Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 inhibit Complex I, alter cellular metabolism, and reduce human primary lung fibroblast proliferation. (A) Effect of leramistat and MBS2133 on mitochondrial oxygen consumption rate. (B) Seahorse analysis of fibroblasts treated with MBS2133. (C) Effect of MBS2133 on mitochondrial ATP synthesis rate (left) glycolytic ATP synthesis (center), and total ATP (right). (D) Effect of leramistat (right) and MBS2133 (left) on cellular proliferation in HLFs in the presence or absence of pyruvate. Each experiment was conducted in duplicate wells or greater. Data shown as mean ± SD from 2 experiments (A), 3 experiments (A, B), or triplicates (C).

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques:

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 activate an ISR. Effect of vehicle (V) and MBS2133 (MBS) at 0.01–10 μ M on the β -actin normalized expression of ISR target genes in HLFs (A) and at 1 μ M in human primary monocytes (B), and on eiF2a phosphorylation (C), total protein synthesis (D), and VEGF secretion (E) in HLFs (10 μ M). Effect of the ISR inhibitors, ISRIB and GCN2IB on MBS2133-induced VEGF secretion from HLFs (F). Each experiment was conducted in duplicate or greater. Data shown as mean ± SD from duplicates, or 4 donors (B).

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Expressing, Phospho-proteomics

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 attenuate fibrosis and inflammation in murine bleomycin-induced fibrosis. (A–D) Effect of oral vehicle (V), nintedanib (Nint, 30 mg/kg twice a day), and leramistat at doses indicated on (A) fibrosis by lung hydroxyproline ( μ g/mg) (left) or Ashcroft score (right); (B) bronchoalveolar lavage counts of leucocytes, lymphocytes, and macrophages); (C) histological signs of vascular and bronchiolar inflammation and pneumonitis); and (D) apoptosis and necrosis in mice given intranasal bleomycin and treated from day 7 to day 21 post-administration. (E) Effect of leramistat on AEC2 size (hypertrophy) and number (hyperplasia). (F) Effect of 10 mg/kg/day lermistat on fibroplastic foci (left) and α -SMA staining (right). (G) Representative images (original magnification, 320×) showing the effect of leramistat on AEC2 morphology in H&E and pan-cytokeratin stained sections. In vehicle-treated animals (G-top) black arrows show degenerating forms (G-top left) and reduced cytokeratin expression with main signals in macrophage foam-cell forms (G-top right). In leramistat-treated animals (G-bottom) red arrows show AEC2 with a more cuboidal morphology with vacuolation indicating active secretion (G-bottom left) and black arrows indicate a variety of normal AEC2-AEC1 intermediate forms (G bottom-left) and reduced alveolar macrophage cytokeratin signal but normal cytokeratin expression in AECs (G-bottom right). (H) Effect of MBS2133 (left) and leramistat (right) on α -SMA positivity and cell number in a fibroblast-myofibroblast transition assay. (I) Effect of MBS2133 on AICAR-induced AMPK phosphorylation (left) and α -SMA-positivity (right) in HLFs. Mean ± SD and individual data points (mean ± SD for panel C). ∗∗∗ P < .001 vs vehicle, §§§ P < .001 vs nintedanib control. N = 10/treatment group, n = 3/naïve group.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Staining, Expressing, Phospho-proteomics, Control

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 suppress transition from pneumonitis to fibroplasia. (A) Representative images (original magnification, 80×) of SMA staining during the early stages of the pneumonitis to fibroplasia transition in the pneumonitis model showing an early pneumonic reaction with fibroblasts mixed with histiocytes and no or minimal SMA signal (top left), pneumonic to fibrotic transition showing weak SMA staining of marginal fibroblasts (top right), diffuse fibrosis reaction showing moderate staining of marginal fibroblasts (bottom left, orange arrowhead), and mature fibrosis showing well demarcated marginal hypertrophic SMA-positive fibroblasts (bottom right, green arrowheads). (B) Effect of MBS2133 (10 and 20 mg/kg/day) on fibrosis (Ashcroft score) and histopathology scores for vascular inflammation, pneumonitis, and apoptosis/necrosis. (C) Effect of MBS2133 on AEC2 hypertrophy (left) and hyperplasia (right). (D) Effect of leramistat (10 mg/kg/day) on Ashcroft score and AEC2 hypertrophy in the early pneumonitis model. (E) Effect of MBS2133 and leramistat (Lera, 10 mg/kg/day) on staining for the proliferation marker, Ki67, per 200 AEC2 cells. Mean ± SD and individual data points. N = 10/treatment group, n = 3/naïve group; ∗ P < .05, ∗∗∗ P < .001 vs vehicle (V).

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Staining, Histopathology, Marker

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 augments transitional zone progenitors prior to suppression of lung fibrosis in the early pneumonitis model. (A) Representative images (original magnification, 160×) showing the effect of MBS2133 (20 mg/kg/day) on staining for SpA (left), pro-surfactant C (proSpC) (middle), and surfactant protein D (SpD) (right). SpA is localized on the alveolar lining (orange arrowheads), or AEC2 (green arrowheads) and AM (blue arrows). (B) Representative image (original magnification, 320×) showing SpD-stained transdifferentiated cell forms with SpD-labeled vacuoles in AEC2 (green arrowhead) and SpD reuptake (blue arrowheads). (C–F) Effect of vehicle (V), MBS2133 (MBS, 20 mg/kg/day), and leramistat (Lera, 10 mg/kg/day) compared with naïve animals (N) on SpA (C), proSpC (D) and SpD (E) in AEC2 cells, and of leramistat on SpA, proSpC, and SpD staining in alveoli (F). (G–I) Representative images showing the effect of vehicle (left) and 20 mg/kg/day MBS2133 (right) on SpD expression. (G) In the transitional zone (original magnification, 160×). (H) In the intermediate alveolar segment (original magnification, 320×). Club cells (blue arrowheads), primary transitional zones (orange arrowhead), and AEC2 (green arrowheads) and SpD-positive intermediate forms (red arrowhead) are visible. (I) SpD expression in club cells and transitional progenitor forms in the transitional zone (original magnification, 320×). (J) Quantitation of SpD in club cells after treatment with 10 mg/kg/day leramistat (Lera) or vehicle (V). Mean ± SD and individual data points. N = 10/treatment group, n = 3/naïve group; ∗ P < .05, ∗∗∗ P < .001 vs vehicle.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Staining, Labeling, Expressing, Quantitation Assay

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Transitional zone progenitors are associated with normal or slightly enhanced expression of surfactants. (A) Quantitative effect of vehicle (V) and 10 mg/kg/day leramistat (Lera) on Krt8 staining (left), signal intensity (middle), and on AEC2 (right). (B) Quantitative effect of V and Lera on CC10 staining (left) and on AEC2 (right). (C, D) Representative images (original magnification, 160×) showing the effect of vehicle (left) and 10 mg/kg/day leramistat (right) on CC10 expression (C) and Krt8 expression (D). Disorganization and metaplasia of the transitional zone (blue arrowheads), conservation of the transitional zone and expansion of the CC10 + or Krt8 + cell populations (orange arrowheads), and a mixed population of Krt8 +/− AEC2 showing loss of signal during maturation (green arrowheads) are observed. (E, F) Quantitative effect of vehicle (V) and MBS2133 at doses indicated in mg/kg/day on (E) Krt8 staining (left), signal intensity (middle), and on AEC2 (right), and (F) on quantitative CC10 staining (left) and on AEC2 (right). Mean ± SD and individual data points. N = 10/treatment group, n = 3/naïve group; ∗ P < .05, ∗∗ P < .01, ∗∗∗ P < .001 vs vehicle.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Expressing, Staining

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 attenuate signs and symptoms of disease in murine CIA. (A) Effect of 10 mg/kg/day MBS2133 (left) and leramistat (right) at doses shown on arthritis index in the murine CIA model. (B, C) Representative images (original magnification, 160×) of mice with CIA treated with vehicle (left), showing marked synovitis, loss of cartilage integrity and expansion of stromal cavities, and marked ankylosis with bone resorption and fusion; treated with 3 mg/kg/day etanercept (center); and treated with 10 mg/kg/day leramistat (right) showing inhibition of inflammatory synovitis and reduced pannus area and maturity (B) and conservation of cartilage and subarticular bone and reduced areas of active bone resorption (C). (D) Effect of vehicle (V), 3 mg/kg/day etanercept (E), and leramistat at doses indicated on aggregate bone resorption counts in the murine CIA model. Mean ± SD and individual data points. N = 10/group; ∗∗ P < .01, ∗∗∗ P < .001 vs vehicle; §§§ P < .001 vs etanercept.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Inhibition

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 reduce the number of CD68 + cells in murine CIA. (A) Representative images showing the effect of vehicle and 0.3 μ M leramistat on human primary osteoclast formation. (B) Effect of MBS2133 and leramistat on human primary osteoclast formation, expressed as mean ± SD of 6 replicates. (C) Effect of vehicle (V), 3 mg/kg/day etanercept (Et) administered subcutaneously, 10 mg/kg/day leramistat (Lera) administered by oral gavage or MBS2133 (MBS) on CD68 + cell counts. (D) Representative images (original magnification, 160×) showing CD68 staining in sections from mice with CIA treated with vehicle, showing osteoclast precursor expansion in the synovium and marrow hyperplasia with multiple resorption pits on the bone margin, and 3 mg/kg/day etanercept or 10 mg/kg/day MBS2133 or leramistat showing reduced osteoclast bone resorption with intact bone and periosteal margin in treated animals. (E) Effect of treatments on CD68 + cell counts in the interstitium (left) and resorption zone (center) and on multinucleate cells in the resorption zone (right), reflecting osteoclasts. (F) Representative images (original magnification, 320×) of CD68 staining of vehicle showing mature multinucleate osteoclasts in a zone of active bone loss and multiple resorption pits, and 10 mg/kg/day MBS2133 or leramistat treated animals showing the presence of osteoclasts but the absence of resorption pits. Blastic osteoclast formation indicative of osteoclast arrest is observed (red box). Mean ± SD. N = 5/group; ∗ P < .05, ∗∗ P < .01, ∗∗∗ P < .001 vs vehicle; § P < .05 vs etanercept.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Staining

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 increase osteoid formation concurrently with, or prior to, control of inflammation. (A) Effect on osteoid score in from mice with CIA treated with vehicle (V), 3 mg/kg/d etanercept (Et) administered subcutaneously or leramistat at doses indicated. (B) Representative images (original magnification, 160×) of osteoid formation in mice treated with vehicle; leramistat (10 mg/kg/day), showing greater osteoid with a more regular distribution (red arrowheads); and etanercept (3 mg/kg/day), showing an erratic morphology localized to areas of reduced osteoclastic absorption and osteolysis. (C) Representative images (original magnification, 320×) showing palisading alkaline phosphatase-positive osteoblast forms and incremental mineralization fronts with normal distribution of osteocytes (red arrowheads) from mice with CIA treated with vehicle, 3 mg/kg/day s.c. etanercept administered subcutaneously, or 10 mg/kg/day leramistat administered by oral gavage. Mean ± SD and individual data points. N = 10/group; ∗∗∗ P < .001 vs vehicle; §§ P < .01, §§§ P < .001 vs etanercept.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Control

Journal: The Journal of Pharmacology and Experimental Therapeutics

Article Title: Phenotypic pharmacology of novel Complex I inhibitors eliciting tissue repair concurrent to control of inflammation

doi: 10.1016/j.jpet.2025.103661

Figure Lengend Snippet: Leramistat and MBS2133 increase osteoid formation concurrently with, or prior to, control of inflammation. Effect of leramistat (0.03 mg/kg/day by oral gavage) (blue) and vehicle (gray) on arthritis index (A), on bone resorption foci (B) and aggregate osteoid counts (C) over time in the murine CIA model, showing that leramistat can elicit changes in bone resorption and osteoid formation despite the presence of ongoing active disease signs. Mean ± SD and individual data points. N = 10/group, ∗∗∗ P < .001 vs vehicle.

Article Snippet: MBS2133 and leramistat (0.03–10 mg/kg) and IACS-010759 hydrochloride (0.01–1 mg/kg; MedChemExpress) were administered once daily; nintedanib esylate (30 mg/kg; MedKoo Biosciences) was administered twice daily.

Techniques: Control