Fig 1.
Neuronal cells were incubated with Aβ1–42 on day 0, and the media containing Aβ1–42 was changed every two days. The LLLT treatment interval was varied, with cells receiving treatment once a day. After treatment with LLLT for 3 or 7 days, cells were assayed at each indicated time point.
Fig 2.
Aβ1–42 induces cell death and neurite retraction.
(A) Relative cell number (% of control). (B) Neurite outgrowth (% of control). The values are means ± SD (n = 4); *P<0.05 between the determined groups. #P<0.05 vs control. T-test was used for statistical analysis. NT stand for not determine.
Fig 3.
Aβ1–42 induces pathological changes in neurite morphology after 24h and 72h.
Scale bars represent 50μm.
Fig 4.
LLLT reduces Aβ1-42-induced toxicity in neuronal cells after 7 days of irradiation.
(A) and (B) Viability (% of control) after treatment with 660 nm and 810 nm, respectively. The values are means ± SD; n = 3. *P<0.05 for the determined groups. *a P<0.05 vs Aβ. #P<0.05 vs control.
Fig 5.
LLLT effects on neurite outgrowth and elongation induced by Aβ1–42 toxicity after 7 days of irradiation.
(A) and (B) Outgrowth per cell (% of control) after treatment with 660 nm and 810 nm, respectively. (C) and (D) Mean length of neurite (% of control) after treatment with 660 nm and 810 nm, respectively. Data are expressed as mean ± SD; n = 3. *P<0.05 for the determined groups. *a P<0.05 vs Aβ. #P<0.05 vs control.
Fig 6.
LLLT modulates depolarized mitochondria in neuronal cells induced by Aβ1–42 toxicity after 3 days of irradiation.
(A) Representative JC-1-stained fluorescent images were obtained with a fluorescence microscope (scale bar represents 100μm). (B) Red and green fluorescence intensity were quantified by using image analysis. Data were obtained on day4 and expressed as mean ± SD; n = 4. *P<0.05 for the determined groups. #P<0.05 vs control.
Fig 7.
LLLT reduces intracellular ROS induced by Aβ1-42-toxicity after 3 days of irradiation.
(A) Representative DCFH-DA stained fluorescent images taken with a fluorescence microscope (scale bars represent 100μm). (B) Intensity quantification by image analysis (% of control). Data were obtained on day4 and expressed as mean ± SD; n = 3. *P<0.05 for the determined groups. #P<0.05 vs control.
Fig 8.
LLLT reduces intracellular Ca2+ influx induced by Aβ1–42 toxicity after 3 days of irradiation.
(A) Representative Fluo-3AM-stained fluorescent images taken with a fluorescence microscope (scale bars represent 100μm). (B) Fluo-3 AM intensity quantification by TECAN. Data were obtained at day4 and were expressed as mean ± SEM; n = 3. *P<0.05 for the determined groups. #P<0.05 vs control.
Fig 9.
LLLT improves neurite outgrowth.
Relative neurite outgrowth (% of control) after LLLT treatment for 3 days and 7 days. Data were expressed as mean ± SD; n = 3. *a P<0.05 vs Aβ. #P<0.05 vs control.
Fig 10.
Schematic diagram of the possible mechanism underlying the therapeutic effects of LLLT on Aβ1-42-induced neuronal death.