Chronic inflammation

What defines chronic inflammation?

[blank_start]Macrophages[blank_end] and [blank_start]granulation[blank_end] tissue are characteristic features. Macrophages come in many different states in chronic inflammation, highlighting their wide range of functions in protecting the body: killing and clearing ([blank_start]phagocytosis[blank_end]), production of [blank_start]cytokines[blank_end], acute phase reactions and [blank_start]antigen[blank_end] presentation

[blank_start]Tuberculosis[blank_end] is caused by mycobacterium which has a protective coat so the stimulus cannot be removed. Granulomas form around the pathogen [blank_start]Amyloidosis[blank_end] is aggregation of misfolded proteins causing atrophy [blank_start]Cystisis[blank_end] is bladder inflammation. Urinary catheters can introduce infection and leads to incontinence and confusion.

 [blank_start]Labile[blank_end] cells: always proliferating so regenerate – epithelia such as skin, GI tract  [blank_start]Stable[blank_end] cells: do not normally proliferate but can do so after injury – liver, kidney  [blank_start]Permanent[blank_end]: cannot regenerate so must scar – neurones, heart muscle

Regeneration can be stimulated by insoluble growth factors

In regeneration soluble transcription factors regulate DNA transcription from cascade of events which can result in:

Another signal for regeneration is [blank_start]physical[blank_end] cell-cell and cell-matrix interactions via the ECM and cell junctions, mediated by [blank_start]integrin[blank_end] proteins (we touched on this in Topic 1) that again produce a cascade.