Neurohormonal and mechanical responses exquisitely regulate various renal glomerular functions. Previously, we found that mechanical stimulation reduces the activity of receptor -activated canonical transient receptor potential 6 (TRPC6) channel in podocytes to enhance the glomerular barrier function. To explore its pathological implications, we carried out the intracellular Ca²⁺ imaging, whole-cell patch clamp and albumin-permeation assay using immortalized mouse podocytes stably expressing wild-type (wt) TRPC6 or its N-terminus mutants associated with focal segmental glomerulosclerosis (FSGS) (P111Q, M131T and N142S). Application of a membrane-expanding agent 2,4,6-trinitrophenol (TNP) immediately suppressed wt Ca²⁺ responses evoked by angiotensin II (Ang II). However, these responses were reversed in P111Q and entirely absent in M131T and N142S. Simultaneous stimulation with Ang II and TNP in wt reduced FITC-labelled albumin leak, while this was weakened in FSGS mutants. Pretreatment with a TRPC6-specific inhibitor SAR7334 enhanced the leaks, the extent being greater in the mutants than wt. These results strongly suggest that FSGS-associated N-terminus TRPC6 mutations may impair the filtration barrier function through the altered efficiency of mechanical stress in suppressing receptor-activated TRPC6 channel activities.