The Activity of Peptides of the Calcitonin Family in Bone

May combine two claims.

The Calca KO phenotype suggested that osteoblasts are the primary target of calcitonin/CGRP in bone and that these peptides inhibit bone formation.

“The phenotype of the Calca KO mice suggested that the osteoblast is the primary target of calcitonin/CGRP in bone and that calcitonin/CGRP inhibit bone formation.”

• cites [97] sourceDisputed

  The paper reports increased bone formation in CT/CGRP knockout mice (Discussion, p. 7), but it does not infer that osteoblasts are the primary target of both peptides. Instead, it describes direct CT action on osteoblasts as less likely (Discussion, p. 7) and says CGRP stimulates, rather than inhibits, osteoblastic bone formation (Discussion, p. 8). (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Procalcitonin is used clinically as a biomarker for assessing risk of sepsis and septic shock.

“There-fore, procalcitonin is currently in clinical use as a biomarker for assessing risk of sepsis and septic shock (208).”

• cites [208] sourceSupported

May combine two claims.

In rats, intermedin is primarily expressed in pituitary and GI tract, and intraperitoneal administration decreases blood pressure in normal and spontaneously hypertensive rats.

“Roh et al. found that, in the rat, intermedin is primarily expressed in the pituitary and gastrointestinal tract and showed that intraperitoneal administration of intermedin decreased blood pressure in both normal and spontaneously hypertensive rats (98, 177).”

• cites [98] sourcePartly supported

  Table 5 (Conclusions; page unavailable) reports that intraperitoneal intermedin reduced arterial pressure in rats and spontaneously hypertensive rats, citing Roh et al. The distribution discussion (Introduction; page unavailable) lists the pituitary and gastrointestinal tract among sites where intermedin is found, but does not say it is primarily expressed in those sites in rats; it instead identifies kidney, hypothalamus, and stomach as having the highest peptide content. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [177] sourceNot checked — no full text of the source

May combine two claims.

Procalcitonin inhibits osteoclast differentiation in bone marrow cultures, and this activity is not mediated by CTR.

“Recently, procalcitonin has been shown to inhibit osteoclast differentiation in bone marrow cultures, and interestingly, this activity was not mediated by the calcitonin receptor (CTR) (119).”

• cites [119] sourceSupported

May combine two claims.

NH2-terminal and COOH-terminal are highly conserved among calcitonin, CGRP, and amylin, while middle region is more divergent.

“The NH 2 -terminal and COOH-terminal are highly conserved among calcitonin, CGPR, and amylin, whereas the middle region is more divergent (21).”

• cites [21] sourceSupported
  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

First CTR cDNA was cloned from porcine, followed by human and rat receptors.

“The first CTR cDNA was cloned from porcine (134), followed by the cloning of the receptors from human and rat (7,81,127,187).”

• cites [134] Lin HY, 1991, Trans Assoc Am PhysiciansNot checked — no full text of the source
• cites [7] sourceNot checked — no full text of the source
• cites [81] sourceSupported
• cites [127] Kuestner RE, 1994, Mol Pharmacol sourceNot checked — no full text of the source
• cites [187] Sexton PM, 1993, Mol Endocrinol sourceNot checked — no full text of the source

May combine two claims.

Each receptor combination typically binds one calcitonin-family peptide with high affinity, while other family members bind same receptor dimer with lower affinities.

“Pharmacological studies of the interactions between peptides of the calcitonin family and their receptors have shown that each of the receptor combinations typically binds one of the calcitonin-family peptides with high affinity, whereas other members of the family can bind to the same receptor dimer with lower affinities (21).”

• cites [21] sourcePartly supported

  The Amylin receptors and Amylin receptor pharmacology sections describe calcitonin-family peptides binding GPCR–RAMP receptor combinations and identify amylin as a high-affinity ligand at AMY1 and AMY3 receptors. They do not establish a general rule that each combination favors one peptide while all other family members bind with lower affinity: the pharmacology section reports that CGRP is also a potent agonist at some AMY receptors, with responses varying by RAMP and species (page not available in our copy). (LLM, conf=0.86)

  Experimental — accuracy not yet measured

May combine two claims.

Different ligands affect receptor conformation and modulate bound G protein and kinetics of downstream signaling.

“Recently, studies that compared the binding of sCT and hCT to the CTR have found that the different ligands not only affect receptor conformation, but also modulate the bound G protein and the kinetics of downstream signaling (9,75).”

• cites [9] sourcePartly supported

  The Discussion (p. 8) reports different G-protein dependence of sCT and hCT dissociation and different durations of downstream cAMP and β-arrestin signaling. But the Discussion (p. 9) presents distinct receptor conformations as a possibility that remains to be elucidated; it does not show that the ligands change which G protein is bound. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [75] sourceNot checked — no full text of the source

May combine two claims.

sCT and hCT are equipotent during short-term stimulation, but long-term sCT sustains CTR activation while hCT loses activity earlier.

“A recent study demonstrated that these ligands are equipotent during short-term stimulation.However, long-term stimulation with sCT results in sustained activation of CTR, whereas hCT loses its activity much earlier (9).”

• cites [9] sourceSupported

May combine two claims.

In mouse bone marrow cells induced by M-CSF and RANKL, CGRP reduced resorption pit area at 0.1 nM or higher, whereas 10 nM was required to inhibit TRAP-positive cell formation.

“In cells cultured from mouse bone marrow and induced to differentiate into osteoclasts by M-CSF and RANKL, the area of resorption pits was reduced by CGRP in a concentration of 0.1 nM or higher, whereas higher concentrations of 10 nM CGRP were required for the inhibition of TRAP-positive cell formation”

• cites [213] sourceSupported

May combine two claims.

In primary human osteoblasts and MG-63 cells, UHMWPE particles induced RANKL and inhibited OPG, while CGRP reduced UHMWPE-induced RANKL expression.

“In both cell types, UHMWPE particles induced RANKL expression and inhibited the expression of OPG, whereas CGRP reduced UHMWPE-induced RANKL expression, suggesting an indirect inhibition of particle-induced bone resorption.”

• cites [117] sourceNot checked — no full text of the source
• cites [224] sourcePartly supported

  The Results (p. 3) show that UHMWPE particles increased RANKL in MG-63 cells and that alpha-CGRP reduced particle-associated RANKL expression. But the study used MG-63 cells, not primary human osteoblasts (MG-63 cells, p. 2), and particle exposure did not consistently inhibit OPG: OPG mRNA increased under some conditions and decreased under another (Results, p. 3). The proposed inhibition of bone resorption is theoretical rather than directly demonstrated (Discussion, p. 4). (LLM, conf=0.92)

  Experimental — accuracy not yet measured

May combine two claims.

Calcitonin stimulated osteoblast proliferation and bone formation when given during the initial phases of bone formation, but inhibited these processes when given after bone formation had begun.

“In one of the earlier studies, calcitonin was found to stimulate osteoblast proliferation and bone formation when administered during the initial phases of bone formation, but when administered after the initiation of bone formation, it had an inhibitory effect (214).”

• cites [214] sourcePartly supported

  The abstract (p. 1) reports that early calcitonin treatment increased bone formation and proliferation of cartilage and bone precursor cells. The Results and Discussion (p. 2) report reduced bone formation when treatment began on day 8. The paper does not establish proliferation of mature osteoblasts or show that later treatment inhibited cell proliferation, as the claim implies. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

Desensitization to calcitonin results from ligand-induced internalization of CTR and inhibition of de novo receptor synthesis, confirmed in human and murine osteoclast cultures.

“The desensitization of the cells to calcitonin was found to be the result of a ligand-induced internalization of the CTR, as well as inhibition of de novo synthesis of the receptor, and has been confirmed in both human and murine osteoclast cultures (194,212).”

• cites [194] sourcePartly supported

  The Results (p. 3) show that calcitonin reduced CTR mRNA expression and calcitonin responsiveness in human osteoclast-like cells. The Discussion (p. 4) proposes reduced CTR gene expression as a possible contributor to desensitization, but does not establish inhibition of new receptor synthesis. It reports receptor internalization in a human breast cancer cell line, not confirmation of the combined mechanism in human and murine osteoclast cultures. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [212] sourceNot checked — no full text of the source

May combine two claims.

Calca KO mice were less sensitive to OVX and maintained bone mass, while WT mice lost one-third of bone mass over 2 months after OVX.

“Calca KO mice were less sensitive to OVX, maintaining their bone mass, whereas WT mice lost one-third of bone mass over 2 mo after OVX.”

• cites [97] sourceSupported

May combine two claims.

Calca KO mice had significantly greater trabecular bone volume due to increased bone formation.

“Surprisingly, the Calca KO mice had significantly greater trabecular bone volume resulting from increased bone formation.”

• cites [97] sourceSupported

May combine two claims.

Intermedin does not affect MC3T3 osteoblast-like cell proliferation or differentiation, but it inhibits dexamethasone- and serum starvation-induced apoptosis, suggesting an overall positive effect in these cells.

“In vitro studies have demonstrated that intermedin does not affect MC3T3 osteoblast-like cell proliferation or differentiation, yet it does appear to inhibit dexamethasone and serum starvation-induced apoptosis, suggesting an overall positive effect in these cells (175).”

• cites [175] sourceSupported

May combine two claims.

Calca KO mice had no developmental defects and normal baseline circulating calcium.

“The mice had no developmental defects and had normal baseline-circulating calcium levels.”

• cites [97] sourceSupported

May combine two claims.

In 12- and 18-month-old Calca KO mice, increased bone formation was accompanied by increased bone resorption, accelerated bone turnover, and hyperostotic lesions in 20% of mice.

“In animals 12 and 18 mo of age, the increased bone formation was accompanied by a parallel increase in bone resorption, with an overall accelerated bone turnover rate that produced hyperostotic lesions in 20% of the Calca KO mice.”

• cites [104] sourcePartly supported

  The Introduction (p. 2) reports increased bone formation and resorption with high turnover in 12-month-old Calca knockout mice. Figure 6 (p. 8) reports hyperostotic lesions in 20% of 12-month-old Calca knockout mice. The Results (p. 4) show cortical porosity at both 12 and 18 months, but the cited passages do not establish the same turnover findings or lesion rate at 18 months. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

Calcr mRNA was expressed in osteocytes isolated from 3-week-old mice, declined with age, and was undetectable at 49 weeks.

“Calcr mRNA was expressed in osteocytes isolated from 3-wk-old mice, but its level declined as mice aged and was undetectable at 49 wk of age.”

• cites [79] sourcePartly supported

  The Results report Calcr mRNA in osteocytes from 3-week-old mice and declining levels with age. At 49 weeks, however, it was undetectable in long-bone osteocytes but still detected in calvarial osteocytes; the claim omits that distinction. (LLM, conf=0.91)

  Experimental — accuracy not yet measured

May combine two claims.

New viable global Calcr KO mice had high bone mass because of increased bone formation, and this phenotype was reproduced in mice with osteoclast-lineage deletion.

“Similar to the previous models of CTR deficiency, the Calcr KO mice had high bone mass because of increased bone formation, a phenotype that was then reproduced in mice that had the gene deletion restricted to the osteoclast lineage.”

• cites [119] sourceSupported

May combine two claims.

Calcr+/- mice had high bone mass caused by increased bone formation without changes in bone resorption.

“Similar to the phenotype described for the Calca-deficient mice (97), Calcr ϩ/Ϫ mice had high bone mass caused by increased bone formation without changes in bone resorption (58).”

• cites [58] sourceSupported

May combine two claims.

Replacing missing peptide with sCT normalized bone parameters, whereas CGRP had no effect, indicating calcitonin is important for calcium balance and maternal skeleton preservation during lactation and recovery.

“Injection of sCT normalized the bone parameters, whereas CGRP was without effect, indicating that calcitonin is the peptide that plays an important role in calcium balance and preservation of the maternal skeleton during lactation and its recovery after weaning (222).”

• cites [222] sourcePartly supported

  The ‘Rescue of skeletal phenotype during lactation’ section reports that salmon calcitonin normalized bone mineral losses in Ctcgrp-null mice, whereas CGRPα did not. But ‘Skeletal recovery after weaning’ says calcitonin is not required for full recovery, although its absence may delay it; the claim overstates its role in postweaning recovery. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

May combine two claims.

Osteoblast number and dynamic histomorphometry-based bone formation rate were similar between amylin KO and WT mice.

“The number of osteoblasts was similar between amylin KO and WT mice, and dynamic histomorphometry using calcein double labeling demonstrated a similar bone formation rate.”

• cites [58] sourceSupported

May combine two claims.

At 24 weeks, male and female amylin KO mice were osteoporotic, with vertebral BV/TV about 50% lower than WT and reduced trabecular and cortical bone thickness.

“At the age of 24 wk, both male and female amylin KO mice were osteoporotic with vertebral bone volume over tissue volume (BV/TV) ~50% lower than that of WT and trabecular and cortical bone thickness reduced.”

• cites [58] sourceSupported

May combine two claims.

Calcitonin binding to CTR on osteoclasts inhibits SPNS2 expression, lowering S1P secretion and thereby inhibiting osteoblast activity.

“Therefore, according to this study, calcitonin binding to CTR on osteoclasts inhibits the expression of SPNS2, causing a drop in S1P secretion and inhibition of osteoblast activity caused by the reduced levels of S1P (119).”

• cites [119] sourceSupported

May combine two claims.

Mechanical loading of the ulna activates periosteal mineralization in WT mice but not in alphaCGRP KO mice.

“Mechanically induced activation of periosteal mineralization was seen in WT mice but not in ␣CGRP KO mice.”

• cites [183] sourcePartly supported

  The Results section (‘Load-induced bone formation responses are different in CGRPa wildtype and knockout mice’) and Fig. 2 report that loading increased periosteal mineralizing surface in wildtype mice, while that response was lost in αCGRP knockout mice. But periosteal mineral apposition and bone formation responses were preserved in the knockout mice, so the broader claim that periosteal mineralization was not activated overstates the finding. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

Genetic deficiency in adrenomedullin, Calcrl, or Ramp2 is embryonic lethal at midgestation due to cardiovascular defects and hypoproliferative lymphatic vasculature, whereas Ramp1 KO and Ramp3 KO are viable.

“Genetic deficiency in either adrenomedullin, Calcrl, or Ramp2 (27,57,74) is embryonic lethal at midgestation because of cardiovascular defects and a hypoproliferative lymphatic vasculature, whereas Ramp1 KO and Ramp3 KO are viable (57,131,203).”

• cites [27] sourcePartly supported

  The Results report that Adm-deficient embryos die around E13.5–E14.5 and have cardiac and arterial abnormalities. The Discussion proposes abnormal lymphatic development as a possible explanation for the hydrops but says the data cannot establish the chain of events; it does not demonstrate hypoproliferative lymphatic vasculature. This paper studies Adm deficiency, not the Calcrl or Ramp knockouts cited alongside it. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [57] sourcePartly supported

  In the ‘Generation of Heterozygous Mice with’ section (page unavailable), the paper reports that RAMP3-null mice survived to adulthood, supporting the RAMP3 part of the clause cited to this paper. The citation is also attached to RAMP1-knockout viability, which our copy does not establish. The earlier claims about embryonic lethality are attached to a different citation group. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [74] sourcePartly supported

  The Results report that AM-, calcrl-, and RAMP2-null embryos died by midgestation and had reduced lymphatic endothelial-cell proliferation; they also state that RAMP3-null mice survive to adulthood. The Discussion describes cardiovascular abnormalities but argues that lymphatic dysfunction is the major contributor to the edema, so it does not establish cardiovascular defects as a cause of lethality. No passage found establishes that RAMP1 knockouts are viable. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [131] sourcePartly supported

  The Introduction states that Calcrl−/−, Ramp2−/− and Adm−/− mice exhibit embryonic lethality and that Ramp3−/− mice are viable. The Results section “Ramp1−/− mice are phenotypically normal” also reports that Ramp1−/− mice are viable. Our copy does not specify midgestation or attribute the lethality to cardiovascular defects and hypoproliferative lymphatic vasculature. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [203] sourcePartly supported

  In Results, under “Generation of RAMP1-Deficient Mice” (page not supplied), the paper reports that RAMP1−/− mice were born at expected Mendelian ratios, supporting the claim that Ramp1 knockout mice are viable. The passages do not establish that Ramp3 knockout mice are viable or that deficiency of adrenomedullin, Calcrl, or Ramp2 causes midgestation death from cardiovascular and lymphatic defects. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

May combine two claims.

Amylin KO mice had increased osteoclast number and increased urine collagen degradation products, suggesting the osteoporotic phenotype resulted from accelerated bone resorption.

“The amylin KO mice had an increased number of osteoclasts and an increase in degradation products of collagen in the urine, suggesting that the osteoporotic phenotype was a result of accelerated bone resorption (58).”

• cites [58] sourceSupported

May combine two claims.

In a Cre/loxP CTR deletion model with residual expression, only male mice had a small increase in bone formation rate, indicating CTR plays a minor role in physiological regulation of bone and calcium homeostasis in the basal state.

“In this animal model, only male mice had a small increase in bone formation rate, indicating that CTR plays a minor role in the physiological regulation of bone and calcium homeostasis in the basal state.”

• cites [62] sourceSupported

May combine two claims.

Unlike amylin KO mice, hemizygous Calcr+/- animals had high bone mass, and compound Calcr+/- Amylin+/- mice displayed a combination of abnormalities from each individual hemizygous KO.

“Unlike amylin KO mice, hemizygous Calcr ϩ/Ϫ animals had high bone mass, and compound hemizygous Calcr ϩ/Ϫ Amylin ϩ/Ϫ mice displayed a combination of abnormalities identified in each of the individual hemizygous KOs.”

• cites [58] sourceSupported

May combine two claims.

Amylin deficiency had no effect on food intake, body weight, or glucose metabolism in the experimental model.

“Amylin deficiency had no effect on the regulation of food intake, body weight, or glucose metabolism in this experimental model.”

• cites [58] sourceSupported

May combine two claims.

After weaning, spine bone mineral content returned to baseline in 13 days in WT mice but took 18 days in Calca KO mice.

“Thirteen days after weaning, spine bone mineral content returned to baseline values in the WT mice, whereas in the Calca KO mice, it took 18 days to reach these values.”

• cites [222] sourcePartly supported

  The “BMC during pregnancy, lactation, and recovery” section says both groups regained baseline BMC after weaning, with recovery taking several more days in Ctcgrp-null mice. Figure 1’s caption distinguishes the mean days to recover baseline total-body BMC (panel B) from spine BMC (panel C). Our copy does not state the claimed 13- and 18-day figures for spine BMC. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

May combine two claims.

In hemizygote CTR KO mice (Calcr+/-), osteoclast CTR expression was half of WT, and these animals were used as a haploinsufficiency model.

“In hemizygote CTR KO mice (Calcr ϩ/Ϫ ), the expres-sion of CTR in osteoclasts was half of that found in the WT, and thus, these animals were used as a model of Calcr haploinsufficiency (58).”

• cites [58] sourceSupported

May combine two claims.

Loss of CTR in osteoclasts increased SPNS2, an exporter required for S1P secretion, and S1P is a potent inducer of bone formation.

“The study found that the loss of CTR in osteoclasts increased the levels of sphingolipid transporter 2 (SPNS2), an exporter protein required for the secretion of sphingosine-1-phosphate (S1P), which is a potent inducer of bone formation.”

• cites [119] sourceSupported

May combine two claims.

In bovine articular cartilage explants, calcitonin induced cAMP production in chondrocytes and inhibited type II collagen degradation and matrix metalloproteinase activity increase.

“In a model of degradation in bovine articular cartilage explants, calcitonin induced cAMP production in chondrocytes and inhibited degradation of type II collagen and the increase in matrix metalloproteinase activity (193).”

• cites [193] sourceSupported

May combine two claims.

Hemizygous Ramp2+/- mice are viable but have severe reproductive defects, fetal growth restriction, enlarged pituitary glands, and additional abnormalities.

“Hemizygous Ramp2 ϩ/Ϫ mice are viable, although they have severe reproductive defects, fetal growth restriction, enlarged pituitary glands, and a number of additional abnormalities (107).”

• cites [107] sourcePartly supported

  The Results report that Ramp2+/− mice survive to adulthood, and that SvEv Ramp2+/− females have small litters and enlarged pituitary glands (no page numbers supplied). But fetal growth restriction is attributed to maternal Ramp2 reduction and occurs regardless of fetal genotype; the paper also says the reproductive phenotype is rescued on another genetic background. The claim omits those important qualifications. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

May combine two claims.

RAMP2 haploinsufficiency caused significant skeletal defects, including delayed development and reduced mineral content and density in femora of 18-week-old females compared with WT controls.

“Haploinsufficiency for RAMP2 caused significant skeletal defects, including delayed development and reduced mineral content and mineral density in femora of 18-wk-old females in comparison to WT controls.”

• cites [107] sourceSupported

May combine two claims.

In experimental animal arthritis models, calcitonin attenuated type II collagen degradation and reduced cartilage erosion, extracellular matrix degradation, and subchondral bone damage.

“In vivo, calcitonin was shown to attenuate type II collagen degradation and to reduce cartilage erosion, extracellular matrix degradation, and subchondral bone damage in experimental animal models of arthritis (32,140,192).”

• cites [32] sourceNot checked — no full text of the source
• cites [140] sourcePartly supported

  The Discussion reports that calcitonin improved bone erosion in rats with experimental arthritis, and the Results describe a nearly intact bone profile when calcitonin was combined with low-dose prednisolone (page not provided). The paper does not report attenuation of type II collagen degradation or reductions in cartilage erosion or extracellular-matrix degradation; it also does not specifically identify the protected bone as subchondral. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [192] sourceNot checked — no full text of the source

May combine two claims.

CGRP and ghrelin, two peptides that promote bone formation, had increased circulating levels in adrenomedullin-deficient mice and are candidate mediators of the indirect effect.

“Candidates that could be involved in such indirect effects are CGRP and ghrelin, two peptides that promote bone formation and had increased circulating levels in the adrenomedullin-deficient mice.”

• cites [144] sourceSupported

May combine two claims.

Some studies demonstrate CTR expression in chondrocytes, while others find no expression.

“However, although some studies demonstrate the expression of CTR in chondrocytes (193), others find no expression (135).”

• cites [193] sourceSupported
• cites [135] sourceSupported

May combine two claims.

Global Calcr knockout mice show high bone mass and increased bone formation.

“Global Calcr KO: high bone mass, increased bone formation.”

• cites [119] sourceSupported

May combine two claims.

Osteoclast-specific Calcr knockout mice show high bone mass and increased bone formation.

“Osteoclast-specific Calcr KO: high bone mass, increased bone formation.”

• cites [119] sourceSupported

May combine two claims.

Hemizygous Calcr mice (Calcr+/-) show high bone mass and increased bone formation.

“Calcr ϩ/Ϫ (hemizygous): high bone mass, increased bone formation.”

• cites [119] sourcePartly supported

  The Discussion (page unavailable) says mice lacking one allele of the calcitonin receptor display increased bone formation. Figure 1’s caption includes six-month-old Calcr+/− mice in the bone-volume assessment, but the available text explicitly reports increased trabecular bone mass for Calcr−/− mice, not for Calcr+/− mice. The high-bone-mass part of the claim is therefore not established for the stated genotype. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

May combine two claims.

Ramp2+/- hemizygous mice show delayed bone development, reduced mineral content, and reduced mineral density.

“Ramp2 ϩ/Ϫ (hemizygous): delayed bone development, reduced mineral content, and mineral density.(107)”

• cites [107] sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

A second gene, CALCB, encodes beta CGRP; beta CGRP is the only mature transcript of CALCB.

“A second, separate gene that encodes CGRP was identified later in both humans and rodents (8,99).The product of this gene was named ␤CGRP, with the previously discovered CALCA-encoded product becoming ␣CGRP.␤CGRP is the only mature transcript of the CALCB gene.”

• cites [8] sourceNot checked — no full text of the source
• cites [99] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Calcitonin is produced by thyroid gland.

“Subsequent studies established that calcitonin is produced by the thyroid gland”

• cites [95] sourceNot checked — no full text of the source

May combine two claims.

Calcitonin inhibits both basal and PTH-stimulated bone resorption.

“The results of the study showed that calcitonin inhibits both basal and PTH-stimulated bone resorption, thus identifying the underlying mechanism of calcitonin's hypocalcemic effect (73).”

• cites [73] sourceNot checked — no full text of the source

May combine two claims.

Genetically modified mouse studies indicate calcitonin's physiological role is inhibition of osteoblast activity and bone turnover, while amylin inhibits osteoclast activity.

“Surprisingly, studies in genetically modified mice have demonstrated that the physiological role of calcitonin appears to be the inhibition of osteoblast activity and bone turnover, whereas amylin inhibits osteoclast activity.”

• AssumptionRests on an assumption: The physiological role of calcitonin in humans can be inferred from genetically modified mouse models.

Probably not a substantial claim: may not pass S3 (load-bearing).

CALCA gene maps to short arm of chromosome 11.

“Linkage analysis mapped the hCT gene CALCA to the short arm of chromosome 11 (122).”

• cites [122] sourceNot checked — no full text of the source

May combine two claims.

Calcitonin lowers blood calcium by inhibiting calcium release from bone because it strongly suppresses bone resorption.

“This effect is caused by the inhibition of calcium efflux from bone, as calcitonin is a potent inhibitor of bone resorption.”

• cites [73] sourceNot checked — no full text of the source

May combine two claims.

Calcitonin rapidly diminishes urinary hydroxyproline excretion, indicating direct inhibition of bone resorption and collagen breakdown.

“The study showed that calcitonin rapidly diminished urinary hydroxyproline excretion, indicating direct inhibition of bone resorption and collagen breakdown.”

• cites [142] sourceNot checked — no full text of the source

May combine two claims.

Calcitonin-family peptides signal through related receptors and share some biological activities, while other activities are peptide-specific.

“Apart from being structurally similar, the peptides signal through related receptors and have some overlapping biological activities, although other activities are peptide specific.”

May combine two claims.

Under normal conditions, CALCA transcript processing is tissue-specific: thyroid C cells produce calcitonin precursor, neuronal tissue produces CGRP precursor.

“Under normal physiological conditions, the processing of the CALCA gene transcript is tissue specific.In the thyroid C cells, mRNA transcribed from the calcitonin gene encodes a precursor of the hormone calcitonin, whereas in neuronal tissue, alternative splicing of the RNA generates mRNA encoding the precursor of the neuropeptide CGRP (181).”

• cites [181] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Human calcitonin is a 32-amino acid peptide with a disulfide bridge near amino-terminal and amidated carboxyterminal; pig and human calcitonin differ considerably in sequence.

“The study determined the amino acid sequence of hCT and found considerable variability between pig calcitonin and hCT, although both are 32-amino acid peptides that contain a disulfide bridge near the amino-terminal and have an amidated carboxyterminal.”

• cites [161] sourceNot checked — no full text of the source

May combine two claims.

Removal of thyroid-parathyroid from dogs left systemic calcium high, leading to conclusion that hypercalcemia stimulates production of a hormone lowering blood calcium.

“They concluded that hypercalcemia does not merely suppress the production of PTH, but stimulates the production of a hormone that lowers calcium levels in the blood (41,42).”

• cites [41] sourceNot checked — no full text of the source
• cites [42] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Thyroid C cells are major source of circulating calcitonin in humans, but calcitonin-like immunoreactivity occurs in prostate, GI tract, thymus, bladder, lung, and CNS.

“Although C cells of the thyroid are undoubtedly the major source of circulating calcitonin in humans, calcitonin-like immunoreactiv-ity has also been identified in the prostate gland, the gastrointestinal tract, thymus, bladder, lung, and central nervous system (70).”

• cites [70] sourceNot checked — no full text of the source

May combine two claims.

In bone, in vitro and animal administration studies generally show calcitonin-family peptides inhibit osteoclasts and bone resorption and stimulate osteoblasts and bone formation.

“In bone, in vitro studies and administration of the peptides to animals generally found inhibitory effects on osteoclasts and bone resorption and positive effects on osteoblasts and bone formation.”

• AssumptionRests on an assumption: Findings from in vitro studies and animal administration about calcitonin-family peptides in bone are relevant to human bone physiology and pharmacology.

Probably not a substantial claim: may not pass S3 (load-bearing).

Adrenomedullin was isolated from human pheochromocytoma by screening for factors that elevate cAMP in platelets.

“Adrenomedullin was discovered by Kitamura et al., who isolated the peptide hormone from human pheochromocytoma by screening for factors that elevate cAMP levels in platelets (121).”

• cites [121] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

In 2004, two groups discovered mammalian ADM2, encoding a peptide highly similar to adrenomedullin, named intermedin or adrenomedullin 2.

“In 2004, two groups discovered the mammalian gene ADM2, which encodes a peptide with high similarity to adrenomedullin, and was named intermedin or adrenomedullin 2 (177, 195).”

• cites [177] sourceNot checked — no full text of the source
• cites [195] sourceNot checked — no full text of the source

May combine two claims.

In fish, five genes Adm1-5 encode five adrenomedullin peptides; in mammals only one additional adrenomedullin family member has been found.

“In fish, five different genes (Adm1-5) that encode a family of five adrenomedullin peptides have been identified, whereas in mammals, only one additional adrenomedullin family member has been found (195).”

• cites [195] sourceNot checked — no full text of the source

May combine two claims.

Elcatonin alleviates pain and inhibits bone resorption in patients with osteoporotic vertebral fractures.

“Elcatonin has been trialed for a number of indications and was recently shown to alleviate pain and inhibit bone resorption in patients with osteoporotic vertebral fractures (198).”

• cites [198] Tanaka S, J Bone Miner MetabNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In mice, intermedin mRNA is expressed in submaxillary gland, kidney, stomach, ovary, lymphoid tissues, and pancreas, but not adrenal medulla.

“Takei et al. identified intermedin in human, mouse, and rat and determined that, in mice, intermedin mRNA was expressed in the submaxillary gland, kidney, stomach, ovary, lymphoid tissues, and pancreas, but not in the adrenal medulla.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

CALCB has similar structure to CALCA, but sequence variation means only mature peptide is beta CGRP, differing from alpha CGRP by one amino acid in rat and three in human.

“The CALCB gene has similar structure to CALCA; however, because of sequence variation, the only mature peptide encoded by this gene is ␤CGRP, which differs from ␣CGRP by one amino acid in the rat and three amino acids in human.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Procalcitonin is a 116-amino acid precursor of calcitonin.

“An additional product of the CALCA gene is procalcitonin, a 116 -amino acid precursor of calcitonin.”

May combine two claims.

Human amylin monomers are soluble but can aggregate into amyloid in type 2 diabetes and spontaneously in vitro, forming fibrils.

“Human amylin monomers are soluble but can aggregate to form amyloid in type 2 diabetes patients and also spontaneously, in a concentration-dependent manner in vitro, in which they form amylin fibrils (124).”

• cites [124] sourceNot checked — no full text of the source

May combine two claims.

CRSPs are present in cattle, dog, horse but absent in human, rat, mouse.

“CRSPs have been identified in other mammals, including cattle, dog, and horse, but are absent in human, rat, and mouse (115).”

• cites [115] sourceNot checked — no full text of the source

May combine two claims.

These modifications increased elcatonin stability relative to parent while retaining biological activity.

“These modifications increased the stability of elcatonin in comparison to the parent molecule while retaining the biological activity.”

Probably not a substantial claim: may not pass S3 (load-bearing).

CRSP-1 is expressed mainly in thyroid gland and CNS.

“CRSP-1 is expressed mainly in the thyroid gland and the central nervous system.”

May combine two claims.

Rapid increase of procalcitonin in circulation is specific to bacterial infection and not seen in viral infection or inflammation of other causes.

“The rapid increase of procalcitonin in the circulation is specific to bacterial infection and is not seen during viral infection or inflammation of other causes.”

May combine two claims.

Administration of CRSP to anesthetized rats decreased serum calcium but did not alter blood pressure.

“Administration of CRSP into anesthetized rats decreased serum calcium, but did not alter their blood pressure.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In healthy individuals, circulating amylin is 5-10 pmol/L and rises to 10-20 pmol/L after a meal.

“In healthy individuals, circulating amylin levels are 5-10 pmol/L, rising to 10 -20 pmol/L following a meal (67).”

• cites [67] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Amylin is stored in same granules as insulin, at about 1-2% of insulin concentration.

“Amylin is stored in the same cellular granules that contain insulin, although the concentration of amylin in the granules is only ~1%-2% of that of insulin.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Elcatonin is an eel calcitonin analog with NH2-terminal amino group replaced by hydrogen and disulfide bond replaced by ethylene linkage.

“Elcatonin (Asu1-7 eel calcitonin analog) is a derivative of eel calcitonin, in which the NH 2 -terminal amino group was replaced by a hydrogen atom and the disulfidebond replaced by ethylene linkage (153).”

• cites [153] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

In nonmammalian species including birds, fish, reptiles, calcitonin is derived from ultimobranchial body.

“In nonmammalian species, including birds, fish, and reptiles, calcitonin is derived from the ultimobranchial body (70,162).”

• cites [70] sourceNot checked — no full text of the source
• cites [162] sourceNot checked — no full text of the source

May combine two claims.

Adrenomedullin is highly expressed in normal adrenal medulla and elicits potent long-lasting hypotensive effect, suggesting it regulates blood pressure.

“The same study showed that the peptide is also highly expressed in normal adrenal medulla and that it elicits a potent and long-lasting hypotensive effect, suggesting that adrenomedullin was a newly identified hormone that regulates blood pressure.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

CALCA, CALCB, ADM are on chromosome 11; IAPP and ADM2 on chromosomes 12 and 22.

“Three of the genes, CALCA, CALCB, and ADM, are located on chromosome 11, whereas IAPP and ADM2 are on chromosome 12 and 22, respectively.”

May combine two claims.

Adrenomedullin is highly expressed throughout vasculature and cardiovascular organs, consistent with central role as vasodilator.

“Further studies demonstrated high expression levels of adrenomedullin throughout the vasculature and in cardiovascular organs, an expression pattern that was considered to reflect its central role as a vasodilator (28,145).”

• cites [28] sourceNot checked — no full text of the source
• cites [145] sourceNot checked — no full text of the source

May combine two claims.

Procalcitonin production is stimulated directly by bacterial endotoxins and lipopolysaccharides and indirectly by inflammatory mediators.

“Studies have shown that procalcitonin production is stimulated directly by bacterial endotoxins and lipopolysaccharides and indirectly by inflammatory mediators.”

May combine two claims.

CALCA spans ~5.6 kb, has six exons; exon IV encodes mature calcitonin, exon V mature alpha CGRP, exons I-III included in both mRNAs.

“CALCA spans ~5.6 kb and contains six exons; exon IV encodes mature calcitonin and exon V encodes mature ␣CGRP, whereas exons I-III are included in both calcitonin and ␣CGRP mRNA (22).”

• cites [22] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

IAPP and ADM2 each contain three exons, with exon III encoding mature peptide.

“The IAPP gene that encodes amylin and the ADM2 gene that encodes adrenomedullin 2 contain three exons each, with exon III encoding the mature peptide.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

ADM encodes adrenomedullin and has four exons, with exon IV encoding mature adrenomedullin.

“ADM encodes adrenomedullin and includes four exons, with exon IV encoding for the mature adrenomedullin peptide.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In all species examined, cysteine residues at positions 1 and 7 and overall length of 32 amino acids are conserved in calcitonin.

“Interestingly, in all the species examined, the cysteine residues at positions 1 and 7 and the overall length of 32 amino acids are conserved.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Adrenomedullin regulates proliferation, migration, differentiation of various cell types and affects hormone release, inflammation, oxidative stress.

“Adrenomedullin regulates the proliferation, migration, and differentiation of various cell types and affects a large number of physiological and pathological processes, including hormone release, inflammation, and oxidative stress (189).”

• cites [189] sourceNot checked — no full text of the source

May combine two claims.

Under normal conditions, procalcitonin expression/processing is mostly restricted to thyroid C cells, where it is quickly cleaved to mature calcitonin, and circulating procalcitonin is very low.

“Under normal physiological conditions, the expression and processing of CALCA mRNA into the form that encodes procalcitonin is mostly restricted to C cells of the thyroid, where the precursor protein is quickly cleaved to generate mature calcitonin.The concentration of procalcitonin in the circulation in these conditions is very low (63).”

• cites [63] sourceNot checked — no full text of the source

May combine two claims.

Amylin stimulates glycogen breakdown in skeletal muscle, opposing insulin's effect on glucose metabolism.

“The effect of amylin on glucose metabolism is opposite to that of insulin, as it stimulates glycogen breakdown in skeletal muscle (221).”

• cites [221] sourceNot checked — no full text of the source

May combine two claims.

CALCA splicing is tissue-specific: in thyroid C cells 99% of primary RNA transcript processed to calcitonin mRNA; in neuronal tissue 95% to alpha CGRP mRNA.

“The splicing of the CALCA gene is tissue specific; in thyroid C cells, 99% of the primary RNA transcript is processed to produce calcitonin mRNA, whereas in neuronal tissue 95% is processed to encode ␣CGRP mRNA (137).”

• cites [137] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Amylin is cosecreted with insulin; hyperglycemia stimulates amylin secretion and hypoglycemia reduces it.

“Amylin is cosecreted with insulin; hyperglycemia stimulates amylin secretion, whereas hypoglycemia reduces it (6,164).”

• cites [6] sourceNot checked — no full text of the source
• cites [164] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Adrenomedullin is expressed in many tissues, and circulating levels are elevated in essential hypertension, renal failure, sepsis, and normal pregnancy.

“Other groups found that adrenomedullin is expressed in many tissues, and marked elevation of circulating adrenomedullin was found to be triggered by essential hypertension, renal failure, sepsis, and normal pregnancy (28).”

• cites [28] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Amylin is a 37-amino acid peptide structurally similar to CGRP, with about 50% identity.

“Amylin is a 37-amino acid peptide that is structurally similar to CGRP, with ~50% identity between the two peptides.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Human calcitonin-family peptides are encoded by five genes with high homology, suggesting derivation from a primordial gene by duplication and mutation.

“Peptides of the calcitonin family in human are encoded by five genes with high degree of homology, suggesting that the family was derived from a primordial gene through duplication and mutation.”

May combine two claims.

Osteoclasts express CTR, CRLR, and RAMP1-3, which suggests that all calcitonin-family peptides can bind these cells.

“The expression of CTR, CRLR, and RAMP1-3 has been detected in osteoclasts, suggesting that all the members of the calcitonin family can bind to these cells (84).”

• cites [84] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Salmon calcitonin differs from eel calcitonin by three amino acids and shares 50% sequence identity with human calcitonin.

“Salmon calcitonin (sCT) differs from eel calcitonin by three amino acids and shares 50% sequence identity with the human peptide.”

May combine two claims.

Alternative splicing producing CTR isoforms appears cell type specific and affects ligand affinity and downstream signaling.

“The alternative splicing that produces the two isoforms, which appears to be cell type specific, has functional implications, as it affects both the affinity of the receptors to ligands of the calcitonin family and the downstream signaling mechanisms (70).”

• cites [70] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Alternative splicing produces CTR isoforms; most common differ by presence/absence of 16-amino acid sequence in intracellular domain 1.

“A number of different isoforms of CTR are produced by alternative splicing; the most common ones differ from each other by the presence or absence of a 16 -amino acid sequence in intracellular domain 1 (70).”

• cites [70] sourceNot checked — no full text of the source

May combine two claims.

Binding of sCT to rat and human CTRs is essentially irreversible, whereas hCT rapidly dissociates; dissociation is independent of G protein coupling and related to ligand's ability to form amphipathic alpha-helical secondary structure.

“Pharmacological studies have established that binding of sCT to rat and human CTRs is essentially irreversible, whereas hCT rapidly dissociates from the receptor.This dissociation was found to be independent of G protein coupling and related to the ability of the ligand to form amphipathic ␣-helical secondary structure.”

May combine two claims.

CTR alone binds calcitonin, but complexes of CTR with any of the three RAMPs form specific amylin receptors.

“Although CTR itself binds calcitonin, complexes of CTR with either of the three RAMPs form specific amylin receptors.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

RAMP1 and RAMP3 extracellular domains contain six cysteine residues, RAMP2 only four.

“The extracellular domain contains six cysteine residues in RAMP1 and 3, but only four residues in RAMP2.”

May combine two claims.

CRLR/RAMP complex also functions as receptor for intermedin, which binds nonselectively to any of the three RAMP/CRLR dimers.

“Later studies have shown that CRLR/RAMP complex also functions as receptor for intermedin, which binds in a nonselective manner to either of the three RAMPs/CRLR dimers (177).”

• cites [177] sourceNot checked — no full text of the source

May combine two claims.

Calcitonin-deficient TPTX rats treated with PTH to induce hypercalcemia showed significant cancellous bone loss in proximal tibia, whereas calcitonin-sufficient PTX rats had no bone loss, suggesting calcitonin protects against bone loss.

“Calcitonindeficient TPTX rats that were treated with PTH to induce hypercalcemia showed a significant cancellous bone loss in the proximal tibia, whereas calcitonin-sufficient PTX rats had no bone loss, suggesting a protective role for calcitonin in these conditions (225).”

• cites [225] sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Two rodent CTR isoforms differ in a 37-amino acid region in extracellular domain 2; insert-negative form predominates in humans and rodents.

“Two isoforms are also found in rodents, with a difference in a 37-amino acid region in extracellular domain 2. The insert negative form is the predominant one in both humans and rodents.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Human CTR gene CALCR is on chromosome 7, contains 14 exons spanning 150 kb.

“The gene encoding the human CTR, CALCR, is located on chromosome 7 and contains 14 exons spanning 150 kb.”

May combine two claims.

The early in vivo animal studies confirmed thyroid as main source of calcitonin and showed endogenous calcitonin can respond to hypercalcemia induced by different protocols.

“These studies confirmed that the thyroid is the main source of calcitonin and demonstrated the capacity of endogenous calcitonin to respond to hypercalcemia induced by different protocols.”

May combine two claims.

Combinations of CTR, CRLR, and RAMP1-3 are recognized as receptors for all calcitonin-family peptides, with consensus nomenclature.

“Thus, the combinations of the CTR, CRLR, and RAMP1-3 have been recognized as the receptors for all the peptides of the calcitonin family, and a consensus nomenclature has been established (FIGURE 2) (37,156,169).”

• cites [37] sourceNot checked — no full text of the source
• cites [156] sourceNot checked — no full text of the source
• cites [169] sourceNot checked — no full text of the source
• cites FIGURE 2Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

CTR is a seven-transmembrane class II (family B) GPCR, a group including PTH/PTHrP, glucagon, VIP, and secretin receptors.

“CTR belongs to the seven-transmembrane domain class II (family B) G protein-coupled receptors (GPCRs), a group that includes other receptors that bind regulatory peptides, including PTH/PTH-related peptide, glucagon, vasoactive intestinal polypeptide, and secretin.”

May combine two claims.

OVX-induced decrease in femur density and calcium content was similar in thyroidectomized and intact-thyroid rats, so experimental evidence does not support calcitonin mediating estrogen deficiency-induced bone loss.

“For example, the OVX-induced decrease in femur density and calcium content were similar in thyroidectomized rats and in animals with intact thyroid (109).”

• cites [109] sourceNot checked — no full text of the source

May combine two claims.

Salmon calcitonin has much higher biological potency in humans than human calcitonin and has been the most widely used preparation clinically.

“sCT has much higher biological potency in humans than hCT, and has, by far, been the most widely used preparation in clinical practice (33).”

• cites [33] sourceNot checked — no full text of the source