Moore S A, Lopez A, Richardson A, Pahlavani M A
Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, Audie Murphy VA Hospital, San Antonio, TX 78284, USA.
Mech Ageing Dev. 1998 Aug 1;104(1):59-73. doi: 10.1016/s0047-6374(98)00052-9.
Dietary restriction (DR) is the only effective experimental manipulation known to retard aging in rodents, and this manipulation has been shown to alter a variety of processes that change with age. However, there is no information on the effect of DR on macrophage Function. In the present study, the effect of aging and DR on the ability of alveolar macrophages (AMs) to express the heat shock gene, hsp70 was studied. AMs were isolated by lavage from the lungs of young (4-6 months) and old (24-26 months) rats fed either ad libitum (AL) or a restricted diet (60% of AL). There was no age-related change in the number of cells recovered from young and old rats fed AL. However, the number of cells recovered from the lungs of the DR rats was reduced, and this decrease was statistically significant in young rats. The expression of heat shock protein 70 (hsp70) was measured by the level of the hsp70 mRNA transcript in total RNA isolated from AMs cultured under two conditions: in suspension and after adherence to plastic. When AMs were incubated at 37 degrees C in suspension, no detectable hsp70 expression was observed; however, hsp70 expression was induced at 37 degrees C when the AMs adhered to the plastic culture dishes. Hsp70 mRNA levels were rapidly induced by heat shock (43 degrees C, 1 h) in AMs cultured both in suspension and on plastic. The induction of hsp70 expression did not change significantly with either age or DR in AMs cultured in suspension. In contrast, the induction of hsp70 mRNA levels by AMs adherent to plastic culture plates decreased approximately 70% with age, and hsp70 induction was greater in AMs isolated from DR rats; this difference was statistically significant in young rats. The induction of hsp70 by heat shock (43 degrees C, 1 h) also decreased with age in the adherent AMs, and DR increased the induction of hsp70 expression three- to fourfold in adherent AMs from both young and old rats.
饮食限制（DR）是已知的唯一能延缓啮齿动物衰老的有效实验性操作，并且这种操作已被证明会改变多种随年龄变化的过程。然而，关于饮食限制对巨噬细胞功能的影响尚无相关信息。在本研究中，研究了衰老和饮食限制对肺泡巨噬细胞（AMs）表达热休克基因hsp70能力的影响。通过灌洗从自由进食（AL）或限制饮食（AL的60%）的年轻（4 - 6个月）和年老（24 - 26个月）大鼠的肺中分离AMs。从自由进食的年轻和年老大鼠中回收的细胞数量没有与年龄相关的变化。然而，从饮食限制大鼠肺中回收的细胞数量减少，并且这种减少在年轻大鼠中具有统计学意义。通过在两种条件下培养的AMs分离的总RNA中hsp70 mRNA转录本水平来测量热休克蛋白70（hsp70）的表达：悬浮培养和贴壁于塑料培养皿后。当AMs在37℃悬浮培养时，未观察到可检测到的hsp70表达；然而，当AMs贴壁于塑料培养皿时，在37℃诱导了hsp70表达。在悬浮培养和贴壁培养的AMs中，热休克（43℃，1小时）均能快速诱导hsp70 mRNA水平。在悬浮培养的AMs中，hsp70表达的诱导在年龄和饮食限制方面均无显著变化。相比之下，贴壁于塑料培养板的AMs中，hsp70 mRNA水平的诱导随年龄增长下降约70%，并且从饮食限制大鼠分离的AMs中hsp70诱导作用更强；这种差异在年轻大鼠中具有统计学意义。在贴壁的AMs中，热休克（43℃，1小时）诱导的hsp70也随年龄增长而下降，并且饮食限制使年轻和年老大鼠贴壁AMs中hsp70表达的诱导增加了三到四倍。
