Table 5.

Type 1 and type 2 macrophages in the interstitium of kidney [3,12,18].

Macrophage Cell Types	Role in Renal Disease
M1 macrophages [3]	M1 macrophages are derived from monocytes which are recruited in renal interstitium due to the influence of adhesion and pro-inflammatory mediators ICAM1, osteopontin, etc. M1 macrophages are implicated in direct renal injury at the level of proximal and distal tubules, as well as in enhancing antigen presentation to T lymphocytes, mediated by IL-12 and IL-23
M1 to M2 macrophage transition in interstitium of kidney [3]	c.Facilitated by macrophage colony stimulating factor and IL-10.
M2 macrophages [3]	d.Repair of renal tubular injury mediated by Wnt7b and IL22 e.Resolution of tubular and interstitial inflammation mediated by IL-10 and HO-1 f.M2 macrophages proposed to play a role in trans-differentiation of pericytes, and myofibroblasts resulting in increased collagen matrix deposition and interstitial fibrosis. These changes are mediated by TGFβ, PDGFβ and galectin 3
M2a macrophages [12,18]	g.Activate M2b macrophages, predominantly through T helper cell mediated pathways
M2b macrophages [12,18]	h.Plays a role in immunoregulation
M2c macrophages [12,18]	i.Take part in matrix remodeling due to inflammation, tissue repair, phagocytosis of degenerated and dead cells

Abbreviations:ICAM1—intercellular adhesion molecule 1, IL—Interleukins, HO1—Haemoxygenase 1, Wnt—wingless related integration site, TGFβ—Transforming growth factor beta, and PDGFβ—platelet derived growth factor beta.