ERCC6 founder mutation identified in Finnish patients with COFS syndrome

Cerebro-oculo-facio-skeletal (COFS) syndrome is an autosomal recessive disorder characterized by microcephaly, congenital cataracts, facial dysmorphism, neurogenic arthrogryposis, growth failure and severe psychomotor retardation. We report a large consanguineous pedigree from northern Finland with six individuals belonging into four different sibships and affected with typical COFS syndrome phenotype. Two deceased patients have been published previously in 1982 as the first cases exhibiting cerebral calcifications typical for this disorder. Two living and one of the deceased patients were all shown to possess a novel homozygous mutation in the ERCC6 [Cockayne syndrome B (CSB)] gene, thereby confirming the diagnosis on molecular genetic level even for the earlier published cases. Genealogical investigation showed a common ancestor living in a northeastern village in Finland in the 18th century for all six patients implying a founder effect.

1,3-Bis{[5-(pyridin-2-yl)-1,3,4-oxadiazol-2-yl]sulfan-yl}propan-2-one

In the distorted W-shaped mol­ecule of the title compound, C₁₇H₁₂N₆O₃S₂, a twofold axis passes through the carbonyl group. The mol­ecules stack in the crystal through π–π inter­actions [centroid—centroid distance = 3.883 Å] and weak C—H⋯N hydrogen-bonding inter­actions, forming a three-dimensional architecture.

trans-Diaquabis[5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ido-κ2N3,O4]zinc(II)

In the title complex, [Zn(C₁₀H₆N₃O₄)₂(H₂O)₂], the Zn^II atom is located on a twofold rotation axis and is coordinated by two trans-positioned N,O-bidentate and zwitterionic 5-carb­oxy-4-carboxyl­ato-2-(4-pyridinio)-1H-imidazol-1-ide (H₂PIDC⁻) ligands and two water mol­ecules, defining a distorted octa­hedral environment. The complete solid-state structure can be described as a three-dimensional supra­molecular framework, stabilized by extensive hydrogen-bonding inter­actions involving the coordinated water mol­ecules, uncoordin­ated imidazole N atom, protonated pyridine N and carboxyl­ate O atoms of the H₂PIDC⁻ ligands.

trans-Diaqua-bis[5-carb-oxy-2-(3-pyrid-yl)-1H-imidazole-4-carboxyl-ato-κN,O]iron(II)

In the title complex, [Fe(C(10)H(6)N(3)O(4))(2)(H(2)O)(2)], the Fe(II) atom is located on an inversion centre and is trans-coordinated by two N,O-bidentate 5-carb-oxy-2-(3-pyrid-yl)-1H-imidazole-4-carb-oxy-l-ate ligands and two water mol-ecules, defining a distorted octa-hedral environment. A two-dimensional network of N-H⋯O and O-H⋯O hydrogen bonds extending parallel to (110) helps to stabilize the crystal packing.

Effect of antisense oligonucleotide against mouse dentine matrix protein 1 on mineralization ability and calcium ions metabolism in odontoblast-like cell line MDPC-23

AIM

To study the mineralization ability and the dynamic changes of intracellular and extracellular concentrations of calcium ions in the odontoblast-like cell line MDPC-23 affected by antisense oligonucleotide (AS-ODN) against mouse dentine matrix protein 1 (DMP1).

METHODOLOGY

The expression of DMP1 in MDPC-23 cells was detected by an immunohistochemical method and its blocking outcome by the Western blot method. The alkaline phosphatase (ALP) activity, size and number of mineralized nodules, and the intracellular free ([Ca2+]if), total ([Ca2+]it) and the extracellular ([Ca2+]e) calcium ion concentrations in MDPC-23 cells in the experimental group affected with AS-ODN were compared with those in the control group (paired-samples t-test).

RESULTS

Dentine matrix protein 1 was stably expressed in a stable way in MDPC-23 cells; the expression was only just detectable at 12 h and became negative after 24 h affected by AS-ODN. Compared with the control groups, ALP activity of MDPC-23 cells in the AS-ODN group was decreased (P < 0.05), and both the number and size of mineralized nodules were smaller than those in the control group. [Ca2+]if in the AS-ODN group increased and then decreased after 24 h. [Ca2+]it dropped substantially to the lowest point at 24 h (P < 0.01). [Ca2+]e increased before treatment for 24 h and then dropped, however, it was still higher than that of the control group.

CONCLUSIONS

Antisense oligonucleotide against DMP1 could decrease mineralization ability and affect the intracellular and extracellular concentrations of calcium ions in MDPC-23 cells. This would indicate that DMP1 regulates the metabolism and transportation of calcium ions in odontoblasts, and thus boosts dentine mineralization.