A requirement for cholesterol and its structural features for a human macrophage‐like cell line

Abstract

The lipid requirements of a human macrophagelike cell line were studied. The cells grew only about one generation in a medium supplemented with delipidated serum; during the growth the cholesterol content of the cells was depleted. Growth was restored by including in the medium serum lipids subjected to alkaline hydrolysis or cholesterol. The extent of growth was dependent on cholesterol concentration. No growth was obtained with 5-cholestene, 5-cholesten-3-one, cholesteryl chloride, coprostanol, beta-sitosterol, or stigmasterol. Very limited growth occurred with cholesterol methylether, epicholesterol, or beta-cholestanol. Therefore, for optimal growth of these cells there is a stringent requirement for the structural features of cholesterol, which include a 3-beta OH group, a delta 5-double bond, a trans ring A/B configuration, and freedom of the side chain from bulky groups. This stringency far exceeds what was previously reported for other cells. Of the six sterols that failed to support growth at all, five were incorporated into cells moderately to extensively. This suggests that assembly of a functional membrane is impaired when these sterols are used as substrates for growth.

Dual roles for cholesterol in mammalian cells

“…Thus, Bloch questioned whether the 3␤-OH is mandatory for sterol function or simply arises as a consequence of sterol synthesis. 5-Cholestene, cholestenone, and 3␣-epicholesterol did not support growth of auxotrophic cells, which agrees with previous work in which cholesteryl methylether and 3␣-epicholesterol failed to support growth of a macrophage-like cell line in lipid-depleted medium (34). These findings suggest that an equatorial hydroxyl group at C-3 is essential for mammalian cells.…”

Effects of distal cholesterol biosynthesis inhibitors on cell proliferation and cell cycle progression

“…Therefore, the requirement of a certain amount of cholesterol in addition to 7-dehydrocholesterol to sustain cell growth cannot be ruled out. In agreement with this, we and others have demonstrated that phytosterols may support the proliferation of animal cells, provided that a suboptimal amount of cholesterol is also available (9,14,28).…”

“…Thus, the results suggested that 7-dehydrocholesterol contributed to cell proliferation. Supplementing the medium with 7-dehydrocholesterol had been shown previously by others to support the growth of cholesterol-auxotroph cells (9,14). In these cells, however, 7-dehydrocholesterol was efficiently converted to cholesterol; thus, the specific role of that sterol intermediate in cell proliferation could not be evaluated.…”

“…Therefore, the role of that sterol in cell proliferation remains to be elucidated. In cholesterol-auxotroph cells, such as U937 human macrophages (14), S2 mutant LM mouse fibroblasts (9), and NS-1 mouse myeloma cells (15), 7-dehycrocholesterol added to the medium supported growth at the same rate as cholesterol, but the significance of these results could not be evaluated because of the extensive conversion of that sterol to cholesterol in these cells (9,14). In addition, 7-dehydrocholesterol has been shown to replace cholesterol in raft and caveolae formation (16,17).…”

Identification of low density lipoprotein as a regulator of Fc receptor-mediated phagocytosis.

“…Heat-inactivated fetal calf serum (FCS) and basal growth medium RPMI 1640 with 2 mM glutamine were obtained from GIBCO. Delipidated FCS (DLFCS) was prepared as described (11).…”