formation of the lacrimal cord
	* Week 9+ - maturation of the excretory lacrimal system		* {{fetal}} Week 9+ - maturation of the excretory lacrimal system

			:'''Links:''' {{vision}}
	==Meibomian Glands==		==Meibomian Glands==
	The Meibomian glands (''glandulae tarsales'') are sebaceous glands located at the margins of the upper and lower eyelids of humans and mammals.{{#pmid:19660571\|PMID19660571}} The gland cells (meibocytes) secrete by a holocrine mechanism and produce constantly a lipid-rich secretion (meibum) that mix with with aqueous tears produced by lacrimal glands. These glands are also regulated through sex hormones, androgens have a supporting function while estrogens act antagonistically.		The Meibomian glands (''glandulae tarsales'') are sebaceous glands located at the margins of the upper and lower eyelids of humans and mammals.{{#pmid:19660571\|PMID19660571}} The gland cells (meibocytes) secrete by a holocrine mechanism and produce constantly a lipid-rich secretion (meibum) that mix with with aqueous tears produced by lacrimal glands. These glands are also regulated through sex hormones, androgens have a supporting function while estrogens act antagonistically.

Z8600021 at 00:20, 9 August 2018

2018-08-09T00:20:17Z

← Older revision		Revision as of 11:20, 9 August 2018
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	* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''~~<ref name="~~PMID25249463~~"><pubmed>25249463</pubmed></ref>~~ "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development ~~PMID~~ 27414798 )		* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''{{#pmid:25249463\|PMID25249463}} "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development {{#pmid:27414798\|PMID27414798}} )
	* '''Hormones and the pilosebaceous unit''' ~~<ref><pubmed>~~20224689~~</pubmed></ref>~~ "The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors."
			* '''Hormones and the pilosebaceous unit'''{{#pmid:20224689\|PMID20224689}} "The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors."
	\|}		\|}
	{\| class="wikitable mw-collapsible mw-collapsed"		{\| class="wikitable mw-collapsible mw-collapsed"
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	==Vernix Caseosa==		==Vernix Caseosa==
	[[File:Newborn - vernix caseosa.jpg\|thumb\|300px\|Newborn - vernix caseosa]]		[[File:Newborn - vernix caseosa.jpg\|thumb\|300px\|Newborn - vernix caseosa]]
	(vernix, Latin, ''vernix'' = varnish, ''caseous'' = cheese=like) This is a specialized coating that forms in late development over the entire fetal surface. The main component, secreted sebum, is secreted by sebaceous glands. The other constituents are cells sloughed off the fetus's skin, and shed lanugo hair. The coating also has a high water content (80%) largely compartmentalized within fetal corneocytes (cells forming the stratum corneum). ~~<ref><pubmed>~~11069626~~</pubmed></ref>~~		(vernix, Latin, ''vernix'' = varnish, ''caseous'' = cheese=like) This is a specialized coating that forms in late development over the entire fetal surface. The main component, secreted sebum, is secreted by sebaceous glands. The other constituents are cells sloughed off the fetus's skin, and shed lanugo hair. The coating also has a high water content (80%) largely compartmentalized within fetal corneocytes (cells forming the stratum corneum).{{#pmid:11069626\|PM ID11069626}}

	This coating develops intially in a cranio-caudal direction and can be absent in preterm infants.		This coating develops intially in a cranio-caudal direction and can be absent in preterm infants.
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	Lacrimal glands produce the aqueous tears that mix with Meibomian glands secretions to form a tear film coating the outer surface of the eye.		Lacrimal glands produce the aqueous tears that mix with Meibomian glands secretions to form a tear film coating the outer surface of the eye.

	'''Human Development''' (based upon data from~~<ref name="PMID16879594"><pubmed>~~16879594~~</pubmed>~~\| ~~[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2100314 PMC2100314]</ref>~~)		'''Human Development''' (based upon data from{{#pmid:16879594\|PMID16879594}})

	* Carnegie stage 16-18 - formation of the lacrimal lamina		* Carnegie stage 16-18 - formation of the lacrimal lamina
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	==Meibomian Glands==		==Meibomian Glands==
	The Meibomian glands (''glandulae tarsales'') are sebaceous glands located at the margins of the upper and lower eyelids of humans and mammals.~~<ref><pubmed>~~19660571~~</pubmed></ref>~~ The gland cells (meibocytes) secrete by a holocrine mechanism and produce constantly a lipid-rich secretion (meibum) that mix with with aqueous tears produced by lacrimal glands. These glands are also regulated through sex hormones, androgens have a supporting function while estrogens act antagonistically.		The Meibomian glands (''glandulae tarsales'') are sebaceous glands located at the margins of the upper and lower eyelids of humans and mammals.{{#pmid:19660571\|PMID19660571}} The gland cells (meibocytes) secrete by a holocrine mechanism and produce constantly a lipid-rich secretion (meibum) that mix with with aqueous tears produced by lacrimal glands. These glands are also regulated through sex hormones, androgens have a supporting function while estrogens act antagonistically.

	The glands were first described in 1666 by Heinrich Meibom (1638 - 1700) a German physician and anatomist.		The glands were first described in 1666 by Heinrich Meibom (1638 - 1700) a German physician and anatomist.
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	===Vernix Caseosa Peritonitis===		===Vernix Caseosa Peritonitis===
	Not an abnormality of development, but a clinical term for a rare post-caesarean section complication due to spilt vernix caseosa at the time of caesarean section mediating a maternal inflammatory reaction.~~<ref><pubmed>~~19208257~~</pubmed></ref>~~		Not an abnormality of development, but a clinical term for a rare post-caesarean section complication due to spilt vernix caseosa at the time of caesarean section mediating a maternal inflammatory reaction.{{#pmid:19208257\|PMID19208257}}

	== References ==		== References ==
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	===Reviews===		===Reviews===
			{{#pmid:19681790}}

			{{#pmid:8919141}}

			{{#pmid:8196943}}

	~~<pubmed>19681790</pubmed>~~		{{#pmid:19020961}}
	~~<pubmed>8919141</pubmed>~~
	~~<pubmed>8196943</pubmed>~~
	~~<pubmed>~~19020961~~</pubmed>~~

	===Articles===		===Articles===
	~~<pubmed>~~19881987~~</pubmed>~~		{{#pmid:19881987}}
	~~<pubmed>~~16179970~~</pubmed>~~
			{{#pmid:16179970}}

	===Search PubMed===		===Search PubMed===
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	</gallery>		</gallery>


	==Terms==		==Terms==

	{{Integumentary terms}}		{{Integumentary terms}}


	== External Links ==		== External Links ==
	{{External Links}}		{{External Links}}
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	{{Footer}}		{{Footer}}

	[[Category:Mammary Gland]] [[Category:Integumentary]]		[[Category:Mammary Gland]] [[Category:Integumentary]][[Category:Gland]][[Category:Ectoderm]]

Z8600021 at 23:40, 21 September 2016

2016-09-21T23:40:35Z

← Older revision		Revision as of 10:40, 22 September 2016
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	* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''<ref name="PMID25249463"><pubmed>25249463</pubmed></ref> "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development)		* '''Involvement of Wnt, Eda and Shh at defined stages of sweat gland development'''<ref name="PMID25249463"><pubmed>25249463</pubmed></ref> "Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways." (this same singling pathway is required for sensory Merkel cell development PMID 27414798 )
	* '''Hormones and the pilosebaceous unit''' <ref><pubmed>20224689</pubmed></ref> "The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors."		* '''Hormones and the pilosebaceous unit''' <ref><pubmed>20224689</pubmed></ref> "The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors."
	\|}		\|}