Confirmation of oxidative stress and fatty acid disturbances in two further Papillon-Lefèvre syndrome families with identification of a new mutation

Two patients with Papillon-Lefèvre syndrome without periodontal involvement of the permanent dentition

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive genodermatosis characterized by palmoplantar keratoderma and severe periodontitis leading to premature loss of primary and permanent teeth. PLS is caused by loss-of-function mutations in CTSC, lacking functional cathepsin C, which impairs the activation of neutrophil serine proteases. Precise pathogenesis of periodontal damage is unknown. Patient 1 presented with well-demarcated, transgredient, diffuse, palmoplantar keratoderma and psoriasiform lesions from the age of 2 years. Based on severe and recurrent periodontal inflammation, his dentist had diagnosed PLS at the age of 3 years and provided a strict oral hygiene regimen with repeated adjunct antibiotic therapies. Oral acitretin 10 mg/day along with tretinoin ointment at the age of 9 greatly improved palmoplantar keratoderma. Aged 18 years, the patient exhibited an intact permanent dentition and absence of periodontal disease. Patient 2, a 30-year-old man, suffered from transgredient, diffuse, palmoplantar keratoderma with fissuring from the age of 2 months, marked psoriasiform plaques on elbows and knees, and nail dystrophy. Intriguingly, without specific dental treatment, teeth and dental records were unremarkable. He was referred with a suspected diagnosis of psoriasis. Both patients were otherwise healthy, blood tests and sonography of internal organs were within normal limits. Panel sequencing revealed loss-of-function mutations in CTSC, c.322A>T (p.Lys108Ter) and c.504C>G (p.Tyr168Ter) in patient 1 and homozygous c.415G>T (p.Gly139Ter) in patient 2. The final diagnosis of unusual PLS was made. PLS should be considered in palmoplantar keratoderma lacking periodontitis or tooth loss.

Nagashima-Type Palmoplantar Keratosis: Clinical Characteristics, Genetic Characterization, and Clinical Management

Nagashima-type palmoplantar keratosis (NPPK) is the most prevalent palmoplantar keratoderma (PPK) in East Asia. Homozygous or compound heterozygous loss-of-function mutations in serpin peptidase inhibitor, clade B (ovalbumin), and member 70 (SERPINB7), which encodes members of the serine protease inhibitor superfamily, have been identified as the cause of NPPK. Clinical manifestations of NPPK include well-demarcated erythema, mild to moderate hyperkeratosis on the whole palm, and sole with transgrediens, extending to the dorsal surfaces of the hands and feet, inner wrists, ankles, and the Achilles tendon areas. In this study, we perform a review of relevant clinical cases aimed at elucidating the clinical characteristics, genetic characterization, differential diagnoses, and clinical management of NPPK. A better understanding of the clinical characteristics and pathogenic gene characterization of NPPK will enhance the diagnosis of NPPK, identify related diseases, and inform on the precise therapy and prognosis. Moreover, it will promote the awareness of NPPK in non-Asian regions.

Effect of micronutrient malnutrition on periodontal disease and periodontal therapy

Periodontitis is a complex chronic inflammatory noncommunicable disease, initiated by the development of a dysbiotic microbial plaque biofilm below the gingival margin. Whilst the pathogenic biofilm is a "necessary cause" of periodontitis, it is insufficient on its own to cause the disease, and a destructive immune-inflammatory response is a key to the translation of risk to destructive events. Other exposures or "component causes" include individual genetic predisposition, lifestyle (including smoking and nutrition), and environmental factors. Dietary nutrients are essential for life as they provide crucial energy sources in the form of macronutrients, as well as important cofactors in the form of micronutrients, which regulate the functionality of enzymes during the regulation of anabolic and catabolic processes in human cells. Moreover, micronutrients can regulate gene transcription factors, such as the proinflammatory nuclear factor kappa B and the anti-inflammatory nuclear factor (erythroid-derived 2)-like 2. This review focuses on the role of vitamins (vitamin A, carotenoids, the vitamin B complex, vitamins C, D, and E, and coenzyme Q10) and minerals (calcium, magnesium, iron, zinc, potassium, copper, manganese, and selenium) in human physiology and the impact of their deficiencies upon periodontal health and disease.

Consequences of cathepsin C inactivation for membrane exposure of proteinase 3, the target antigen in autoimmune vasculitis

Membrane-bound proteinase 3 (PR3^m) is the main target antigen of anti-neutrophil cytoplasmic autoantibodies (ANCA) in granulomatosis with polyangiitis, a systemic small-vessel vasculitis. Binding of ANCA to PR3^m triggers neutrophil activation with the secretion of enzymatically active PR3 and related neutrophil serine proteases, thereby contributing to vascular damage. PR3 and related proteases are activated from pro-forms by the lysosomal cysteine protease cathepsin C (CatC) during neutrophil maturation. We hypothesized that pharmacological inhibition of CatC provides an effective measure to reduce PR3^m and therefore has implications as a novel therapeutic approach in granulomatosis with polyangiitis. We first studied neutrophilic PR3 from 24 patients with Papillon-Lefèvre syndrome (PLS), a genetic form of CatC deficiency. PLS neutrophil lysates showed a largely reduced but still detectable (0.5-4%) PR3 activity when compared with healthy control cells. Despite extremely low levels of cellular PR3, the amount of constitutive PR3^m expressed on the surface of quiescent neutrophils and the typical bimodal membrane distribution pattern were similar to what was observed in healthy neutrophils. However, following cell activation, there was no significant increase in the total amount of PR3^m on PLS neutrophils, whereas the total amount of PR3^m on healthy neutrophils was significantly increased. We then explored the effect of pharmacological CatC inhibition on PR3 stability in normal neutrophils using a potent cell-permeable CatC inhibitor and a CD34⁺ hematopoietic stem cell model. Human CD34⁺ hematopoietic stem cells were treated with the inhibitor during neutrophil differentiation over 10 days. We observed strong reductions in PR3^m, cellular PR3 protein, and proteolytic PR3 activity, whereas neutrophil differentiation was not compromised.

Autophagic dysfunction in patients with Papillon-Lefèvre syndrome is restored by recombinant cathepsin C treatment

BACKGROUND

Cathepsin C (CatC) is a lysosomal enzyme involved in activation of serine proteases from immune and inflammatory cells. Several loss-of-function mutations in the CatC gene have been shown to be the genetic mark of Papillon-Lefèvre syndrome (PLS), a rare autosomal recessive disease characterized by severe early-onset periodontitis, palmoplantar hyperkeratosis, and increased susceptibility to infections. Deficiencies or dysfunction in other cathepsin family proteins, such as cathepsin B or D, have been associated with autophagic and lysosomal disorders.

OBJECTIVES

Here we characterized the basis for autophagic dysfunction in patients with PLS by analyzing skin fibroblasts derived from patients with several mutations in the CatC gene and reduced enzymatic activity.

METHODS

Skin fibroblasts were isolated from patients with PLS assessed by using genetic analysis. Authophagic flux dysfunction was evaluated by examining accumulation of p62/SQSTM1 and a bafilomycin assay. Ultrastructural analysis further confirmed abnormal accumulation of autophagic vesicles in mutant cells. A recombinant CatC protein was produced by a baculovirus system in insect cell cultures.

RESULTS

Mutant fibroblasts from patients with PLS showed alterations in oxidative/antioxidative status, reduced oxygen consumption, and a marked autophagic dysfunction associated with autophagosome accumulation. These alterations were accompanied by lysosomal permeabilization, cathepsin B release, and NLR family pyrin domain containing 3 (NLRP3) inflammasome activation. Treatment of mutant fibroblasts with recombinant CatC improved cell growth and autophagic flux and partially restored lysosomal permeabilization.

CONCLUSIONS

Our data provide a novel molecular mechanism underlying PLS. Impaired autophagy caused by insufficient lysosomal function might represent a new therapeutic target for PLS.

Papillon-Lefevre Syndrome In An Adolescent Female: A Case Study

Papillon-Lefevre Syndrome (PLS) is a rare inherited autosomal-recessive condition with one-third of the patients' showing consanguinity of the parents. Lesions are characterised by palmar-plantar hyperkeratosis and hyperhidrosis. Early onset of periodonditis, severe periodontal destruction in both primary and permanent dentitions, and calcification of the duramater form the three important features of this disease. Here, we present a case of a 14-year-old female who presented to the Department of Oral Medicine and Radiology with a complaint of mobility of the teeth since four months. Oral examination of the patient showed generalised mobility of the teeth. General physical examination of the patient showed dry scaly skin on dorsum of bilateral feet, hands, and knee. The patient had familial history positive for consanguinity. The patient was medically diagnosed as positive for PLS. The patients with PLS show combination of dermatological and dental lesions and it requires the dentist to assume a more prominent role in early treatment and rehabilitation. There is a need for symbiotic and synergetic approach between the two specialties for effective management of this rare disease.